WO2025163893A1 - Terminal, wireless communication method, and base station - Google Patents

Abstract

A terminal according to one aspect of the present disclosure comprises a reception unit that receives settings related to: at least one of a two-dimensional arrangement of a plurality of antennas for 32 or less ports, a two-dimensional arrangement of a plurality of antennas for more than 32 ports, and a plurality of groups of the plurality of antennas for more than 32 ports; and a plurality of channel state information (CSI)-reference signal (RS) resources. The terminal further comprises a control unit that, on the basis of the settings, associates each of the CSI-RS resources with 32 or less ports, associates the plurality of CSI-RS resources with more than 32 ports, and controls transmission of a report indicating a plurality of beams and one or more CSI-RS resources corresponding to the plurality of beams among the plurality of CSI-RS resources.

Description

Terminal, wireless communication method and base station

This disclosure relates to terminals, wireless communication methods, and base stations in next-generation mobile communication systems.

Long Term Evolution (LTE) was specified for Universal Mobile Telecommunications System (UMTS) networks with the aim of achieving even higher data rates and lower latency (Non-Patent Document 1). Furthermore, LTE-Advanced (3GPP Rel. 10-14) was specified with the aim of achieving even greater capacity and sophistication over LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8 and 9).

Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 or later, etc.) are also being considered.

3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Univers al　Terrestrial　Radio　Access　Network　(E-UTRAN);　Overall　description;　Stage 2　(Release　8)”, April 2010

In future wireless communication systems (e.g., NR), it is being considered that terminals (User Equipment (UE)) will control transmission and reception processing based on information regarding quasi-co-location (Quasi-Co-Location (QCL), Transmission Configuration Indication (TCI) state, and beam).

However, sufficient consideration has not been given to the measurement and reporting of the numerous channel state information-reference signal (CSI-RS) resources required to manage a large number of beams. If such measurement and reporting is not adequately considered, it could result in a decline in communication quality and throughput.

Therefore, one of the objectives of this disclosure is to provide a terminal, a wireless communication method, and a base station that efficiently utilize CSI-RS resources.

A terminal according to one aspect of the present disclosure includes a receiver that receives configurations relating to at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources; and a controller that, based on the configurations, controls the transmission of a report indicating each CSI-RS resource with 32 or fewer ports, the multiple CSI-RS resources with more than 32 ports, and multiple beams and one or more CSI-RS resources among the multiple CSI-RS resources that correspond to the multiple beams.

According to one aspect of the present disclosure, multiple CSI-RS resources can be properly measured and reported.

FIG. 1 is a diagram showing an example of a CSI-RS position within a slot. FIG. 2 shows the association between the supported number of CSI-RS ports and the base station antenna layout for a single panel of the existing specification. FIG. 3 shows the association between the supported number of CSI-RS ports and base station antenna layout for multi-panel in the existing specification. FIG. 4 shows an example of mapping from i _1,3 to k ₁ and k ₂ for two-layer CSI reporting. FIG. 5 shows an example of mapping from i _1,3 to k ₁ and k ₂ for 3-layer and 4-layer CSI reporting. FIG. 6 shows an example of a codebook for 1-layer CSI reporting and codebookMode=1. FIG. 7 shows an example of a codebook for 1-layer CSI reporting and codebookMode=2 and N ₂ >1. FIG. 8 shows an example of a codebook for 1-layer CSI reporting and codebookMode=2 and N ₂ =1. FIG. 9 shows an example of a codebook for two-layer CSI reporting and codebookMode=1. FIG. 10 shows an example of a codebook for two-layer CSI reporting and codebookMode=2 and N ₂ >1. FIG. 11 shows an example of a codebook for two-layer CSI reporting and codebookMode=2 and N ₂ =1. FIG. 12 shows an example of a codebook for 3-layer CSI reporting and codebookMode=1-2. FIG. 13 shows an example of a codebook for 5-layer CSI reporting and codebookMode=1-2. FIG. 14 shows an example of a codebook for 7-layer CSI reporting and codebookMode=1-2. FIG. 15 shows an example of a codebook for 8-layer CSI reporting and codebookMode=1-2. FIG. 16 shows an example of multiple CSI-RS resources that are FDM-modulated. FIG. 17 shows an example of multiple CSI-RS resources that are TDMed. FIG. 18 shows an example of settings related to option 1 of embodiment B1. FIG. 19 shows a first example of settings related to option 2 of embodiment B1. FIG. 20 shows a second example of settings related to option 2 of embodiment B1. 21A and 21B show an example of a base station antenna layout according to option 2 of embodiment B1. FIG. 22 shows a first example of settings related to option 3 of embodiment B1. FIG. 23 shows a second example of settings related to option 3 of embodiment B1. 24A and 24B show an example of a base station antenna layout according to option 3 of embodiment B1. 25A and 25B show an example of a new (64,1) configuration for 128 ports according to embodiment C1. 26A to 26C show an example of a new (16,4) configuration for 128 ports according to embodiment C1. FIG. 27 shows an example of option 1-d of the new (16,4) setting for 128 ports according to embodiment C1. FIG. 28 shows an example of option 2-a of the new (16,4) setting for 128 ports according to embodiment C1. FIG. 29 shows an example of association candidates taking into consideration 32 existing ports (N ₁ , N ₂ ) in option 1 of embodiment C1. FIG. 30 shows an example of association candidates that take into account the 32 existing ports (N ₁ , N ₂ ) in option 1 of embodiment C2-1. FIG. 31 shows an example of association candidates that take into account 24 existing ports (N ₁ , N ₂ ) in option 1 of embodiment C2-2. FIG. 32 shows an example of association candidates that take into account 24 existing ports (N ₁ , N ₂ ) in option 1 of embodiment C3. FIG. 33 shows an example of association candidates that take into account 32 existing ports (N ₁ , N ₂ ) in option 1 of embodiment C4. FIG. 34 shows an example of association candidates that take into account 24 existing ports (N ₁ , N ₂ ) in option 1 of embodiment C5. FIG. 35 shows an example of 32 port association candidates for a multi-panel. Figure 36 shows an example of multiple CSI-RS resources for multiple panels. FIG. 37 shows an example of SD beam selection based on embodiment B. Figure 38 shows an example of SD beam selection according to embodiment D1. FIG. 39 shows an example of option A of embodiment D1. FIG. 40 shows an example of option B of embodiment D1. FIG. 41 shows an example of option C1 of embodiment D1. FIG. 42 shows an example of option C2 of embodiment D1. Figure 43 shows an example of reporting multiple SD beams. FIG. 44 shows an example of option 2 of embodiment E1. FIG. 45 shows an example of embodiment E2. FIG. 46 shows an example of option 3 and option A of embodiment E3. FIG. 47 shows an example of association according to embodiment E0. FIG. 48 shows an example of a parameter combination in the extended type 2CB. Figure 49 shows an example of a parameter combination in an extended type 2 PSCB. Figure 50 shows an example of a parameter combination in an additional extended type 2 PSCB. FIG. 51 shows an example of option 1 of embodiment F2. FIG. 52 shows an example of option 2 of embodiment F2. FIG. 53 shows an example of option 3 of embodiment F2. FIG. 54 shows an example of option 4 of embodiment F2. FIG. 55 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 56 is a diagram illustrating an example of the configuration of a base station according to an embodiment. FIG. 57 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. FIG. 58 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to an embodiment. FIG. 59 is a diagram illustrating an example of a vehicle according to an embodiment.

(CSI report or reporting)
In Rel. 15 NR, a terminal (also referred to as a user terminal, User Equipment (UE), etc.) generates (also referred to as determining, calculating, estimating, measuring, etc.) channel state information (CSI) based on a reference signal (RS) (or a resource for the RS), and transmits (also referred to as reporting, feedback, etc.) the generated CSI to a network (e.g., a base station). The CSI may be transmitted to the base station, for example, using an uplink control channel (e.g., a Physical Uplink Control Channel (PUCCH)) or an uplink shared channel (e.g., a Physical Uplink Shared Channel (PUSCH)).

The RS used to generate the CSI may be, for example, at least one of a Channel State Information Reference Signal (CSI-RS), a Synchronization Signal/Physical Broadcast Channel (SS/PBCH) block, a Synchronization Signal (SS), a Demodulation Reference Signal (DMRS), etc.

The CSI-RS may include at least one of a non-zero power (NZP) CSI-RS and a CSI-Interference Management (CSI-Interference Measurement, CSI-IM). The SS/PBCH block is a block that includes an SS and a PBCH (and corresponding DMRS), and may be referred to as an SS block (SSB). The SS may also include at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS).

CSI includes the Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), CSI-RS Resource Indicator (CRI), SS/PBCH Block Resource Indicator (SSBRI), and Layer Indicator (Layer Indicator). It may include at least one of L1-RSRP (Layer 1 Reference Signal Received Power), L1-RSRQ (Reference Signal Received Quality), L1-SINR (Signal to Interference plus Noise Ratio), L1-SNR (Signal to Noise Ratio), etc.

The UE may receive information regarding CSI reporting (report configuration information) and control CSI reporting based on the report configuration information. The report configuration information may be, for example, the "CSI-ReportConfig" information element (IE) of Radio Resource Control (RRC).

The reporting configuration information (for example, the RRC IE "CSI-ReportConfig") may include, for example, at least one of the following:
Information about the type of CSI report (report type information, e.g., RRC IE “reportConfigType”)
Information on one or more quantities of CSI to be reported (one or more CSI parameters) (report quantity information, e.g., RRC IE “reportQuantity”)
Information on the RS resource used to generate the amount (the CSI parameter) (resource information, for example, "CSI-ResourceConfigId" of the RRC IE)
Information on the frequency domain to which the CSI is reported (frequency domain information, for example, the RRC IE “reportFreqConfiguration”)

For example, the report type information may indicate periodic CSI (P-CSI) reporting, aperiodic CSI (A-CSI) reporting, or semi-persistent CSI (SP-CSI) reporting.

Furthermore, the reporting amount information may specify a combination of at least one of the above CSI parameters (e.g., CRI, RI, PMI, CQI, LI, L1-RSRP, etc.).

The resource information may also be the ID of a resource for the RS. The resource for the RS may include, for example, a non-zero-power CSI-RS resource or SSB, and a CSI-IM resource (e.g., a zero-power CSI-RS resource).

Frequency domain information may also indicate the frequency granularity of CSI reporting. The frequency granularity may include, for example, wideband and subband. The wideband is the entire CSI reporting band. The wideband may be, for example, the entirety of a certain carrier (component carrier (CC)), cell, serving cell), or the entire bandwidth part (BWP) within a certain carrier. The wideband may also be referred to as the CSI reporting band, the entire CSI reporting band, etc.

Furthermore, a subband may be a portion of a wideband and may be composed of one or more resource blocks (RBs or PRBs). The size of the subband may be determined according to the size of the BWP (number of PRBs).

The frequency domain information may indicate whether wideband or subband PMI is to be reported (the frequency domain information may include, for example, the RRC IE "pmi-FormatIndicator" used to determine whether wideband PMI reporting or subband PMI reporting is to be performed). The UE may determine the frequency granularity of the CSI report (i.e., whether wideband PMI reporting or subband PMI reporting) based on at least one of the above-mentioned reporting amount information and frequency domain information.

If wideband PMI reporting is configured, one wideband PMI may be reported for the entire CSI reporting band, whereas if subband PMI reporting is configured, a single wideband indication i ₁ may be reported for the entire CSI reporting band, and one subband indication i ₂ (e.g., one subband indication for each subband) may be reported for each of one or more subbands within the entire CSI reporting band.

The UE performs channel estimation using the received RS and estimates the channel matrix H. The UE then feeds back an index (PMI) determined based on the estimated channel matrix.

The PMI may indicate the precoder matrix (also simply referred to as a precoder) that the UE considers appropriate for use in downlink (DL) transmissions to the UE. Each value of the PMI may correspond to one precoder matrix. A set of PMI values may correspond to a set of different precoder matrices, called a precoder codebook (also simply referred to as a codebook).

In the space domain, a CSI report may include one or more types of CSI. For example, the CSI may include at least one of a first type (Type 1 CSI) used for selecting a single beam and a second type (Type 2 CSI) used for selecting multiple beams. Single beam may be rephrased as a single layer, and multiple beams may be rephrased as multiple beams. Furthermore, Type 1 CSI does not assume multi-user multiple input multiple output (MU-MIMO), while Type 2 CSI may assume multi-user MIMO.

The codebooks may include a codebook for Type 1 CSI (also referred to as a Type 1 codebook, etc.) and a codebook for Type 2 CSI (also referred to as a Type 2 codebook, etc.). Type 1 CSI may also include Type 1 single-panel CSI and Type 1 multi-panel CSI, and different codebooks (Type 1 single-panel codebook, Type 1 multi-panel codebook) may be defined for each.

In this disclosure, Type 1 and Type I may be interpreted interchangeably. In this disclosure, Type 2 and Type II may be interpreted interchangeably.

The uplink control information (UCI) type may include at least one of the following: Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK), scheduling request (SR), and CSI. The UCI may be carried by the PUCCH or the PUSCH.

In Rel. 15 NR, UCI can contain one CSI part for wideband PMI feedback. CSI report #n contains PMI wideband information if reported.

In Rel. 15 NR, UCI can include two CSI parts for subband PMI feedback. CSI Part 1 contains wideband PMI information. CSI Part 2 contains one wideband PMI and some subband PMI information. CSI Part 1 and CSI Part 2 are coded separately.

In Rel. 15 NR, a UE is configured by higher layers with N (N≧1) CSI reporting configuration report settings and M (M≧1) CSI resource configuration resource settings. For example, the CSI reporting configuration (CSI-ReportConfig) includes resource settings for channel measurement (resourcesForChannelMeasurement), CSI-IM resource settings for interference (csi-IM-ResourceForInterference), NZP-CSI-RS settings for interference (nzp-CSI-RS-ResourceForInterference), and report quantity (reportQuantity). The resource settings for channel measurement, CSI-IM resource settings for interference, and NZP-CSI-RS settings for interference are each associated with a CSI resource configuration (CSI-ResourceConfig, CSI-ResourceConfigId). The CSI resource configuration includes a list of CSI-RS resource sets (csi-RS-ResourceSetList, e.g., NZP-CSI-RS resource set or CSI-IM resource set).

For both FR1 and FR2, evaluation and provision of CSI reporting for DL multi-TRP and/or multi-panel transmissions is being considered to enable more dynamic channel/interference hypotheses for NCJT.

(Codebook settings)
The UE is configured with parameters (Codebook Config) related to the codebook (CB) by higher layer signaling (RRC signaling). The Codebook Config is included in the CSI Report Config (CSI-Report Config) of the higher layer (RRC) parameters.

In the codebook setting, at least one codebook is selected from multiple codebooks including type 1 single panel (typeI-SinglePanel), type 1 multi-panel (typeI-MultiPanel), type 2 (typeII), and type 2 port selection (typeII-PortSelection).

The codebook parameters include parameters related to the codebook subset restriction (CBSR) ("...Restriction" in CodebookConfig). The CBSR setting is a bit that indicates which PMI reports are allowed ("1") and which are not allowed ("0") for the precoder associated with the CBSR bit. One bit in the CBSR bitmap corresponds to one codebook index/antenna port.

(CSI report settings)
The CSI reporting configuration (CSI-ReportConfig) of Rel. 16 includes a channel measurement resource (CMR), an interference measurement resource (IMR), etc. in addition to a codebook configuration (CodebookConfig). The IMR may be at least one of a zero power-interference measurement resource (ZP-IMR) and a non-zero power-interference measurement resource (NZP-IMR). Of the parameters of CSI-ReportConfig, parameters other than codebookConfig-r16 are also included in the CSI reporting configuration of Rel. 15.

In the present disclosure, CMR, NZP CSI-RS resources, and resourcesForChannelMeasurement may be interchangeable. In the present disclosure, ZP-IMR, CSI-IM resources, and csi-IM-ResourcesForInterference may be interchangeable. In the present disclosure, NZP-IMR, NZP CSI-RS resources for interference measurement, and nzp-CSI-RS-ResourcesForInterference may be interchangeable.

In Rel. 17, an extended CSI reporting configuration (CSI-ReportConfig) is being considered for CSI measurement/reporting of multi-TRP using NCJT. In this CSI reporting configuration, two CMR groups are configured, one for each of the two TRPs. The CMRs in a CMR group may be used for at least one of multi-TRP and single-TRP measurements using NCJT. The N CMR pairs of the NCJT are configured by RRC signaling. The UE may be configured by RRC signaling to determine whether to use a CMR in a CMR pair for single-TRP measurements.

For CSI reporting related to multi-TRP/panel NCJT measurements configured by a single CSI reporting configuration, it is considered that at least one of the following options 1 and 2 will be supported.

<Option 1>
The UE is configured to report X CSIs (X=0, 1, 2) related to single-TRP measurement hypotheses/hypotheses and one CSI related to NCJT measurements. If X=2, the two CSIs are related to two different single-TRP measurements using CMRs from different CMR groups.

<Option 2>
The UE may be configured to report one CSI associated with the best measurement result among the measurement hypotheses for NCJT and single TRP.

As mentioned above, in Rel. 15/16, the CBSR is configured for each codebook setting for each CSI reporting setting. In other words, the CBSR applies to all CMRs, etc. within the corresponding CSI reporting setting.

However, in the CSI reporting configuration for multi-TRP in Rel. 17, when the above-mentioned options 1 and 2 are applied, the following measurement configuration may be performed:
◆ Option 1 (X = 0): Measurement of NCJT CSI only.
◆Option 1 (X=1): Measurement of the CSI of the NCJT and the CSI of a single TRP (one TRP).
◆Option 1 (X=2): Measurement of CSI of NCJT and CSI of single TRP (two TRPs).
◆Option 2: Measure both the CSI of the NCJT and the CSI of the single TRP.

The multiple subbands for a given CSI report #n as indicated by the higher layer parameter csi-ReportingBand may be numbered consecutively in ascending order, with the lowest subband in csi-ReportingBand as subband 0.

(PMI/Type 1 Codebook)
The Type 1 (type I) codebook (Rel. 15) specifies a Type 1 single-panel codebook and a Type 1 multi-panel codebook for base station panels. In the Type 1 single-panel codebook, the antenna model (antenna configuration) of the CSI antenna port array (logical configuration) is specified for (N ₁ , N ₂ ). The number of CSI-RS antenna ports, P _CSI-RS , is 2N ₁ N ₂ . In the Type 1 multi-panel codebook, the number of CSI-RS antenna ports, P _CSI-RS , and the antenna model of the CSI antenna port array (logical configuration) are specified for (N _g , N ₁ , N ₂ ).

In this disclosure, the terms Type 1 codebook, Type 1 single-panel codebook, and Type 1 multi-panel codebook may be interpreted interchangeably.

(Type 1 Single Panel Codebook)
For Rel. 15 Type 1 Single Panel CSI, the UE sets the codebook type upper layer parameter (subType in type1 in codebookType in CodebookConfig) to Type 1 Single Panel ('typeI-SinglePanel'). If the number of layers v is not {2,3,4}, the PMI values correspond to three codebook indices _i1,1 , _i1,2 , and _i2 . If the number of layers v is {2,3,4}, the PMI values correspond to four codebook indices _i1,1 , _i1,2 , _i1,3 , and _i2 . If the number of layers v is not {2,3,4}, the composite codebook index _i1 = [ _{i1,1 i1,2} ]. If the number of layers v is {2,3,4}, the composite codebook index _i1 = [ _{i1,1 i1,2 i1,3} ].

For _PCSI-RS , the supported settings (combinations of values) of ( _N1 , _N2 ) and ( _O1 , _O2 ) are defined in the specification. ( _N1 , _N2 ) indicates the number of two-dimensional (2D) antenna elements and is set by the upper layer parameters n1-n2 in moreThanTwo in nrOfAntennaPorts in _typeI - _SinglePanel . n1-n2 are _N1O1N2O2 - _bit bitmap parameters. ( _O1 , _O2 ) is the 2D oversampling factor.

The precoding matrix for v=1 is denoted as W _l,m,n ^(v) . The precoding matrix for v=2 is denoted as W _l,l',m,m',n ^(v) . The precoding _{matrix for P CSI-RS} < 16 and v=3,4 is denoted as W _l,l',m,m',n ^(v) . The precoding matrix for _{P CSI-RS} ≧ 16 and v=3,4 is denoted as W _l,m,p,n ^(v) . The precoding matrix for v=5,6 is denoted as W _{l,l',l'',m,m',m'',n} ^(v) . The precoding matrix for v=7,8 is denoted as W _{l,l',l'',l''',m,m',m'',m''',n} ^(v) . l,l',l'',l''' are determined by _i1,1 and _k1 . m,m',m'',m''' are determined by _i1,2 and _k2 . n is determined by i _2. p is 0 for the first half of the P _CSI-RS (≧16) ports and 1 for the second half of the P CSI-RS (≧16) ports.

The precoding matrix W can be expressed as the product of two matrices _{, W1W2} . _W1 indicates wideband and long-term channel properties and is represented by codebook index _i1 (e.g., _i1,1 and _i1,2 ). _i1,1 and _i1,2 indicate beam selection in two dimensions, respectively. _W2 indicates frequency selectivity (subband) and short-term channel properties and is represented by codebook index _i2 . _i2 may indicate phase adjustment between the two polarizations. _W1 may be given by the following equation E1 using matrix B:

B shows L 2D DFT beams, each oversampled by (O ₁ , O ₂ ).

If the rank is {1, 5, 6, 7, 8}, the codebook index for each PMI is _i1,1 , _i1,2 , _i2 . If the rank is {2, 3, 4}, the codebook index for each PMI is _i1,1 , _i1,2 , _i1,3 , _i2 . _i1,3 is mapped to _k1 and _k2 according to the table in the specification. For rank = 2, 3, 4, the beams selected for different layers can be different when generating the PMI.

The codebook for one-layer CSI reporting and codebookMode=1 includes indices _i1,1 =l=0,1,..., _N1O1-1 corresponding to the horizontal components of the beams, indices _i1,2 =m=0,1,..., _N2O2-1 corresponding to the vertical components _of the beams, and indices _i2 = _n =0,1,2,3 corresponding to the subbands. The precoding matrix Wl _,m,n ⁽¹⁾ for one-layer CSI reporting using antenna ports 3000 to 2999+P _CSI-RS is given by the following equation E2:

The φ _n , θ _p , u _m , v _l,m and v ^≡ _l,m for the precoding matrix are given by the following equation E3:

where [ _i1,1 , _i1,2 , _i2 ] = [l,m,n]. _vl,m is an _N1xN2 DFT vector (spatial domain (SD) vector, _2D -DFT vector, SD DFT vector, SD basis vector, SD beam) expressed by exp( _j2πln1 / _O1N1 ) × exp( _j2πmn2 / _O2N2 ), _n1 = 0, 1,..., _N1-1 , _n2 = 0, 1,..., _N2-1 , _and identified by v, _l . _vl,m denotes one beam. The phase difference (co-phasing, phase compensation between polarizations) between two polarizations (first polarization and second polarization, horizontal polarization and vertical polarization) is φ _n =exp(jπn/2), which indicates the difference in phase of the second polarization relative to the phase of the first polarization. θ _p indicates the phase of the second port relative to the phase of the first port.

(Type 1 Multi-Panel Codebook)
For Rel. 15 Type 1 multi-panel CSI, the UE sets the codebook type upper layer parameter (subType in type1 in codebookType in CodebookConfig) to Type 1 multi-panel ('typeI-MultiPanel'). For Rel. 15 Type 1 multi-panel CSI, compared to the Type 1 single-panel codebook, the number of panels _Ng is configured in addition to _N1 and _N2 . Compared to the Type 1 single-panel codebook, the (wideband) inter-panel phase compensation between panels i, _{1, and 4} are additionally reported. The same SD beam (DFT vector v _l,m , SD basis index l,m ) is selected for each panel, and only the inter-panel phase compensation is additionally reported.

For P _CSI-RS , the supported settings ( _Ng , _N1 , _N2 ) and ( _O1 , _O2 ) are specified in the specification. ( _N1 , _N2 ) are set by ng-n1-n2 in typeI-MultiPanel. _i1,1 = l = {0, 1, ..., _N1O1-1 } is the horizontal component of the oversampled SD basis. _i1,2 = m = {0, 1, ..., _N2O2-1 } is the vertical component of the oversampled SD basis. _{i1,4, q} = p = {0, 1, ₂ , ₃ } for q = 1, ..., _Ng -1 is the number of panels. _i2 = n = {0, 1, 2, 3} is the number of beams per panel.

The antenna configuration parameters for the type 1 multi-panel codebook are ng-n1-n2 ( _Ng , _N1 , _N2 ). In the existing specifications, ranks up to 4 are supported, but ranks above 5 are not supported.

Each PMI value corresponds to a codebook index _i1 , _i2 . v is the RI value (number of layers). For v=1, _i1 = [ _{i1,1 i1,2 i1,4} ]. For v∈{2,3,4}, _i1 = [ _{i1,1 i1,2 i1,3 i1,4} ].

When codebook mode is set to 1, _i1,4 = _i1,4,1 for _Ng = 2. For _Ng = 4, _i1,4 = [ _{i1,4,1 i1,4,2 i1,4,3} ]. When codebook mode is set to 2, _i1,4 = [ _{i1,4,1 i1,4,2} ]. _i1,4 is related to the panel number _Ng and the codebook mode. Codebook mode 2 is supported only for _Ng = 2. [ _{i1,4,1 i1,4,2} ] in codebook mode 2 correspond to two polarizations, respectively. Each of the two values represents the wideband phase difference of the second panel (panel 1) relative to the first panel (panel 0) for the corresponding polarization. Only one value of _i1,4 is reported for _Ng = 2 and codebook mode 1. The single value represents the wideband phase difference of the second panel (Panel 1) relative to the first panel (Panel 0).

When the codebook mode is set to 2, _i2 = [ _{i2,0 i2,1 i2,2} ]. The number and value of _i2 are related to the codebook mode and may differ from the Type 1 single-panel codebook. When subband reporting is set, _i2 is the index for the subband. When wideband reporting is set, _i2 is the index for the wideband. In codebook mode 1, the number and value of _i2 are the same as in the Type 1 single-panel codebook, and _i2 has one value for each subband. In codebook mode 2 ( _Ng = 2), the subband phase difference has three values, representing the inter-polarization and inter-panel phase differences.

Codebook mode 2 has a larger feedback overhead because it reports more phase differences for more accurate CSI, and is only supported for N _g =2.

The Type 1 multi-panel codebook is based on the Type 1 single-panel codebook. In the Type 1 multi-panel codebook, the codebook for the first panel (panel 0) follows the Type 1 single-panel codebook. The codebooks for the other panels apply the same precoder, with additional phase differences between the panels.

The φ _n , a _p , b _p , u _m , and v _l,m for the precoding matrix are given by the following equation E4:

The precoding matrix for v-layer CSI reporting using 2999+P _CSI-RS from antenna port 3000 is denoted by W ^(v) . The precoding matrix for the i-th layer, number of panels _Ng , and codebook mode X is denoted by Wl _,m,p,n ^i,N_g,X , where [ _i1,1 , _i1,2 , _i1,4 , _i2 ] = [l,m,p,n].

For codebook mode 1 and N _g ={2,4}, the precoding matrix W _l,m,p,n ⁽¹⁾ for 1-layer CSI reporting is denoted by W _l,m,p,n ^1,N_g,1 . For codebook mode 1 and N _g ={2,4}, the precoding matrix W _{l,l',m,m',p,n} ⁽²⁾ for 2-layer CSI reporting is denoted by (1/sqrt(2))[W _l,m,p,n ^(1,N_g,1) W _l',m',p,n ^(2,N_g,1) ]. Here, W _l,m,p,n ^1,N_g,1 and W _l,m,p,n ^2,N_g,1 for _{N g} ={2,4} (W _l,m,p,n ^1,2,1 and W _l,m,p,n ^2,2,1 for N _g =2, and W _l,m,p,n ^1,4,1 and W _l,m,p,n ^2,4,1 for N g =4) are given by the following equation E5.

Here, _φn = ^ejπn/2 . For _Ng = 2, p = _p1 , and for _Ng = 4, p = [ _p1 , _p2 , _p3 ]. _{φp_1} , _{φp_2} , and _{φp_3} represent inter-panel phase differences (inter-panel phase compensation). In each precoding matrix, rows 1 and 2 correspond to the first panel (panel 0), rows 3 and 4 correspond to the second panel (panel 1), rows 5 and 6 correspond to the third panel (panel 2), and rows 7 and 8 correspond to the fourth panel (panel 3). Because the same SD beam is selected for all panels, each row has the same vl _,m . _{φp_1} represents the phase difference of the second panel relative to the first panel. _{φp_2} represents the phase difference of the third panel relative to the first panel. _{φp_3} represents the phase difference of the fourth panel relative to the first panel.

For codebook mode 2 and _Ng = 2, the precoding matrix Wl _{,m,p,n (1) for one-layer CSI reporting is denoted by Wl,m,p,n1,2,1. For codebook mode 2 and Ng = 2, the precoding matrix Wl,l',m,m',p,n} ⁽²⁾ _for ^two _{- layer} ^CSI reporting is denoted by (1/sqrt(2)) [Wl _,m,p, ^n1,2,2 _Wl',m',p, ^n2,2,2 ], where _Wl,m,p, ^n1,2,2 and Wl _,m,p, ^n2,2,2 are given by the following equation E6.

In each precoding matrix, the first and second rows correspond to the first panel (Panel 0), and the third and fourth rows correspond to the second panel (Panel 1). Because the same SD beam is selected for all panels, each row has the same v _l,m . p = [p ₁ p ₁ ] and n = [n ₀ , n ₁ , n ₂ ]. _{a p_1} represents the phase difference of the second panel (Panel 1) relative to the first panel (Panel 0) in the first polarization. _{a p_2} represents the phase difference of the second panel (Panel 1) relative to the first panel (Panel 0) in the second polarization. φ _{n_0} represents the phase difference of the second polarization of the first panel relative to the first polarization of the first panel for each subband. b _{n_1} represents the phase difference of the first polarization of the second panel relative to the first polarization of the first panel for each subband. b _{n_2} represents the phase difference of the second polarization of the second panel relative to the first polarization of the first panel for each subband.

(PMI/Type 2 Codebook)
In the present disclosure, the terms type II codebook, extended type II codebook, type II port selection (PS) codebook, extended type II PS codebook, additional extended type II port PS codebook, CJT codebook, and Doppler codebook may be interchangeable.

((Type 2 Codebook))
For type II codebook (Rel. 15, type 2 CSI), the UE is configured with the upper layer parameter codebookType set to 'type II'.

In this disclosure, a matrix Z with X rows and Y columns may be expressed as Z(X×Y).

In Rel. 15 Type 2 CSI, for a given layer l, the subband-wise (SB-wise) precoding matrix is based on the following equation F1:
W _l (N _t ×N ₃ ) = W ₁ W _2,l
(F1)

_Nt is the number of antennas/antenna ports, and _N3 is the total number of precoding (beamforming) matrices (precoders) indicated by the PMI (number of subbands).

W ₁ (N _t × 2L) is 2L DFT vectors (oversampled DFT vectors) and indicates the selected spatial domain basis. L∈{2,4} is the number of beams per layer. The actual number of beams considering two polarizations at one location is 2L. For example, the DFT vectors of L=2 SD beams may be expressed as b _i and b _j , respectively.

W _2,l (2L×N ₃ ) is a matrix (LC coefficient matrix) consisting of linear combination (LC) coefficients (subband complex LC coefficients, coupling coefficients) for layer l. _{W 2,l} represents beam selection and the phase difference (co-phasing) between two polarizations. For example, the LC coefficients corresponding to L=2 SD beams b _i , b _j are c _i and c _j , respectively. For example, the channel vector h is approximated by a linear combination of L=2 SD beams c _i b _i ,+c _j b _j . The feedback overhead is mainly due to the LC coefficient matrix W _2,l . Furthermore, Rel. 15 Type-2 CSI only supports ranks 1 and 2.

In Type-2 CSI, the channel (channel matrix) for a user is represented by a linear combination of two polarizations and L SD beams. Rel. 15 Type-2 CSI supports ranks 1 and 2.

((Extended Type 2 Codebook (Rel. 16)))
For Rel. 16 Type 2 CSI (enhanced Type 2 codebook), the UE is configured with the upper layer parameter codebookType set to 'typeII-r16'.

Rel. 16 Type-2 CSI reduces the overhead associated with the LC coefficient matrix W2 _,l through frequency domain (FD) compression. Rel. 16 Type-2 CSI supports ranks 3 and 4 in addition to ranks 1 and 2.

In Rel. 16 Type 2 CSI, the precoding matrix W _l for a given layer l is expressed by the following equation F2:
W _l = W ₁ W ^~ _l W _f,l ^H
(F2)

W _2,l in Rel. 15 Type 2 CSI is approximated by W ^~ _l W _f,l ^H. The matrix W ^~ may be expressed by adding ~ above W. W ^~ _l may be expressed as W ^~ _2,l . W _f,l ^H is the adjoint matrix of W _f,l and is obtained by conjugate transpose of W _f,l .

For CSI reporting, the UE may be configured with one of two subband sizes. The subband (CQI subband) is defined as N _PRB ^SB contiguous PRBs and may depend on the total number of PRBs in the BWP. The number of PMI subbands per CQI subband, R, is configured by the RRC IE (numberOfPMI-SubbandsPerCQI-Subband). R controls the total number of precoding matrices, _N3 , represented by the PMI as a function of the number of subbands configured in the csi-ReportingBand, the subband size configured by subbandSize, and the total number of PRBs in the BWP.

W ₁ (N _t ×2L) denotes the 2L DFT vectors. To represent this matrix, the indices of the SD basis and the two-dimensional over-sampling factor are reported.

W ^~ _l (2L × _Mv ) is the LC coefficient matrix. To represent this matrix, up to _K0 non-zero coefficients (NZCs, LC coefficients with non-zero amplitude) are reported. The report consists of two parts: a bitmap indicating the NZC positions and the quantized NZCs.

W _f,l (N ₃ ×M _v ) is M _v DFT vectors (frequency domain (FD) DFT vectors, FD basis vectors, FD beams) for layer l, indicating the selected frequency domain basis. Each DFT vector uses N ₃ FD bases (subbands). N ₃ is the total number of precoding (beamforming) matrices (precoders) indicated by the PMI as a function of the number of subbands configured in the csi-ReportingBand. The csi-ReportingBand indicates the contiguous or discontinuous subbands within a BWP for which CSI for that BWP is reported. There are M _v FD DFT vectors per layer. If N ₃ > 19, M _v FD DFT vectors (FD bases) from the intermediate subset (InS) of size N ₃ '(< N ₃ ) are selected. For N ₃ ≦19, log ₂ (C(N ₃ −1,M _v −1)) bits are reported, where C(N ₃ −1,M _v −1) represents the number of combinations (combinatorial coefficients) of N ₃ −1 to M _v −1, also known as binomial coefficients.

The frequency domain response/distribution (frequency response) represented by a linear combination of the FD DFT vector and the LC coefficients may be called an FD beam. The FD beam may correspond to a delay profile (time response).

The PMI subband size is given by CQI subband size/R, where R∈{1,2}. In other words, R is the ratio of the CQI subband size to the PMI subband size. The number of FD DFT vectors _Mv for a given rank v is given by ceil( _pv × _N3 /R). The number of FD DFT vectors _Mv is the same for all layers l∈{1,2,3,4}. _pv is set by higher layers.

The multiple precoding matrices indicated by the PMI are determined from L+M _v vectors.

The L SD beams (SD DFT vectors) v _{m_1^(i),m_2^(i)} for beam index i=0,1,...,L-1 are identified by q ₁ , q ₂ , n ₁ , n ₂ and denoted by i _1,1 , i _1,2 .

The M _v FD DFT vectors are identified by M _initial ∈{-2M _v +1,-2M _v +2,...,0}, n _3,l =[n _3,l ⁽⁰⁾ ,...,n _3,l ^(M_v-1) ], and n _3,l ^(f) ∈{0,1,...,N ₃ -1}.

In the FD DFT vector, the element (FD basis) for FD basis (subband) index t=0,1,..., _N3-1 and layer l=1,...,v is yt _,l ^(f) =exp( _j2πtn3,l ^(f) / _N3 ). The Mv FD DFT vectors for _Mv indices f=0,1,...,Mv _{- 1} of the FD DFT vector are [y0 _,l ^(f) , _y1,l ^(f) ,..., _{yN_3-1,l} ^(f) ] ^T .

Each row of W _2,l represents the channel frequency response of a specific SD beam. If the SD beam is highly directional, the channel taps per beam are limited (the power delay profile is sparse in the time domain). As a result, the channel frequency response for each SD beam is highly correlated (approaching flat in the frequency domain). In this case, the channel frequency response can be approximated by a linear combination of a small number of FD DFT vectors. For example, if M _v =2, using the FD DFT vectors f ₂ ,f _q and the LC coefficients d ₁ ⁰ ,d ₂ ⁰ , the frequency response associated with SD beam b ₀ is approximated by d ₁ ⁰ f ₂ +,d ₂ ⁰ f _q .

The dominant _Mv FD DFT vectors are selected. By setting _Mv ≪ _N3 , the overhead of W ^~ _l is significantly smaller than that of W2 _,l . All or some of the _Mv FD DFT vectors are used to approximate the frequency response of each SD beam. A bitmap is used to report only the selected FD DFT vector for each SD beam. If no bitmap is reported, all FD DFT vectors are selected for each SD beam. In this case, the NZCs of all FD DFT vectors are reported for each SD beam. The NZC number within a layer ^{, KlNZ} _{≦ K0} = ceil(β × _2LMv ), and the NZC number across all layers, ^KNZ ≦ _2K0 = ceil(β × _2LMv ), are set by higher layers.

In the extended type-2 codebook, the combination of L, β, and _pv values (parameter combination) is determined by the upper layer parameter paramCombination-r16 (parameter combination setting). L is the number of SD beams. _pv is a parameter for calculating the number of FD basis vectors for rank v, _Mv = ceil( _pv × _N3 /R). β is a parameter for calculating the maximum number of NZCs.

In this disclosure, the terms codebook parameter combination, codebook parameter combination, parameter combination, and parameter combination setting may be interpreted interchangeably.

Type 2 CSI feedback on PUSCH in Rel. 16 includes two parts. CSI Part 1 has a fixed payload size and is used to identify the number of information bits in CSI Part 2. The size of Part 2 is variable (the UCI size depends on the number of NZCs, which is unknown to the base station). The UE reports the number of NZCs in CSI Part 1, which determines the size of CSI Part 2. The base station knows the size of CSI Part 2 after receiving CSI Part 1.

In Rel. 16 Enhanced Type 2 CSI feedback, CSI Part 1 includes the RI (if reported), the CQI, and an indicator of the total number of non-zero amplitude coefficients across layers for Enhanced Type 2 CSI. The fields in Part 1, RI (if reported), CQI, and the indicator of the total number of non-zero amplitude coefficients across layers, are coded separately. CSI Part 2 includes the PMI for Enhanced Type 2 CSI. Parts 1 and 2 are coded separately. The CSI Part 2 (PMI) includes at least one of the oversampling factor, the index of the SD basis corresponding to each SD beam, the index M _initial of the initial FD DFT vector (starting offset) of the selected DFT window, the selected FD basis for each layer, the NZC (amplitude and phase) for each layer, the strongest coefficient indicator (SCI) for each layer, and the amplitude of the strongest coefficient for each layer/polarization.

The multiple PMI indices (PMI values, codebook indices) associated with different CSI Part 2 information are expressed by the following equation F21 for the l-th layer of rank v:
i ₁ = [i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 ] (v=1)
i ₁ = [i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i _1,8,2 ] (v=2)
i ₁ = [i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i 1,7,2 i _1,8,2 i _{1,6,3 i 1,7,3 i 1,8,3} ] (v=3)
i ₁ = [i _1,1 i _1,2 i _1,5 i _1,6,1 i _1,7,1 i _1,8,1 i _1,6,2 i _1,7,2 i 1,8,2 i _1,6,3 i _1,7,3 i _{1,8,3 i 1,6,4} i _1,7,4 i _1,8,4 ] (v=4)
(F21)

Each index is defined as follows:
◆i _1,1 : Rotation factor [q ₁ q ₂ ] for two-dimensional oversampling. q ₁ ∈{0,1,...,O ₁ -1}, q ₂ ∈{0,1,...,O ₂ -1}. A beam index within each (SD) beam group is selected and reported/indicated by i _1,1 .
◆i _1,2 : Multiple indices of the SD basis corresponding to each SD beam. i _1,2 ∈ {0,1,...,C(N ₁ N ₂ ,L)-1}. L beam groups are selected from N ₁ N ₂ (SD) beam groups and reported/indicated by i _1,2 .
◆i _1,5 : Codebook indicator. The index of the FD basis of the selected DFT window. _{i 1,5} ∈{0,1,...,2M _v −1}.
◆i _1,6,l : Codebook indicator. The FD basis selected for the l-th layer. If N ₃ ≦19, then i _1,6,l ∈{0,1,...,C(N ₃ -1,M _v -1)-1}. If N ₃ >19, then i _1,6,l ∈{0,1,...,C(2M _v -1,M _v -1)-1}.
◆i _1,7,l : Bitmap indicator for the l-th layer. Non-zero bits in the bitmap identify which coefficients in i _2,4,l and i _2,5,l are reported. _{i 1,7,l} =[k _l,0 ⁽³⁾ ... k _{l,M_v-1} ⁽³⁾ ], k _l,f ⁽³⁾ =[k _l,0,f ⁽³⁾ ... k _{l,M_v-1,f} ⁽³⁾ ], k _l,i,f ⁽³⁾ ∈{0,1}.
◆i _1,8,l : Strongest coefficient indicator for the lth layer (largest element k _l,i,f ⁽²⁾ in the amplitude coefficient indicator). The strongest coefficient of layer l, identified by i _1,8,l ∈{0,1,...,2L-1}, is given as i _1,8,l =Σ _i=0 ^{i_1^*} k _l,i,0 ⁽³⁾ -1 for v=1 and as i _1,8,l =i _l ^* for 1<v≦4.
◆i _2,3,l : Amplitude coefficient indicator (for both polarizations) of the (wideband) coefficients of the l-th layer, _{i 2,3,l} =[k _l,0 ⁽¹⁾ k _l,1 ⁽¹⁾ ].
◆i _2,4,l : amplitude coefficient indicator of the reported (subband) coefficient of the l-th layer. _{i 2,4,l} =[k _l,0 ⁽²⁾ ... k _{l,M_v-1} ⁽²⁾ ].
◆i _2,5,l : Phase coefficient indicator of the reported (subband) coefficient of the l-th layer. _{i 2,5,l} =[c _l,0,f ... c _{l,M_v-1,f} ].

Let f _l ^* ∈ {0,1,...,M _v -1} be the index of i _2,4,l and i _l ^* ∈ {0,1,...,2L-1} be the index of k _{l,f_l^*} ⁽²⁾ . The f _l ^* and i _l ^* identify the strongest coefficients for layers l=1,...,v, i.e., the elements k _{l,i_l^*,f_l^*} ⁽²⁾ of i _2,4,l for layer l. The codebook index n _3,l is remapped as n _{3, l} ^{(f) =} (n _3,l ^(f) -n _3,l ^{(f_l^*)} ) mod N ₃ on n _3,l ^{(f_l^*), so that n 3,l (f_l^*)} = 0 after remapping. The index f is remapped as f = ( _{ff l *} ⁾ mod M _v on f l ^* , so that f _l ^* = 0 (l=1,...,v) after remapping. i _2,4,l , i _2,5,l , and i _1,7,l denote the amplitude coefficient, phase coefficient, and bitmap, respectively, after remapping.

Each reported LC coefficient (complex coefficient) in W ^≡ _l is a separately quantized amplitude and phase.
◆ Amplitude Quantization The polarization-specific reference amplitude is quantized to 16 levels using a table defined in the specification (mapping of elements in the amplitude coefficient indicator _i2,3,l : mapping of amplitude coefficient indicator element kl _,p ⁽¹⁾ to amplitude coefficient _pl,p ⁽¹⁾ ). This table quantizes _pl ⁽¹⁾ = [pl _,0 ⁽¹⁾ pl _,1 ⁽¹⁾ ] to [ _kl,0 ⁽¹⁾ kl _,1 ⁽¹⁾ ], kl _,p ⁽¹⁾ ∈ {0,...,15}. All other coefficients are quantized to 8 levels using a table defined in the specification (mapping of elements in the amplitude coefficient indicator _i2,4,l : mapping of amplitude coefficient indicator element kl _,i,f ⁽²⁾ to amplitude coefficient pl _,i,f ⁽²⁾ ). This table quantizes p _l ⁽²⁾ =[p _l,0 ⁽²⁾ ... p _{l,M_v-1} ⁽²⁾ ], p _l,f ⁽²⁾ =[p _l,0,f ⁽²⁾ ... p _l,2L-1.f ⁽²⁾ ] to k _l,f ⁽²⁾ =[k _l,0,f ⁽²⁾ ... k _l,2L-1.f ⁽²⁾ ], k _l,i,f ⁽²⁾ ∈{0,...,7}.
◆ Phase quantization The elements (amplitude coefficient indicator elements) [c _l,0 ... c _{l,M_v-1} ] in the amplitude coefficient indicator i _2,5,l are reported by the UE (using 4 bits). All phase coefficients are quantized using 16-PSK. The phase coefficients in the quantity φ _l,i,f = exp(j2πc _l,i,f /16) for the phase difference are quantized to c _l,f = [c _l,0,f ... c _l,2L-1.f ], c _l,i,fi ∈ {0,...,15}.

The amplitude coefficient indicator element k _{l,floor(i_l^*/L)} ⁽¹⁾ =15 (maximum value), amplitude coefficient indicator element k _{l,i_l^*,0} ⁽²⁾ =7 (maximum value), and phase coefficient indicator element c _{l,i_l^*,0} ⁽²⁾ =0 (minimum value) correspond to the strongest coefficient of layer l. For l=1,...,v, k _{l,floor(i_l^*/L)} ⁽¹⁾ , k _{l,i_l^*,0} ⁽²⁾ , and c _{l,i_l^*,0} ⁽²⁾ =0 are not reported.

i _1,5 and i _1,6,l are PMI indices for reporting on the FD basis. i _1,5 is reported only if _{N 3} >19.

The precoding matrix W ^(v) represented by the codebook for v (=1 to 4) layer CSI reporting using 3000 to 2999+P _CSI-RS is based on the precoding matrix ^Wl for layer l (=1 to v). The precoding matrix ^Wl is expressed by the following equation F3:

Here, the beam index i = 0, 1,..., L-1, _m1 ⁽ⁱ⁾ = _O1n1 ⁽ⁱ⁾ + _{q1 , m2} ⁽ⁱ⁾ = _O2n2 ⁽ⁱ⁾ + _q2 , _n1 ⁽ⁱ⁾ ∈ {0, 1,..., _N1-1 }, _n2 ⁽ⁱ⁾ ∈ {0, 1,..., _N2-1 }. _n1 ⁽ⁱ⁾ and _n2 ⁽ⁱ⁾ are the SD basis for SD beam i. _{vm_1 ^(i), m_2^(i)} are DFT vectors representing the SD beams. _pl,0 ⁽¹⁾ denotes the wideband amplitude coefficient. _pl,i,f ⁽²⁾ denotes the subband amplitude coefficient. _φl,i,f denotes the phase coefficient. Thus, the codebook for each layer includes the strongest coefficient for each polarization, the amplitude coefficient for each polarization, each FD beam, and each SD beam, and the phase coefficient for each polarization, each FD beam, and each SD beam.

For CSI Part 2 grouping, for a given CSI report, the PMI information is organized into three groups (groups 0 to 2). This is important in case of CSI omission. Each reported element with index _i2,4,l , _i2,5,l , and _i1,7,l is associated with a specific priority rule. Groups 0 to 2 follow the following:
◆ Group 0: Index i _1,1 , i _1,2 , i _1,8,l (l=1,...,v)
◆ Group 1: The highest (top) v2LM _v -floor(K ^NZ /2) priority elements among index _i1,5 (if reported), index _i1,6,l (if reported), and index i1,7, _l , the highest (top) ceil(K ^NZ /2)-v priority elements among i2,3 _,l and _i2,4,l, and the highest (top) ceil(K ^NZ /2)-v priority elements among _i2,5, l (l=1,...,v).
◆ Group 2: The lowest (lowest) floor(K ^NZ /2) priority elements among i _{1, 7, l} , the lowest (lowest) floor(K ^NZ /2) priority elements among i _{2, 4, l} , the lowest (lowest) floor(K ^NZ /2) priority elements among i _{2, 5, l} (l=1,...,v)

In Type-1 CSI, an SD beam represented using an SD DFT vector is sent towards the UE. In Type-2 CSI, L SD beams are linearly combined and sent towards the UE. Each SD beam can be associated with multiple FD DFT vectors (FD beam, FD basis, frequency response). For the corresponding SD beam, the channel frequency response can be obtained by linearly combining these FD DFT vectors. The channel frequency response corresponds to the power delay profile.

((Type 2 Port Selection Codebook))
For Rel. 15 Type 2 port selection (PS) CSI (Type 2 PS codebook), the UE is configured with the higher layer parameter codebookType set to 'typeII-PortSelection'.

In Rel. 15's Type 2 port selection CSI, the UE does not need to derive an SD beam by considering an SD DFT vector as in Type 2 CSI. The base station transmits CSI-RS using K CSI-RS ports beamformed by considering a set of SD beams. The UE selects/identifies the best L (≦K) CSI-RS ports for each polarization and reports their indices in _W1 . Rel. 15's Type 2 PS CSI supports ranks 1 and 2.

The value of d is set using the higher layer parameter portSelectionSamplingSize, where d∈{1,2,3,4} and d≦min(P _CSI-RS /2,L).

For each polarization, L antenna ports are selected by i _1,1 , where i _1,1 ∈ {0, 1,..., ceil(P _CSI-RS /(2d))−1}.

((Extended Type 2-Port Selective Codebook (Rel. 16)))
For Rel. 16 Type 2 PS CSI (enhanced Type 2 PS codebook), the UE is configured with the higher layer parameter codebookType set to 'typeII-PortSelection-r16'.

The operation of Rel. 16 Type 2 PS CSI is similar to Rel. 16 Type 2 CSI, except for SD beam selection. Rel. 15 Type 2 PS CSI supports ranks 1 through 4.

For layer lε{1, 2, 3, 4}, the precoding matrix W _l for generating a subband-wise (subband (SB)-wise) precoder is expressed by the following equation F4.
W _l (N _t ×N ₃ ) = QW ₁ W ^~ _l W _f,l ^H
(F4)

Here, Q(N _t ×K) denotes the K SD beams used for CSI-RS beamforming. _{W 1} (K×2L) is a block diagonal matrix. ^{W ∼} _l (2L×M) is the LC coefficient matrix. _{W f,l} (N ₃ ×M) is a matrix consisting of M vectors (FD basis vectors), each containing N ₃ FD bases. K is set by upper layers. L is set by upper layers. _{P CSI-RS} ∈{4, 8, 12, 16, 24, 32}. If _{P CSI-RS} > 4, L∈{2, 3, 4}.

In Rel. 15/16 Type 2PS CSI, each CSI-RS port #i is associated with an SD beam b _i .

The enhanced Type-2 PS CSI reduces overhead compared to the Rel. 15 Type-2 PS CSI by reducing the number of FD basis vectors from _N3 to _Mv ( _Mv << _N3 ) in the same way as the Rel. 16 Type-2 CSI.

In the extended type-2 PS codebook, the combination of values of L, β, and _pv (parameter combination) is determined by the upper layer parameter paramCombination-r16 (parameter combination setting).

((Additional Extended Type 2-Port Selective Codebook (Rel. 17)))
For the Rel. 17 Type 2 PS CSI/codebook (further enhanced Type 2 PS codebook), the UE is configured with the higher layer parameter codebookType set to 'typeII-PortSelection-r17'.

In Rel. 17 Type-2 PS CSI, each CSI-RS port #i is associated with an SD-FD beam pair (SD beam b _i and FD beam f _i,j, where j is the frequency index) instead of an SD beam. In this example, ports 3 and 4 are associated with the same SD beam but different FD beams.

The frequency selectivity of the channel frequency response observed at the UE based on an SD beam-FD beam pair can be reduced compared to the frequency selectivity of the channel frequency response observed at the UE based on an SD beam by delay pre-compensation.

The primary scenario for the Type 2 PS codebook in Rel. 17 is FDD. Channel reciprocity based on SRS measurements is not perfect (the angles of the UL beam and DL beam may differ, the UL frequency and DL frequency may differ in FDD, and the effective antenna spacing at the UL frequency and DL frequency may differ). However, the base station can obtain/select some partial information (dominant angle and delay (SD beam and FD beam)). By using SRS measurements at the base station in addition to CSI reports, the base station can obtain CSI for determining the DL MIMO precoder. In this case, some CSI reports may be omitted to reduce CSI overhead.

In the supplemental enhanced type 2 PS codebook, the values of α, M, and β (codebook parameter combination, parameter combination) are determined by the upper layer parameter paramCombination-r17 (codebook parameter setting). In the parameter combination α, M, and β for the supplemental enhanced type 2 PS codebook in Rel. 17, α is a parameter for calculating the number of selected CSI-RS ports in the PS codebook, _K1 = αP _CSI-RS . M is the number of FD basis vectors. β is a parameter for calculating the maximum number of NZCs. The precoding matrix indicated by the PMI is determined from L + M vectors, where L = _K1 /2 and _K1 = αP _CSI-RS .

_K1 ports are selected from the P _CSI-RS ports based on L vectors v _m̂(i) (i = 0, 1, ..., L-1). The vectors v _m̂(i) are identified by m = [m ⁽⁰⁾ ... [m ^(L-1) ], m ⁽ⁱ⁾ ∈ {0, 1, ..., P _CSI-RS /2-1}. ^{m (i)} is reported/indicated by index i _1,2 ∈ {0, 1, ..., C(P _CSI-RS /2, L)-1}.

In the Rel. 17 additional enhanced Type 2PS CSI, each CSI-RS port is beamformed using SD and FD beams. Each port is associated with an SD-FD beam pair.

The precoding matrix W _l for a given layer l is expressed by the following equation F5:
W _l (K×N ₃ ) = W ₁ W ^~ _l W _f,l ^H
(F5)

For _W1 (K×2L), each matrix block consists of L columns of a K×K identity matrix. The base station transmits K beamformed CSI-RS ports. Each port is associated with an SD-FD beam pair. The UE selects L ports out of the K and reports the index of the selected port to the base station as part of the PMI. Note that in Rel. 16, each port is associated with an SD beam.

W ^~ _l (2L × _Mv ) is a matrix of combining coefficients (subband complex LC coefficients). Up to _K0 NZCs are reported. The report consists of two parts: a bitmap indicating the NZC positions and the quantized NZCs.

In the Rel. 17 supplemental extended type 2PS CSI, K _l ^NZ =Σ _i=0 ^k1-1 Σ _f=0 ^M-1 k _l,i,f ⁽³⁾ ≦K ₀ is the number of nonzero coefficients in layers l=1,...,v, and K ^NZ =Σ _l=1 ^v K _l ^NZ ≦2K ₀ is the total number of nonzero coefficients. If v≦2 and K ^NZ =K ₁ Mv, i _1,7,l (bitmap indicator for the l-th layer) for layers l=1,...,v is not reported. That is, if the total number of reported NZCs is equal to the maximum number in K ₁ Mv and v≦2, reporting of the bitmap indicating the NZC positions is omitted. Note that in Rel. 16, the NZC position bitmap is always reported.

W _f,l (N ₃ ×M _v ) is a matrix consisting of M _v (M _v =1 or 2) FD basis vectors for each layer. Each vector contains N ₃ FD basis vectors (FD-DFT basis vectors). The base station may turn off W _f,l . When M _v =1, W _f,l is off and no additional FD basis vectors are reported. When _{M v} =2, W _f,l is on and M _v additional FD basis vectors are reported. When M _v =2, the FD basis window size N∈{2,4} is set by the upper layer parameter (valueOfN). Note that in Rel. 16, W _f,l is always reported.

(JT)
A joint transmission (JT) may refer to simultaneous data transmission from multiple points (eg, TRPs) to a single UE.

Rel. 17 supports non-coherent joint transmission (NCJT) from two TRPs. The PDSCHs from the two TRPs may be independently precoded and independently decoded. The frequency resources may be non-overlapping, partially overlapping, or fully overlapping. When overlap occurs, the PDSCH from one TRP will interfere with the PDSCH from the other TRP.

In Rel. 18, support for coherent joint transmission (CJT, mTRP CJT) using up to four TRPs is being considered. Data from four TRPs may be coherently precoded and transmitted to the UE on the same time-frequency resource. For example, the same precoding matrix may be used to consider channels from all four TRPs. "Coherent" may mean that there is a fixed relationship between the phases of multiple received signals. Using four-TRP joint precoding, signal quality may be improved and there may be no interference between the four TRPs. Data may only be subject to interference outside the four TRPs.

(NCJT CSI/Type 1 Codebook)
In Rel. 17, the applicable scenario for NCJT CSI reporting is single-DCI-based MTRP NCJT with Type 1 single-panel codebook. For NCJT CSI measurement, two channel measurement resource (CMR) groups, each with a CMR from one TRP, can be configured within a single CSI-ReportConfig. One CSI reporting mode can be configured from two modes:

Using RRC signaling, the CSI-ReportConfig for Rel. 17 non-coherent joint transmission (NCJT) CSI configures the CMR and the CSI reporting mode (csi-ReportMode).

Two CMR groups with _Ks = _K1 + _K2 CMRs are configured in the UE. 2≦ _Ks ≦8. The _Ks CMRs correspond to the NZP-CSI-RS resource set for channel measurement. _K1 and _K2 are the numbers of CMRs in the two CMR groups, respectively. N CMR pairs (resource pairs) are configured by higher layers by selecting from all possible pairs. N=1 and _Ks =2 are supported. Support for _Nmax =2 is an optional UE feature. Support for _Ks,max =X is an optional UE feature. Each CMR can contain up to 32 CSI-RS ports, depending on the UE capabilities. Each CMR pair is associated with one CRI value.

The bitmap sent by RRC signaling indicates the N (N=1, 2) CMR pairs actually used for NCJT measurement by indicating one CMR from each CMR group. The UE uses the CMRs in the two CMR groups to measure single TRP CSI for TRP1 and single TRP CSI for TRP2, and measures NCJT CSI using the N CMR pairs.

The UE selects one or more CSIs to report based on the mode (CSI reporting mode) set by csi-ReportMode, which indicates one of the following two modes (NCJT CSI modes): Mode 1 and 2.
◆ Mode 1
The UE may be configured to report X CSIs associated with a single-TRP measurement hypothesis and one CSI associated with an NCJT measurement hypothesis, where X=0, 1, 2. If X=2, two CSIs are associated with two different single-TRP measurement hypotheses with CMRs from different CMR groups. Support for X=1, 2 is an optional UE feature for UEs that support option 1.
◆Mode 2
The UE is configured to report one CSI associated with the best one of the measurement assumptions of NCJT and single TRP.

In Mode 1, the UE reports a total of X+1 CSIs, including X (X=0, 1, 2) single-TRP CSIs and one NCJT CSI. In Mode 2, the UE reports one best CSI (one CSI) from all single-TRP CSIs and one NCJT CSI.

Up to two single-TRP CSIs and one NCJT CSI can be reported within one CSI report (mode 1 with X=2). NCJT CSI includes one CRI, two RIs (with one joint RI index), two PMIs, two LIs, and one CQI (up to four layers). Single-TRP CSI is the same as the existing CSI and includes one CRI, one RI/PMI/LI, and one or two CQIs (up to eight layers, one CQI per CW).

New mapping orders (tables) of multiple fields within one CSI report are defined for some cases below.
◆Mapping order of wideband CSI for mode 1 with X=0. Wideband CSI is supported only for mode 1 with X=0, i.e., NCJT CSI.
◆ CSI Part 1 mapping order for modes 1 and 2.
◆ CSI Part 2 Wideband Mapping Order for Modes 1 and 2.
◆ CSI Part 2 subband mapping order for modes 1 and 2.

(CJT CSI/Type 2 Codebook)
In the ideal case (where four TRPs are co-located), a joint estimation of the aggregated channel matrix H can be performed, and a joint precoding matrix V can be fed back. However, the large-scale path losses of the four paths can vary significantly. A joint precoding matrix V based on a constant module codebook is not accurate. In this case, the feedback per TRP and the inter-TRP coefficients can be matched by the current NR type-2 codebook.

For a CJT with up to four TRPs in FR1, the selection of the four TRPs may be semi-static. Therefore, the selection and configuration of the four CMRs (four CSI-RS resources) for channel measurement may also be semi-static. Dynamic indication of the four TRPs from a list of CSI-RS resources is also possible, but unlikely.

The path losses from the four TRPs to the UE are different, making it difficult to simply report a single aggregated CSI that represents the joint channel matrix.

Considering fallback operation to NCJT (i.e., single TRP), CSI per TRP (i.e., single TRP CSI like the NCJT CSI in Rel. 17) is also possible.

Assuming an ideal backhaul, synchronization, and the same number of antenna ports across multiple TRPs, CSI acquisition for coherent joint transmission (CJT) for FR1 and up to four TRPs is considered. For CJT multi-TRP for FDD, improvements to the extended (Rel. 16) Type 2 codebook and the additional extended (Rel. 17) Type 2 PS codebook are considered.

_W1 (matrix representing the SD DFT vector) / _Wf (matrix representing the FD DFT vector) for each TRP may be the same or different. _Wl (NZC) for each TRP may be different. _W1 / _Wf / _Wl for each TRP may be selected jointly or individually. Different scenarios with different options for the design of _W1 / _Wf / _Wl are preferred. _Wφ may be reported as an individual entity or within _Wl . These used policies relate to deployment scenarios (e.g., intra-site multi-TRP or inter-site multi-TRP).

For example, a precoding matrix for a 4-TRP CJT CSI (codebook) may be represented by W ₁ /W _f /W _l for each TRP. W ₁ for each TRP may be the same or different, and may be selected jointly or individually. W _l for each TRP may be different, selected jointly or individually. W _f for each TRP may be the same or different, and may be selected jointly or individually.

There are two codebook mode settings for FD basis selection. In mode 1, the i _1,9 report is required to indicate the FD basis offset for the j-th selected CSI-RS resource, for j=2,...,N. In mode 2, the i _1,9 report is not required. All CSI-RS resources have the same FD basis selection.

◆Mode 1 is SD/FD basis selection per TRP/TRP group. It allows independent FD basis selection across N TRPs/TRP groups. For example, its codebook structure is given by the following formula G1, where N is the number of TRPs or TRP groups.

◆Mode 2 is SD basis selection per TRP/TRP group (port group or resource) and joint/common FD basis selection (across N TRPs/TRP groups). For example, its codebook structure is given by the following formula G2, where N is the number of TRPs or TRP groups.

In these two modes, detailed designs such as parameter combination, basis selection, TRP (group) selection, reference amplitude, and _W2 quantization scheme may be shared.

For the enhanced Type II codebook for CJT (Type 2 CSI for CJT in Rel. 18), the UE may configure the higher layer parameter codebookType set to 'typeII-CJT-r18'. For the further enhanced Type II port selection codebook for CJT (Type 2 PS CSI for CJT in Rel. 18), the UE may configure the higher layer parameter codebookType set to 'typeII-CJT-PortSelection-r18'.

The UE can be configured with N _TRP ∈ {1, 2, 3, 4} CSI-RS resources within a resource set for channel measurement.

In the extended type 2 codebook for CJT, the upper layer parameter paramCombination-CJT-L-r18 specifies a set of N _L ∈ {1, 2, 4} combinations of the values {L ₁ ,..., L _{N_TRP} }. The value of N _L is specified by the upper layer parameter numberOfSDCombinations.

In the CJT supplemental extended type 2 PS codebook, the upper layer parameter paramCombination-CJT-PS-alpha-r18 specifies a set of N _L ∈ {1, 2, 4} combinations of values {α ₁ ,...,α _{N_TRP} }. The value of N _L is specified by the upper layer parameter numberOfSDCombinations-PS.

The UE may configure the higher layer parameter restrictedCMR-Selection. If restrictedCMR-Selection is configured, the number of selected CSI-RS resources N is N _TRPs . Otherwise, the UE is expected to select N CSI-RS resources, for 1≦N≦N _TRPs , and the selection is reported using a bitmap of N _TRP bits.

When selecting/reporting an SD beam, selection/reporting of an SD beam for each CSI-RS resource is applied.

In the extended type-2 codebook for CJT, the precoding matrix indicated by the PMI is determined from Σ _j=1 ^N L _{σ_j} +M _v vectors, where {σ ₁ ,...,σ _N } are indices of N CSI-RS resources selected in ascending order such that 1≦σ ₁ <...<σ _N ≦N _TRPs . N _TRPs may be the number of CSI-RS resources configured for CSI reporting or the number of TRPs for CJT. {L _{σ_1} ,...,L _{σ_N} } are the corresponding values from the selected combination of {L ₁ ,...,L _{N_TRP} }.

For j=1,...,N, i=0,1,..., _{Lσ_j} -1, the _{Lσ_j} vectors v _{m_1,f̂(i),m_2,f̂(i)} corresponding to the j-th selected CSI-RS resource are denoted/reported by i _1,1 , i _1,2 , where i _1,1 , i _1,2 are given by the following equation G3:
i _1,1 =[i _1,1,1 ... i _1,1,N ]
i _1,1,j =[q _1,j q _2,j ]
q _1,j ∈{0,1,...,O ₁ -1}
q _2,j ∈{0,1,...,O ₂ -1}
i _1,2 =[i _1,2,1 ... i _1,2,N ]
i _1,2,j ∈{0,1,...,C(N ₁ N ₂ ,L _{σ_j} )-1}
(G3)

In the supplemental extended type-2PS codebook for CJT, the precoding matrix indicated by the PMI is determined from Σ _j=1 ^N L _{σ_j} +M vectors, where {σ ₁ ,...,σ _N } are the indices of N CSI-RS resources selected in ascending order such that 1≦σ ₁ <...<σ _N ≦N _TRP . L _{σ_j} =K _{1,σ_j} /2, K _{1,σ_j} =α _{σ_j} *P _CSI-RS . {α _{σ_1} ,...,α _{σ_N} } are the corresponding values from the selected combinations of {α ₁ ,...,α _{N_TRP} }.

Based on the L _{σ_j} vectors v _{m_ĵ(i)} , for j=1,...,N, i=0,1,...,L _{σ_j} -1, K _{1,σ_j} ports are selected from the P _{CSI-RS ports of the j-th selected CSI-RS} resource and denoted/reported by i _1,2 , where i _1,2 is given by the following equation G4:
i _1,2 =[i _1,2,1 ... i _1,2,N ]
i _1,2,j ∈{0,1,...,C(P _CSI-RS ,L _{σ_j} )-1}
(G4)

In this disclosure, the terms CJT codebook, CJT type 2 codebook, CJT extended type 2 codebook, Rel. 18 CJT type 2 codebook, type II-CJT-r18, CJT additional extended type 2 PS codebook, Rel. 18 CJT type 2 PS codebook, type II-CJT-PortSelection-r18' may be read interchangeably.

(Doppler CSI/Type 2 Codebook)
It has been considered to extend/improve CSI reporting for UEs moving at high/medium speeds by utilizing time-domain correlation/Doppler-domain (DD) information. For example, it has been considered to improve the extended (Rel. 16) Type 2 codebook and the additional extended (Rel. 17) Type 2 PS codebook without changing the spatial and frequency domain basis, and to report from the UE the time-domain channel characteristics (time-domain correlation profile) measured via tracking CSI-RS (TRS).

The channel coherent time (CCT) depends on the maximum Doppler shift. The channel coherent time is the time until the measured channel characteristics are available or until the measured channel characteristics become unavailable (channel aging). The maximum Doppler shift is estimated by the relative velocity between the transmitter and receiver. The channel coherent time _Tc is approximated by 1/Δf _max , where Δf _max = v/λ. As the UE's moving speed increases, the channel coherent time decreases. For example, at a carrier frequency of 4.5 GHz, when the moving speed exceeds approximately 25 km/h, the channel coherent time falls below 10 ms. How to deal with such high moving speeds and short channel coherent times becomes a problem.

TRS is supported to track the Doppler shift. However, TRS has the following problems:
◆ The number of ports per CSI-RS resource set is limited to only one. Each CSI-RS resource uses a single port.
◆The settable period is 10 ms or more.
◆ CSI reporting is not assumed for TRS. There is no reporting configuration for P-TRS. Reporting can be configured, but the report quantity (reportQuantity) is set to 'none' only. A maximum of 16 CSI-RS resources are used per CSI-RS resource set.

TRS are allocated to time-domain and frequency-domain resources. To measure the impact of Doppler shift, multiple time-domain RSs are required within a specific frequency-domain resource.

CMR can be used to measure the effects of Doppler shift. However, the RS used for measurement depends on the UE implementation.

The amount of CSI reporting does not support information about Doppler shift. Through the CSI codebook (PMI), the UE reports information for determining W = _{W1 W2} , where _W1 is the wideband characteristic and indicates the spatial beam, and _W2 is the subband characteristic and indicates the amplitude/phase coefficient for each spatial beam.

Considering measurements related to Doppler shift, there are three possible cases: Case 1, in which the UE performs measurements based on CSI-RS, and Case 2, in which the base station performs measurements based on SRS. Regarding the assessment of the impact of Doppler shift, there are three possible cases: Case 1-1, in which the UE performs measurements based on CSI-RS measurement results, Case 1-2, in which the base station performs measurements based on CSI-RS measurement results reported by the UE, and Case 2-1, in which the base station performs measurements based on SRS measurement results.

CSI-RS measurement windows and CSI reporting windows are considered. Within a CSI-RS measurement window, one or more CSI-RS occasions may be measured. The reported CSI may be associated with a CSI reporting window.

Assuming a CSI report in slot n, the length of the Doppler domain (DD)/time domain (TD) basis vectors (DFT basis vectors) (the number of DD/TD bases) may be _N4 . One or more CSI occasions for calculating the CSI report may be measured within the CSI measurement window of slot [k, k+W _meas −1]. Here, k may be a slot index, and W _meas may be the measurement window length (number of slots). The CSI occasions may be configured in CSI-ReportConfig. The CSI reporting window of slot [l, l+W _CSI −1] may be associated with the CSI report in slot n. Here, l may be a slot index, and W _CSI may be the reporting window length (number of slots). The location of the CSI reference resource may be denoted as n _ref .

The duration of the CSI reporting window is W _CSI = dN ₄ , where d and N ₄ are determined by the CMR setting. The start of the CSI reporting window is slot l. l may be (nN _CSI,ref ). l may be (n+δ). δ may be {0,2} or δ may be {0,1,2}.

A d slot may have a duration in DD units.

When UE-side prediction is assumed, the UE is supported to predict the CSI/channel after slot l, and the position of slot l (from multiple candidates) is configured by the base station via higher layer signaling. The multiple candidates for the slot l position include the legacy CSI reference resource position (nN _CSI,ref ) and (n+δ), where δ>0. The legacy CSI reference resource in legacy operation, i.e., (nN _CSI,ref ), is reused/repurposed to indicate the position of the last CSI-RS occasion used for CSI reporting.

For parameter δ, an additional value of 2 is supported.

_N4 is configured by the base station via higher layer signaling.

When N ₄ =1, the DD basis may be the identity. There may be no DD compression. In this case, the codebook structure may be, for example, the following formula H1:

When N ₄ > 1, the Doppler domain orthogonal DFT basis may be commonly selected for all SD/FD basis. In this case, the codebook structure may be, for example, the following formula H2.

Only Q>1, indicating the number of selected Doppler domain (DD) basis vectors, is allowed. The detailed design of the SD/FD basis, including the associated UCI parameters, follows existing specifications.

For an enhanced Type II codebook for predicted PMI (Rel. 18 Type 2 CSI for predicted PMI), the UE may configure the higher layer parameter codebookType set to 'typeII-Doppler-r18'. For a further enhanced Type II port selection codebook for predicted PMI (Rel. 18 Type 2 PS CSI for predicted PMI), the UE may configure the higher layer parameter codebookType set to 'typeII-Doppler-PortSelection-r18'.

In the present disclosure, the terms Doppler codebook, Doppler type 2 codebook, extended type 2 codebook for predicted PMI, Rel. 18 type 2 CSI codebook for predicted PMI, type II-Doppler-r18, extended type 2 PS codebook for predicted PMI, Rel. 18 type 2 PS codebook for predicted PMI, and type II-Doppler-PortSelection-r18 may be interpreted interchangeably.

(CSI-RS)
In Rel. 15, for example, the CSI-RS is used as a DL RS for at least one of channel state information (CSI) acquisition, beam management (BM), beam failure recovery (BFR), and fine time and frequency tracking. The CSI-RS supports 1, 2, 4, 8, 12, 16, 24, and 32 ports (antenna ports, CSI-RS ports). The CSI-RS supports periodic, semi-persistent, and aperiodic transmission. The frequency density of the CSI-RS is configurable to adjust overhead and CSI estimation accuracy.

Figure 1 shows an example of the CSI-RS location within a slot. Each row in the table indicates the row number, number of ports, frequency domain density, CDM type, time and frequency (time/frequency) location (component resource location (k bar, l bar)), code division multiplexing (CDM) group index, and each resource location within the component resource ((RE, symbol), (k', l')). Here, the time/frequency location is the location of the time and frequency resource (component resource) of the CSI-RS corresponding to one port. The k bar is represented by an overlined "k." The k bar indicates the starting resource element (RE) index of the component resource, and the l bar indicates the starting symbol (OFDM symbol) index of the component resource.

CDM groups include no CDM (no CDM, N/A), FD-CDM2, CDM4, and CDM8. FD-CDM2 multiplexes two-port CSI-RSs at the same time and frequency by multiplying a frequency domain (FD)-orthogonal cover code (OCC) of length 2 on an RE-by-RE basis (FD2). CDM4 multiplexes four-port CSI-RSs at the same time and frequency by multiplying a length-2 FD-OCC with a length-2 time domain (TD)-OCC on an RE-by-symbol basis (FD2TD2). CDM8 multiplexes eight-port CSI-RSs at the same time and frequency by multiplying a length-2 FD-OCC with a length-4 TD-OCC on an RE-by-symbol basis (FD2TD4).

The maximum number of CSI-RS ports, 32, is greater than the maximum number of layers, 8, allowing the UE to measure more channel conditions and improving measurement accuracy.

In Rel. 19 and later, massive MIMO using more than 32 ports is being considered.

(Base station antenna layout)
Figure 2 shows a table relating the supported number of CSI-RS ports to the base station antenna layout (configuration of (N ₁ , N ₂ ) and (O ₁ , O ₂ )) for a single panel of the existing specifications. Figure 3 shows a table relating the supported number of CSI-RS ports to the base station antenna layout (configuration of (N _g , N ₁ , N ₂ ) and (O ₁ , O ₂ )) for a multi-panel of the existing specifications.

(Type 1 Single Panel Codebook)
In addition to the codebook for 1-layer CSI reporting and codebook mode (codebookMode)=1 described above, type 1 single-panel codebooks for at least one of other codebook modes and other ranks (number of layers) are defined.

For rank {1,5,6,7,8}, the codebook index for each PMI is _i1,1 , _i1,2 , and _i2 . For rank {2,3,4}, the codebook index for each PMI is _i1,1 , _i1,2 , _i1,3 , and _i2 . _i1,1 and _i1,2 correspond to two dimensions, respectively, and are indices for beam selection. _i2 is an index for the phase difference (co-phasing) between the two polarizations. _i1,3 is mapped to _k1 and _k2 according to the mapping (table) in the specification. Figure 4 shows the mapping from _i1,3 to _k1 and _k2 for two-layer CSI reporting. Figure 5 shows the mapping from _i1,3 to _k1 and _k2 for three-layer and four-layer CSI reporting.

The codebook (relationship between precoding matrix and codebook index) for 1-layer CSI reporting and codebookMode=1 is specified in the specifications (Figure 6).

For 1-layer CSI reporting and codebookMode=2, the specification specifies a codebook for _N2 >1 (Fig. 7) and a codebook for _N2 =1 (Fig. 8). For _N2 =1, there is no oversampling in the _N2 dimension, so _i1,2 is not reported.

The specification defines the codebook for two-layer CSI reporting and codebookMode=1 (Figure 9). _{v l,m} and φ _n v _l,m correspond to the first layer. _{v l',m'} and -φ _n v _l',m' correspond to the second layer. The beam for the second layer is determined by l' and m'. l' and m' are determined by i _1,1 +k ₁ and i _1,2 +k ₂ , respectively. _{k 1} and k ₂ are determined by i _1,3 reported by the UE as described above.

As codebooks for 2-layer CSI reporting and codebookMode=2, the specifications specify a codebook for _N2 >1 (Fig. 10) and a codebook for _N2 =1 (Fig. 11). For _N2 =1, there is no oversampling in the _N2 dimension, so _i1,2 is not reported.

The specification defines the codebooks for 3-layer CSI reporting and codebookMode=1-2 (Fig. 12). θ _p denotes the phase difference of the second port relative to the first port.

The codebook structure for 4-layer CSI reporting and codebookMode=1-2 is the same as the codebook structure for 3-layer CSI reporting and codebookMode=1-2.

The specification specifies 5-layer CSI reporting and codebooks for codebookMode=1-2 (see FIG. 13). The relationship (PMI) for N ₂ >1 is different from the relationship (PMI) for N ₂ =1.

The codebook structure for 6-layer CSI reporting and codebookMode=1-2 is the same as the codebook structure for 5-layer CSI reporting and codebookMode=1-2.

The specification defines 7 layer CSI reporting and codebooks for codebookMode=1-2 (Figure 14). The relationship (PMI) varies depending on the values of _N1 and _N2 .

The codebook structure for 8-layer CSI reporting and codebookMode=1-2 is the same as the codebook structure for 7-layer CSI reporting and codebookMode=1-2.

For CSI-RS using more than 32 ports, CSI/codebooks based on the Rel. 15 Type 1 Single Panel CSI (Type 1 Single Panel Codebook) have not been fully considered.

(analysis)
<Analysis 1>
For some ranks (rank=2, 3, 4), the CSI feedback is different, e.g., i _1,3 is selective feedback.

For different layers, the beams selected in _W1 cannot be different. Based on the beams selected by _i1,1 and _i1,2 , additional orthogonal beam (SD) bases for other layers can be selected by reporting _i1,3 .

For example, in the above-mentioned two-layer CSI reporting and codebook of codebook mode 1, the beam for the first layer is determined by l and m, which are determined by _i1,1 and _i1,2 , respectively. The beam for the second layer is determined by l' and m', which are determined by _i1,1 + _k1 and _i1,2 + _k2 , respectively.

For some ranks (rank = 5, 6, 7, 8), different orthogonal beam bases are defined for some other layers from the precoding matrix W in the table of the specification, even without additional feedback of _i1,3 . For example, in the codebook for the 8-layer CSI report and codebookMode = 1-2 in Figure 15, beams for each layer are defined. For layers 1 and 2, beams l and m are determined by _i1,1 and _i1,2 , respectively. For layers 3 and 4, beams l' and m' are determined by _i1,1 + _O1 and _i1,2 , respectively. For layers 5 and 6, beams l'', m'' are determined by _i1,1 and _i1,2 + _O2, respectively. For layers 7 and 8, beams l''', m''' are determined by _i1,1 + _O1 and _i1,2 + _O2 , respectively.

<Analysis 2>
For different codebook modes (1 and 2), the PMI may be different.

In codebook mode 1, the beam for the wideband is selected from all _N1N2O1O2 beams. The phase difference is considered for each subband. On the other hand, in codebook mode 2, the beam for the wideband is selected from _{either N1O1 beams or N2O2 beams} . Both the beam and the phase difference are selected for each subband. For example, in the above-mentioned one-layer CSI report and codebook for codebook mode 2 _{, i1,1 or i1,2 ,} which indicates the wideband beam, is selected from _N1O1 beams or _half of _{the N2O2} beams, respectively. In addition to changing n for the phase difference, _i2 for the subband can be changed from ( _2i1,1 , _2i1,2 ), ( _2i1,1 +1, _2i1,2 ), ( _2i1,1 , _2i1,2 +1), or ( _2i1,1 +1, _2i1,2 +1).

<Analysis 3>
For different ranks, there are different numbers of CSI-RS ports and different codebook (precoding matrix) structures.

Two different structures of W are considered for different ranks in the different cases of CSI-RS port number ≦ 16 and CSI-RS port number > 16.

The structure A of W applied to ranks 1, 2, 5, 6, 7, 8 and ranks 3, 4 with the number of CSI-RS ports ≦16 may be given by the following equation J1:

In structure A, only the phase difference for the two polarizations is considered. In structure A, the number of rows of W is the number of CSI-RS ports, and the number of columns of W is the number of layers. For different layers, the N ₁ N ₂ row-by-1 column precoder v may be the same or different. For different layers, the phase difference φ may exist, may not exist, or may be -φ.

The structure B of W applied to ranks 3 and 4 with CSI-RS port numbers > 16 may be given by the following equation J2:

When the number of CSI-RS ports is large, W also provides the phase difference θ between the CSI-RS ports. This structure is a simplified method. Here, the beams selected for the first half ports and the beams selected for the second half ports are the same, and the phase difference θ between the first half ports and the second half ports is taken into account. This method is used when the number of CSI-RS ports is large. The precoder v ^∼ has N ₁ N ₂ /2 rows and 1 column.

<Analysis 4>
The PMI may be different for different _N2 values ( _N2 >1 and _N2 =1) and/or different n1-n2 ( _N1 and _N2 ) values.

For _N2 = 1, the oversampling factor is 1, and reporting of _i1,2 is not required. For different values of n1-n2, in the case of different PMIs, the selected beam ( _i1,1 , _i1,2 ) is selected from a subset _{of N1O1} beams and _{N2O2 beams} . For example, in the above-mentioned 7-layer CSI reporting and codebook for codebookMode = 1-2, for certain values of n1-n2 ( _N1 = 4 and _N2 = 1), beam _i1,1 is selected from a subset (half) _{of N1O1} beams. For certain values of n1-n2 ( _N1 > 2 and _N2 = 2), beam _i1,2 is selected from a subset (half) _{of N2O2} beams. For certain values of n1-n2 ( _N2 = 1), reporting of _i1,2 = 0.

<Analysis 5>
In the existing CSI reporting based on the Type 1 codebook, when multiple CSI-RS resources are configured, the UE selects one CRI to report and reports the RI/LI/PMI/CQI corresponding to the reported CSI-RS resource (CRI).

In the case of hybrid beamforming, when a network (NW) attempts to perform multi-user (MU) pairing for a specific CSI-RS resource, the NW has CSI from multiple UEs for the same CSI-RS resource. If different UEs select and report different CSI-RS resources, it is difficult for the NW to perform MU pairing.

By extending CRI-based reporting, it is possible to select and report multiple CRIs and request multiple UEs to report the RI/LI/PMI/CQI corresponding to each selected CSI-RS resource (CRI).

The following points can be considered:
Issue 1: How to configure and report multiple CRIs in one CSI direction, e.g., bit size for multiple CRIs.
Issue 2: How to determine the mapping order of multiple CSIs corresponding to multiple CRIs.
- Issue 3: Are there any relationships/constraints on multiple CSIs corresponding to multiple CRIs?
Issue 4: How the zero power (ZP)-interference measurement resource (IMR)/non-zero power (NZP)-IMR is set.

(Consider)
A CSI that supports up to 128 CSI-RS ports is being studied, with FR1 as the target. Specifically, the following items are being studied:
◆Item a: Based on an extension of the existing codebook, an improvement to the Type 1 codebook that supports up to a total of 128 CSI-RS ports across all resources, assuming existing CSI-RS resources (with up to 32 CSI-RS ports per resource).
◆Item b: An improvement to the Type 2 codebook that supports up to a total of 128 CSI-RS ports across all resources, assuming existing CSI-RS resources (with up to 32 CSI-RS ports per resource), based on an extension of the existing codebook without changing any codebook parameters other than the introduction of an additional value for the codebook parameter for the number of ports.
◆Item c: Extension of CRI-based CSI reporting (reporting of CQI/PMI/RI calculated per CRI for one or more CRIs) for hybrid beamforming supporting up to 32 CSI-RS ports per resource and up to 128 total CSI-RS ports across all resources without new codebook design.

However, the method of configuring/reporting CSI to support more than 32 CSI-RS ports has not been fully considered. If such a method is not fully considered, there is a risk that communication quality/throughput will deteriorate.

The inventors therefore considered methods for setting and reporting CSI and came up with the following embodiments.

Embodiments of the present disclosure will be described in detail below with reference to the drawings. The wireless communication methods according to the embodiments may be applied independently or in combination.

(Various reading changes)
In the present disclosure, a word enclosed in "( )" in a sentence may indicate an explanation of the word immediately preceding it (for example, an explanation of spelling), a paraphrase, a specific example, a supplementary explanation, etc. Also, in the present disclosure, a word enclosed in "[ ]" in a sentence may be interpreted including the word in the meaning of the entire sentence, or may be interpreted excluding the word in the meaning of the entire sentence (ignoring the word in the meaning of the entire sentence). Note that "( )" and "[ ]" may also be used for purposes/meanings other than those mentioned above.

In this disclosure, "A/B" and "at least one of A and B" may be interpreted interchangeably. Also, in this disclosure, "A/B/C" may mean "at least one of A, B, and C."

In this disclosure, terms such as notify, activate, deactivate, indicate (or indicate), select, configure, update, and determine may be read interchangeably. In this disclosure, terms such as support, control, controllable, operate, and operateable may be read interchangeably.

In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, upper layer parameters, fields, information elements (IEs), settings, etc. may be interchangeable. In this disclosure, Medium Access Control control elements (MAC Control Elements (CEs)), update commands, activation/deactivation commands, etc. may be interchangeable.

In the present disclosure, higher layer signaling may be, for example, Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., messages from the core network such as positioning protocol (e.g., NR Positioning Protocol A (NRPPa)/LTE Positioning Protocol (LPP)) messages), or a combination of these.

In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. Broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), etc.

In the present disclosure, ceil(x), ceiling function, and ceiling function may be interchangeable. In the present disclosure, floor(x), floor function, and floor function may be interchangeable. In the present disclosure, sqrt(x), square root of x, and root x may be interchangeable. In the present disclosure, x mod y, mod(x, y), mod function, and modulo operation may be interchangeable. In the present disclosure, Σ _i=M ^M+N-1 f(i), Σ _i=M ^M+N-1 f _i , the summation of f(i) or f _i over i=M, M+1, ..., M+N-1, f(M) + f(M+1) + ... + f(M+N-1), and f _M + f _M+1 + ... + f _M+N-1 may be interchangeable. C(n, k) is the number of combinations of selecting k values from n values (combinatorial coefficient), binomial coefficients, _{nCk and Cnk} may be read as interchangeable. In the present disclosure, x/y and floor(x/ ^y ) may be read as interchangeable.

In the present disclosure, A _b , A_b, Ab, and A with a b added to the lower right may be read as interchangeable. In the present disclosure, A ^c , A^c, and A with a c added to the upper right may be read as interchangeable. In the present disclosure, A _b ^c , A_b^c, and A with a b added to the lower right and a c added to the upper right may be read as interchangeable. In the present disclosure, x ^~ may be represented by adding ~ above x, or may be referred to as x tilde. In the present disclosure, x ^- may be represented by adding - above x, or may be referred to as x bar. In the present disclosure, x ^{^} may be represented by adding ^ above x, or may be referred to as x hat.

In the present disclosure, FR may be, for example, at least one of FR1, FR2, FR2-1, FR2-2, FR3, sub-terahertz, and terahertz. In the present disclosure, the frequency range corresponding to FR1 may be 410-7125 MHz. In the present disclosure, FR2 may include FR2-1 and FR2-2, and the frequency range corresponding to FR2-1 may be 24250-52600 MHz, and the frequency range corresponding to FR2-1 may be 52600-71000 MHz.

The following abbreviations may be used in this disclosure:
◆FDM: frequency division multiplexing
◆TDM: time division multiplexing

In this disclosure, the terms indicate, report, and select may be read interchangeably.

In the present disclosure, the first dimension, the _N1 dimension, one of the horizontal domain and the vertical domain, and the horizontal domain may be interchanged. In the present disclosure, the second dimension, the dimension perpendicular to the first dimension, the _N2 dimension, the other of the horizontal domain and the vertical domain, and the vertical domain may be interchanged. In the present disclosure, the _N1 and _N2 may be interchanged, and the horizontal domain and the vertical domain may be interchanged.

In this disclosure, the terms port, antenna port, CSI-RS port, port index, and port number may be interpreted interchangeably.

In the present disclosure, the number of extended ports, the number of extended CSI-RS ports, the new P _CSI-RS , the number of new ports, the number of ports greater than 32, and 48/64/72/96/128 may be read as interchangeable. In the present disclosure, the number of existing ports, the number of existing CSI-RS ports, the existing P _CSI-RS , and the number of ports equal to or less than 32 may be read as interchangeable.

In the present disclosure, ( _N1 , _N2 ), ( _N1 , _N2 ) setting, ( _N1 , _N2 ) value, n1-n2, antenna setting, antenna arrangement, antenna position, gNB antenna, two-dimensional antenna, two-dimensional arrangement, two-dimensional position, two-dimensional arrangement setting, setting regarding the size of the two-dimensional matrix for antenna arrangement/beam selection may be read interchangeably.

In the present disclosure, the terms "existing (N ₁ , N ₂ ),""(N ₁ , N ₂ ) for the existing number of ports,""a configuration of a two-dimensional antenna arrangement for 32 or fewer ports," and "a first configuration relating to a two-dimensional arrangement of multiple antennas for 32 or fewer ports" may be interchangeable. In the present disclosure, the terms "new (N ₁ , N ₂ ),""(N ₁ , N ₂ ) for the extended number of ports,""a configuration of a two-dimensional antenna arrangement for more than 32 ports," and "a second configuration relating to a two-dimensional arrangement of multiple antennas for more than 32 ports" may be interchangeable. In the present disclosure, the terms "new (N _g1 , N _g2 ),""a third configuration relating to a two-dimensional arrangement of multiple groups of antennas based on (N ₁ , N ₂ ) for the extended number of ports,""a configuration of a two-dimensional panel arrangement for more than 32 ports," and "a configuration relating to a two-dimensional arrangement of multiple groups of antennas each associated with a multiple CSI-RS resource" may be interchangeable.

In the present disclosure, the terms x-port CSI-RS resource, CSI-RS resource associated with x-port, and CSI-RS resource using x-port may be interpreted interchangeably.

In the present disclosure, CSI-RS resources, existing port CSI-RS resources, CSI-RS, CMR, port group, group of 32 or fewer ports, port group, group of 32 or fewer ports associated with one CSI-RS resource, CSI-RS resources associated with a group of 32 or fewer ports, CSI-RS resources associated with a group of N ₁ N ₂ O ₁ O ₂ SD beams based on existing (N ₁ , N _{2 )} , CSI-RS resources associated with a group of N ₁ N ₂ O ₁ O ₂ gNB antennas based on existing (N ₁ , N 2 ), existing N ₁ N ₂ O ₁ O ₂ antennas, existing N ₁ N ₂ O ₁ O ₂ SD beams may be read as interchangeable.

In the present disclosure, groups, sets, blocks, and pools of 32 or less ports for supporting an expanded port count may be interchangeable. In the present disclosure, groups, sets, blocks, and pools of _{N1N2O1O2 SD} beams based on existing _{( N1} , _N2 ) for supporting an expanded port count may be interchangeable. In the present disclosure, groups, sets, blocks, pools, and panels _{of N1N2O1O2 gNB} antennas based on existing ( _N1 , _N2 ) for supporting an _{expanded port} count may be interchangeable.

In the present disclosure, CSI-RS resources for an extended port number, new port CSI-RS resources, extended port CSI-RS resources, extended CSI-RS, extended CMR, new group, multiple port group, CSI-RS resources associated with more than 32 ports, CSI-RS resources associated with a group of N _{1 N 2} O ₁ O ₂ SD beams based on a new (N ₁ , N ₂ ), CSI-RS resources associated with a group of _{N 1} N ₂ O ₁ O ₂ gNB antennas based on a new (N ₁ , N 2 ), new N ₁ N 2 O ₁ O ₂ antennas, new N ₁ N ₂ O ₁ O ₂ SD beams may be read interchangeably.

In the present disclosure, (N _g1 , N _g2 ), ng1-ng2, panel setting, gNB panel setting, arrangement/position/two-dimensional arrangement of CSI-RS resources/port groups/panels/antenna groups may be read as interchangeable. In the present disclosure, N _g , ng, panel setting, gNB panel setting, CSI-RS resources/port groups/panels/antenna groups may be read as interchangeable.

In the present disclosure, new _N1N2 and _N1 × _N2 based on new ( _N1 , _N2 ) may be read as interchangeable. In the _present disclosure, existing _N1N2 and _{N1 × N2} based on existing ( _N1 , _N2 ) may be read as interchangeable.

In the present disclosure, new _{N1N2O1O2 and N1O1×N2O2 based on} new _{(N1,N2) may be read as interchangeable. In the present disclosure, existing N1N2O1O2 and N1O1 × N2O2 based on existing ( N1 , N2 ) may be read as interchangeable} .

In the present disclosure, the positions within new (N ₁ , N ₂ ), the positions of gNB antennas based on new (N ₁ , N ₂ ), and the positions within _{N 1 N 2 O 1} O ₂ gNB antennas based on new (N ₁ , N ₂ ) may be read as interchangeable. In the present disclosure, the positions within existing (N ₁ , N 2 ), the positions of gNB antennas based on existing (N ₁ , N ₂ ), the positions within _{N 1} N ₂ O ₁ O ₂ gNB antennas based on existing (N _{1 , N 2 ), and the positions within existing N 1} N ₂ O ₁ O ₂ gNB antennas may be read as interchangeable.

In this disclosure, the _terms "SD beam based on new ( _N1 , _N2 )" and "SD beam within _{N1N2O1O2 SD} beams based on new ( _N1 , _N2 )" may be interchangeable. In this disclosure, _the terms "position within existing ( _N1 , _N2 ), _" "SD beam based on existing ( _N1 , _N2 )," _{and "SD beam within N1N2O1O2 SD} beams based on existing ( _N1 , _N2 )" may be interchangeable.

In the present disclosure, ( _i1,1 , _i1,2 ), an index indicating a beam, a first index, a third index, and a two-dimensional index may be interchangeable. In the present disclosure, _i1,4 , an index indicating a CSI-RS resource corresponding to a beam, a second index, a one-dimensional index, and a two-dimensional index may be interchangeable.

(Wireless communication method)
The UE may calculate the CSI by measuring a CSI-RS (resource) using a port to which at least one embodiment is applied, and report the CSI.

((Embodiment A))
<Consideration A>
It may be difficult to share the same CSI-RS resources between the legacy (e.g., Rel. 15-18, up to 32 ports) CSI-RS and the new (e.g., Rel. 19, more than 32 ports) CSI-RS. Because legacy UEs cannot despread the new TD-OCC/FD-OCC, the base station needs to configure separate sets of CSI-RS resources for legacy (e.g., Rel. 15-18) UEs and new (e.g., Rel. 19) UEs. This causes CSI-RS overhead. Attempts to reduce CSI-RS overhead may limit performance improvements for more than 32 CSI-RS ports.

<Embodiment A1>
Different CSI-RS resources may use different CSI-RS ports without introducing more than 32 ports in the same CSI-RS resource (time and frequency resource). Multiple CSI-RS resources may be aggregated for a new UE.

For example, two CSI-RS resources may be configured, with the first CSI-RS resource associated with CSI-RS ports #0 to #31 and the second CSI-RS resource associated with CSI-RS ports #32 to #63. In this case, it becomes easier to share the CSI-RS resources between the existing UE and the new UE. For example, only the first CSI-RS resource may be configured for the existing UE, and both the first and second CSI-RS resources may be configured for the new UE.

According to this embodiment A1, by changing the definition of the CSI-RS port mapping, it is possible to define more than 32 CSI-RS ports, thereby minimizing the impact on the specifications.

As shown in the example of FIG. 16, CSI-RS resource #1 and CSI-RS resource #2 may be configured to be FDM-multiplexed, with CSI-RS resource #1 associated with CSI-RS ports #0 to #31 and CSI-RS resource #2 associated with CSI-RS ports #32 to #63.

As shown in the example of FIG. 17, TDM CSI-RS resource #1 and CSI-RS resource #2 may be configured, with CSI-RS resource #1 associated with CSI-RS ports #0 to #31 and CSI-RS resource #2 associated with CSI-RS ports #32 to #63.

The time resource size of each CSI-RS resource may be slot/subslot/subframe, and the frequency resource size of each CSI-RS resource may be PRB/2 ^N consecutive PRBs (N=-2, -1, 1, 2, ...).

A method for mapping more than 32 CSI-RS ports across multiple CSI-RS resources may follow at least one of several embodiments A1-X below.

<<Embodiment A1-1>>
If the UE is configured with higher layer parameters enabling more than 32 CSI-RS ports and configured with x CSI-RS ports and y CSI-RS resources, the UE may map the CSI-RS ports according to at least one of the following rules, where x may be less than or equal to 32:
The first resource of the y CSI-RS resources (or CSI-RS resource set) is mapped to CSI-RS ports #0 to #x-1.
- The second resource of the y CSI-RS resources (or CSI-RS resource set) is mapped to CSI-RS ports #x to #2x-1.
- The third resource of the y CSI-RS resources (or CSI-RS resource set) is mapped to CSI-RS ports #2x to #3x-1.
The i-th resource in the y CSI-RS resources (or CSI-RS resource set) is mapped to CSI-RS ports #(i-1)x to #ix-1, where the i-th resource may be the CSI-RS resource corresponding to the i-th time resource (e.g., slot) or the CSI-RS resource corresponding to the i-th frequency resource (e.g., PRB).

<<Embodiment A1-2>>
The aggregated CSI-RS resources may be associated with more than 32 CSI-RS ports. Each CSI-RS resource may be associated with 32 or fewer CSI-RS ports. The CSI-RS resources for aggregation may comply with at least one of the following optional constraints:
- Option 1: The number of CSI-RS resources for aggregation is M. For example, M may be 2.
Option 2: The number of ports associated with each CSI-RS resource for aggregation is fixed to N or is greater than or equal to O. For example, N may be 32. For example, O may be 16.
- Option 3: Multiple CSI-RS resources for aggregation are configured within the same CSI-RS resource set or CSI-RS resource group.
- Option 4: Multiple CSI-RS resources for aggregation may have the same configuration of at least one of density, number of ports, time operation setting, frequency resource allocation, time resource allocation, QCL assumption, scrambling ID, and new scrambling ID. The time operation setting may indicate a P, SP, or AP. The frequency resource allocation may be at the wideband level or the RB level. The wideband level may be the number of PRBs and the starting PRB. The time resource allocation may be at the slot level. The QCL assumption may be an associated SSB. Multiple CSI-RS resources for aggregation may have different configurations of at least one of time resource allocation, frequency resource allocation, and scrambling ID.
- Option 5: Multiple CSI-RS resources for aggregation may be in up to M consecutive slots or in consecutive/comb frequency resources.
For example, M=2 CSI-RS resources may be aggregated and associated with 64 CSI-RS ports, and each CSI-RS resource may be associated with 32 CSI-RS ports, where the two CSI-RS resources are in the same CSI-RS resource set or CSI-RS resource group, have the same frequency resource allocation, and are respectively arranged in two consecutive slots.

<<Embodiment A1-3>>
For aggregated multiple CSI-RS resources having more than 32 ports, some parameters may be added or existing parameters may be overwritten. For example, the parameters may be at least one of density, new scrambling ID, number of PRBs, and starting PRB. A density smaller than the existing density may be configured to reduce the complexity of UE measurements.

((Embodiment B))
<Consideration B>
For more than 32 CSI-RS ports, the base station antenna layout and configuration has not been fully considered.

<Embodiment B1>
The novel antenna layout and configuration for CSI-RS with more than 32 ports may follow at least one of the following options:

- Option 1
New (N ₁ , N ₂ ) and new (O ₁ , O ₂ ) may be defined in the specification and configured in the UE. A new row may be added to the existing table. The new row may be used only if a CSI-RS with more than 32 ports for the CSI codebook is configured. A new table separate from the existing table may be added. The new table may be used only if a CSI-RS with more than 32 ports for the CSI codebook is configured, otherwise the existing table may be used.

18 shows an example of a configuration according to Option 1 of embodiment B1. At least one row in this table may be supported. This table shows multiple combinations (rows) of the number of CSI-RS ports (>32), (N ₁ , N ₂ ), and (O ₁ , O ₂ ).

- Option 2
(Similar to the configuration for multi-panel), a new parameter ng may be added to the configuration, indicating _Ng , which is combined with at least one of the existing ( _N1 , _N2 ) and ( _O1 , _O2 ) values. The new configuration may be defined in the specification and configured in the UE.

_Ng may be configured as a parameter separate from the ( _N1 , _N2 ) configuration. For example, two parameters ng and n1-n2 may be configured, indicating _Ng and ( _N1 , _N2 ), respectively. FIG. 19 shows a first example of configuration according to Option 2 of Embodiment B1. At least one combination of the combinations in this table may be supported. This table shows multiple combinations of the number of CSI-RS ports (>32), _Ng , existing ( _N1 , _N2 ), and ( _O1 , _O2 ). Different ( _N1 , _N2 ) may be included in separate rows. As with the example of Option 1, different ( _O1 , _O2 ) may be used for different ( _N1 , _N2 ). Rows marked with an asterisk may not be needed by reusing the existing configuration of many ports.

_Ng may be configured as a new parameter joint with the ( _N1 , _N2 ) configuration. For example, one parameter ng-n1-n2 indicating ( _Ng , _N1 , _N2 ) may be configured. FIG. 20 shows a second example of configuration according to option 2 of embodiment B1. At least one row in this table may be supported. This table shows multiple combinations (rows) of the number of CSI-RS ports (>32), new ( _Ng , _N1 , _N2 ), and ( _O1 , _O2 ). For the rows marked with *, the rows may not be needed by reusing the existing configuration of many ports.

The UE may recognize that only one dimension is extended by the _Ng value. As in the example of Figure 21A, an antenna layout ( _Ng , N1, N2) = (2, ₈ , ₂ ) for 64 ports may mean a two-antenna layout ( _N1 , _N2 ) = (8, 2) in the horizontal direction. As in the example of Figure 21B, an antenna layout ( _Ng , _N1 , N2) = (4, 8, ₂ ) for 128 ports may mean a four-antenna layout ( _N1 , N2) = (8, ₂ ) in the horizontal direction. In these examples, the spacing between two adjacent antenna elements in the horizontal or vertical direction is d.

- Option 3
New parameters ng1-ng2 may be added to the configuration, indicating (N _{g1 , N g2 ) combined with at least one value of the existing (N 1 , N 2} ) and the existing (O ₁ , O ₂ ). The new parameters may be defined in the specification and configured to the UE.

(N _g1 , N _g2 ) may be configured as a parameter separate from the (N ₁ , N ₂ ) configuration. For example, two parameters ng1-ng2 and n1-n2 may be configured, indicating (N _g1 , N _g2 ) and (N ₁ , N ₂ ), respectively. FIG. 22 shows a first example of configuration according to Option 3 of embodiment B1. At least one combination in this table may be supported. This table shows multiple combinations of the number of CSI-RS ports (>32), (N _g1 , N _g2 ), existing (N ₁ , N ₂ ), and (O ₁ , O ₂ ). For the rows marked with an asterisk, the rows marked with an asterisk may not be needed by reusing the configuration of the existing many ports.

(N _g1 , N _g2 ) may be configured as a new parameter joint with the (N ₁ , N ₂ ) configuration. For example, one parameter ng1-ng2-n1-n2 indicating (N _g1 , N _g2 , N ₁ , N ₂ ) may be configured. FIG. 23 shows a second example of configuration according to Option 3 of embodiment B1. At least one row in this table may be supported. This table shows multiple combinations (rows) of the number of CSI-RS ports (>32), new (N _g1 , N _g2 , N ₁ , N ₂ ), and (O ₁ , O ₂ ). For the rows marked with an asterisk, the row may not be needed by reusing the existing configuration of many ports.

The UE may recognize that two dimensions are extended by the (N _g1 , N _g2 ) values. N _g1 may correspond to N ₁ (horizontal direction), and N g2 may correspond to N ₂ (vertical direction). As in the example of FIG. 24A , an antenna layout (N _g1 , N _g2 , N ₁ , N ₂ ) = (2, ₂ , 8, 2) for 128 ports may mean an antenna layout (N ₁ , N _{2 ) = (8, 2} ) with two antennas in the horizontal direction and two in the vertical direction. As in the example of FIG. 24B , an antenna layout (N _g1 , N _g2 , N ₁ , N ₂ ) = (4, 1, 8, 2) for 128 ports may mean an antenna layout (N ₁ , N ₂ ) = (8, 2) with four antennas in the horizontal direction and one antenna in the vertical direction. In these examples, the spacing between two adjacent antenna elements in the horizontal or vertical direction is d.

<<Variations>>
The values of ( _O1 , _O2 ) for each value of ( _N1 , _N2 ) may be defined in the specification or may be configurable. The values of ( _O1 , _O2 ) may follow at least one of the following options:
Option 1: The values of (O ₁ , O ₂ ) are common to all ranks (number of layers).
- Option 2: For different ranks, the values of ( _O1 , _O2 ) are different. For example, for lower ranks, ( _O1 , _O2 ) have larger values, and for higher ranks, ( _O1 , _O2 ) have smaller values. For example, in ( _N1 , _N2 )=(16,2), for ranks 1 to 2, ( _O1 , _O2 )=(4,4), and for ranks 3 to 8, ( _O1 , _O2 )=(1,1).

According to this embodiment B1, the UE can appropriately configure the base station antenna layout for CSI-RS using more than 32 ports.

((Embodiment C))
<Consideration C>
It is contemplated that CSI-RS resources with more than 32 ports will not be directly designed and transmitted, instead, multiple existing CSI-RS resources will be used for measurements, with each resource carrying up to 32 CSI-RS ports.

However, the method for mapping/associating each existing CSI-RS resource to a gNB antenna from the antenna configuration (N ₁ , N ₂ ) has not been fully considered, which would lead to different UE behaviors regarding how to perform CSI calculations based on measurements of multiple CSI-RS resources. This association ensures that the gNB and UE have the same understanding of the reported SD beam.

The following mapping/association between the three factors A, B and C is possible:
◆Factor A: Port of CSI-RS resource.
◆ Factor B: Indexing of ports for the number of expanded ports.
◆Factor C: Position within new (N ₁ , N ₂ ).

Embodiment A1 shows the association between factors A and B.

<Embodiment C1>
Embodiment C1 relates to the generation of 128 ports.

To generate 128 ports, four 32-port CSI-RS resources (existing CSI-RS resources) may be configured to be transmitted. The four 32-port CSI-RS resources may be TDM'd within the same slot or multiple consecutive slots.

For each port of the transmitted 32-port CSI-RS, the mapping/association to a gNB antenna in the antenna configuration may be defined in the specification using the existing (N ₁ , N ₂ ) configuration for the 32 ports, or may be indicated/configured by a new (N _g1 , N _g2 ) configuration. The mapping/association may be based on at least one of several options:

◆ Option 1: Association of 32-port CSI-RS to multiple antennas considers only existing (N ₁ , N ₂ ) for 32 ports. Existing (N ₁ , N ₂ ) may be, for example, (4,4), (8,2), or (16,1).

◆ Option 2: Association of 32-port CSI-RS to multiple antennas is not limited to the existing (N ₁ , N ₂ ) for 32 ports. Any rule defined in the specification may be considered.
-◆For example, the association may be such that the 32 ports are first mapped to a gNB antenna in the horizontal domain dimension and then mapped to a gNB antenna in the vertical dimension, or the 32 ports are first mapped to a gNB antenna in the vertical domain dimension and then mapped to a gNB antenna in the horizontal dimension.
-◆For example, the association may be such that the 32 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the horizontal dimension and then mapped to the 2nd, (2+d)th, ... gNB antennas in the vertical dimension, or the 32 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the vertical dimension and then mapped to the 2nd, (2+d)th, ... gNB antennas in the horizontal dimension.
-◆The association may map the 32 ports to multiple gNB antennas according to other rules.

For each port of one CSI-RS and antenna position within the existing (N ₁ , N ₂ ), the existing rules may be applied/transferred to each embodiment for port mapping within each existing (N ₁ , N ₂ ).

Several new (N ₁ , N ₂ ) configurations for 128 ports may be supported:

◆ New (64,1) setting for 128 ports If this setting is supported, at least one rule of the following options may be defined:
◆ Option 1-a: Each 32-port CSI-RS resource may be defined to be associated with an existing (16,1) antenna using a specific order. In the example of FIG. 25A, four 32-port CSI-RSs are mapped to four (16,1) antennas arranged in the horizontal domain. As in the example of FIG. 25B, the four 32-port CSI-RSs may be TDM. The indexing of ports within the existing (N ₁ , N ₂ ) = (16,1) of the 32-port CSI-RS may follow existing rules. The mapping of each CSI-RS port to a gNB antenna within the existing (N ₁ , N ₂ ) may follow existing rules. The existing rules map ports first to antennas of one polarization, then to antennas of the other polarization. For example, of the 32 ports, ports 0 through 15 may be mapped to a horizontally polarized antenna in (16,1), and ports 16 through 31 may be mapped to a vertically polarized antenna in (16,1).

◆ New (16,4) setting for 128 ports If this setting is supported, at least one rule of the following options may be defined:

-◆Option 1-a: Each 32-port CSI-RS may be defined to be associated with an existing (4,4) antenna using a specific order. In the example of Figure 26A, four 32-port CSI-RSs are mapped to four (4,4) antennas. The four (4,4) antennas are arranged in the horizontal domain.

-◆Option 1-b: Each 32-port CSI-RS may be defined to be associated with an existing (8,2) antenna using a specific order. In the example of Figure 26B, four 32-port CSI-RSs are mapped to four (8,2) antennas. Of the four (8,2) antennas, two (8,2) antennas are arranged in the vertical domain, followed by the horizontal domain.

-◆Option 1-c: Each 32-port CSI-RS may be defined to be associated with an existing (16,1) antenna using a specific order. In the example of Figure 26C, four 32-port CSI-RSs are mapped to four (16,1) antennas. The four (16,1) antennas are arranged in the vertical domain.

-◆Option 1-d: Association with at least one existing ( _N1 , _N2 ) of (4,4), (8,2), and (16,1) is supported, and is indicated/set by new ( _Ng1 ,Ng2) and existing (N1, _N2 ) for 32 ports. In the example of Figure 27, existing ( _N1 , _N2 ) of (4,4), (8,2), and (16,1) are associated with new ( _Ng1 , _Ng2 ) of ( _4,1 ), (2,2), and ( _1,4 ), respectively.

-◆Option 2-a: The rule is that each CSI-RS is associated with multiple antennas distributed in the horizontal domain. In the example of Figure 28, the first CSI-RS is associated with antennas (1, 5, 9, 13) in the horizontal domain and antennas 1 to 4 in the vertical domain. The second CSI-RS is associated with antennas (2, 6, 10, 14) in the horizontal domain and antennas 1 to 4 in the vertical domain. The third CSI-RS is associated with antennas (3, 7, 11, 15) in the horizontal domain and antennas 1 to 4 in the vertical domain. The fourth CSI-RS is associated with antennas (4, 8, 12, 16) in the horizontal domain and antennas 1 to 4 in the vertical domain. If i = 1, 2, 3, 4 and j = 1, 2, 3, 4, the i-th CSI-RS is associated with the i+4(j-1)th antenna in the horizontal domain and the 1st to 4th antennas in the vertical domain.

--◆Antenna arrangement is not limited to the above example. The number of antennas arranged in the horizontal domain and the number of antennas arranged in the vertical domain may be reversed.

-◆For different associations, the measurements at the UE and the method of calculating the complete channel/CSI based on the four measurements may be different.

-◆When channel variations in the four CSI-RS resources at different times are taken into account, the performance of each association method (rule) may also differ.

◆ New (32,2) setting for 128 ports If this setting is supported, at least one rule of the following options may be defined:

-◆Option 1-a: Each 32-port CSI-RS may be defined to be associated with an existing (8,2) antenna using a specific order.

-◆Option 1-b: Each 32-port CSI-RS may be defined to be associated with an existing (16,1) antenna using a specific order.

-◆Option 1-c: Association of (8,2) and (16,1) with at least one existing (N ₁ ,N ₂ ) is supported and is indicated/configured by new (N _g1 ,N _g2 ) and existing (N ₁ ,N ₂ ) for 32 ports.

-◆Option 2-a: The rule is not limited to the existing (N ₁ ,N ₂ ) of (8,2) and (16,1).

◆ New (8,8) setting for 128 ports If this setting is supported, at least one rule of the following options may be defined:

-◆Option 1-a: Each 32-port CSI-RS may be defined to be associated with an existing (4,4) antenna using a specific order.

-◆Option 1-b: Each 32-port CSI-RS may be defined to be associated with an existing (8,2) antenna using a specific order.

-◆Option 1-c: Each 32-port CSI-RS may be defined to be associated with an existing (16,1) antenna using a specific order.

-◆Option 1-d: Association of at least one existing (N ₁ , N ₂ ) of (4,4), (8,2), and (16,1) is supported and is indicated/configured by new (N _g1 , N _g2 ) and existing (N ₁ , N ₂ ) for 32 ports.

-◆Option 2-a: The rule is not limited to the existing (N ₁ ,N ₂ ) of (4,4), (8,2) and (16,1).

29 shows an example of association candidates considering 32 existing ports (N ₁ , N ₂ ) in Option 1. As described above, this example shows associations between 128 CSI-RS antenna ports, new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the multiple associations in this example may be supported or configurable.

According to embodiment C1, multiple CSI-RSs, each using 32 or fewer ports, can be appropriately mapped/associated to multiple gNB antennas, allowing for appropriate utilization of 128 CSI-RS ports.

<Embodiment C2>
Embodiment C2 relates to the generation of 96 ports.

At least one of the following embodiments C2-1 and C2-2 may be supported. At least one of the following embodiments C2-1 and C2-2 may be configurable.

<<Embodiment C2-1>>
To generate 96 ports, three 32-port CSI-RS resources (existing CSI-RS resources) may be configured to be transmitted, and the three 32-port CSI-RS resources may be TDM'd within the same slot or consecutive slots.

For each port of the transmitted 32-port CSI-RS, the mapping/association to a gNB antenna in the antenna configuration may be defined in the specification using the existing (N ₁ , N ₂ ) configuration for the 32 ports, or may be indicated/configured by a new (N _g1 , N _g2 ) configuration. The mapping/association may be based on at least one of several options:

◆ Option 1: Association of 32-port CSI-RS to multiple antennas considers only existing (N ₁ , N ₂ ) for 32 ports. Existing (N ₁ , N ₂ ) may be, for example, (4,4), (8,2), or (16,1).

◆ Option 2: Association of 32-port CSI-RS to multiple antennas is not limited to the existing (N ₁ , N ₂ ) for 32 ports. Any rule defined in the specification may be considered.
-◆For example, the association may be such that the 32 ports are first mapped to a gNB antenna in the horizontal domain dimension and then mapped to a gNB antenna in the vertical dimension, or the 32 ports are first mapped to a gNB antenna in the vertical domain dimension and then mapped to a gNB antenna in the horizontal dimension.
-◆For example, the association may be such that the 32 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the horizontal dimension and then mapped to the 2nd, (2+d)th, ... gNB antennas in the vertical dimension, or the 32 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the vertical dimension and then mapped to the 2nd, (2+d)th, ... gNB antennas in the horizontal dimension.
-◆The association may map the 32 ports to multiple gNB antennas according to other rules.

For each port of one CSI-RS and antenna position within the existing (N ₁ , N ₂ ), the existing rules may be repurposed or applied to the below-described embodiments for port mapping within each existing (N ₁ , N ₂ ).

30 shows an example of association candidates considering 32 existing ports (N ₁ , N ₂ ) in Option 1. This example shows associations between 96 CSI-RS antenna ports, new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the multiple associations in this example may be supported or configurable.

In the case where new (N ₁ , N ₂ ) = (12, 4), existing (N ₁ , N ₂ ) = (4, 4), and new (N _g1 , N _g2 ) = (3, 1), as in this example, three CSI-RS may each be associated with a (4, 4) antenna arranged in the horizontal domain.

<<Embodiment C2-2>>
To generate 96 ports, four 24-port CSI-RS resources (existing CSI-RS resources) may be configured to be transmitted, and the four 24-port CSI-RS resources may be TDM'd within the same slot or multiple consecutive slots.

For each port of the transmitted 24-port CSI-RS, the mapping/association to a gNB antenna in the antenna configuration may be defined in the specification using the existing (N ₁ , N ₂ ) configuration for the 24 ports, or may be indicated/configured by a new (N _g1 , N _g2 ) configuration. The mapping/association may be based on at least one of several options:

◆ Option 1: Association of 24-port CSI-RS to multiple antennas considers only existing (N ₁ , N ₂ ) for 24 ports. Existing (N ₁ , N ₂ ) may be, for example, (4, 3), (6, 2), or (12, 1).

◆ Option 2: Association of 24-port CSI-RS to multiple antennas is not limited to the existing (N ₁ , N ₂ ) for 24 ports. Any rule defined in the specification may be considered.
-◆For example, the association may be such that the 24 ports are first mapped to a gNB antenna in the horizontal domain dimension and then mapped to a gNB antenna in the vertical dimension, or the 24 ports are first mapped to a gNB antenna in the vertical domain dimension and then mapped to a gNB antenna in the horizontal dimension.
-◆For example, the association may be such that the 24 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the horizontal dimension, and then mapped to the 2nd, (2+d)th, ... gNB antennas in the vertical dimension, or the 24 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the vertical dimension, and then mapped to the 2nd, (2+d)th, ... gNB antennas in the horizontal dimension.
-◆The association may map the 24 ports to multiple gNB antennas according to other rules.

For each port of one CSI-RS and antenna position within the existing (N ₁ , N ₂ ), the existing rules may be repurposed or applied to the below-described embodiments for port mapping within each existing (N ₁ , N ₂ ).

31 shows an example of association candidates considering 24 existing ports (N ₁ , N ₂ ) in Option 1. This example shows associations between 96 CSI-RS antenna ports, new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the multiple associations in this example may be supported or configurable.

In the case of new (N ₁ , N ₂ ) = (12, 4), existing (N ₁ , N ₂ ) = (12, 1), and new (N _g1 , N _g2 ) = (1, 4), as in this example, four CSI-RS may be associated with four (12, 1) antennas arranged in the horizontal domain, respectively.

In the case where new (N ₁ , N ₂ ) = (12, 4), existing (N ₁ , N ₂ ) = (6, 2), and new (N _g1 , N _g2 ) = (2, 2), as in this example, of the four CSI-RSs, two CSI-RSs may first be associated with the vertical domain and then with the horizontal domain.

According to embodiment C2, multiple CSI-RSs, each using 32 or fewer ports, can be appropriately mapped/associated to multiple gNB antennas, allowing for appropriate utilization of 96 CSI-RS ports.

<Embodiment C3>
Embodiment C3 relates to the generation of 72 ports.
To generate 72 ports, three 24-port CSI-RS resources (existing CSI-RS resources) may be configured to be transmitted, and the three 24-port CSI-RS resources may be TDM'd within the same slot or multiple consecutive slots.

For each port of the transmitted 24-port CSI-RS, the mapping/association to a gNB antenna in the antenna configuration may be defined in the specification using the existing (N ₁ , N ₂ ) configuration for the 24 ports, or may be indicated/configured by a new (N _g1 , N _g2 ) configuration. The mapping/association may be based on at least one of several options:

◆ Option 1: Association of 24-port CSI-RS to multiple antennas considers only existing (N ₁ , N ₂ ) for 24 ports. Existing (N ₁ , N ₂ ) may be, for example, (4, 3), (6, 2), or (12, 1).

◆ Option 2: Association of 24-port CSI-RS to multiple antennas is not limited to the existing (N ₁ , N ₂ ) for 24 ports. Any rule defined in the specification may be considered.
-◆For example, the association may be such that the 24 ports are first mapped to a gNB antenna in the horizontal domain dimension and then mapped to a gNB antenna in the vertical dimension, or the 24 ports are first mapped to a gNB antenna in the vertical domain dimension and then mapped to a gNB antenna in the horizontal dimension.
-◆For example, the association may be such that the 24 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the horizontal dimension, and then mapped to the 2nd, (2+d)th, ... gNB antennas in the vertical dimension, or the 24 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the vertical dimension, and then mapped to the 2nd, (2+d)th, ... gNB antennas in the horizontal dimension.
-◆The association may map the 24 ports to multiple gNB antennas according to other rules.

For each port of one CSI-RS and antenna position within the existing (N ₁ , N ₂ ), the existing rules may be repurposed or applied to the below-described embodiments for port mapping within each existing (N ₁ , N ₂ ).

32 shows an example of association candidates considering 24 existing ports (N ₁ , N ₂ ) in Option 1. This example shows associations between 72 CSI-RS antenna ports, new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the multiple associations in this example may be supported or configurable.

In the case where new (N ₁ , N ₂ ) = (12, 3), existing (N ₁ , N ₂ ) = (12, 1), and new (N _g1 , N _g2 ) = (1, 3), as in this example, three CSI-RS may be associated with three (12, 1) antennas arranged in the vertical domain, respectively.

In the case where new (N ₁ , N ₂ ) = (12, 3), existing (N ₁ , N ₂ ) = (4, 3), and new (N _g1 , N _g2 ) = (3, 1), as in this example, three CSI-RS may be associated with three (4, 3) antennas arranged in the horizontal domain, respectively.

For the new ( _N1 , _N2 ) = (9,4), it may not be possible to map to the 24 existing ports ( _N1 , _N2 ) = (4,3), (6,2), (12,1). For the new ( _N1 , _N2 ) = (9,4), at least one of the following options may be defined:
◆ Option a: For 72 ports, the new antenna setting (N ₁ , N ₂ ) = (9, 4) is not supported.
◆ Option b: Association of 24-port CSI-RS follows the other rules of Option 2.
◆ Option c: A 12-port CSI-RS is considered. That is, six 12-port CSI-RSs may be configured to be transmitted. The six 12-port CSI-RS resources may be TDM'd within the same slot or multiple consecutive slots. Each CSI-RS resource may be associated with an existing (N ₁ , N ₂ ) = (3, 2) antenna using a new (N _g1 , N _g2 ) = (3, 2) antenna.

According to embodiment C3, multiple CSI-RSs, each using 32 or fewer ports, can be appropriately mapped/associated to multiple gNB antennas, allowing for appropriate utilization of 72 CSI-RS ports.

<Embodiment C4>
Embodiment C4 relates to the generation of 64 ports.
To generate 64 ports, two 32-port CSI-RS resources (existing CSI-RS resources) may be configured to be transmitted, and the two 32-port CSI-RS resources may be TDM'd within the same slot or consecutive slots.

For each port of the transmitted 32-port CSI-RS, the mapping/association to a gNB antenna in the antenna configuration may be defined in the specification using the existing (N ₁ , N ₂ ) configuration for the 32 ports, or may be indicated/configured by a new (N _g1 , N _g2 ) configuration. The mapping/association may be based on at least one of several options:

◆ Option 1: Association of 32-port CSI-RS to multiple antennas considers only existing (N ₁ , N ₂ ) for 32 ports. Existing (N ₁ , N ₂ ) may be, for example, (4,4), (8,2), or (16,1).

◆ Option 2: Association of 32-port CSI-RS to multiple antennas is not limited to the existing (N ₁ , N ₂ ) for 32 ports. Any rule defined in the specification may be considered.
-◆For example, the association may be such that the 32 ports are first mapped to a gNB antenna in the horizontal domain dimension and then mapped to a gNB antenna in the vertical dimension, or the 32 ports are first mapped to a gNB antenna in the vertical domain dimension and then mapped to a gNB antenna in the horizontal dimension.
-◆For example, the association may be such that the 32 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the horizontal dimension and then mapped to the 2nd, (2+d)th, ... gNB antennas in the vertical dimension, or the 32 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the vertical dimension and then mapped to the 2nd, (2+d)th, ... gNB antennas in the horizontal dimension.
-◆The association may map the 32 ports to multiple gNB antennas according to other rules.

For each port of one CSI-RS and antenna position within the existing (N ₁ , N ₂ ), the existing rules may be repurposed or applied to the below-described embodiments for port mapping within each existing (N ₁ , N ₂ ).

33 shows an example of association candidates considering 32 existing ports (N ₁ , N ₂ ) in Option 1. This example shows associations between 64 CSI-RS antenna ports, new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the multiple associations in this example may be supported or configurable.

In the cases of new (N ₁ , N ₂ ) = (8, 4), existing (N ₁ , N ₂ ) = (8, 2), and new (N _g1 , N _g2 ) = (1, 2), as in this example, two CSI-RS may be associated with two (8, 2) antennas arranged in the vertical domain, respectively.

In the case of new (N ₁ , N ₂ ) = (8, 4), existing (N ₁ , N ₂ ) = (4, 4), and new (N _g1 , N _g2 ) = (2, 1), as in this example, two CSI-RS may be associated with two (4, 4) antennas arranged in the horizontal domain, respectively.

According to embodiment C4, multiple CSI-RSs, each using 32 or fewer ports, can be appropriately mapped/associated to multiple gNB antennas, allowing for appropriate utilization of 64 CSI-RS ports.

<Embodiment C5>
Embodiment C5 relates to the generation of 48 ports.
To generate 48 ports, two 24-port CSI-RS resources (existing CSI-RS resources) may be configured to be transmitted, and the two 24-port CSI-RS resources may be TDM'd within the same slot or consecutive slots.

For each port of the transmitted 24-port CSI-RS, the mapping/association to a gNB antenna in the antenna configuration may be defined in the specification using the existing (N ₁ , N ₂ ) configuration for the 24 ports, or may be indicated/configured by a new (N _g1 , N _g2 ) configuration. The mapping/association may be based on at least one of several options:

◆ Option 1: Association of 24-port CSI-RS to multiple antennas considers only existing (N ₁ , N ₂ ) for 24 ports. Existing (N ₁ , N ₂ ) may be, for example, (4, 3), (6, 2), or (12, 1).

◆ Option 2: Association of 24-port CSI-RS to multiple antennas is not limited to the existing (N ₁ , N ₂ ) for 24 ports. Any rule defined in the specification may be considered.
-◆For example, the association may be such that the 24 ports are first mapped to a gNB antenna in the horizontal domain dimension and then mapped to a gNB antenna in the vertical dimension, or the 24 ports are first mapped to a gNB antenna in the vertical domain dimension and then mapped to a gNB antenna in the horizontal dimension.
-◆For example, the association may be such that the 24 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the horizontal dimension, and then mapped to the 2nd, (2+d)th, ... gNB antennas in the vertical dimension, or the 24 ports are first mapped to the 1st, (1+d)th, ... gNB antennas in the vertical dimension, and then mapped to the 2nd, (2+d)th, ... gNB antennas in the horizontal dimension.
-◆The association may map the 24 ports to multiple gNB antennas according to other rules.

For each port of one CSI-RS and antenna position within the existing (N ₁ , N ₂ ), the existing rules may be repurposed or applied to the below-described embodiments for port mapping within each existing (N ₁ , N ₂ ).

34 shows an example of association candidates considering 24 existing ports (N ₁ , N ₂ ) in Option 1. This example shows associations between 48 CSI-RS antenna ports, new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the multiple associations in this example may be supported or configurable.

According to embodiment C5, multiple CSI-RSs, each using 32 or fewer ports, can be appropriately mapped/associated to multiple gNB antennas, allowing for appropriate utilization of 48 CSI-RS ports.

<Variation 1 of Embodiment C>
For an extension port number greater than 32, multiple CSI-RS resources having an existing port number smaller than the port number in embodiments C1 to C4 may be configured. The extension port number may include, for example, at least one of 48, 64, 72, 96, and 128. The existing port number may include, for example, at least one of 12 and 16. Association of gNB antennas using CSI-RS resources for the existing port number may take into account the existing (N ₁ , N ₂ ) configuration of the existing port number.

If more CSI-RS resources are used (using the existing number of ports per CSI-RS resource), they need to be transmitted over a longer time period. This makes the measurement results less accurate due to the varying channel during that time period. It also makes the UE measurements more complex.

<Variation 2 of Embodiment C>
With respect to the factors A, B, and C described above, embodiment A1 shows the association between factors A and B, and embodiments C1 to C5 show the association between factors A and C.

<<Variation 2A>>
An association between factors A and C may be defined/established. This association may be combined with the association between factors A and B in embodiment A1. The association between factors A and C may be based on at least one of several options:

◆ Option 1: At each position in the new ( _N1 , _N2 ), the ports may be indexed first into the horizontal domain, then into the vertical domain, and then into the polarization domain. In the indexing, the order of the horizontal domain, the vertical domain, and the polarization domain may be other orders. The ports may be numbered from 0 to X-1 or from 1 to X. For example, X may be 128/96/72/64/48.

◆ Option 2: At each position in new (N ₁ , N ₂ ), new (N _g1 , N _g2 ) and existing (N ₁ , N ₂ ) may be set. New (N _g1 , N _g2 ) may result in N _g1 × N _g2 group domains. Ports may be indexed first into the horizontal domain, then into the vertical domain, then into the polarization domain, and then into the group domain. In the indexing, the order of horizontal domain, vertical domain, polarization domain, and group domain may be other orders. Ports may be from 0 to 127 or from 1 to 128.

<<Variation 2B>>
An association between factors A and C and an association between factors B and C may be defined/configured. The association between factors A, B, and C may be established without using the association between factors A and B in embodiment A1. The final result may not be that the first CSI-RS resource is mapped to port indexes 0 to 31. This may lead to other associations between factors A and B.

<<Variation 2C>>
An association between factors A, B and C may be defined/established.

<Variation 3 of Embodiment C>
Embodiment C may be applied to extensions based on Type 1/Type 2/Extended Type 2/Additional Extended Type 2 using new (N ₁ , N ₂ ). In extensions based on Rel. 15 Type 1 multi-panel CSI, the mapping/association defined/set may be based on at least one of the following options:
◆ Option 1: An association between factors A and B and an association between factors A and C are defined/configured. For example, each CSI-RS resource may correspond to one panel or multiple panels. Consecutive ports may be indexed for each panel.
Option 2: An association between factors A and B and an association between factors A and C are defined/established.
Option 3: An association between factors A and C and an association between factors B and C are defined/established.
◆ Option 4: Associations between factors A, B, and C are defined/configured. A table for the associations between factors A, B, and C may be defined, and a new association indicator may be defined to indicate/configure the associations between factors A, B, and C. For example, association indicator = 1 may be associated with four antenna groups #1 to #4 of (16,1) antennas. Each group may be associated with a CSI-RS resource. Antenna group #1 may be associated with port indexes 0 to 31, antenna group #2 may be associated with port indexes 32 to 63, antenna group #3 may be associated with port indexes 64 to 95, and antenna group #4 may be associated with port indexes 96 to 127.

Figure 35 shows an example of 32-port association candidates for a multi-panel. In this example, the multi-panel is two panels based on new (N _g1 , N _g2 ). This example shows 64 CSI-RS antenna ports and associations between new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ), and new (N _g1 , N _g2 ). Only a portion of the associations in this example may be supported or configurable.

In the cases of new (N ₁ , N ₂ ) = (8, 4), existing (N ₁ , N ₂ ) = (8, 2), and new (N _g1 , N _g2 ) = (1, 2), as in this example, two CSI-RS may be associated with two (8, 2) antennas arranged in the vertical domain, respectively.

In the case of new (N ₁ , N ₂ ) = (8, 4), existing (N ₁ , N ₂ ) = (4, 4), and new (N _g1 , N _g2 ) = (2, 1), as in this example, two CSI-RS may be associated with two (4, 4) antennas arranged in the horizontal domain, respectively.

As in the example of Figure 36, two CSI-RS resources may be TDM'd, with the first CSI-RS using ports 0 to 31 and the second CSI-RS using ports 32 to 64.

((Embodiment D))
<Consideration D>
In embodiment B, in SD beam selection and reporting by _i1,1 , _i1,2 (and also _i1,3 for some ranks), new ( _N1 , _N2 ) are defined for the number of extension ports greater than 32. The number of extension ports may be, for example, 48/64/72/96/128.

In embodiment B, due to larger N ₁ O ₁ and N ₂ O ₂ , the feedback range and feedback bits of i _1,1 and i _1,2 for each rank need to be extended. For example, i _1,1 may be 0,1,...,N ₁ O ₁ -1 or 0,1,...,N ₁ O ₁ /2-1, and i _1,2 may be 0,1,...,N ₂ O ₂ -1 or 0,1,...,N ₂ O ₂ /2-1.

For example, in embodiment B, in the case of new ( _N1 , _N2 ) = (16, 4), existing ( _N1 , _N2 ) = (8, 2), and new ( _Ng1 , _Ng2 ) = (2, 2) for 128 ports, if ( _O1 , _O2 ) = ( ₄ , ₄ ) is assumed, as in the example of Figure 37, the UE may select an SD beam from _{N1O1 × N2O2} = ( ₁₆ × 4) × (4 × 4) = 64 × 16 SD beams based on the new (N1, N2) and report the selected SD beam by ( _i1,1 , _i1,2 ) = (12, 1).

However, other methods of reporting the selected SD beam are possible, considering the setting of new (N ₁ , N ₂ ) for the expansion port number based on the existing (N ₁ , N ₂ ) for the existing port number.

<Embodiment D1>
In the SD beam report for a particular new ( _N1 , _N2 ) configuration, the feedback range and feedback bits of _i1,1 and _i1,2 for each rank are set to indicate the SD beam within multiple ports from the associated existing port CSI-RS resource and are based on the associated existing ( _N1 , _N2 ) value. An additional feedback content of _i1,4 may be introduced to indicate the CSI-RS resource (port group) selected for that SD beam.

In the present disclosure, _i1,4 may be represented by other indexes, which may be _ix , ix _,y , or ix _,y,z , where x, y, and z may be any integers.

At least one of the following options may be defined:
◆ Option 1: i _1,4 is one index. Its bit size may be ceil(log ₂ (N _g1 N _g2 )).
◆ Option 2: _i1,4 is two indexes ( _i1,4,1 , _i1,4,2 ). Its bit size may be ceil( _log2 ( _Ng1 )) and ceil( _log2 ( _Ng2 )) respectively. If _Ng1 = 1 or _Ng2 = 1, there may be no bit of the corresponding feedback _i1,4,1 or _i1,4,2 .

In the example of Figure 38, for 128 ports, new ( _N1 , _N2 ) = (16, 4), existing ( _N1 , _N2 ) = (8, 2), and new ( _Ng1 , _Ng2 ) = ( ₂ , ₂ ), (O1, O2) = (4, 4) is _assumed . In this example, ( _i1,1 , _i1,2 ) = ( ₁₂ , ₁ ) indicates an SD beam selected (for a _{certain layer) from N1N2O1O2 SD beams} based on _existing (N1, N2 ₎ ( _N1O1 × _N2O2 = 32 × 8 SD beams). In option 2, ( _i1,4,1 , _i1,4,2 ) = (0,0) indicates a CSI-RS resource selected from _Ng1 × _Ng2 = 2 _{× 2} CSI-RS resources. One CSI-RS resource corresponds to _{N1N2O1O2 SD} beams based on the existing ( _N1 , _N2 ). The association between the CSI-RS resource, the CSI-RS port index, and the new ( _N1 , _{N2 )} antenna positions may be based on embodiment C. In this example, four CSI-RS resources correspond to four _N1N2O1O2 antenna groups based on the existing ( _N1 , _N2 ), respectively _. In this example, the UE selects an SD beam for the third CSI- _RS resource.

With regard to the SD beams selected for different layers (determined via _i1,3 or via rules in the specification when the SD beam for the first layer is represented by _i1,1 , _i1,2 , _i1,4 above), for additional SD beams (for one or more other layers) determined from _i1,1 + _k1 , or _i1,2 + _k2 , or _i1,1 + _O1 , or _i1,2 + _O2 , _i1,1 , _i1,2 are recognized as at least one of the following options:

◆ Option A: Representation of i _1,1 and i _1,2 from N ₁ N ₂ O ₁ O ₂ SD beams based on new (N ₁ , N ₂ ).
39, for 128 ports, in the case where new ( _N1 , _N2 ) = (16, 4), existing ( _N1 , _N2 ) = (8, 2), and new ( _Ng1 , Ng2) = (2, ₂ ), ( _O1 , _O2 ) = (4, 4) is assumed. In this example, the SD beam of the first layer is represented by ( _i1,1 , _i1,2 ) = ( ₁₂ , ₁ ), which indicates _an SD beam from _{N1N2O1O2 SD} beams based on new ( _N1 , N2) based on embodiment B. In this example, the SD beams of the other layers are represented by ( _i1,1 , _i1,2 + _{2O2) = (12,1 + 8), which indicates the SD beams from the N1N2O1O2 SD beams based on} the new ( _N1 , _N2 ). In this example, the offset from the SD beam ( _i1,1 , _i1,2 ) of the first layer to the SD beams of the other layers _{may be represented by (0,2O2) = (0,8) for the N1N2O1O2 SD beams ( N1O1 × N2O2 two} -dimensional SD beams) based on the new ( _{N1 ,} N2 ₎ .

◆ Option B: Indication of _{i1,1 , i1,2} from _{N1N2O1O2 SD} beams based on existing ( _N1 , _N2 ). Additional determined SD beams are restricted to the CSI-RS resource or port group indicated by _i1,4,1 , _{i1,4,2 .} Multiple SD beams for all _layers may be selected from one _and the same CSI-RS resource ( _N1N2O1O2 SD beams based on existing _{( N1} , _N2 )).
40 , for 128 ports, new (N ₁ , N ₂ ) = (16, 4), existing (N ₁ , N ₂ ) = (8, 2), and new (N _g1 , N _g2 ) = (2, 2), it is assumed that (O ₁ , O ₂ ) = (4, 4). The association between the CSI-RS resources and the groups of N ₁ N ₂ O ₁ O ₂ antennas based on the existing (N ₁ , N ₂ ) may be based on embodiment C. In this example, four CSI-RS resources correspond to four groups of N ₁ N ₂ O ₁ O ₂ antennas based on the existing (N ₁ , N ₂ ), respectively. In this example, the UE selects an SD beam for the third CSI-RS resource. The selected CSI-RS resource, or the selected group _{of N1N2O1O2} antennas based on the existing ( _{N1 , N2 )} , is denoted by ( _i1,4,1 , _i1,4,2 ) = (0,0). In this example, the SD beam for the first layer is denoted by ( _i1,1 , _i1,2 ) = ( _12,1 ), which indicates an SD beam from the group of _N1N2O1O2 SD beams based on the existing ( _N1 , _N2 ) corresponding to the third CSI-RS resource. In this example, the SD beam for the other layer is denoted by ( _i1,1 , _{i1,2 +2O2} ) = ( _12,1 ), which indicates an SD beam from the group of _{N1N2O1O2 SD} beams based on the existing _{( N1} , _N2 ) _{for the} same third CSI-RS resource. In this example, the offset from the SD beam ( _i1,1 , _i1,2 ) of the first layer to the SD beams of the other layers is indicated by ( _0,2O2 ) in ( _N1O1 × _{N2O2 two} -dimensional SD beams). In this example, the position ( _i1,1 , _i1,2 + _2O2 ) = ( _i1,1 mod _N1O1 , _{( i1,2} + _2O2 ) mod _{N2O2 )} = _{( 12 mod 64,1} + ₈ mod _{8 )} = (12,1).

◆ Option C: Indication of i _1,1 , i _1,2 from N ₁ N ₂ O ₁ O ₂ SD beams based on new (N ₁ , N ₂ ). Additional determined SD beams may be beyond the CSI-RS resource or port group indicated by i _1,4,1 , i _1,4,2 . The calculation of option C may be based on at least one of the following several options Cx:

- Option C1: The calculation is based on the positions of multiple gNB antennas (N ₁ , N ₂ ) in this option. In this option, the final result is the same as in Option A.
41 , for 128 ports, new (N ₁ , N ₂ ) = (16, 4), existing (N ₁ , N ₂ ) = (8, 2), and new (N _g1 , N _g2 ) = (2, 2), it is assumed that (O ₁ , O ₂ ) = (4, 4). The association between the CSI-RS resources and the groups of N ₁ N ₂ O ₁ O ₂ antennas based on the existing (N ₁ , N ₂ ) may be based on embodiment C. In this example, four CSI-RS resources correspond to the four groups of N ₁ N ₂ O ₁ O ₂ antennas based on the existing (N ₁ , N ₂ ), respectively. The CSI-RS resources selected for the first layer may be different from the CSI-RS resources selected for the other layers. In this example, the UE selects an SD beam for the third CSI-RS resource for _{the first layer. The selected CSI-RS resource, or the selected group of N1N2O1O2 antennas} based on the existing _{( N1} , _{N2 )} , is denoted by ( _i1,4,1 , _i1,4,2 ) = (0,0). In this example, the SD beam for the first layer is denoted by ( _i1,1 , _i1,2 ) = ( _12,1 ), indicating the SD beam from the group of _N1N2O1O2 SD beams based on _the existing ( _N1 , _N2 ) that corresponds to the _third CSI-RS resource. In this example, the SD beams of the other layers are denoted by (i1,1,i1,2 + 2O2) = ( _12,1 + ₈ ), which indicates an SD beam from the _{N1N2O1O2 SD} beams based on the existing ( _N1 , _N2 ) in the first CSI- _RS resource. In this example, the offset from _the SD beam ( _i1,1 , _i1,2 ) _of the first layer to the SD beams of the other layers is denoted by ( _{0,2O2) = (0,8) in the N1N2O1O2 SD} beams _{(N1O1 × N2O2 two -} dimensional SD beams) based on the _new ( _N1 , _{N2 )} .

- Option C2: The calculation is based on the order of the CSI-RS resources.
42 , for 128 ports, new (N ₁ , N ₂ ) = (16, 4), existing (N ₁ , N ₂ ) = (8, 2), and new (N _g1 , N _g2 ) = (2, 2), it is assumed that (O ₁ , O ₂ ) = (4, 4). The association between the CSI-RS resources and the groups of N ₁ N ₂ O ₁ O ₂ antennas based on the existing (N ₁ , N ₂ ) may be based on embodiment C. In this example, four CSI-RS resources correspond to the four groups of N ₁ N ₂ O ₁ O ₂ antennas based on the existing (N ₁ , N ₂ ), respectively. The CSI-RS resources selected for the first layer may be different from the CSI-RS resources selected for the other layers. In this example, the UE selects an SD beam for the third CSI-RS resource for _{the first layer. The selected CSI-RS resource, or the selected group of N1N2O1O2 antennas} based on the existing _{( N1} , _{N2 )} , is denoted by ( _i1,4,1 , _i1,4,2 ) = (0,0). In this example, the SD beam for the first layer is denoted by ( _i1,1 , _i1,2 ) = ( _12,1 ), indicating the SD beam from the group of _N1N2O1O2 SD beams based on _the existing ( _N1 , _N2 ) that corresponds to the _third CSI-RS resource. In this example, the SD beam of the other layer is denoted by ( _i1,1 , _{i1,2 + 2O2) = (12,1), which indicates an SD beam from the N1N2O1O2 SD beams} based on the existing ( _N1 , _N2 ) in the first CSI-RS resource. In this example, the offset from the SD beam ( _i1,1 , _i1,2 ) of _the first layer to the SD beam _of the _{other layer is denoted by (0,2O2) in the N1N2O1O2 SD beams (N1O1 × N2O2 two - dimensional SD beams ) based on the} existing ( _N1 , _N2 ). In this example, the position ( _i1,1 , _{i1,2 +} 2O2) beyond the two-dimensional SD beam range of _N1O1 × _N2O2 based on the existing ( _N1 , _N2 ) becomes (i1,1 mod _N1O1 , ( _i1,2 + _2O2 ) mod _N2O2 ) = (12 mod _64,1 + 8 mod ₈ ) = ( _12,1 ) within _{the two} -dimensional SD beam range of _N1O1 × _N2O2 corresponding to _the adjacent CSI-RS _resource .

-◆Option C3: The calculation is based on the indexing order of the ports in the expansion port number. In this option, the final result may be determined by the association of the ports in the expansion port number with the base station antenna positions in embodiment C.

<Supplementary Note on Embodiment D>
The SD beam reporting method extended by embodiment D may be applied to extensions based on (Rel. 15) Type 1 single-panel CSI and extensions based on (Rel. 15) Type 1 multi-panel CSI.

Various SD beam reporting methods (e.g., SD beam reporting methods including at least one of embodiment B and embodiment D) may be configurable by the NW depending on UE capabilities.

Various SD beam reporting methods (e.g., SD beam reporting methods including at least one of embodiment B and embodiment D) may be applied to different cases. For example, the SD beam reporting method of embodiment B may be applied to an extension based on (Rel. 15) Type 1 single-panel CSI, and the SD beam reporting method of embodiment D may be applied to an extension based on (Rel. 15) Type 1 multi-panel CSI. _{i 1,4} may indicate the selected panel.

((Embodiment E))
<Consideration E1>
Regarding the selection and reporting of SD beams for a certain rank according to _i1,1 , _i1,2 (and further _i1,3 for some ranks), embodiment D describes a method that follows the association of CSI-RS resources, port indices, and gNB antennas in embodiment C. Embodiment D can be applied to Type 1 single-panel codebooks and Type 1 multi-panel codebooks (based on Rel. 15) when the number of SD beams L=1.

Embodiment E considers a new method for reporting SD beams when L = 2, 4, or 6 SD beams are configured in the (Rel. 15) Type 2 codebook, (Rel. 16) Extended Type 2 codebook, (Rel. 16) Extended Type 2 PS codebook, and (Rel. 17) Additional Extended Type 2 PS codebook.

L SD beams may be reported by _i1,1 and _i1,2 . For 128 ports, in the case of new ( _N1 , _N2 ) = (16,4), existing ( _N1 , _N2 ) = (8,2), and new ( _Ng1 , _Ng2 ) = (2,2), assuming ( _O1 , _O2 ) = (4,4) and L = 4, _i1,1 = [ _q1q2 ], _q1 ∈ {0,1,..., _O1-1 }, _q2 ∈ {0,1,..., _O2-1 } may indicate/report/select a beam group, as in the _example of Figure 43. Existing ( _N1 , _N2 ) in _i1,2 ∈ {0,1,...,C( _N1N2 ,L ₎ -1} may be extended to new ( _N1 , _N2 ). i _1,2 may display/report/select L=4 SD beams from the beam group.

In the present disclosure, i _1,4 and i _1,5 may be represented by other indexes, which may be i _x , i _x,y , or i _x,y,z , where x, y, and z may be any integers.

Embodiment E may be applied to cases where the total number of ports used for multiple existing port CSI-RS resources exceeds 32 (number of expansion ports), or to cases where the total number of ports used for multiple existing port CSI-RS resources is 32 or less (number of existing ports).

<Embodiment E1>
A constraint may be defined or set in the specification that the reporting of L SD beams for a certain new (N ₁ , N ₂ ) value is based on the existing (N ₁ , N ₂ ) value and the existing port CSI-RS resources associated with the new (N ₁ , N ₂ ) value, and all L beams are selected from the same existing port CSI-RS resources or the same port group.

The feedback range and feedback bits for i _1,2 may be based on the associated existing (N ₁ ,N ₂ ) value, i.e., i _1,2 ∈ {0, 1,..., C(existing N ₁ N ₂ ,L)-1}.

The feedback format of i _1,1 may remain unchanged from Type 2 CB in Rel. 15/16. The size (number of bits) of i _1,1 may be related to (O ₁ ,O ₂ ) for larger port numbers.

_i1,1 may be _{[ q1q2} ] indicating one beam group from _O1O2 beam groups. One _beam group may have _N1N2 existing _SD beams. _i1,2 may be an index indicating L beams from one beam group (existing _N1N2 SD beams ₎ .

An additional feedback content i _1,4 may be introduced to indicate/report/select one selected (associated) CSI-RS resource (or one selected port group) for the L SD beams, which may be based on at least one of the following options:
◆ Option 1: i _1,4 has one index, whose size may be ceil(log ₂ (N _g1 N _g2 )).
◆ Option 2: _i1,4 has two indices ( _i1,4,1 , _i1,4,2 ), whose sizes may be ceil( _log2 ( _Ng1 )) and ceil( _log2 ( _Ng2 )), respectively. If _Ng1 = 1 or _Ng2 = 1, there may be no corresponding feedback bit for _i1,4,1 or _i1,4,2 .

In the example of Figure 44, assuming ( _O1 , _O2 ) = (4,4), L = 4, and Option 2 for 128 ports, where new ( _N1 , _N2 ) = (16,4), existing ( _N1 , _N2 ) = (8,2), and new ( _Ng1 , _Ng2 ) = (2,2), ( _i1,4,1 , _i1,4,2 ) indicate a selected CSI-RS resource from _Ng1 x _Ng2 = 2 x 2 CSI-RS resources #1 to # ₄ or a selected one existing _N1N2O1O2 = 8 x _{2 x 4} x ₂ antenna based on the association of embodiment C. _i1,2 indicates L = 4 SD beams based on the selected _CSI -RS resource or the selected existing _N1N2O1O2 antennas. In other words, the L=4 SD beams are restricted to the selected CSI-RS resources or the selected existing N ₁ N ₂ O ₁ O ₂ antennas.

According to embodiment E1, multiple SD beams based on the number of extended ports can be appropriately reported while reducing reporting overhead.

<Embodiment E2>
In reporting L SD beams for a given new (N ₁ , N ₂ ) value, each SD beam may be represented/reported/selected by a combination of several of the following indices:
◆i _1,4 . The index may indicate the CSI-RS resource or port group to which the SD beam belongs. Its size may be ceil(log ₂ (N _g1 N _g2 )).
◆i _1,2 ∈{0,1,...,existing N ₁ N ₂ −1}, where the index may indicate one SD beam from the existing N ₁ N ₂ SD beams associated with the CSI-RS resource or port group indicated by i _1,4 .

The L sets of i _1,4 and i _1,2 , along with one i _1,1 , may be used to represent L SD beams.

The feedback format of i _1,1 may remain unchanged from Type 2 CB in Rel. 15/16. The size (number of bits) of i _1,1 may be related to (O ₁ ,O ₂ ) for larger port numbers.

_i1,1 may be _{[ q1q2} ] indicating one beam group from _O1O2 beam groups. One beam group may have _N1N2 existing _SD beams. _i1,2 may be an _index indicating one SD beam from one beam group.

In the example of Figure 45, for 128 ports, in the case of new ( _N1 , _N2 ) = (16, ₄ ), existing ( _N1 , N2) = (8, 2), new ( _Ng1 , _Ng2 ) = ( ₂ , ₂ ), (O1, O2) = (4, 4), and L = ₄ , _i1,1 represents a beam group containing new _N1N2 = 16 × 4 SD beams. One of the L = 4 sets of _i1,4 and _i1,2 represents one SD beam. In one set, i _1,4 indicates a CSI-RS resource selected from N _g1 ×N _g2 =2×2 CSI-RS resources #1 to #4, and i _1,2 indicates an SD beam selected from the existing N ₁ N ₂ =8×2 SD beams based on the beam group selected by i _1,1 and the CSI-RS resource selected by i _1,4 .

According to embodiment E2, multiple SD beams based on the number of extended ports can be appropriately reported without limiting CSI-RS resources.

<Embodiment E3>
A constraint may be defined or configured in the specification that the reporting of L SD beams for a new (N ₁ , N ₂ ) value is based on the existing (N ₁ , N ₂ ) value and the existing port CSI-RS resources configured in association with the new (N ₁ , N ₂ ) value, and all of the L beams are selected from M existing port CSI-RS resources or M port groups, for example, M∈{1, 2, ..., N _g1 N _g2 }.

An additional feedback content i _1,4 may be introduced to indicate/report/select one selected (associated) CSI-RS resource (or one selected port group) for the L SD beams, which may be based on at least one of the following options:
◆ Option 1: i _1,4 has M indices. Each index may indicate one selected CSI-RS resource or one port group. The size of each index may be ceil(log ₂ (N _g1 N _g2 )).
◆ Option 2: i _1,4 has one field to indicate the combination of M selected CSI-RS resources or M port groups. The size of the field may be ceil(log ₂ (C(N _g1 N _g2 ,M))).
◆ Option 3: _i1,4 is a bitmap having N _g1 N _g2 bits, where each bit corresponds to one CSI-RS resource or port group among the N _g1 N _g2 CSI-RS resource or port groups, and may indicate whether the corresponding CSI-RS resource or port group is selected.

The feedback range and feedback bits for i _1,2 may be based on at least one of several options:

◆ Option A: The feedback range and feedback bits are based on the M × existing _N1N2 antennas. _The existing _N1N2 antennas in the M antenna groups denoted by _{i1,4 may} be indexed according to at least one of the CSI-RS resource index, port index, and horizontal/vertical/polarization index for _i1,2 reporting. _i1,2 ∈ {0, 1, ..., C(M × _{existing N1N2} ,L)-1}.

◆ Option B: Similar to embodiment E2, each SD beam may be represented/reported/selected by a combination of several of the following indexes:
-◆i _1,5 . The index may indicate the CSI-RS resource or port group to which the SD beam belongs. The size may be ceil(log ₂ (M)).
-◆i _1,2 ∈{0,1,...,existing N ₁ N ₂ −1}, where the index may indicate one SD beam from the existing N ₁ N ₂ SD beams associated with the CSI-RS resource or port group indicated by i _1,5 .
Thus, L sets of i _1,5 and i _1,2 may be reported, along with one value of i _1,4 and one value of i _1,1 .

The feedback format of i _1,1 may remain unchanged from Type 2 CB in Rel. 15/16. The size (number of bits) of i _1,1 may be related to (O ₁ ,O ₂ ) for larger port numbers.

_i1,1 may be _{[ q1q2} ], which indicates one beam group from _O1O2 beam groups. A beam group may have _N1N2 existing beams. _i1,2 may be an index _indicating L beams from M beam groups (M _{x N1N2} existing beams) _.

In the example of Figure 46, assuming new ( _N1 , _N2 ) = (16, 4), existing ( _N1 , N2) = (8, ₂ ), new ( _Ng1 , _Ng2 ) = (2, 2) for 128 ports, ( _O1 , _O2 ) = (4, 4), L = 4, M = 2, Option 3, and Option A, _i1,1 indicates a beam group including new _N1N2 = ₁₆ × 4 beams. _i1,4 indicates M = 2 CSI-RS resources among _Ng1 × _Ng2 = 2 × 2 CSI-RS resources #1 to #4. In Option 3, _i1,4 is a bitmap "1010" indicating CSI-RS resources #1 and #3. In Option A, i _1,2 denotes L=4 SD beams from the M×existing N ₁ N ₂ =2×8×2 SD beams in CSI-RS resources #1 and #3.

The extended SD beam reporting method in embodiment E may be applied to at least one of the (Rel. 15) Type 2 codebook, the (Rel. 16) extended Type 2 codebook, the (Rel. 16) extended Type 2 PS codebook, and the (Rel. 17) additional extended Type 2 PS codebook.

According to embodiment E3, multiple SD beams based on the number of extended ports can be appropriately reported while reducing reporting overhead.

<Variations of Embodiments E1 to E3>
A plurality of SD beam reporting methods may be applied to a plurality of cases, respectively. The plurality of cases may be defined by at least one of a plurality of codebook types, a plurality of numbers of extension ports (e.g., 48/64/72/96/128), a plurality of antenna configurations, a plurality of associations with existing (N ₁ , N ₂ ) or new (N _g1 , N _g2 ) antennas, a plurality of L values, a plurality of parameter combinations (paramCombinations), and a plurality of ranks. The plurality of SD beam reporting methods may be configurable by the NW according to UE capabilities.

<Study E2>
Embodiment E considers a new method of port reporting for (Rel. 17) Type 2 PS CB.

The precoding matrix indicated by the PMI is determined from L+M vectors, where L=K ₁ /2 and K ₁ =αP _CSI-RS .

_K1 ports are selected from the P _CSI-RS ports based on L vectors v _m̂(i) (i = 0, 1, ..., L-1). The vectors v _m̂(i) are identified by m = [m ⁽⁰⁾ ... [m ^(L-1) ], m ⁽ⁱ⁾ ∈ {0, 1, ..., P _CSI-RS /2-1}. ^{m (i)} is reported/indicated by index i _1,2 ∈ {0, 1, ..., C(P _CSI-RS /2, L)-1}.

The L ports selected for each polarization are reported by i _1,2 . The existing P _CSI-RS /2 means the number of ports for one polarization.

<Embodiment E0>
In (Rel. 15/16/17) Type 2 PS CB, legacy P _CSI-RS (number of legacy ports) ∈ {4, 8, 12, 16, 24, 32} are supported. For new P _CSI-RS (number of new ports) ∈ {48, 64, 72, 96, 128} for extension based on Type 2 PS CB, similar to embodiment C, the association between port indexes in the new P _CSI-RS ports and legacy port CSI-RS resources may be defined or configured in the specification.

The difference between Type 2CB and Type 2CB or Extended Type 2CB is that ports or CSI-RS resources do not need to be associated with gNB antenna locations. CSI reporting may be for selected ports. The gNB antenna structure may be transparent to the UE.

As shown in the example of Figure 47, associations between new P _CSI-RS , legacy P _CSI-RS , and N _g new ports for Type-2 PS CB may be supported/defined/configured. In this example, one association corresponds to N _g legacy port CSI-RS resources. The first legacy P _CSI-RS port corresponds to port indices 0 to (legacy P CSI- _RS -1) for the new P _CSI-RS ports. The second legacy P _CSI-RS ports correspond to port indices 0 to (2 x legacy P _{CSI -RS} -1) for the new P _CSI- RS ports.

According to embodiment E0, when extending a Type 2 PS CB, a port selected from the number of ports in the extension port count can be reported appropriately.

<Embodiment E4>
(Rel. 17) In an extension based on Type 2 PS CB, a constraint may be defined or configured in the specification that the L ports selected for a new P _{CSI-RS are} selected based on the existing P _CSI-RS configured in association with the new P CSI-RS, and all of the L ports are selected from the same existing port CSI-RS resource or the same port group.

The feedback range and feedback bits of i _1,2 may be based on the associated legacy P _CSI-RS value, i.e., i _1,2 ∈ {0, 1, ..., C(legacy P _CSI-RS , L) - 1}.

An additional feedback content i _1,4 may be introduced that indicates/reports/selects one selected (associated) CSI-RS resource (or one selected port group) for the L ports.

According to embodiment E4, when extending a Type 2 PS CB, L ports selected from the number of extension ports can be appropriately reported.

<Embodiment E5>
In an extension based on (Rel. 17) Type 2 PS CB, each port among the L ports selected for a new P _CSI-RS may be indicated/reported/selected by a combination of several of the following indexes:
◆i _1,4 , where the index may indicate the CSI-RS resource or port group to which the port belongs, and the size may be ceil(log ₂ (N _g )).
◆i _1,2 ∈ {0, 1, ..., existing P _CSI-RS /2 - 1}, where the index may indicate one port _from the existing P _CSI-RS /2 ports associated with the CSI-RS resource or port group indicated by i 1,4.

The L sets of i _1,4 and i _1,2 may be used to represent the L ports.

According to embodiment E5, when extending a Type 2 PS CB, L ports selected from the number of extended ports can be appropriately reported.

<Embodiment E6>
In an extension based on (Rel. 17) Type 2 PS CB, a constraint may be defined or configured in the specification that the L ports selected for a new P _{CSI-RS are} based on the existing P _CSI-RSs configured in association with the new P CSI-RS, and all of the L ports are selected from M existing port CSI-RS resources or M port groups, where M may be {1, 2, ..., N _g }.

An additional feedback content i _1,4 may be introduced that indicates/reports/selects one selected (associated) CSI-RS resource (or one selected port group) for the L ports, which may be based on at least one of several options:
◆ Option 1: i _1,4 has M indices. Each index may indicate one selected CSI-RS resource or one port group. The size of each index may be ceil(log ₂ (N _g )).
◆ Option 2: i _1,4 has one field to indicate the combination of M selected CSI-RS resources or M port groups. The size of the field may be ceil(log ₂ (C(N _g ,M))).
◆ Option 3: i _1,4 is a bitmap having N _g bits, where each bit corresponds to one CSI-RS resource or port group among the N _g CSI-RS resource or port groups, and may indicate whether the corresponding CSI-RS resource or port group is selected.

The feedback range and feedback bits for i _1,2 may be based on at least one of several options:

◆ Option A: The feedback range and feedback bits are based on M×Legacy P _CSI-RS antennas, where i _1,2 ∈ {0, 1, ..., C(M×Legacy P _CSI-RS /2, L)−1}.

◆ Option B: Similar to embodiment E5, each port may be represented/reported/selected by a combination of several of the following indices:
-◆i _1,5 . The index may indicate the CSI-RS resource or port group to which the port belongs. The size may be ceil(log ₂ (M)).
-◆i _1,2 ∈ {0, 1, ..., existing P _CSI-RS /2-1}, where the index may indicate one port from the existing P CSI-RS ports associated with the _CSI-RS resource or port group indicated by i _1,5 .
Thus, L sets of i _1,5 and i _1,2 may be reported.

According to embodiment E6, when extending a Type 2 PS CB, L ports selected from the number of extension ports can be appropriately reported.

<Variations of Embodiments E4 to E6>
In Rel. 15/16 Type 2 PS CB, L ports for each polarization are selected by i _1,1 , where i _1,1 ∈ {0, 1,..., ceil(P _CSI-RS /(2d))-1}.

Similar to embodiment E4/Embodiment E5/Embodiment E6, L ports may be displayed for each polarization by considering the selected/associated existing P _CSI-RS .

A plurality of port reporting methods may be applied to a plurality of cases, respectively. The plurality of cases may be defined by at least one of a plurality of codebook types, a plurality of numbers of extended ports (e.g., 48/64/72/96/128), a plurality of antenna configurations, a plurality of associations with existing P _CSI-RS , a plurality of L values, a plurality of parameter combinations (paramCombinations), and a plurality of ranks. The plurality of port reporting methods may be configurable by the NW according to UE capabilities.

<Study E3>
(Rel. 16) The parameter combination (paramCombination) setting in the extended type 2 CB is defined as shown in Figure 48. (Rel. 16) The paramCombination setting in the extended type 2 PS CB is defined as shown in Figure 49. (Rel. 17) The paramCombination setting in the additional extended type 2 PS CB is defined as shown in Figure 50.

Parameter settings of ranks 5 to 8 for more than 32 ports are considered. The parameter settings may vary depending on at least one of the codebook type, the number of ports, the ranks 1 to 8, the antenna configuration ( _N1 , _N2 ), and the number of subbands _N3 , R. Even if the supported ranks are not extended for more than 32 ports, new values may be considered for the parameter settings.

<Embodiment E7>
In setting the parameters/paramCombination for a codebook, specific values of specific parameters may be supported/defined/set according to at least one of several options:
◆ Option 1: Values of L greater than the existing (extended type 2 CB/extended type 2 PS CB/additional extended type 2 PS CB) values (for example, at least one of 8 and 10) are not supported.
◆Option 2: Values other than the existing (Extended Type 2 CB/Extended Type 2 PS CB/Additional Extended Type 2 PS CB) values of p _v (for example, at least one of a value smaller than the existing value, a value larger than the existing value, 1/16, 3/4) are not supported.
◆Option 3: Values other than the existing values of β (Extended Type 2 CB/Extended Type 2 PS CB/Additional Extended Type 2 PS CB) (e.g., values smaller than the existing value, values larger than the existing value, or at least one of 1/8, 1/16, 7/8, and 1) are not supported.
◆ Option 4: Values other than the existing values of M (extended type 2CB/extended type 2PS CB/additional extended type 2PS CB) (for example, 3/4) are not supported.
◆ Option 4: Values other than the existing values of α (extended type 2CB/extended type 2PS CB/additional extended type 2PS CB) (for example, at least one of 1/4 and 1/8) are not supported.

A new paramCombination may be defined taking into account revisions of one or more of the aforementioned parameters. The new paramCombination may differ depending on at least one factor of the codebook type, the number of ports, the rank 1 to 8, the antenna configuration ( _N1 , _N2 ), the number of subbands _N3 , and R.

The value of the parameter/paramCombination may depend on the UE capabilities. The UE capabilities may be defined/reported for each value of at least one of its factors.

According to embodiment E7, appropriate parameters can be set in the extension of Type 2 CB/Type 2 PS CB.

<Supplementary Note on Embodiment E>
The UE may receive configuration for at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports (e.g., existing (N ₁ , N ₂ )), a two-dimensional arrangement of multiple antennas for more than 32 ports (e.g., new (N ₁ , N ₂ )), and multiple groups of multiple antennas for more than 32 ports (e.g., new (N _g1 , N _g2 ) or new N _g ), multiple CSI-RS resources, and a CSI codebook. Based on the configuration, the UE may associate each CSI-RS resource with 32 or fewer ports, associate multiple CSI-RS resources with more than 32 ports, and determine multiple beams and one or more CSI-RS resources corresponding to the multiple beams among the multiple CSI-RS resources for reporting.

((Embodiment F))
<Analysis F1>
In embodiment A, configuring multiple CSI-RS resources using the existing port number to support the extended port number is described. In embodiment A1-2, constraints on multiple CSI-RS resources for aggregation of CSI-RS resources to use the extended port number are described.

<Analysis F2>
In embodiment C, the association setup between new (N ₁ , N ₂ ), existing (N ₁ , N ₂ ) and existing port CSI-RS resources is described.

<Analysis F2>
In embodiment E, association setup between a new P _CSI-RS and an existing P _CSI-RS is described.

<Consideration F>
The following are some possible considerations:
◆ Consideration F1: When configuring multiple CSI-RS resources using the existing number of ports to support the expanded number of ports, the constraints and configuration details have not been sufficiently considered.
◆ Consideration F2: When setting up CMR and IMR for measuring/reporting CSI, the details of the setting have not been sufficiently considered.

Embodiment F may be applied to at least one of the above items a, b, and c.

Embodiment F may be applied to cases where the total number of ports used for multiple existing port CSI-RS resources exceeds 32 (number of expansion ports), or to cases where the total number of ports used for multiple existing port CSI-RS resources is 32 or less (number of existing ports).

<Embodiment F1>
For multiple CSI-RS resources (e.g., NZP CSI-RS resources) for using an extended port count, the constraint imposed on the constraint in embodiment A may be based on at least one of several options below (the multiple CSI-RS resources may be configured with at least one constraint from several options below).

◆ Option 1: All of the multiple CSI-RS resources have the same setting for powerControlOffset, which indicates the power offset of the PDSCH RE relative to the NZP CSI-RS resource element (RE). The same ratio of PDSCH EPRE to NZP CSI-RS energy per resource element (EPRE) may be set across all of the multiple CSI-RS resources.

◆ Option 2: All of the multiple CSI-RS resources have the same setting for powerControlOffsetSS, which indicates the power offset of the NZP CSI-RS RE relative to the SSS RE. The same ratio of NZP CSI-RS EPRE to SS/PBCH block EPRE may be set across all of the multiple CSI-RS resources.

◆Option 3: All of the multiple CSI-RS resources have the same configuration of TCI state, or at least the same configuration for QCL type D.

◆ Option 4: All of the plurality of CSI-RS resources have the same port number. For this option, the plurality of CSI-RS resources may be based on at least one of the following examples.
-◆Example: To support 128 ports, four TDM 32-port CSI-RS resources are configured.
-◆Example: To support 96 ports, 33 TDM 2-port CSI-RS resources are configured.
-◆Example: To support 64 ports, two TDMed 32-port CSI-RS resources are configured.
-◆Example: To support 96 ports, four TDM 24-port CSI-RS resources are configured.
-◆Example: To support 72 ports, three TDM 24-port CSI-RS resources are configured.
-◆Example: To support 48 ports, two TDM 24-port CSI-RS resources are configured.

◆Option 5: All of the multiple CSI-RS resources have the same location in the frequency domain and the same RE mapping in the frequency domain.

◆Option 6: All of the multiple CSI-RS resources have the same RE density.

◆ Option 7: All of the multiple CSI-RS resources are within M consecutive slots within the same discontinuous reception (DRX) active time, where M may be according to the UE capabilities. For this option, the multiple CSI-RS resources may be based on at least one of the following examples:
-◆Example: Two TDMed 32-port CSI-RS resources are within one slot in the same DRX active time.
- ◆ Example: Three or four TDMed 32-port CSI-RS resources within two slots in the same DRX active time.
-◆Example: Two TDMed 32-port CSI-RS resources are within two slots of the same DRX active time.
-◆Example: Four TDMed 32-port CSI-RS resources are within four slots in the same DRX active time.

According to embodiment F1, multiple CSI-RS resources can be appropriately configured to support an expanded number of ports.

<Embodiment F2>
The method (signaling structure) for realization of one or more constraints in embodiment F1 may be based on at least one of the following options:

◆ Option 1: Each existing port CSI-RS resource configuration has the same setting of one or more parameters. This option may be based on the following example.
- Example: An example of configuration of a new group #N (new port CSI-RS resource #N) of CSI-RS resources to support 96 ports (Figure 51) includes a new group ID (new CSI-RS resource ID) = N and a list including CSI-RS resources #1 to #3. Each CSI-RS resource uses 32 ports. The configuration of each CSI-RS resource includes a CSI-RS resource ID ∈ {1, 2, 3}, a parameter A set to value X, a parameter B set to value Y, and a parameter C set to value Z.

◆ Option 2: One or more corresponding parameters are configured for one existing port CSI-RS resource (specific CSI-RS resource). The specific CSI-RS resource may be, for example, the first CSI-RS resource or the reference CSI-RS resource. The other CSI-RS resources may follow one or more parameters for the specific CSI-RS resource. In this case, the one or more parameters for the other CSI-RS resources may be configured with the same values as the one or more parameters for the specific CSI-RS resource, may be configured with values different from those for the specific CSI-RS resource, or may not be configured at all. The UE may assume that one or more parameters for the other CSI-RS resources follow one or more parameters of the specific CSI-RS resource. This option may be based on the following example.
-◆ Example: An example of a configuration of a new group #N (new port CSI-RS resource #N) of CSI-RS resources to support 96 ports (Figure 52) includes a new group ID (new CSI-RS resource ID) = N and a list including CSI-RS resources #1 to #3. Each CSI-RS resource uses 32 ports. The configuration of each CSI-RS resource includes a CSI-RS resource ID ∈ {1, 2, 3}. The configuration of CSI-RS resource #1 includes parameter A set to value X, parameter B set to value Y, and parameter C set to value Z. Within each configuration of CSI-RS resources #2 and #3, the settings/fields for parameters A, B, and C are not present.

◆ Option 3: One set of one or more parameters is configured/applied to one group. The group includes multiple existing port CSI-RS resources. For example, a new group ID or a new CSI-RS resource ID may be configured. The ID may correspond to multiple CSI-RS resources. One or more parameters may be configured for the new group ID or new CSI-RS resource ID. This option may be based on the following example:
-◆ Example: An example of a configuration of a new group #N (new port CSI-RS resource #N) of CSI-RS resources to support 96 ports (Figure 53) includes a new group ID (new CSI-RS resource ID) = N, a parameter A set to value X, a parameter B set to value Y, a parameter C set to value Z, and a list including CSI-RS resources #1 to #3. Each CSI-RS resource uses 32 ports. Each CSI-RS resource configuration includes a CSI-RS resource ID ∈ {1, 2, 3}. Within each CSI-RS resource configuration, the settings/fields for parameters A, B, and C are not present.

◆ Option 4: To realize the expanded number of ports, one existing port CSI-RS resource is configured with a repetition factor X∈{2,3,4}. For this new repetition configuration, a new parameter (e.g., largerPort-r18) may be introduced to distinguish it from the existing repetition configuration. This option may be based on at least one of the following examples:
- ◆ Example: To support 128-port CSI-RS, one 32-port CSI-RS resource is configured with a repetition factor X = 4 and largerPort-r18 = 1 (enabled).
-◆Example: To support a 48-port CSI-RS, one 24-port CSI-RS resource is configured with a repetition factor X=2 and largerPort-r18=1 (enabled).
Example: An example of the configuration of a new group #N (new port CSI-RS resource #N) of CSI-RS resources for supporting 128 ports (Figure 54) includes a new group ID (new CSI-RS resource ID) = N, CSI-RS resource #1, a repetition factor set to 4, and largerPort-r18 set to 1 (enabled). CSI-RS resource #1 uses 32 ports. The configuration of CSI-RS resource #1 may include parameter A set to value X, parameter B set to value Y, and parameter C set to value Z. The repetition factor and largerPort-r18 may be included in the configuration of CSI-RS resource #1.

According to embodiment F2, multiple CSI-RS resources can be appropriately configured to support an expanded number of ports.

<Embodiment F3>
The CMR configuration in CSI-ReportConfig for CSI measurement/reporting may be based on at least one of several options:

◆ Option 1: For CSI extension based on Type 2 or Extended Type 2, only one new port CSI-RS resource having a new CSI-RS resource may be configured. Instead of the new port CSI-RS resource, a new group having a new group ID and including multiple existing port CSI-RS resources may be configured. The new port CSI-RS resource or the new group may be considered as one CMR.

◆Option 2: Configuration for CSI extension based on Type 1 or multi-CRI reporting may be based on at least one of the following options 2x:

-- Option 2a: Only one new port CSI-RS resource may be configured. Instead of the new port CSI-RS resource, a new group including multiple existing port CSI-RS resources may be configured. The new port CSI-RS resource or the new group may be considered as one CMR. This option may be based on the following example:

- Option 2b: Multiple new port CSI-RS resources may be configured. The new port CSI-RS resources may be considered as CMRs. Multiple new groups may be configured instead of new port CSI-RS resources. Each new group may include multiple existing port CSI-RS resources. The maximum number of configurable new port CSI-RS resources (or new groups) may depend on the UE capability. The UE capability may be defined/reported for each value of at least one of the parameters of the number of ports and the rank. Multiple new port CSI-RS resources or multiple new groups may be considered as multiple CMRs. This option may be based on at least one of the following features:
In this case, the constraints of embodiment A and embodiment F1 may be applied across multiple new groups for multiple existing port CSI-RS resources in different new groups. For example, at least one of the number of ports and RE density may be set to the same value across multiple new groups. The QCL/TCI state settings may be different between multiple groups.
In this case, information such as a CRI for indicating one or more selected new port CSI-RS resources or one or more selected new groups may be reported. In an extension based on multi-CRI reporting, multiple CRIs for indicating multiple selected new port CSI-RS resources or multiple selected new groups may be reported (using a method similar to embodiment D).
In an extension based on multi-CRI reporting, the total number of ports for multiple legacy port CSI-RS resources may be 32 or less. For example, a UE may be configured with two 12-port CSI-RS resources and configured to report two CRIs using two CSIs, respectively. The restrictions on multiple legacy port CSI-RS resources in embodiments A and F1 may also be applied to cases where the total number of ports used for multiple legacy port CSI-RS resources is 32 or less. The configuration method in embodiment F2 may also be applied to cases where the total number of ports used for multiple legacy port CSI-RS resources is 32 or less.
--◆In an extension based on multi-CRI reporting, in the case where the total number of ports used for multiple existing port CSI-RS resources is 32 or less, the new port CSI-RS resources may include two 4-port CSI-RS resources, may include three 4-port CSI-RS resources, may include four 4-port CSI-RS resources, may include five 4-port CSI-RS resources, may include six 4-port CSI-RS resources, or may include three 8-port CSI-RS resources.
--◆In extensions based on multi-CRI reporting, in cases where the total number of ports used for multiple existing port CSI-RS resources exceeds 32, the new port CSI-RS resources may include five 8-port CSI-RS resources, may include three 12-port CSI-RS resources, may include four 12-port CSI-RS resources, may include five 12-port CSI-RS resources, or may include five 16-port CSI-RS resources.

Option 1/2a may be based on Example 1/2 below.

◆ Example 1: One CMR #1 is configured for 128 ports. CMR #1 has a new CSI-RS resource ID #A or a new group ID #A. The new port CSI-RS resource or new group may be configured based on embodiment F2.

◆ Example 2: One CMR #1 is configured. CMR #1 directly configures multiple existing port CSI-RS resources #1 to #4. Each existing port CSI-RS resource uses 32 ports.

Option 2b may be based on examples 3/4 below.

◆ Example 3: Two CMRs, #1 and #2, are configured. CMR #1 includes multiple legacy port CSI-RS resources #1 to #4. CMR #2 includes multiple legacy port CSI-RS resources #5 to #8. Each legacy port CSI-RS resource uses 32 ports.

◆ Example 4: Three CMRs #1 to #3 are configured. CMR #1 is a new port CSI-RS resource (new CSI-RS resource ID #A) or a new group (new group ID #A) that uses 128 ports. CMR #2 is a new port CSI-RS resource (new CSI-RS resource ID #B) or a new group (new group ID #B) that uses 128 ports. CMR #3 is a new port CSI-RS resource (new CSI-RS resource ID #C) or a new group (new group ID #C) that uses 128 ports. Each new port CSI-RS resource or each new group may be configured based on embodiment F2.

The ZP-IMR (CSI-IM resource) setting may be configured in the CSI-ReportConfig for CSI measurement/reporting.

In the case of CMR configuration according to Option 1 or Option 2a of embodiment F3 (where one new port CSI-RS resource or one new group of multiple existing port CSI-RS resources is configured as one CMR), there may be only one ZP-IMR configured for one CMR. When measuring the ZP-IMR, the UE may assume the same QCL type D as that CMR.

For example, CMR#1 and ZP-IMR#1 may be configured. CMR#1 may include CSI-RS resources #1 to #4. Each of CSI-RS resources #1 to #4 may use 32 ports. ZP-IMR#1 may be CSI-IM resource #1.

The case of CMR configuration of option 2b of embodiment F3 (multiple new port CSI-RS resources or multiple new groups are configured as multiple CMRs) may be based on at least one of the following options:
◆ Option 1: There may be only one ZP-IMR configured for multiple CMRs. When measuring the ZP-IMR, the UE may assume the same QCL type D as the CMR mapped to each CSI.
◆ Option 2: There may be multiple ZP-IMRs configured for multiple CMRs. Multiple ZP-IMRs may be mapped one-to-one to multiple CMRs. When measuring each ZP-IMR, the UE may assume the same QCL type D as the mapped (corresponding) CMR.

For example, CMRs #1 and #2 and ZP-IMRs #1 and #2 may be configured. CMR #1 may include CSI-RS resources #1 to #4. CMR #2 may include CSI-RS resources #5 to #8. Each of CSI-RS resources #1 to #8 may use 32 ports. ZP-IMR #1 is CSI-IM resource #1 and may be mapped to CMR #1. ZP-IMR #2 is CSI-IM resource #2 and may be mapped to CMR #2.

In the CSI-ReportConfig for CSI measurement/reporting, an NZP-IMR (NZP CSI-RS resource for interference measurement) configuration may be configured. The NZP-IMR configuration may be based on at least one of the following options:
◆ Option A: NZP-IMR setting is not supported. Only ZP-IMR setting may be supported.
◆ Option B: One NZP-IMR setting is supported.
◆ Option C: Multiple NZP-IMR settings are supported, one to one for multiple CMRs. Multiple NZP-IMRs may be mapped one to one for multiple CMRs.

Multiple options from options A to C may be applied to at least one of multiple cases of codebook type, number of ports, rank, CMR setting method, and ZP-IMR setting method.

According to embodiment F3, the CMR/IMR can be appropriately configured to support the number of expansion ports.

<Supplementary Note on Embodiment F>
The resource configuration for CSI may indicate one or more CMRs. A CMR may be a new port CSI-RS resource or a new group. A CMR may indicate N occasions. The N occasions may be TDM. The N occasions may correspond to N existing port CSI-RS resources or N repetitions of one existing port CSI-RS resource.

The N legacy port CSI-RS resources may be associated with N occasions. The UE may associate the legacy port CSI-RS resources with P ports, where P is less than or equal to 32, and associate the N occasions with N×P ports, where P may be the number of legacy ports (legacy P _CSI-RS ). The UE may determine CSI based on measurements at the N occasions for the CMR and report the CSI for the CMR.

The resource configuration for the CSI may further indicate one or more IMRs. Each CMR may be associated with one or more IMRs.

The UE may report one or more CRIs, each indicating one or more selected existing port CSI-RS resources, and the CQI/PMI/RI calculated for each CRI.

<Additional Information>
<<Notification of information to UE>>
In the above-described embodiments, any information may be notified to the UE [from a network (NW) (e.g., a base station (BS)] (in other words, the UE receives any information from the BS) using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal/channel (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

If the above notification is made by a MAC CE, the MAC CE may be identified by including a new Logical Channel ID (LCID) in the MAC subheader that is not specified in existing standards.

If the notification is made by DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble the Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

Furthermore, notification of any information to the UE in the above-described embodiments may be performed periodically, semi-persistently, or aperiodically.

<<Notification of information from UE>>
In the above-described embodiments, notification of any information from the UE [to the NW] (in other words, transmission/reporting of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals/channels (e.g., PUCCH, PUSCH, PRACH, reference signals), or a combination thereof.

If the above notification is made by a MAC CE, the MAC CE may be identified by including a new LCID in the MAC subheader that is not specified in existing standards.

If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

Furthermore, any information notification from the UE in the above-described embodiments may be performed periodically, semi-persistently, or aperiodically.

<<Application of each embodiment>>
In a UE/BS, the specific process/operation/control/assumption/information(s) of at least one of the above-described embodiments may be applied (used) when one or more of the following conditions are met:
- Upper layer parameters indicating the specific processing/operation/control/assumption/information are set;
The specific process/action/control/assumption/information is determined based on relevant higher layer parameters;
The specific process/action/control/assumption/information is specified/activated/triggered by MAC CE/DCI/UCI/resource/channel/RS,
Reporting or supporting specific UE capabilities indicating (or relating to) the specific processes/actions/controls/assumptions/information;
The application of the specific process/action/control/assumption/information is determined based on specific conditions.

The specific UE capabilities may indicate at least one of the following:
- Supporting the above specific processes/actions/controls/assumptions/information;
- Capabilities of each embodiment.
- The capabilities of each option in each embodiment, or the capabilities of a combination of multiple options in each embodiment.
- The capabilities of each option in each embodiment, or the capabilities of a combination of multiple options in each embodiment.
Support association between multiple ports from each existing transmitted CSI-RS resource and multiple gNB antennas from new (N ₁ , N ₂ ) configurations for 48/64/72/96/128 ports.
UE capability for option 1 of at least one of embodiments C1 to C5, which may be at least one of the following:
-◆Supported associations between each 12/16/24/32 port CSI-RS transmitted and the considered existing (N ₁ ,N ₂ ) (and new (N _g1 ,N _g2 )) for new (N ₁ ,N ₂ ) for 48/64/72/96/128 ports.
- Supporting specific associations within the tables in at least one of embodiments C1 to C5.
UE capability for at least one option 2 of embodiments C1 to C5. Supported rules for association between each transmitted 12/16/24/32 port CSI-RS and the considered existing (N ₁ ,N ₂ ) (and new (N _g1 ,N _g2 )) for new (N ₁ ,N ₂ ) for 48/64/72/96/128 ports.
UE capabilities for variations 2A/2B/2C of embodiment C.
Different/separate UE capabilities for different types of codebooks/CSI based extensions for more than 32 ports.

Furthermore, the above-mentioned specific UE capabilities may be capabilities that are applied across all frequencies (commonly regardless of frequency), capabilities for each frequency (e.g., one or a combination of cell, band, band combination, BWP, component carrier, etc.), capabilities for each frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), capabilities for each subcarrier spacing (SubCarrier Spacing (SCS)), or capabilities for each Feature Set (FS) or Feature Set Per Component-carrier (FSPC)).

Furthermore, the above-mentioned specific UE capabilities may be capabilities that apply across all duplexing methods (commonly regardless of the duplexing method), or may be capabilities for each duplexing method (e.g., Time Division Duplex (TDD) or Frequency Division Duplex (FDD)).

If the above conditions are not met, the UE/BS may follow the behavior specified in existing 3GPP releases.

(Additional Note)
Regarding one embodiment of the present disclosure (Embodiment E, Consideration E1), the following inventions are noted.
[Appendix 1]
a receiver that receives configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources;
A terminal having a control unit that, based on the setting, associates each CSI-RS resource with 32 or fewer ports, associates the multiple CSI-RS resources with more than 32 ports, and controls the transmission of a report indicating multiple beams and one or more CSI-RS resources among the multiple CSI-RS resources that correspond to the multiple beams.
[Appendix 2]
The control unit determines the plurality of beams and one resource corresponding to the plurality of beams from the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources;
the report indicating the plurality of beams and the one resource.
2. The terminal of claim 1.
[Appendix 3]
The control unit determines the plurality of beams and a corresponding resource for each beam from the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources;
the report indicating the plurality of beams and a plurality of resources corresponding to the plurality of beams, respectively.
10. The terminal according to claim 1 or 2.
[Appendix 4]
The control unit determines the plurality of beams and corresponding resources for each beam from among a portion of the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources;
the report indicating the plurality of beams and a plurality of resources corresponding to the plurality of beams, respectively.
4. A terminal according to any one of Supplementary Note 1 to Supplementary Note 3.

(Additional Note)
Regarding one embodiment of the present disclosure (Embodiment E, Consideration E2), the following inventions are noted.
[Appendix 1]
a receiver configured to receive configurations for at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, multiple channel state information (CSI)-reference signal (RS) resources, and a port selection codebook;
and a control unit that, based on the setting, associates each CSI-RS resource with 32 or fewer ports, associates the plurality of CSI-RS resources with more than 32 ports, and controls transmission of a report indicating the plurality of ports and one or more CSI-RS resources among the plurality of CSI-RS resources that correspond to the plurality of ports.
[Appendix 2]
The control unit determines the plurality of ports and one resource corresponding to the plurality of ports from the plurality of CSI-RS resources based on measurement of the plurality of CSI-RS resources;
the report indicating the plurality of ports and the one resource.
2. The terminal of claim 1.
[Appendix 3]
The control unit determines the plurality of ports and a corresponding resource for each port from the plurality of CSI-RS resources based on measurement of the plurality of CSI-RS resources;
the report indicating the plurality of ports and a plurality of resources respectively corresponding to the plurality of ports;
10. The terminal according to claim 1 or 2.
[Appendix 4]
The control unit determines the plurality of ports and a corresponding resource for each port from among a portion of the plurality of CSI-RS resources based on measurement of the plurality of CSI-RS resources;
the report indicating the plurality of ports and a plurality of resources respectively corresponding to the plurality of ports;
4. A terminal according to any one of Supplementary Note 1 to Supplementary Note 3.

(Additional Note)
Regarding one embodiment of the present disclosure (embodiment F, setting one CMR), the following inventions are noted.
[Appendix 1]
a receiver for receiving a configuration indicating a channel measurement resource;
a control unit that determines N occasions based on the setting, associates each occasion with P ports, where P is 32 or less, associates the plurality of occasions with N×P ports, and controls transmission of channel state information (CSI) reports based on measurements in the N occasions.
[Appendix 2]
The channel measurement resource indicates N CSI-reference signal (RS) resources corresponding to the N occasions.
2. The terminal of claim 1.
[Appendix 3]
The channel measurement resource indicates N repetitions of a CSI-reference signal (RS) resource, and the N repetitions correspond to the N occasions.
10. The terminal according to claim 1 or 2.
[Appendix 4]
the configuration indicates one or more interference measurement resources associated with the channel measurement resource;
4. A terminal according to any one of Supplementary Note 1 to Supplementary Note 3.

(Additional Note)
Regarding one embodiment of the present disclosure (embodiment F, setting of multiple CMRs), the following inventions are noted.
[Appendix 1]
a receiver for receiving a configuration indicating a plurality of channel measurement resources;
a control unit that determines N occasions for each channel measurement resource based on the setting, associates each occasion with P ports, where P is 32 or less, associates the plurality of occasions with N×P ports, and controls transmission of channel state information (CSI) reports based on measurements at the N occasions for each channel measurement resource.
[Appendix 2]
Each channel measurement resource indicates N CSI-reference signal (RS) resources corresponding to the N occasions.
2. The terminal of claim 1.
[Appendix 3]
Each channel measurement resource indicates N repetitions of a CSI-reference signal (RS) resource, and the N repetitions correspond to the N occasions.
10. The terminal according to claim 1 or 2.
[Appendix 4]
The configuration indicates one or more interference measurement resources associated with each channel measurement resource.
4. A terminal according to any one of Supplementary Note 1 to Supplementary Note 3.

(wireless communication system)
The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

Figure 55 is a diagram showing an example of the schematic configuration of a wireless communication system according to one embodiment. Wireless communication system 1 (which may simply be referred to as system 1) may be a system that achieves communication using Long Term Evolution (LTE) specified by the Third Generation Partnership Project (3GPP), 5th generation mobile communication system New Radio (5G NR), or the like.

The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity where both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form a small cell C2 that is smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The location, number, shape, size, etc. of each cell and user terminal 20 are not limited to the configuration shown in the figure. Hereinafter, when base stations 11 and 12 are not to be distinguished, they will be collectively referred to as base station 10.

The wireless communication system 1 may also utilize multi-input multi-output (MIMO). For example, one cell may be formed by one antenna/base station 10, or by multiple antennas/base stations 10. One [virtual] cell (which may be called, for example, a supercell) may be made up of multiple [virtual] cells (which may be called, for example, subcells). A supercell may correspond to a cell with a fixed physical range, and a subcell may correspond to a cell with a quasi-static/dynamically changing physical range. In this case, the wireless communication system 1 may be called a cell-free system.

The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may use at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). Macrocell C1 may be included in FR1, and small cell C2 may be included in FR2. For example, FR1 may be a frequency band below 6 GHz (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

Furthermore, the user terminal 20 may communicate using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

Multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), X2/Xn interface, etc.) or wirelessly (e.g., NR communication). For example, if NR communication is used as a backhaul between base stations 11 and 12, base station 11, which corresponds to the upper station, may be called an Integrated Access Backhaul (IAB) donor, and base station 12, which corresponds to the relay station (relay), may be called an IAB node.

A base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), etc.

The core network 30 may include network functions (Network Functions (NF)) such as, for example, a User Plane Function (UPF), an Access and Mobility management Function (AMF), a Session Management Function (SMF), a Unified Data Management (UDM), an Application Function (AF), a Data Network (DN), a Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). Note that multiple functions may be provided by a single network node. Communication with an external network (e.g., the Internet) may also be performed via the DN.

The user terminal 20 may be a terminal that supports at least one of the communication methods such as LTE, LTE-A, and 5G.

In the wireless communication system 1, a wireless access method based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, in at least one of the downlink (DL) and uplink (UL), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

The radio access method may also be called a waveform. Note that in the wireless communication system 1, other radio access methods (e.g., other single-carrier transmission methods, other multi-carrier transmission methods) may be used as the UL and DL radio access methods.

In the wireless communication system 1, the downlink channel may be a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), or the like.

Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

User data, upper layer control information, System Information Block (SIB), etc. are transmitted via PDSCH. User data, upper layer control information, etc. may also be transmitted via PUSCH. Furthermore, Master Information Block (MIB) may also be transmitted via PBCH.

Lower layer control information may be transmitted via the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and PUSCH.

Note that the DCI that schedules the PDSCH may be referred to as a DL assignment or DL DCI, and the DCI that schedules the PUSCH may be referred to as a UL grant or UL DCI. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to the resources to search for DCI. The search space corresponds to the search area and search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that in this disclosure, "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. may be read interchangeably.

The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK/NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

Note that in this disclosure, downlink, uplink, etc. may be expressed without adding the word "link." Also, various channels may be expressed without adding "Physical" to the beginning.

In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

The synchronization signal may be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS/PBCH block, an SS block (SSB), etc. Note that SS, SSB, etc. may also be referred to as a reference signal.

Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). DMRS may also be called a user equipment-specific reference signal (UE-specific Reference Signal).

(base station)
56 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

Note that this example mainly shows the functional blocks that characterize the present embodiment, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, a control circuit, etc., as described based on common understanding in the technical field to which this disclosure pertains.

The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may also control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurements, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may also perform call processing of communication channels (setting up, releasing, etc.), status management of the base station 10, management of radio resources, etc.

The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be composed of a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field to which this disclosure relates.

The transceiver unit 120 may be configured as an integrated transceiver unit, or may be composed of a transmitter unit and a receiver unit. The transmitter unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiver unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

The transmitting and receiving antenna 130 can be composed of an antenna described based on common understanding in the technical field to which this disclosure pertains, such as an array antenna.

The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may also receive the above-mentioned uplink channel, uplink reference signal, etc.

The transceiver unit 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

The transmitter/receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

The transceiver unit 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30 (e.g., network nodes providing NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

Note that the transmitter and receiver of the base station 10 in this disclosure may be configured by at least one of the transmitter/receiver 120, the transmitter/receiver antenna 130, and the transmission path interface 140.

The base station 10 may be separated into three elements: a radio unit (RU), a distributed unit (DU), and a central unit (CU). For example, the RU may perform RF processing (digital beamforming, digital-to-analog conversion, analog beamforming, etc.) and lower-level physical layer functions (precoding, IFFT, FFT, etc.). The DU may perform higher-level physical layer functions (encoding to resource element mapping, etc.), MAC layer functions, and RLC layer functions. The CU may perform PDCP layer, Service Data Adaptation Protocol (SDAP) layer, and RRC layer functions.

In the present disclosure, the base station 10 may include a single device that implements all of the functions of the RU, DU, and CU, or may include multiple devices that each implement some of the functions of the RU, DU, and CU and are connected to each other. In the present disclosure, the base station 10 may be interchangeably referred to as the RU/DU/CU.

The transceiver unit 120 may transmit configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources. Based on the configurations, the control unit 110 may associate each CSI-RS resource with 32 or fewer ports, associate the multiple CSI-RS resources with more than 32 ports, and control the reception of reports indicating multiple beams and one or more CSI-RS resources among the multiple CSI-RS resources corresponding to the multiple beams.

The transceiver unit 120 may transmit configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, multiple channel state information (CSI)-reference signal (RS) resources, and a port selection codebook. Based on the configurations, the control unit 110 may associate each CSI-RS resource with 32 or fewer ports, associate the multiple CSI-RS resources with more than 32 ports, and control the reception of reports indicating multiple ports and one or more CSI-RS resources from the multiple CSI-RS resources corresponding to the multiple ports.

The transceiver unit 120 may transmit a configuration indicating channel measurement resources. The control unit 110 may determine N occasions based on the configuration, associate each occasion with P ports, where P is 32 or less, associate the occasions with N×P ports, and control reception of channel state information (CSI) reports based on measurements in the N occasions.

The transceiver unit 120 may transmit a configuration indicating multiple channel measurement resources. Based on the configuration, the control unit 110 may determine N occasions for each channel measurement resource, associate each occasion with P ports, where P is 32 or less, associate the multiple occasions with N×P ports, and control the reception of channel state information (CSI) reports based on measurements at the N occasions for each channel measurement resource.

(user terminal)
57 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

Note that this example mainly shows the functional blocks that characterize the present embodiment, and the user terminal 20 may also have other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., as described based on common understanding in the technical field to which this disclosure pertains.

The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc. using the transmission and reception unit 220 and the transmission and reception antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transmission and reception unit 220.

The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be composed of a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to this disclosure.

The transceiver unit 220 may be configured as an integrated transceiver unit, or may be composed of a transmitter unit and a receiver unit. The transmitter unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiver unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

The transmitting and receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which this disclosure pertains, such as an array antenna.

The transceiver unit 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver unit 220 may also transmit the above-mentioned uplink channel, uplink reference signal, etc.

The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

The transceiver unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

Whether or not to apply DFT processing may be based on the settings for transform precoding. If transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform; if not, it may not be necessary to perform DFT processing as the transmission processing.

The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

The transceiver unit 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

The measurement unit 223 may derive channel measurements for CSI calculation based on channel measurement resources. The channel measurement resources may be, for example, non-zero power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on interference measurement resources. The interference measurement resources may be at least one of NZP CSI-RS resources for interference measurement, CSI-Interference Measurement (IM) resources, etc. CSI-IM may also be referred to as CSI-Interference Management (IM) or may be interchangeably read as Zero Power (ZP) CSI-RS. In this disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc. may be interchangeable.

Note that the transmitter and receiver of the user terminal 20 in this disclosure may be configured by at least one of the transmitter/receiver 220 and the transmitter/receiver antenna 230.

The transceiver unit 220 may receive configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources. Based on the configurations, the control unit 210 may associate each CSI-RS resource with 32 or fewer ports, associate the multiple CSI-RS resources with more than 32 ports, and control the transmission of a report indicating multiple beams and one or more CSI-RS resources among the multiple CSI-RS resources corresponding to the multiple beams.

The control unit 210 may determine the plurality of beams and one resource corresponding to the plurality of beams from the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources, and the report may indicate the plurality of beams and the one resource.

The control unit 210 may determine the multiple beams and corresponding resources for each beam from the multiple CSI-RS resources based on measurements of the multiple CSI-RS resources, and the report may indicate the multiple beams and the multiple resources corresponding to each of the multiple beams.

The control unit 210 may determine the plurality of beams and corresponding resources for each beam from among a portion of the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources, and the report may indicate the plurality of beams and the plurality of resources corresponding to each of the plurality of beams.

The transceiver unit 220 may receive configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, multiple channel state information (CSI)-reference signal (RS) resources, and a port selection codebook. Based on the configurations, the control unit 210 may associate each CSI-RS resource with 32 or fewer ports, associate the multiple CSI-RS resources with more than 32 ports, and control transmission of a report indicating multiple ports and one or more CSI-RS resources among the multiple CSI-RS resources that correspond to the multiple ports.

The control unit 210 may determine the multiple ports and one resource from the multiple CSI-RS resources corresponding to the multiple ports based on the measurement of the multiple CSI-RS resources, and the report may indicate the multiple ports and the one resource.

The control unit 210 may determine the multiple ports and corresponding resources for each port from the multiple CSI-RS resources based on measurements of the multiple CSI-RS resources, and the report may indicate the multiple ports and the multiple resources corresponding to each of the multiple ports.

The control unit 210 may determine the multiple ports and corresponding resources for each port from among a portion of the multiple CSI-RS resources based on measurements of the multiple CSI-RS resources, and the report may indicate the multiple ports and the multiple resources corresponding to each of the multiple ports.

The transceiver unit 220 may receive a configuration indicating channel measurement resources. The control unit 210 may determine N occasions based on the configuration, associate each occasion with P ports, where P is 32 or less, associate the occasions with N×P ports, and control transmission of channel state information (CSI) reports based on measurements in the N occasions.

The channel measurement resource may indicate N CSI-reference signal (RS) resources corresponding to the N occasions.

The channel measurement resource may indicate N repetitions of a CSI-reference signal (RS) resource, and the N repetitions may correspond to the N occasions.

The configuration may indicate one or more interference measurement resources associated with the channel measurement resource.

The transceiver unit 220 may receive a configuration indicating channel measurement resources. Based on the configuration, the control unit 210 may determine N occasions for each channel measurement resource, associate each occasion with P ports, where P is 32 or less, associate the multiple occasions with N×P ports, and control the transmission of channel state information (CSI) reports based on measurements at the N occasions for each channel measurement resource.

Each channel measurement resource may indicate N CSI-reference signal (RS) resources corresponding to the N occasions.

Each channel measurement resource may represent N repetitions of a CSI-reference signal (RS) resource, and the N repetitions may correspond to the N occasions.

The configuration may indicate one or more interference measurement resources associated with each channel measurement resource.

(Hardware configuration)
The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of hardware and/or software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. The functional block may also be realized by combining software with the single device or multiple devices.

Here, functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission functions may be called a transmitting unit, transmitter, etc. As mentioned above, there are no particular limitations on how these functions are implemented.

For example, a base station, a user terminal, etc. in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 58 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to one embodiment. The above-mentioned base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

In this disclosure, terms such as apparatus, circuit, device, section, and unit may be used interchangeably. The hardware configuration of the base station 10 and user terminal 20 may be configured to include one or more of the devices shown in the figures, or may be configured to exclude some of the devices.

For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by a single processor, or processing may be performed by two or more processors simultaneously, sequentially, or using other techniques. Furthermore, the processor 1001 may be implemented by one or more chips.

The functions of the base station 10 and the user terminal 20 are realized, for example, by loading specific software (programs) onto hardware such as the processor 1001 and memory 1002, causing the processor 1001 to perform calculations, control communications via the communication device 1004, and control at least one of reading and writing data from and to the memory 1002 and storage 1003.

The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) that includes an interface with peripheral devices, a control unit, an arithmetic unit, registers, etc. For example, at least a portion of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

In addition, the processor 1001 reads programs (program code), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and similar implementations may be used for other functional blocks.

Memory 1002 is a computer-readable recording medium and may be composed of, for example, at least one of Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. Memory 1002 may also be referred to as a register, cache, main memory, etc. Memory 1002 can store executable programs (program code), software modules, etc. for implementing a wireless communication method according to one embodiment of the present disclosure.

Storage 1003 is a computer-readable recording medium and may be composed of at least one of a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

The communication device 1004 is hardware (transmitting/receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, or communication module. The communication device 1004 may be configured to include high-frequency switches, duplexers, filters, frequency synthesizers, etc. to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmitter/receiver unit 120 (220), transmitter/receiver antenna 130 (230), etc. may be implemented by the communication device 1004. The transmitter/receiver unit 120 (220) may be implemented as a transmitter unit 120a (220a) and a receiver unit 120b (220b) that are physically or logically separated.

The input device 1005 is an input device (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, speaker, Light Emitting Diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

Furthermore, each device, such as the processor 1001 and memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

Furthermore, the base station 10 and user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

In addition, devices included in the core network 30 (e.g., network nodes that provide NF) may also be realized using the above-mentioned functional block/hardware configuration.

(Modification)
Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

Here, numerology may be a communication parameter applied to at least one of the transmission and reception of a signal or channel. Numerology may indicate, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transmitter/receiver in the frequency domain, and specific windowing processing performed by the transmitter/receiver in the time domain.

A slot may consist of one or more symbols in the time domain (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols or Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols). A slot may also be a time unit based on numerology.

A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

Radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals. Radio frame, subframe, slot, minislot, and symbol may each be referred to by a different name. Note that the time units used in this disclosure, such as frame, subframe, slot, minislot, and symbol, may be interchangeable.

For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) as in existing LTE, or may be a period shorter than 1 ms (e.g., 1-13 symbols), or may be a period longer than 1 ms. Note that the unit representing a TTI may be called a slot, minislot, etc. instead of a subframe.

Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as the frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

The TTI may be a transmission time unit for a channel-encoded data packet (transport block), code block, code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., number of symbols) to which a transport block, code block, code word, etc. is actually mapped may be shorter than the TTI.

Note that when one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the smallest time unit for scheduling. Furthermore, the number of slots (minislots) that make up the smallest time unit for scheduling may be controlled.

A TTI with a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, minislot, subslot, slot, etc.

Note that a long TTI (e.g., a normal TTI, subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length of 1 ms or more but less than the TTI length of a long TTI.

A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, and may be, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

Furthermore, an RB may include one or more symbols in the time domain and may be one slot, one minislot, one subframe, or one TTI in length. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

Note that one or more RBs may also be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

A Bandwidth Part (BWP) (which may also be referred to as a partial bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier. Here, the common RBs may be identified by the index of the RB relative to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

BWPs may include UL BWPs (BWPs for UL) and DL BWPs (BWPs for DL). One or more BWPs may be configured for a UE within one carrier.

At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal/channel outside the active BWP. Note that "cell," "carrier," etc. in this disclosure may be read as "BWP."

Note that the structures of the radio frames, subframes, slots, minislots, and symbols described above are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, as well as the number of symbols in a TTI, symbol length, and cyclic prefix (CP) length can be changed in various ways.

Furthermore, the information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values from a predetermined value, or other corresponding information. For example, radio resources may be indicated by a predetermined index.

The names used for parameters and the like in this disclosure are not limiting in any way. Furthermore, the mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not limiting in any way.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

Information, signals, etc. may be output from a higher layer to a lower layer and/or from a lower layer to a higher layer. Information, signals, etc. may be input/output via multiple network nodes.

Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added to. Output information, signals, etc. may be deleted. Input information, signals, etc. may be sent to another device.

With regard to any information (e.g., variables, constants, parameters) described in this disclosure, even if not specifically stated in the above embodiments, any first device (e.g., UE/base station) may notify any second device (e.g., base station/UE) of information indicating/identifying (or relating to) the value of that information.

The notification of information is not limited to the aspects/embodiments described in this disclosure, and may be performed using other methods. For example, the notification of information in this disclosure may be performed using physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI))), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), etc.), Medium Access Control (MAC) signaling), other signals, or a combination of these.

Note that physical layer signaling may also be referred to as Layer 1/Layer 2 (L1/L2) control information (L1/L2 control signal), L1 control information (L1 control signal), etc. Furthermore, RRC signaling may also be referred to as RRC messages, such as RRC Connection Setup messages or RRC Connection Reconfiguration messages. Furthermore, MAC signaling may also be notified using, for example, MAC Control Elements (CEs).

Furthermore, notification of specified information (e.g., notification that "X is true") is not limited to explicit notification, but may also be done implicitly (e.g., by not notifying the specified information or by notifying other information).

The determination may be made based on a value represented by a single bit (0 or 1), a Boolean value represented as true or false, or a comparison of numerical values (for example, a comparison with a predetermined value).

Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

In addition, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and/or wireless technology (such as infrared or microwave), then the wired and/or wireless technology is included within the definition of transmission medium.

As used in this disclosure, the terms "system" and "network" may be used interchangeably. "Network" may refer to devices included in the network (e.g., base stations).

In this disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "layer," "number of layers," "rank," "resource," "resource set," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," "UE panel," "transmitting entity," "receiving entity," etc. may be used interchangeably.

In the present disclosure, the term "antenna port" may be interchangeably read as an antenna port for any signal/channel (e.g., a demodulation reference signal (DMRS) port). In the present disclosure, the term "resource" may be interchangeably read as a resource for any signal/channel (e.g., a reference signal resource, an SRS resource, etc.). The resource may include time/frequency/code/space/power resources. The spatial domain transmit filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

The above groups may include, for example, at least one of a spatial relationship group, a Code Division Multiplexing (CDM) group, a Reference Signal (RS) group, a Control Resource Set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, a panel group, etc.

Furthermore, in this disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, codeword (CW), transport block (TB), RS, etc. may be read as interchangeable terms.

Furthermore, in this disclosure, terms such as TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, and joint TCI state may be interpreted interchangeably.

Furthermore, in this disclosure, terms such as "QCL," "QCL assumptions," "QCL relationships," "QCL type information," "QCL properties," "specific QCL type (e.g., Type A, Type D) properties," and "specific QCL types (e.g., Type A, Type D)" may be read interchangeably.

In this disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interchangeable. In this disclosure, terms such as sequence, list, set, group, cluster, and subset may be interchangeable.

Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and spatial relationship information (TCI state) may be interchangeable. "Spatial relationship information (TCI state)" may be interchangeable as "set of spatial relationship information (TCI state)", "one or more pieces of spatial relationship information", etc. TCI state and TCI may be interchangeable. Spatial relationship information and spatial relationship may be interchangeable.

In this disclosure, terms such as "Base Station (BS)," "Radio Base Station," "Fixed Station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "Access Point," "Transmission Point (TP)," "Reception Point (RP)," "Transmission/Reception Point (TRP)," "Panel," "Cell," "Sector," "Cell Group," "Carrier," and "Component Carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms "cell" or "sector" refer to part or all of the coverage area of at least one of the base station and base station subsystems that provide communication services within this coverage area.

In this disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control/operate based on that information.

In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a wireless communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

The mobile body in question refers to an object that can move at any speed, and of course also includes cases where the mobile body is stationary. Examples of the mobile body in question include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted on these. The mobile body in question may also be a mobile body that moves autonomously based on operation commands.

The moving object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving object (e.g., a drone, a self-driving car, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

FIG. 59 is a diagram showing an example of a vehicle according to one embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, an axle 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

The drive unit 41 is composed of, for example, at least one of an engine, a motor, or a hybrid of an engine and a motor. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (e.g., an input/output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

Signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the motor current, a rotation speed signal for the front wheels 46/rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal for the front wheels 46/rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal for the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal for the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal for the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

The information service unit 59 is composed of various devices, such as a car navigation system, audio system, speakers, displays, televisions, and radios, that provide (output) various information such as driving information, traffic information, and entertainment information, as well as one or more ECUs that control these devices. The information service unit 59 uses information obtained from external devices via the communication module 60, etc., to provide various information/services (e.g., multimedia information/multimedia services) to the occupants of the vehicle 40.

The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

The driving assistance system unit 64 is composed of various devices that provide functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Unit (IMU) and Inertial Navigation System (INS)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance or autonomous driving functions.

The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 between the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, all of which are provided on the vehicle 40.

The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with external devices. For example, it sends and receives various information to and from external devices via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or user terminal 20 described above. The communication module 60 may also be, for example, at least one of the base station 10 and user terminal 20 described above (or may function as at least one of the base station 10 and user terminal 20).

The communications module 60 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 50-58 described above input to the electronic control unit 49; information obtained based on these signals; and information based on input from the outside (user) obtained via the information service unit 59. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may also be referred to as input units that accept input. For example, the PUSCH transmitted by the communications module 60 may include information based on the above input.

The communications module 60 receives various information (traffic information, traffic signal information, vehicle-to-vehicle information, etc.) transmitted from external devices and displays it on the information service unit 59 installed in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communications module 60 (or data/information decoded from the PDSCH)).

Furthermore, the communication module 60 stores various information received from external devices in memory 62 that can be used by the microprocessor 61. Based on the information stored in memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and other components provided on the vehicle 40.

Furthermore, the base station in the present disclosure may be read as a user terminal. For example, the aspects/embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions possessed by the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (for example, "sidelink"). For example, terms such as uplink channel and downlink channel may be read as sidelink channel.

Similarly, the term "user terminal" in this disclosure may be interpreted as "base station." In this case, the base station 10 may be configured to have the functions possessed by the user terminal 20 described above.

In this disclosure, operations described as being performed by a base station may in some cases also be performed by its upper node. In a network including one or more network nodes having base stations, it is clear that various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) or a Serving-Gateway (S-GW)), or a combination thereof.

Each aspect/embodiment described in this disclosure may be used alone, in combination, or switched between depending on the implementation. Furthermore, the processing procedures, sequences, flowcharts, etc. of each aspect/embodiment described in this disclosure may be rearranged as long as they are consistent. For example, the methods described in this disclosure present various step elements in an exemplary order, and are not limited to the specific order presented.

Each aspect/embodiment described in this disclosure may be applied to any of the following mobile communication systems: Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio The present invention may be applied to systems that use Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, as well as next-generation systems that are extended, modified, created, or defined based on these. It may also be applied to a combination of multiple systems (for example, a combination of LTE or LTE-A with 5G).

As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

As used in this disclosure, the term "determining" may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., searching in a table, database, or other data structure), ascertaining, etc.

Furthermore, "determination" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

Furthermore, "judgment (decision)" may be considered to mean "judging (deciding)" resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment (decision)" may be considered to mean "judging (deciding)" some kind of action. In this disclosure, "judgment (decision)" may be read interchangeably with the above-mentioned actions.

Furthermore, in this disclosure, "determine/determining" may be interpreted interchangeably as "assume/assuming," "expect/expecting," "consider/considering," etc. Furthermore, in this disclosure, "does not expect to do..." may be interpreted interchangeably as "assumes not to do...."

In the present disclosure, "expect" may be interchangeably read as "be expected." For example, "expect(s)..." ("..." may be expressed, for example, as a that clause, a to-infinitive, etc.) may be interchangeably read as "be expected..." or "does... (if the above "..." is a to-infinitive, a verb with "to")." "does not expect..." may be interchangeably read as "be not expected..." or "does not... (if the above "..." is a to-infinitive, a verb with "to")." Furthermore, "An apparatus A is not expected..." may be interchangeably read as "apparatus B other than apparatus A does not expect..." from apparatus A (for example, if apparatus A is a UE, apparatus B may be a base station).

The term "maximum transmit power" used in this disclosure may refer to the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

As used in this disclosure, the terms "connected," "coupled," or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

For the purposes of this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." Note that this term may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

In this disclosure, where articles are added by translation, such as a, an, and the in English, this disclosure may include the noun following these articles being plural.

In this disclosure, terms such as "less than or equal to," "less than," "greater than," "more than," "equal to," etc. may be read interchangeably. Furthermore, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be read interchangeably, not limited to the positive, comparative, and superlative. Furthermore, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be read interchangeably, not limited to the positive, comparative, and superlative, as expressions with the prefix "i-th" (i is any integer) (for example, "highest" may be read interchangeably as "i-th highest").

In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

In the present disclosure, expressions such as "when A, B," "if A, (then) B," "B upon A," "B in response to A," "B based on A," "B during/while A," "B before A," "B at (the same time as)/on A," "B after A," "B since A," and "B until A" may be interchangeable. Note that A and B may be replaced with other appropriate expressions, such as nouns, gerunds, and regular sentences, depending on the context. The time difference between A and B may be nearly zero (immediately after or immediately before). A time offset may also be applied to the time at which A occurs. For example, "A" may be interpreted interchangeably as "before/after the time offset at which A occurs." The time offset (e.g., one or more symbols/slots) may be predefined or may be determined by the UE based on signaled information.

In the present disclosure, terms such as timing, time, duration, time instance, any time unit (e.g., slot, subslot, symbol, subframe), period, occasion, and resource may be interpreted interchangeably.

The invention according to the present disclosure has been described in detail above, but it will be clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described herein. The description of the present disclosure is for illustrative purposes only and does not pose any limitations on the invention according to the present disclosure.

Claims (6)

a receiver that receives configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources;
A terminal having a control unit that, based on the setting, associates each CSI-RS resource with 32 or fewer ports, associates the multiple CSI-RS resources with more than 32 ports, and controls the transmission of a report indicating multiple beams and one or more CSI-RS resources among the multiple CSI-RS resources that correspond to the multiple beams. The control unit determines the plurality of beams and one resource corresponding to the plurality of beams from the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources;
The terminal of claim 1 , wherein the report indicates the plurality of beams and the one resource. The control unit determines the plurality of beams and a corresponding resource for each beam from the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources;
The terminal of claim 1 , wherein the report indicates the plurality of beams and a plurality of resources corresponding to the plurality of beams, respectively. The control unit determines the plurality of beams and corresponding resources for each beam from among a portion of the plurality of CSI-RS resources based on measurements of the plurality of CSI-RS resources;
The terminal of claim 1 , wherein the report indicates the plurality of beams and a plurality of resources corresponding to the plurality of beams, respectively. receiving a configuration for at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources;
and controlling, based on the setting, the transmission of a report indicating each CSI-RS resource to 32 or fewer ports, the plurality of CSI-RS resources to more than 32 ports, and indicating a plurality of beams and one or more CSI-RS resources among the plurality of CSI-RS resources corresponding to the plurality of beams. a transmitter that transmits configurations regarding at least one of a two-dimensional arrangement of multiple antennas for 32 or fewer ports, a two-dimensional arrangement of multiple antennas for more than 32 ports, and multiple groups of multiple antennas for more than 32 ports, and multiple channel state information (CSI)-reference signal (RS) resources;
a control unit that, based on the setting, associates each CSI-RS resource with 32 or fewer ports, associates the plurality of CSI-RS resources with more than 32 ports, and controls reception of a report indicating a plurality of beams and one or more CSI-RS resources among the plurality of CSI-RS resources that correspond to the plurality of beams.