RU2787683C2 - User terminal and radio communication method - Google Patents

Abstract

FIELD: communication.

SUBSTANCE: invention relates to a user terminal and to a radio communication method in mobile communication systems of the next generation. The user terminal, according to the aspect of the present invention, contains a control section made with the possibility of control, during retransmission of an uplink shared channel, of determination of time density of a phase tracking reference signal (hereinafter – PTRS) based on the fact of whether an index of a modulation and coding scheme (MCS) is contained in a range higher than a specific value, and a transmission section made with the possibility of transmission of the specified PTRS signal.

EFFECT: possibility of proper control of PTRS transmission.

5 cl, 13 dwg

Description

The field of technology to which the invention belongs

The present invention relates to a user terminal and a radio communication method in next generation mobile communication systems.

State of the art

For the Universal Mobile Telecommunications System (UMTS) network, a Long Term Evolution (LTE) specification project was proposed, the purpose of which is to further increase the data rate, reduce latency, etc. (see non-patent document 1). In order to further increase the capacity, the development of LTE (LTE version 8, version 9), etc. specifications for an advanced LTE system (English LTE-Advanced, LTE-A), also called LTE versions 10-13, were proposed.

LTE successor systems are also being developed, for example, under the name Future Radio Access (FRA), 5th generation mobile communication system, 5G and 5G +, New Radio (English New Radio, NR), New Radio Access (English New Radio Access, NX), Future generation radio access (English Future generation radio access, FX), LTE system versions 14, 15, etc.

In existing LTE systems (e.g. 3GPP versions 8-14), the user terminal (User Equipment, UE) controls the reception from the radio base station of a downlink shared channel (e.g., Physical Downlink Shared Channel (PDSCH)) based on Downlink Control Information (DCI), also called downlink allocation, or the like. In addition, the user terminal controls transmission of an uplink shared channel (eg, a Physical Uplink Shared Channel (PUSCH)), based on a DCI (also called an uplink grant or the like).

List of Cited Materials

Non-Patent Documents

Non-Patent Document 1: 3GPP TS 36.300 V8.12.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)," April, 2010 (" Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN; General Description; Stage 2 (Release 8)", April 2010).

Disclosure of the essence of the invention

Technical problem

For future radio communication systems (eg, NR), the transmission of Phase Tracking Reference Signals (PTRS) by base stations (eg, gNB stations) in the downlink is being studied. In addition, time domain PTRS density control based on the Modulation and Coding Scheme (MCS) index, which is specified in the DCI, is being studied.

However, it has not yet been fully clarified how to determine the MCS index when the Uplink Control Information (UCI) is transmitted using an uplink common channel (for example, PUSCH) in which uplink data is not multiplexed, for example, an uplink common channel ( "UCI on PUSCH without data"). From this follows the question of determining the density of PTRS in the time domain. Improper transmission of PTRS (for example, when the PTRS density in the time domain cannot be properly determined) can reduce the quality of the connection.

Thus, it is an object of the present invention to provide a user terminal and a radio communication method capable of properly controlling PTRS transmission.

Solution

A user terminal according to an aspect of the present invention comprises: a control section configured, upon retransmission of an uplink common channel, to control the determination of a phase tracking reference signal (PTRS) time density based on whether a modulation and coding scheme (MCS) index is contained in range above a specific value; and a transmission section configured to transmit said PTRS.

Positive effects of the invention

According to an aspect of the present invention, PTRS transmission can be properly controlled.

Brief description of the drawings

Fig. 1 represents an example of an MCS table.

Fig. 2 represents an example of an MCS table.

Fig. 3 shows an example of an MCS table.

Fig. 4 shows an example of a mapping table between MCS indices and PTRS densities in the time domain.

Fig. 5 shows an example of determining the PTRS density in the time domain.

Fig. 6 represents another example of determining the PTRS density in the time domain.

Fig. 7 represents another example of determining the PTRS density in the time domain.

Fig. 8 is an example of a schematic structure of a radio communication system in accordance with one embodiment.

Fig. 9 represents an example of a generalized structure of a radio base station in accordance with one embodiment.

Fig. 10 shows an example of a functional structure of a radio base station according to one embodiment.

Fig. 11 shows an example of a schematic structure of a user terminal according to one embodiment.

Fig. 12 shows an example of a functional structure of a user terminal according to one embodiment.

Fig. 13 shows an example of a hardware structure of a radio base station and a user terminal according to one embodiment.

Implementation of the invention

In an NR system, a base station (eg, gNB) transmits a phase tracking reference signal (PTRS) on the downlink. The base station may transmit the PTRS, for example, by continuously or discontinuously mapping this PTRS to the temporal direction on one subcarrier. The base station may transmit PTRS for at least part of a period (slot, symbol, or the like) to transmit a downlink shared channel (Physical Downlink Shared Channel (PDSCH)). The PTRS transmitted by the base station may also be referred to as downlink PTRS.

The UE transmits PTRS on the uplink. The UE may transmit the PTRS, for example, by continuously or discontinuously mapping this PTRS to the time direction on one subcarrier. The UE may transmit PTRS for at least part of a period (slot, symbol, or the like) to transmit an uplink shared channel (Physical Uplink Shared Channel (PUSCH)). The PTRS transmitted by the UE may also be referred to as uplink PTRS. Hereinafter, the ascending PTRS is simply called PTRS.

The UE may determine the presence of PTRS in the uplink based on the upper layer signaling configuration (eg, the presence or absence of the PTRS-UplinkConfig information element). The UE may consider that the PTRS is contained in the resource block for PUSCH. Based on the PTRS transmitted from the UE, the base station can determine the phase noise and correct the phase error in the received signal.

In this case, the higher layer signaling can be one of the Radio Resource Control (RRC) layer signaling, Medium Access Control (MAC) layer signaling, broadcast information, and the like. , or a combination of the above.

For example, MAC layer control elements (MAC control elements, MAC CE), MAC layer protocol data units (Protocol Data Units, PDU), etc. can be used in MAC layer signaling. The specified broadcast information can be, for example, Master Information Block (MIB), System Information Block (SIB), Remaining Minimum System Information (RMSI), other system information. information (English Other System Information, OSI), etc.

For NR, control of at least one of the modulation method (or modulation order) and coding rate (modulation order/code rate) of the physical uplink common channel (eg, PUSCH) scheduled by downlink control information (DCI) is studied based on a particular field (eg, modulation and coding scheme (MCS) field) to be included in that DCI (in an upstream grant, eg, in DCI format 0_0, 0_1).

More specifically, the UE's determination of the modulation order/coding rate for the PUSCH according to the MCS index indicated in the MCS field of the DCI information is developed using a table (MCS table) relating MCS indexes to modulation orders and TBS indexes.

Each modulation order here is a value corresponding to the modulation method. For example, for Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM, 64QAM, and 256QAM), the modulation orders are defined as 2, 4, 6, and 8, respectively.

In FIG. 1-3 are examples of the MCS table. Note that the values in the MCS tables shown in FIG. 1-3 are only examples and do not limit the possible values in these tables. Some of the elements associated with the MCS index (I _MCS ), such as spectral efficiency, may be omitted, or another element may be added.

The user terminal may determine the MCS table to be used to determine the modulation order/coding rate for the PUSCH using at least one of the following conditions (1) to (3):

(1) whether Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing, DFT-Spread-OFDM, DFT-s-OFDM ) or orthogonally multiplexed signal with frequency division (eng. Orthogonal Frequency Division Multiplexing, OFDM signal));

(2) whether the information indicating the MCS table (MCS table information) to be used by the user terminal indicates a specific modulation method (eg, 256QAM); and

(3) which Radio Network Temporary Identifier (Radio Network Temporary Identifier) used in the radio network is used for DCI scrambling with Cyclic Redundancy Check (CRC).

For example, when a DCI (eg, DCI format 0_0 or 0_1) is CRC-scrambled with a particular RNTI (eg, C-RNTI, TC-RNTI, or CS-RNTI), no transform precoding is applied and the MCS table information does not indicate 256QAM, the user the terminal may determine the modulation order/coding rate corresponding to the MCS index (I _MCS ) in the specified DCI using the table shown in FIG. 1.

When transform precoding is not applied and the MCS table information indicates 256QAM, the user terminal can determine the modulation order/coding rate corresponding to the MCS index (I _MCS ) in the specified DCI using the table shown in FIG. 2.

When transform precoding is applied and the MCS table information does not indicate 256QAM, the user terminal can determine the modulation order/coding rate corresponding to the MCS index (I _MCS ) in the specified DCI using the table shown in FIG. 3.

Note that, for example, when the specific condition in FIG. 3 (for example, Binary Phase Shift Keying (BPSK) is supported), the modulation order q corresponding to a particular MCS index (eg, 0, 1) may be 1 (BPSK). When the above specific condition is not met, the modulation order q may be 2 (QPSK).

When transform precoding is applied and the MCS table information indicates 256QAM, the user terminal can determine the modulation order/coding rate corresponding to the MCS index (I _MCS ) in the specified DCI using the table shown in FIG. 2.

It should be noted that the conditions of use shown in Figs. Tables 1-3 are not limited to the above conditions.

Next, for NR, the determination of the PTRS density in the time domain based on the MCS index specified in the DCI is studied by referring to a specific table.

In FIG. 4 shows a table mapping between MCS indices (eg, MCS index ranges) and PTRS temporal densities (hereinafter also referred to as specific table). For example, the PTRS temporal density is 4 when the MCS index specified in the DCI is not less than MCS 1 and less than MCS 2; the PTRS temporal density is 2 when the MCS index is not less than MCS 2 and less than MCS 3, and the PTRS temporal density is 1 when the MCS index is not less than MCS 3 and less than MCS 4. It should be understood that the correspondence relationship between MCS indices and temporal densities ( or time-domain densities) PTRS are not limited to the given correspondence relationships.

The NR system supports the transmission of information (report) about the channel state (English Channel State Information, CSI), which at a specific time as feedback from the user terminal is transmitted to the radio base station and contains the result of the measurement of the channel state by the user terminal, performed using the reference signal .

This reference signal for measuring the channel state can also be called, for example, without limitation, the reference signal information about the state of the channel (eng. Channel State Information-Reference Signal, CSI-RS). The CSI may comprise at least one of a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), and a Rank Indicator (RI). The CSI may also comprise at least one of a first CSI (CSI Part 1) and a second CSI (CSI Part 2).

Supported CSI reports include Periodic CSI report (P-CSI), Semi-Persistent CSI report (SP-CSI), and Aperiodic CSI report. report, A-CSI).

The transmission of the A-CSI report by the UE is performed according to a CSI trigger (CSI request) from the radio base station. For example, the UE transmits an A-CSI report at a specific time (eg, 4 subframes) after receiving the CSI trigger.

The A-CSI trigger is included in the Downlink Control Information (DCI) transmitted using the Downlink Control Channel (Physical Downlink Control Channel, PDCCH). The DCI containing the A-CSI trigger is an uplink grant, and has, for example, at least one of DCI formats 0_0 and 0_1.

When transmitting an A-CSI report, the user terminal transmits the CSI using the PUSCH that is indicated by the upstream grant containing the A-CSI trigger. This PUSCH, when there is no corresponding transport channel (also called Uplink Shared Channel (UL-SCH), uplink data, uplink user data, or the like) is also called "PUSCH without uplink shared channel" or etc.

Whether a particular PUSCH is a PUSCH without an uplink shared channel (UL-SCH) may be indicated by a specific field (eg, UL-SCH indicator field) in the uplink grant. For example, it is possible to indicate whether PUSCH without UL-SCH or PUSCH with UL-SCH is being used with a one-bit UL-SCH indicator field.

Thus, the PUSCH without UL-SCH is used to transmit uplink control information (eg, A-CSI) and may transmit data other than the data transmitted on the PUSCH with UL-SCH (which is, for example, at least one upstream user data and higher layer control information).

It is perfectly acceptable for PUSCH with UL-SCH and for PUSCH without UL-SCH to use different methods for determining the modulation order/coding rate of the PUSCH.

However, the question of how the MCS index is determined by the DCI information in the case of a UCI on a PUSCH without data (eg, A-CSI on a PUSCH without data) has not been sufficiently clarified. This leads to the question of how to control the time domain PTRS density for UCI on PUSCH without data.

For example, in UCI on PUSCH without data (for example, in A-CSI on PUSCH without data), when a specific MCS index is indicated (for example, MCS index in the first range (0 to 27)), the PTRS density in the time domain is determined according to the specific table.

At the same time, in the case of a PUSCH transmission (including at least the case of a UCI transmission on a PUSCH with no data), it is possible that any of the MCS indices 0 to 27 or any of the MCS indices 28 to 31 will be indicated in the retransmission. For example, it may turn out that a value is specified that is not specified in a particular table (as, for example, for an MCS index of 30 or the like). In other words, it is not clear how to control PTRS transmission (eg, PTRS density in time domain) upon retransmission (eg, upon retransmission of at least one of PUSCH and UCI).

The inventors of the present invention proposed the idea of controlling the method for determining the density of PTRS in the time domain based on the range in which the MCS index that was specified is contained (for example, based on the content of this MCS index in the first range or in the second range). Said first range may be an MCS index range of 0 to 27, and said second range may be an MCS index range of 28 to 31. Alternatively, the first range may be an MCS index range of 0 to 28, and the second range may be an MCS index range 29 to 31. It should be understood that the MCS indices are not limited to the examples.

Next, with reference to the drawings, embodiments of the present invention are explained in detail. Aspects according to this embodiment may be used independently or in combination. Although the following configuration is described in terms of PUSCH transmission without data (eg, UL-SCH), the above configuration may be applied to PUSCH transmission with data. The following configuration may apply to CP-OFDM or DFT-S-OFDM. The following configuration may apply to downlink or to signals other than PTRS.

(First aspect)

In a first aspect, the PTRS time density on retransmission (eg, on PUSCH retransmission) is determined using a range containing an MCS index and at least one of specific rules.

When, upon retransmission, the MCS index that has been indicated is contained in the first range (e.g., 0 to 27 (or 0 to 28)), the UE determines the time domain PTRS density based on this MCS index and a specific table (e.g., shown in Fig. 4).

The UE may determine that the transmission is a retransmission when the value of the new data indicator field contained in the DCI transmitted to the UE is different from the value of the same field in the previous DCI. For example, the UE may determine that the transmission is a retransmission if the value of the new data indicator field in the DCI has changed from 0 to 1 or from 1 to 0.

At the same time, while keeping the MCS index in the second range (eg, 28 to 31 (or 29 to 31)), the UE may use at least one of the following rules 1-1, 1-2, and 1-3.

<Rule 1-1>

The UE uses the same time domain PTRS density as used in the original transmission. In this case, the UE also uses the PTRS temporal density corresponding to the MCS index (eg, any index from 0 to 27) indicated in the initial transmission when retransmitting.

Thus, it is possible to properly determine the PTRS temporal density in retransmission even when the MCS index in a specific table is not associated with a PTRS temporal density value.

<Rule 1-2>

The UE determines the time domain density according to the specific mapping method based on the PTRS time domain density used in the initial transmission.

For example, the UE may use the time domain PTRS density specified in a specific table (eg, the table in FIG. 4) in a row different from the row used in the original transmission. For example, the UE may use the time domain PTRS density from the line above or below the line used in the original transmission.

Setting the PTRS time domain density used in the retransmission to a smaller value than the time domain density in the initial transmission reduces the coding rate, which improves performance. On the other hand, setting the PTRS time domain density used in the retransmission to a larger value than the time domain density in the initial transmission contributes to more effective phase noise correction and improves performance.

<Rule 1-3>

The UE determines the PTRS density in the time domain using the MCS index indicated in the retransmission, a specific table, and a specific transform formula (see FIGS. 5-7). The table in FIG. 5 is used in the initial transmission, and the tables in FIG. 6 and 7 are used in retransmission. In this example, the used (reported to the UE) MCS index in the initial transmission is in the range of 0 to 27, and the used (reported to the UE) MCS index in the retransmission is in the range of 28 to 31, not limited to the specified values.

For example, the UE may determine the PTRS density in the time domain in the retransmission according to the modulation order indicated by the MCS index from 28 to 31 and the MCS index threshold indicated by the upper layer.

In this example, the possible upper layer MCS index thresholds (e.g., RRC signaling) are set to between MCS indexes 4 and 5, between MCS indexes 11 and 12, and between MCS indexes 19 and 20, but the possibilities of the specified thresholds are and given values of the MCS indexes are not limited.

Fig. 6 and 7 represent the case in which the UE determines the PTRS density in the time domain in the retransmission based on the modulation order corresponding to the MCS index that was specified (any index from the range 28-31) (in this example, index 28 corresponds to the value q modulation order, index 29 corresponds to the value 2, index 30 corresponds to the value 4 and index 31 corresponds to the value 6).

In the example in FIG. 6 The UE considers PTRS unused (missing) when the modulation order is q (MCS index=28). When the modulation order is 2 (MCS index=29), the UE considers the time domain PTRS density to be 4. When the modulation order is 4 (MCS index=30), the UE considers the time domain PTRS density to be 2. When the modulation order is 6 ( index MCS=31), the UE assumes the PTRS density in the time domain to be 1.

In the example in FIG. 7, the UE considers the PTRS unused (missing) when the MCS index is 28. When the MCS index is 29, the UE considers the time domain PTRS density to be 4. When the MCS index is 30, the UE considers the time domain PTRS density to be 2.

Alternatively, in the example of FIG. 7 The UE considers the PTRS unused (missing) when the MCS index is 28 or 29. When the MCS index is 30, the UE considers the time domain PTRS density to be 4. When the MCS index is 31, the UE considers the time domain PTRS density to be 2.

Thus, if an MCS index in the range of 28 to 31 is indicated in the retransmission, then using this MCS index, a specific table, and a specific conversion formula, it is possible to properly determine the PTRS temporal density even when the value of the specified density in the specified specific table is not given.

(second aspect)

In a second aspect, when the MCS index indicated in the initial transmission is contained in a specific range (eg, 28 to 31 (or 29 to 31)), the time domain PTRS density is determined according to a specific rule.

For example, in the initial transmission, when the MCS index included in the DCI is contained in a specific range (eg, 28 to 31), the UE determines the time domain PTRS density according to this MCS index, a specific table, and a specific transform formula (see FIG. five). For example, the UE may use rule 1-3 from the first aspect described above (with "retransmission" replaced by "initial transmission").

For example, the UE may determine the PTRS density in the time domain according to the MCS index that has been specified and the MCS index threshold specified in the upper layer. For example, the UE considers the PTRS unused (missing) when the MCS index that has been indicated is 28. When the MCS index is 29, the UE considers the PTRS density in the time domain to be 4. When the MCS index is 30, the UE considers the density of the PTRS in the time domain equal to 2. When the MCS index is equal to 31, the UE considers the PTRS density in the time domain to be equal to 1.

Thus, it is possible to properly determine the PTRS temporal density even when the value of this density specified in the initial transmission is not set in a specific table for some MCS index.

(Modification)

For the uplink PTRS configuration (e.g., PTRS-UplinkConfig) indicated from the base station to the UE, a value from 0 to 27 can be used. Thus, compared to the commonly considered case of setting PTRS-UplinkConfig in the range of 0-29, unnecessary RRC bits can be removed . The uplink PTRS configuration may be transmitted using an upper layer (eg, RRC signaling or the like).

(Radio communication system)

Next, the configuration of a radio communication system according to an embodiment of the present invention will be described. In this radio communication system, the radio communication method illustrated in the above-described embodiment may be used for communication individually or in combination.

Fig. 8 is an example of a schematic structure of a radio communication system in accordance with one embodiment. The radio communication system 1 is configured to carry carrier aggregation (CA, from carrier aggregation) and/or dual connectivity (DC, from dual connectivity) to combine a plurality of elementary frequency blocks (elementary carriers) into one block, with one the combining element is the frequency band of the LTE system (eg, 20 MHz).

It should be noted that the radio communication system 1 may be called, for example, an LTE system, an advanced LTE system (English LTE-Advanced, LTE-A), an extended LTE system (English LTE-Beyond, LTE-B), SUPER 3G, IMT-Advanced , fourth generation mobile communication system (4G), fifth generation mobile communication system (5G), new radio (English New Radio, NR), future radio access (English Future Radio Access, FRA), new radio access technology (English New- RAT), etc., or may be referred to as a system that implements the listed systems.

The radio communication system 1 includes a radio base station 11 forming a macro cell C1 with a relatively wide coverage, and radio base stations 12 (12a-12c) located in the macro cell C1 and forming small cells C2 with less coverage than macro cell C1. In addition, there are user terminals 20 in the macro cell C1 and each of the small cells C2. Location, number, and the like. cells and user terminals 20 is not limited in any way to the aspect shown in the diagram.

User terminals 20 are configured to connect to both radio base station 11 and radio base stations 12. It is understood that user terminals 20 are configured to simultaneously use macro cell C1 and small cell C2 via CA or DC. User terminals 20 are configured to use CA or DC by using a plurality of cells (component carriers (CC, from the English component carrier), for example, five CC or less, or six CC or more).

Communication between user terminals 20 and radio base station 11 may be carried out using a carrier from a relatively low frequency band (eg, 2 GHz) and narrow band (called, for example, an existing carrier, an old type carrier, etc.). At the same time, between the user terminals 20 and the radio base stations 12, a carrier from a relatively high frequency range (for example, 3.5 GHz, 5 GHz, etc.) and a wide frequency band may be used, or the same carrier as used between the user terminals 20 and the radio base station 11. It should be appreciated that the configuration of the frequency band to be used in each radio base station is in no way limited to these configurations.

User terminals 20 are configured to communicate using Time Division Duplexing (TDD) and/or Frequency Division Duplexing (FDD) in each cell. Each cell (on each carrier) may use one numerology or many different numerologies.

Numerologies may refer to the communication parameters applied to the transmission and/or reception of a particular signal and/or channel; numerologies may indicate, for example, at least one of subcarrier spacing, frequency band, symbol length, cyclic prefix length, subframe length, TTI length, number of symbols per TTI, radio frame structure, specific filtering processing performed by the transceiver in the frequency domain , specific windowing performed by the transceiver in the time domain, and so on.

For example, if some physical channels use different subcarrier spacings and/or use different numbers of OFDM symbols in the OFDM symbols forming these channels, then the numerologies of these channels can be said to be different.

A wired configuration may be used (for example, Common Public Radio Interface (CPRI) means, such as fiber optic cable, X2 interface, etc.), or between radio base station 11 and radio base stations 12 (or between two radio base stations 12) can establish a wireless connection.

The radio base station 11 and each of the base radio stations 12 are connected to the higher level station apparatus 30, and via the upper level station apparatus 30 are connected to the core network 40. It should be noted that the upper layer station apparatus 30 may be, for example, an access gateway, a radio network controller ( Radio Network Controller (RNC), Mobility Management Entity (MME), etc., but the possibilities are not limited to the above list. In addition, each radio base station 12 can be connected to the higher level station apparatus 30 via the radio base station 11.

Note that the radio base station 11 has a relatively large coverage area and may be called a macro base station, a central node, an eNB (eNodeB), a transmitting/receiving point, and so on. Radio base stations 12 have local coverage and may be referred to as small base stations, micro base stations, pico base stations, femto base stations, eNB home nodes (Home eNodeB, HeNB), remote radio units (Remote Radio Heads, RRH), transmitting / receiving points, etc. .d. Hereinafter, radio base stations 11 and 12 are collectively referred to as radio base stations 10, unless otherwise indicated.

Each of the user terminals 20 is a terminal capable of supporting various communication schemes such as LTE and LTE-A, and can be both a mobile communication terminal (mobile station) and a fixed communication terminal (fixed station).

In the radio communication system 1, the downlink radio access schemes use an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, and the uplink uses a Single Carrier Frequency Division Multiple Access (OFDMA) scheme. Single-Carrier Frequency Division Multiple Access, SC-FDMA) and/or OFDMA scheme.

OFDMA is a multi-carrier communication scheme in which communication is performed by dividing a frequency band into a plurality of narrower frequency bands (subcarriers) and mapping data to each subcarrier. SC-FDMA is a single carrier communication scheme capable of reducing mutual interference between terminals by dividing the system bandwidth between all terminals into frequency bands formed by one or more contiguous resource blocks and allowing each of a plurality of terminals to use its own frequency band. It should be appreciated that the uplink and downlink radio access schemes are not limited to the above combination, and other radio access schemes may be used.

In the radio communication system 1, the physical downlink shared channel (Physical Downlink Shared CHannel, PDSCH), which is shared by all user terminals 20, the physical broadcast channel (Physical Broadcast CHannel, PBCH), downlink control channels L1 / L2 etc. The PDSCH carries user data, higher layer control information, System Information Blocks (SIBs), and so on. The Strategic Missile Forces channel transmits blocks of basic information (Eng. Master Information Block, MIB).

The L1/L2 downlink control channels include at least one of the downlink control channels (for example, a Physical Downlink Control Channel (PDCCH) and/or an Enhanced Physical Downlink Control Channel , EPDCCH), etc.), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid-ARQ Indicator Channel (PHICH), etc. P. Downlink Control Information (DCI) containing PDSCH and/or PUSCH scheduling information is transmitted on the PDCCH.

It should be appreciated that scheduling information may be communicated via DCI. For example, a DCI for scheduling downlink data reception may be referred to as a downstream allocation, and a DCI for scheduling uplink data transmission may be referred to as an upstream grant.

The number of OFDM symbols to be used for the PDCCH is signaled on the PCFICH. The transmission acknowledgment information (also called, for example, retransmission control information, HARQ-ACK, ACK/NACK, etc.) of the Hybrid Automatic Repeat reQuest (HARQ) for the PUSCH is transmitted on the PHICH. The EPDCCH is frequency division multiplexed with the PDSCH (downlink common data channel) and, like the PDCCH, is used to transmit DCI, etc.

In the radio communication system 1, the Physical Uplink Shared Channel (PUSCH) shared by all user terminals 20, the Physical Uplink Control Channel (PUCCH), the Physical Random Access Channel are used as uplinks. (Eng. Physical Random Access Channel, PRACH), etc. The PUSCH carries user data, upper layer control information, and so on. The PUCCH carries downlink radio quality information (Channel Quality Indicator (CQI)), delivery confirmation information, scheduling request (3P), and so on. The PRACH communicates random access preambles for establishing cell connections.

In the radio communication system 1, the cell-specific reference signal (CRS), the Channel State Information Reference Signal (CSI-RS), the reference signal are transmitted as downlink reference signals. demodulation (Eng. Demodulation Reference Signal, DMRS), reference positioning signal (Eng. Positioning Reference Signal, PRS), etc. As uplink reference signals in the radio communication system 1, a reference measuring signal (Sounding Reference Signal, SRS), a demodulation reference signal (Demodulation Reference Signal, DMRS), etc. are transmitted. Note that DMRS signals may be referred to as user terminal specific reference signals (UE specific reference signals). The reference signals to be transmitted are not limited to the above list.

<Radio Base>

Fig. 9 represents an example of a generalized structure of a radio base station in accordance with one embodiment. The radio base station 10 includes a plurality of transmit/receive antennas 101, gain sections 102, transmit/receive sections 103, baseband signal processing section 104, call processing section 105, and a link interface 106. Note that the radio base station 10 may be configured with one or more transmit/receive antennas 101, one or more gain sections 102, and one or more transmit/receive sections 103.

The user data to be transmitted from the radio base station 10 to the user terminal 20 in the downlink comes from the upper station apparatus 30 to the baseband signal processing section 104 via the link interface 106 .

In the baseband signal processing section 104, the user data is subjected to transmission processing, such as Packet Data Convergence Protocol (PDCP) layer processing, splitting and combining, and Radio Link Control transmission processing. , RLC), e.g., RLC level retransmission control, Medium Access Control (MAC) retransmission control, e.g., processing for HARQ transmission, scheduling, transport format selection, channel coding, inverse fast conversion Fourier (IFFT) and precoding, and the result is transmitted to each section 103 transmission/reception. The downstream control signals are also subjected to transmission processing operations, such as channel coding and inverse fast Fourier transform, and are transmitted to each transmission/reception section 103.

The transmit/receive sections 103 are configured to convert the precoded baseband signals transmitted from the baseband signal processing section 104 individually for each antenna to the radio frequency band and transmit this result. RF signals that have undergone frequency conversion in the transmit/receive sections 103 are amplified in the gain sections 102 and radiated into the air from the transmit/receive antennas 101. The transmit/receive sections 103 may be implemented using transmitters/receivers, transmit/receive circuits, or transmit/ receiving devices well known in the field of technology to which the present invention relates. It should be noted that each transmission/reception section 103 may be a single transmission/reception section, or may contain a separate transmission and reception section.

As for the uplink signals, the RF signals received at the transmitting/receiving antennas 101 are amplified in the gain sections 102. The transmission/reception sections 103 are configured to receive uplink signals amplified in the gain sections 102. The transmission/reception sections 103 are configured to convert the received signals into a baseband signal by frequency conversion, and to transmit this signal to the baseband signal processing section 104 .

In the baseband signal processing section 104, the user data contained in the received uplink signals are subjected to a Fast Fourier Transform (FFT) operation, an Inverse Discrete Fourier Transform (IDFT) operation, error correction decoding, a receive operation in MAC layer retransmission control, a receive operation the RLC layer and the PDCP layer and are transmitted to the higher layer station apparatus 30 via the link interface 106 . The call processing section 105 is configured to process a call (setup and release) for communication channels and the like, state control of the radio base station 10, radio resource control, and so on.

The link interface 106 is configured to transmit signals to the upper layer station apparatus 30 and to receive signals from the higher layer station apparatus 30 via a specific interface. The link interface 106 is configured to transmit and/or receive signals (reverse connection signaling) of other radio base stations 10 via a tie-to-station interface (for example, fiber optic cable in accordance with the CPRI (Common Public Radio Interface) standard) and an X2 interface ).

The transmit/receive sections 103 are configured to receive a phase tracking reference signal (PTRS) for an uplink control channel without data used in transmitting uplink control information.

Fig. 10 shows an example of a functional structure of a radio base station according to one embodiment. It should be noted that the radio base station 10, in addition to the functional blocks presented in this example, related to the elements important for this embodiment, may contain other functional blocks that are also necessary for radio communication.

The baseband signal processing section 104 includes at least a control (scheduler) section 301 , a transmitted signal generation section 302 , a mapping section 303 , a received signal processing section 304 , and a measurement section 305 . It should be appreciated that these functional blocks may be contained in the radio base station 10, but some or all of these functional blocks are not necessarily contained in the baseband signal processing section 104 .

The control section 301 (scheduler) is configured to control the radio base station 10 as a whole. The control section 301 may be formed by a controller, a control circuit, or a control device well known in the art to which the present invention pertains.

The control section 301, for example, controls signal generation in the transmission signal generation section 302, signal display by the display section 303, and so on. The control section 301 is configured to control signal reception operations in the received signal processing section 304, measurement of signals in the measurement section 305, and so on.

The control section 301 is configured to control scheduling (e.g., resource allocation) of system information, downlink data signal (e.g., signal transmitted on PDSCH), downlink control signal (e.g., signal transmitted on PDCCH and/or EPDCCH, delivery confirmation information etc.). The control section 301 is configured to control generation of a downstream control signal, downstream data signal, and the like. based on the results of checking whether retransmission control is necessary with respect to the uplink data signal, or the like.

The control section 301 is configured to control the scheduling of the synchronization signal (e.g., Primary Synchronization Signal/Secondary Synchronization Signal, PSS/SSS), downstream reference signals (e.g., CRS, CSI-RS, DMRS). ) etc.

The control section 301 is configured to determine a method for determining the PTRS density in the time domain at the UE based on whether the modulation and coding scheme (MCS) index indicated in the downstream control information is contained in a specific band (for example, in the first band or in the second band ).

The transmission signal generating section 302 is configured to generate downlink signals (downlink control signals, downlink data signals, downlink reference signals, etc.) based on commands from the control section 301 and to transmit these signals to the display section 303 . The transmission signal generating section 302 may be formed by a signal generator, a signal conditioning circuit, or a signal conditioning apparatus well known in the art to which the present invention pertains.

For example, the transmission signal generation section 302 is configured, based on commands from the control section 301, to generate a downstream allocation for reporting downstream data allocation information and/or an upstream grant for reporting upstream data allocation information. Both the downstream allocation and the upstream grant are DCI information and conform to the requirements of the DCI format. Encoding processing and modulation processing are performed on the downlink data signal according to a coding rate, a modulation scheme, or the like determined based on the channel state information (CSI) from each user terminal 20.

The mapping section 303 is configured to map the downlink signals generated in the transmitted signal generation section 302 to specific radio resources based on commands from the control section 301, and to transmit the received signals to the transmit/receive section 103. The display section 303 may be implemented using a display, display circuit, or display device commonly known in the art to which the present invention relates.

The received signal processing section 304 is configured to perform receiving operations (eg, inverse mapping, demodulation, decoding, etc.) on the signals received from the transmit/receive sections 103. The received signals here include, for example, uplink signals transmitted from the user terminals 20 (uplink control signals, uplink data signals, uplink reference signals, etc.). The received signal processing section 304 may be formed by a signal processor, signal processing circuit, or signal processing apparatus well known in the art to which the present invention pertains.

The received signal processing section 304 is configured to transmit the decoded information obtained by receiving operations to the control section 301 . For example, the received signal processing section 304 is configured, upon receiving a PUCCH containing a HARQ-ACK signal, to transmit this signal to the control section 301 . In addition, the received signal processing section 304 is configured to transmit received signals and/or signals after receiving operations to the measurement section 305 .

The measurement section 305 is configured to perform measurements on the received signals. Measurement section 305 may be implemented using a meter, measurement circuit, or measurement device well known in the art to which the present invention pertains.

For example, the measurement section 305 may, based on the received signals, perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, and the like. Measurement section 305 can measure reception power (for example, Reference Signal Received Power, RSRP), reception quality (for example, Reference Signal Received Quality, RSRQ), signal-to-sum ratio interference and noise (Signal to Interference plus Noise Ratio, SINR), signal-to-noise ratio (Signal to Noise Ratio, SNR), signal strength (for example, Received Signal Strength Indicator, RSSI) ), transmission path status information (eg, CSI), etc. The measurement results may be transmitted to the control section 301 .

<User Terminal>

Fig. 11 shows an example of a schematic structure of a user terminal according to one embodiment. The user terminal 20 includes a plurality of transmit/receive antennas 201, gain sections 202, transmit/receive sections 203, a baseband signal processing section 204, and an application section 205. It should be appreciated that the user terminal 20 may be configured to contain one or more transmit/receive antennas 201, one or more gain sections 202, and one or more transmit/receive sections 203.

RF signals received at the transmitting/receiving antennas 201 are amplified in the gain sections 202. The downlink signals amplified in the gain sections 202 are received by the transmit/receive sections 203. The transmission/reception sections 203 are configured to convert these received signals into baseband signals by frequency conversion, and to transmit these baseband signals to the baseband signal processing section 204 . The transmit/receive sections 203 may be formed by transmitters/receivers, transmitter/receiver circuits, or transmitter/receiver devices well known in the art to which the present invention pertains. It should be appreciated that each transmission/reception section 203 may be a single transmission/reception section, or may comprise a transmission section and a reception section.

The baseband signal processing section 204 is configured to perform an FFT operation, error correction decoding, a receive operation in retransmission control, and so on, on each received baseband signal. The downstream user data is transmitted to the application section 205. The application section 205 is configured to perform operations related to the layers above the physical layer, the MAC layer, and so on. Broadcast information may also be sent to the application module 205 among these downstream data.

At the same time, uplink user data is transmitted from the application section 205 to the baseband signal processing section 204 . The baseband signal processing section 204 is configured to perform a transmission operation in retransmission control (for example, a HARQ transmission operation), channel coding, precoding, a Discrete Fourier Transform (DFT) operation, an IFFT operation, etc., and capable of transmitting result to the transmission/reception section 203 .

The transmit/receive sections 203 are configured to convert the baseband signals transmitted from the baseband signal processing section 204 to RF and transmit the result. RF signals that have undergone frequency conversion in the transmit/receive sections 203 are amplified in the gain sections 202 and radiated into the air from the transmit/receive antennas 201.

The transmit/receive sections 203 are configured to transmit a phase tracking reference signal (PTRS) for an uplink control channel without data used in transmitting uplink control information.

Fig. 12 shows an example of a functional structure of a user terminal according to one embodiment. It should be noted that the user terminal 20, in addition to the functional blocks presented in this example, related to the elements important for this embodiment, may contain other functional blocks that are also necessary for radio communication.

The baseband signal processing section 204 provided in the user terminal 20 includes at least a control section 401, a transmitted signal generation section 402, a display section 403, a received signal processing section 404, and a measurement section 405. It should be appreciated that these functional blocks may be contained in the user terminal 20, but some or all of these functional blocks may not be contained in the baseband signal processing section 204 .

The control section 401 is configured to control the user terminal 20 as a whole. The control section 401 may be formed by a controller, a control circuit, or a control device well known in the art to which the present invention pertains.

The control section 401 controls, for example, signal generation in the transmission signal generation section 402, signal distribution by the display section 403, and so on. The control section 401 is configured to control signal reception operations in the received signal processing section 404, measurement of signals in the measurement section 405, and so on.

The control section 401 is configured to receive from the received signal processing section 404 the downlink control signal and the downlink data signal transmitted from the radio base station 10. The control section 401 is configured to control the generation of the uplink control signal and/or the uplink data signal based on the results of the control need check. retransmission with respect to the downlink control signal and/or the downlink data signal.

The control section 401 is configured to, upon receiving from the received signal processing section 404 various pieces of information reported from the radio base station 10, change the parameters used for control based on said information.

The control section 401 is configured to determine a method for determining the PTRS density in the time domain based on whether the modulation and coding scheme (MCS) index indicated in the downstream control information is contained in a specific band (for example, in the first band or in the second band).

The transmission signal generation section 402 is configured to generate uplink signals (uplink control signals, uplink data signals, uplink reference signals, etc.) based on commands from the control section 401, and to transmit these signals to the display section 403. The transmission signal conditioning section 402 may be formed by a signal generator, a signal conditioning circuit, or a signal conditioning apparatus well known in the art to which the present invention pertains.

For example, the transmission signal generation section 402 may generate uplink control signals related to delivery confirmation information, channel state information (CSI), and so on based on commands from the control section 401. The transmission signal generating section 402 is configured to generate uplink data signals based on commands from the control section 401 . For example, the control section 401 may, when an uplink grant is included in the downlink control signal transmitted from the radio base station 10, command the transmission signal generation section 402 to generate an uplink data signal.

The mapping section 403 is configured to map the uplink signals generated in the transmit signal generation section 402 to radio resources based on commands from the control section 401, and to transmit the result to the transmit/receive section 203. The display section 403 may be formed by a display, a display circuit, or a display device well known in the art to which the present invention pertains.

The received signal processing section 404 is configured to perform receiving operations (eg, inverse mapping, demodulation, decoding, etc.) on the signals received from the transmit/receive sections 203. The received signals here are, for example, downlink signals transmitted from the radio base station 10 (downlink control signals, downlink data signals, downlink reference signals, etc.). The received signal processing section 404 may be formed by a signal processor, signal processing circuit, or signal processing device well known in the art to which the present invention pertains. The received signal processing section 404 may form a receiving section in accordance with the present invention.

The received signal processing section 404 is configured to transmit the decoded information obtained by receiving operations to the control section 401 . For example, the received signal processing section 404 transmits broadcast information, system information, RRC signaling, DCI, and so on, to the control section 401 . The received signal processing section 404 is configured to transmit received signals and/or signals after receiving operations to the measurement section 405 .

The measurement section 405 is configured to perform measurements on the received signals. The measurement section 405 may be formed by a meter, a measurement circuit, or a measurement device well known in the art to which the present invention pertains.

For example, the measurement section 405 may perform radio resource management (RRM) measurements, CSI measurements, and the like based on the received signals. The measurement section 405 can measure receive power (eg, RSRP), reception quality (eg, RSRQ, SINR, SNR, etc.), signal strength (eg, RSSI), transmission path state information (eg, CSI), etc. .P. The measurement results may be transmitted to the control section 401 .

(Hardware structure)

In the functional diagrams used to describe the above embodiments, blocks are shown in functional modules. These functional blocks (components) can be implemented by arbitrary combinations of at least hardware and/or software. Here, the implementation method of each function block is not specifically limited. In other words, each functional block may be implemented by one physically and/or logically single part of the device, or may be implemented by directly and/or indirectly connecting two or more physically and/or logically separate parts of the device (via, for example, a wired and/or wireless connection or the like) and use of this plurality of device parts.

For example, radio base station, user terminal, etc. in accordance with one embodiment of the present invention may function as a computer executing the operations of the radio communication method of the present invention. Fig. 13 shows an example of a hardware structure of a radio base station and a user terminal according to one embodiment. Physically, the radio base stations 10 and user terminals 20 described above may be implemented as a computer device including a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and so on.

It should be noted that in the following description, the word "device" can be interpreted as "circuit", "module", etc. The hardware configuration of the radio base station 10 and the user terminal 20 may contain one or more instances of each of the devices shown in the drawings, or may not contain some of these devices.

For example, although only one processor 1001 is shown, multiple processors may be provided. In addition, the operations may be performed by a single processor or by two or more processors simultaneously, sequentially, or in other ways. It should be appreciated that processor 1001 may be implemented using one or more integrated circuits.

Each function of radio base station 10 and user terminals 20 is implemented, for example, by reading particular software(s) into hardware, for example, into processor 1001 and into memory 1002, and by enabling processor 1001 to perform calculations to control communications through the device. 1004 communications and the ability to read and/or write data to memory 1002 and storage device 1003.

The processor 1001 is configured to control the entire computer by, for example, executing an operating system. The processor 1001 may be configured with a central processing unit (CPU) having interfaces with a peripheral device, a control device, a computing device, a register, and so on. For example, the above-described baseband signal processing section 104 (204), call processing section 105, etc., may be implemented by the processor 1001.

Further, the processor 1001 reads programs (program codes), program modules, data, and so on. from the storage device 1003 and/or the communication device 1004 to the memory 1002 and performs various operations in accordance therewith. With regard to these programs, programs that enable the computer to perform at least part of the operations of the above-described embodiments can be used. For example, the control section 401 of each user terminal 20 may be implemented by control programs stored in the memory 1002 and executed by the processor 1001; other functional blocks can be implemented similarly.

Memory 1002 is a computer-readable, writable storage medium and may be formed using, for example, at least one of the following devices: read-only memory (ROM), erasable and programmable read-only memory (EPROM), electrically erasable and programmable read-only memory ( EEPROM), Random Access Memory (RAM), and/or other suitable storage media. Memory 1002 may be referred to as a register, cache, main memory (main storage), and so on. The memory 1002 is configured to store executable programs (program codes), program modules, and the like. to implement a radio communication method according to an embodiment of the present invention.

The storage device 1003 is a machine-readable writable medium and can be formed using, for example, at least one of a floppy disk, a floppy disk (a registered trademark of floppy disk), a magneto-optical disk (for example, a Compact Disc ROM, CD-ROM), etc.), Digital Versatile Disc, Blu-ray Disc (registered trademark), removable disk, hard disk, smart card, flash memory device (such as , memory card, removable storage, removable disk, etc.), magnetic tape, database, server, and other suitable media. The storage device 1003 may be referred to as an auxiliary storage device.

Communication device 1004 is a hardware (transmitter/receiver) for computer-to-computer communication via wired and/or wireless networks, and may be referred to as a network device, network controller, network card, communication module, etc., for example. The communication device 1004 may be configured to include a high frequency switch, an antenna switch, a filter, a frequency synthesizer, and so on. in order to implement, for example, frequency division duplex (FDD) and/or time division duplex (TDD). For example, the above-described transmit/receive antennas 101 (201), gain sections 102 (202), transmit/receive sections 103 (203), link interface 106, etc., can be implemented by the communication device 1004.

The input device 1005 is a device (eg, keyboard, mouse, microphone, switch, button, sensor, etc.) for receiving information from outside. The output device 1006 is an output device (eg, display, acoustic emitter, LED indicator, etc.) for outputting information. It should be noted that the input device 1005 and the output device 1006 may be combined into a single structure (eg, a touch panel).

Devices of these types, including processor 1001, memory 1002, etc., are connected by bus 1007 to exchange information. Bus 1007 may be formed using a single bus or buses that differ in different parts of the device.

The radio base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (ASIC), a programmable logic device (English Programmable Logic Device, PLD), programmable matrix of logical elements (English Field Programmable Gate Array, FPGA), etc., and all or part of the functional blocks can be implemented by the specified hardware. For example, processor 1001 may be implemented by at least one of these hardware.

(Modifications)

It should be appreciated that the terminology described in this disclosure and the terminology necessary for understanding this disclosure may be replaced by other terms that have the same or similar meaning. For example, at least one of the "channels" and "symbols" may be "signals" ("signaling"). Also "signals" can be "messages". The reference signal may be abbreviated as OC and referred to as pilot, pilot, and so on. depending on the applicable standard. Component carrier (CC, from the English component carrier) can be called a cell, frequency carrier, carrier frequency, etc.

A radio frame may be formed from one or more periods (frames) in the time domain. Each of one or more periods (frames) constituting a radio frame may be referred to as a subframe. Further, a subframe in the time domain may be formed from one or more slots. The subframe may have a fixed time duration (eg, 1 ms) independent of numerology.

Further, a slot in the time domain may be formed from one or more symbols (OFDM symbols, SC-FDMA symbols, etc.). The slot can be a temporary element depending on numerology.

A slot may contain a plurality of mini-slots. Each mini-slot in the time domain may be formed from one or more symbols. A mini-slot may be referred to as a sub-slot. A mini-slot may be formed from symbols that are less than the number of slots. PDSCH or PUSCH transmission in a tile larger than a minislot may be referred to as PDSCH/PUSCH Mapping Type A. PDSCH and PUSCH transmission using a minislot may be referred to as PDSCH/PUSCH mapping type B.

The radio frame, subframe, slot, mini-slot, and symbol are temporary elements in signaling operations. The radio frame, subframe, slot, mini-slot, and symbol may be referred to by other suitable names. For example, one subframe, multiple consecutive subframes, one slot, or one mini-slot may be referred to as a transmission time interval (TTI). Thus, at least one of the subframe and TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (eg, 1 to 13 symbols), or a period longer than 1 ms. Note that an element representing a TTI may not be referred to as a subframe, but as a slot, mini-slot, or the like.

In this document, TTI is understood to mean, for example, the smallest scheduling time element in a radio communication. For example, in LTE systems, a radio base station schedules the allocation of RF resources (eg, bandwidth and transmit power allowed for use by each user terminal) for each user terminal in units of TTI. The definition of TTI intervals is not limited to this.

The TTIs may be time units for transmitting channel-encoded data packets (transport blocks), code blocks, or codewords, or the TTI may be a processing time unit in scheduling, link adaptation, and so on. It should be appreciated that even with given TTIs, the time interval (eg, number of symbols) for which transport blocks, code blocks and/or codewords are actually mapped may be shorter than these TTIs.

Note that when a TTI is referred to as one slot or one mini-slot, the minimum time element in scheduling may be one or more such TTIs (ie, one or more slots or one or more mini-slots). Moreover, the number of slots (the number of mini-slots) constituting this minimum scheduling time element can be controllable.

A TTI with a time duration of 1 ms may be referred to as a normal TTI (TTI in LTE Releases 8-12), a long TTI, a normal subframe, a long subframe, and so on. A TTI that is shorter than a regular TTI may be referred to as a short TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini-slot, a sub-slot, and the like.

Note that a long TTI (eg, normal TTI, subframe, etc.) may be interpreted as a TTI with a time duration greater than 1 ms, and a short TTI (eg, abbreviated TTI) may be interpreted as a TTI with a TTI duration shorter than the TTI. long TTI and not less than 1 ms.

A resource block (RB), which is a resource allocation element in the time domain and in the frequency domain, may comprise one subcarrier or a plurality of subcarriers contiguous in the frequency domain. In the time domain, a resource block may contain one symbol or multiple symbols, and may be one slot, one mini-slot, one subframe, or one TTI in length. One TTI and one subframe may be formed by one resource block or multiple resource blocks. It should be appreciated that one or a plurality of resource blocks may be referred to as a physical resource block (PRB), a subcarrier group, a resource element group (REG), a PRB pair, a RB pair, and the like.

Further, a resource block may be formed by a single resource element (RE) or a plurality of REs. For example, one RE may correspond to a radio resource area of one subcarrier and one symbol.

It should be appreciated that the above-described configurations of radio frames, subframes, slots, mini-slots, symbols, etc. are only examples. For example, various changes are possible with respect to the number of subframes contained in a radio frame, the number of slots per subframe or radio frame, the number of mini-slots contained in a slot, the number of symbols and RBs contained in a slot or mini-slot, the number of subcarriers contained in a RB, number of symbols in TTI, symbol duration, cyclic prefix (CPU) length, etc.

The information and parameters described in this disclosure may be represented by absolute values or relative values with respect to specific values, or may be represented by other relevant information. For example, radio resources may be indicated by specific indexes.

Names used for parameters, etc. in the present disclosure are not limiting in any respect. For example, since the various channels (Physical Uplink Control Channel (PUCCH), Physical Downlink Control Channel (PDCCH), etc.) and information elements may be referred to by any suitable names, the various names assigned to these individual channels and information elements are in no way relation are not limiting.

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

Information, signals, etc. may be transmitted from higher layers to lower layers and/or from lower layers to higher layers. Information, signals, etc. may be transmitted and/or received through a plurality of network nodes.

The information, signals, etc. that are received and/or transmitted may be stored in a specific location (eg, memory) or may be stored using a control table. Information, signals, etc. to be received and/or transmitted may be overwritten, updated or supplemented. Transmitted information, signals, etc. can be removed. Received information, signals, etc. can be transferred to another device.

The communication of information is in no way limited to the aspects/embodiments described in this disclosure, and other methods may be used. For example, reporting information can be performed by using physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI)), upper layer signaling (e.g., radio resource control (RRC) layer signaling), broadcast information (basic information block ( MIBs), System Information Blocks (SIBs), etc.), Media Access Layer (MAC) signaling, other signals, and/or combinations thereof.

The physical layer signaling may be referred to as L1/L2 control information (L1/L2 control signals) (Layer 1/Layer 2, layer 1/layer 2), L1 control information (L1 control signal), etc. The RRC layer signaling may also be referred to as an RRC message, which may be, for example, an RRC Connection Setup (RRCConnectionSetup) message, an RRC Connection Reconfiguration (RRCConnectionReconfiguration) message, and so on. MAC layer signaling can be transmitted using, for example, MAC control elements (MAC CE).

The message of specific information (eg, the message that X does not change) need not be communicated explicitly, but may be communicated implicitly (by, for example, not reporting that particular information, or by reporting another piece of information).

Tests can be performed on values represented by a single bit (0 or 1), on boolean values representing true or false, or by comparing numeric values (eg, against a specific value).

Software, whether called program, internal program, middleware, microcode, hardware description language, or otherwise, should be understood in a broad sense to include instructions, instruction sets, code, code segments, program codes, programs, subroutines, program modules, applications, application programs, software packages, objects, executable files, threads of execution, procedures, functions, etc.

Programs, commands, information, etc. can be transmitted and received over the communication medium. For example, if a program is transmitted from a website, server, or other remote source using at least one of the wired technologies (coaxial cables, fiber optic cables, twisted pair cables, digital subscriber lines (Eng. Digital Subscriber Line, DSL), etc.) and wireless technical means (infrared radiation, microwaves, etc.), these wired and wireless technical means are also included in the concept of a communication medium.

The terms "system" and "network" as used in this disclosure may be used interchangeably.

In this disclosure, terms such as "base station (BS)", "radio base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point" , “transmission point”, “reception point”, “transmission / reception point”, “cell”, “sector”, “cell group”, “carrier”, “elementary carrier”, “bandwidth part” (English Bandwidth Part , BWP) can be used interchangeably. The base station may be referred to by terms such as "macro cell", "small cell", "femto cell", "pico cell", etc., for example.

The base station may be configured to serve one or more (eg, three) cells (also referred to as sectors). When a base station serves many cells, the entire coverage area of that base station can be divided into many smaller areas, in each of which communication services can be provided through subsystems of the base station, for example, small base stations for premises (remote radio units, English Remote Radio Head ). The term "cell" or "sector" refers to part or all of the coverage area of a base station and/or a subsystem of a base station providing communication services in that coverage area.

In the present disclosure, the terms "mobile station (MS)", "user terminal", "user equipment (UE)" and "terminal" can be used in the same sense.

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

At least one of a base station and a mobile station may be referred to as a transmitter, a receiver, and so on. It should be appreciated that at least one of the base station and the mobile station may be a device mounted on a mobile unit, the mobile unit itself, and so on. The specified moving object can be a vehicle (for example, a car, an airplane, etc.), a moving object, the movement of which is carried out without a pilot on board (for example, a drone, a car without a driver, etc.) or a robot (controlled by human type or unmanned type). It should be appreciated that at least one of the base station and the mobile station also includes a device that does not necessarily move during a communication operation.

The base station in the present disclosure can be interpreted as a user terminal. For example, each aspect/embodiment of the present invention, instead of a configuration in which communication is carried out between a radio base station and a user terminal, may be applied to a configuration in which communication is carried out between a plurality of user terminals (for example, this type of communication may be called device-to-device communication). Device-to-Device, D2D), communication between a vehicle and a wide range of objects (Vehicle-to-Everything), etc.). In this case, the user terminals 20 may comprise functional modules of the radio base stations 10 described above. The words "upstream" and "downstream" may be interpreted as corresponding terminal-to-terminal communications (eg, "relating to the communication side"). For example, the uplink can be interpreted as a link side channel.

Similarly, in the present disclosure, a user terminal can be interpreted as a radio base station. In this case, the radio base stations 10 may contain functional modules of the user terminals 20 described above.

The actions described herein as being performed by a base station may, in some cases, be performed by older nodes. Obviously, in a network containing one or more network nodes with base stations, various operations performed to communicate with terminals can be performed by base stations, one or more network nodes other than base stations (for example, mobility management nodes (eng. Mobility Management Entity, MME), serving gateways (English Serving-Gateway, S-GW), etc., but the list is not limiting) or combinations of the listed nodes.

Aspects/embodiments illustrated in this disclosure may be used singly or in combination, which may vary depending on the preferred embodiment. The order of operations, sequences, flow charts, etc. used in the present disclosure to describe aspects/embodiments may be changed if this does not lead to contradictions. For example, while the various methods are illustrated in the present disclosure with various components of the steps in the order given by way of example, the specific order presented here is in no way limiting.

Aspects/embodiments illustrated in this disclosure may apply to LTE, LTE-A, LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, fourth and fifth generation (4G, 5G) mobile communications systems, FRA , New RAT, New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications, GSM (registered trademark)), CDMA2000, for Ultra Mobile Broadband (UMB), for IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (Wi-MAX) systems (registered trademark)), IEEE 802.20, for a short range communication system using Ultra-Wide Band (UWB) signals, for a Bluetooth system (registered trademark), for systems using other P suitable methods of radio communication, for next generation systems, improved on the basis of these systems, etc. Multiple systems can be combined and used (eg combination of LTE or LTE-A and 5G, etc.).

In this disclosure, the phrase "based on" (or "based on") does not mean "only based on" (or "only based on"), unless otherwise indicated. In other words, the phrase "on the basis of" (or "on the basis of") means both "on the basis of" and "on the basis of at least" ("only on the basis of" and "at least on the basis of").

Referencing elements using designations such as "first", "second", etc. the present disclosure does not generally limit the number or order of these elements. These designations may be used in the present disclosure for convenience only, as a way to distinguish between two or more elements. Thus, the mention of the first and second elements does not imply that only two elements can be used, or that the first element must in any way precede the second element.

The term "decision" ("determination") in the present disclosure can cover a wide variety of actions. For example, the term “decision” (“definition”) can be interpreted as meaning making decisions (carrying out checks) related to judgment, calculation, calculation, processing, derivation, research, search (for example, search in a table, database or other other structure data), establishing a fact, etc.

Further, the term “decision” (“determining”) can be interpreted as meaning making decisions (carrying out checks) related to receiving (for example, receiving information), transmitting (for example, transmitting information), input, output, access (for example, access to data in memory), etc.

In addition, the term "decision" ("determining") in this document can be interpreted as meaning making decisions (carrying out checks) related to disambiguation, selection, selection, establishment, comparison, etc. In other words, "decision" ("determination") can be interpreted as making decisions (carrying out checks) about the performance of some action.

In addition, “decision” (“determination”) can be interpreted as “guess”, “expectation”, “consideration”, etc.

In this disclosure, the terms "connected", "connected" and any of their options means all direct or indirect connections or connections between two or more elements, and may allow the presence of one or more intermediate elements between two elements that are "connected" or "connected" between themselves. The relationship or connection between these elements may be physical, logical, or a combination of both. For example, "connection" can be interpreted as "access".

When the present disclosure indicates that two elements are connected, the two elements may be considered connected or interconnected using one or more electrical conductors, cables, printed electrical connections, and the like, and, as a few non-limiting and non-exclusive examples, using electromagnetic energy having wavelengths in radio frequency, microwave and optical (both visible and invisible) ranges, or the like.

In the present disclosure, the expression "A and B are different" can mean "A and B are different from each other. The terms "separate", "connected" and the like can be interpreted similarly.

When used in the present disclosure or in the claims, for example, terms such as "comprise", "comprising" and variations thereof, these terms are to be understood in a similar sense to that in which the term "comprising" is used. The union "or" in the present disclosure and in the claims is not to be understood as meaning an exclusive disjunction.

In the present disclosure, when the singular is used, the noun given in the singular may be interpreted as containing the plural meaning as well.

(Additional note)

Additional remarks have been added to the disclosure of the present invention.

<Prior Art>

- PTRS density in time domain

Determined based on the MCS index and the specific table.

- MCS index

Reported to DCI.

- UCI on PUSCH without data

It is not specified how the MCS index in the DCI is determined, and therefore there is no way to determine the time domain PTRS density in the UCI on a PUSCH without data.

The UL-SCH indicator indicates the presence or absence of uplink data using one bit, and the MCS is determined by the bit of the _MCS field I in the DCI.

<Problem>

In a UCI on a no data PUSCH (eg, an A-CSI on a no data PUSCH), when an MCS index in the range of 0 to 27 is reported, the time domain PTRS density is determined according to a particular table.

In the case of a PUSCH transmission (including at least the case of a UCI transmission on a PUSCH without data), an MCS index in the range of 0 to 27 or in the range of 28 to 31 may be reported in the retransmission.

The method of determining PTRS (eg, density in the time domain) in the retransmission is not defined.

<Suggested Option 1>

In other words, when in the retransmission the value of the new data indicator field in the reported DCI differs from the value of the same field in the previous DCI (for example, the value of the new data indicator field in the reported DCI changed from 0 to 1 or from 1 to 0), and also an MCS index ranging from 0 to 27, wherein the UE determines the time domain PTRS density according to the reported MCS index and a specific table.

If the MCS index is reported in the range from 28 to 31, then any of the proposed options 1-1, 1-2, 1-3 is used.

- Proposed option 1-1

The time domain PTRS density used in the original transmission is used.

- Proposed option 1-2

The time domain density is determined according to a specific conversion method based on the PTRS time domain density used in the original transmission.

<<Suggested Option 1-2-1>>

The specified table uses a row that is higher than the row used in the original transmission. This reduces the encoding density and speed, which improves performance.

<<Suggested Option 1-2-2>>

This particular table uses a row below the row used in the original transmission. This increases the density and contributes to more effective phase noise correction, which improves performance.

- Proposed option 1-3

The PTRS time domain density is determined according to the MCS index reported in the retransmission, a specific table, and a specific transform formula (see FIGS. 5-7).

For example, the PTRS density in the time domain in the retransmission is determined according to the modulation order reported by the MCS index in the range of 28 to 31 and the MCS index threshold reported by the upper layer. For example, as shown in FIG. 6 or 7, the PTRS time domain density in the retransmission is determined according to the modulation order corresponding to the MCS index in the range of 28 to 31 and the MCS index threshold reported in the upper layer.

<Suggested Option 2>

When an MCS index in the range of 28 to 31 is reported in the initial transmission, the time domain PTRS density may be determined using the above suggestion 1-3. For example, the PTRS time domain density is determined from a reported MCS index, a specific table, and a specific transform formula.

<Suggested Option 3>

For the uplink PTRS configuration (eg, PTRS-UplinkConfig) reported from the base station to the UE, a value of 0 to 27 can be used. Thus, an unnecessary RRC bit can be removed compared to the case of configuring PTRS-UplinkConfig in the range of 0-29. The uplink PTRS configuration may be transmitted using an upper layer (eg, RRC signaling or the like).

In view of the foregoing, the following structures are proposed.

[Structure 1] A user terminal, comprising: a transmission section configured to transmit a phase tracking reference signal (PTRS) for an uplink control channel without data (UL-SCH or a transport channel) that is used to transmit uplink control information; and a control section configured to control a time domain PTRS density determination method based on whether the modulation and coding scheme (MCS) index reported in the downstream control information is contained in the first band or the second band.

[Structure 2] A radio communication method, comprising: transmitting a phase tracking reference signal (PTRS) for an uplink control channel without data (UL-SCH or a transport channel) that is used to transmit uplink control information; and a step of controlling the time domain PTRS density determination method based on whether the modulation and coding scheme (MCS) index reported in the downstream control information is contained in the first band or the second band.

Now, while the present invention has been described in detail above, it should be apparent to those skilled in the art that the invention according to the present disclosure is in no way limited to the embodiments described in this disclosure. The invention in accordance with the present disclosure can be carried out with various changes and in various modifications without deviating from the essence and scope of the present invention, defined by the claims. Accordingly, the description of the present disclosure is provided for illustrative purposes only and should in no way be construed as limiting the present invention in any way.

This patent application is based on Japanese Patent Application No. 2018-110697 filed May 23, 2018, the entire contents of which are incorporated herein.

Claims (33)

1. Terminal (20), containing: a receiving section (203) configured to receive downlink control information comprising at least an uplink common channel (UL-SCH) indicator field; a control section (401) configured, if the uplink common channel is retransmitted, to determine a phase tracking reference signal (PTRS) time density based on whether the modulation and coding scheme (MCS) index is greater than a specific value; and a transmission section (203) configured to transmit said phase tracking reference signal based on the thus determined time density of the phase tracking reference signal, wherein, when the value of the UL-SCH indicator field indicates an uplink common channel with no uplink data, if the MCS index is greater than the specified specific value, determination of the time density of the phase tracking reference signal is provided based on the reported in the initial transmission of the MCS index less than or equal to the specified specific value, and if the MCS index is less than or equal to the specified specific value, determination of the time density of the phase tracking reference signal is provided based on the MCS index and the correspondence between the MCS indices and the time densities of the phase tracking reference signal. 2. The terminal (20) according to claim 1, wherein the determination of the PTRS temporal density is provided according to the MCS index threshold specified in the upper layer, the correspondence between the MCS indices and the PTRS temporal densities, and the specific conversion formula. 3. A method of radio communication, in which: receiving downlink control information comprising at least an uplink common channel (UL-SCH) indicator field; if the uplink common channel is retransmitted, determining a phase tracking reference signal (PTRS) time density based on whether the modulation and coding scheme (MCS) index is greater than a specific value; and transmitting said phase tracking reference signal based on the thus determined time density of the phase tracking reference signal, wherein, when the value of the UL-SCH indicator field indicates an uplink common channel with no uplink data, if the MCS index is greater than the specified specific value, the time density of the phase tracking reference signal is determined based on the MCS index reported in the initial transmission being less than or equal to the specified specific value, and if the MCS index is less than or equal to said specific value, the time density of the phase tracking reference is determined based on the MCS index and the correspondence between the MCS indices and the time densities of the phase tracking reference. 4. Base station (10), containing: a transmission section (103) configured to transmit downlink control information comprising at least an uplink common channel (UL-SCH) indicator field; a control section (301) configured to control the retransmission of the uplink common channel; and a receiving section (103) configured, if the uplink common channel is retransmitted, to receive a phase tracking reference signal (PTRS) whose time density is determined based on whether the modulation and coding scheme (MCS) index is greater than a specific value, wherein, when the value of the UL-SCH indicator field indicates an uplink common channel with no uplink data, if the MCS index is greater than the specified specific value, determination of the time density of the phase tracking reference signal is provided based on the reported in the initial transmission of the MCS index less than or equal to the specified specific value, and if the MCS index is less than or equal to the specified specific value, determination of the time density of the phase tracking reference signal is provided based on the MCS index and the correspondence between the MCS indices and the time densities of the phase tracking reference signal. 5. Radio communication system (1), comprising a terminal (20) and a base station (10), in which the terminal contains: a receiving section (203) configured to receive downlink control information comprising at least an uplink common channel (UL-SCH) indicator field; a control section (401) configured, if the uplink common channel is retransmitted, to determine a phase tracking reference signal (PTRS) time density based on whether the modulation and coding scheme (MCS) index is greater than a specific value; and a transmission section (203) configured to transmit said phase tracking reference signal based on the thus determined time density of the phase tracking reference signal, wherein, when the value of the UL-SCH indicator field indicates an uplink common channel with no uplink data, if the MCS index is greater than the specified specific value, determination of the time density of the phase tracking reference signal is provided based on the reported in the initial transmission of the MCS index less than or equal to the specified specific value, and if the MCS index is less than or equal to the specified specific value, determining the temporal density of the phase tracking reference signal is provided based on the MCS index and the correspondence between the MCS indices and the temporal densities of the phase tracking reference signal; and the base station (10) contains: a transmission section (103) configured to transmit downlink control information comprising at least an uplink common channel (UL-SCH) indicator field; a control section configured to control the retransmission of the uplink common channel; and a receiving section configured, if the uplink common channel is retransmitted, to receive a phase tracking reference signal (PTRS) whose temporal density is determined based on whether the modulation and coding scheme (MCS) index is greater than a specific value.

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