WO2025033637A1

WO2025033637A1 - Method and device for supporting synchronization sequence/channel with improved papr performance

Info

Publication number: WO2025033637A1
Application number: PCT/KR2024/003917
Authority: WO
Inventors: Seungmin Lee; Jinyup HWANG; Pudeev ANDREY; Serunin IGOR; Joongkwan Huh; Hanbyul Seo
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2023-08-09
Filing date: 2024-03-28
Publication date: 2025-02-13
Anticipated expiration: 2026-02-09

Abstract

According to an embodiment of the present disclosure, a method for performing, by a first device, wireless communication may be proposed. For example, the method may comprise: generating N inter-device primary synchronization signals based on phase rotation and ID combining; mapping N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum; and transmitting, to a second device, the N inter-device synchronization signal blocks.

Description

METHOD AND DEVICE FOR SUPPORTING SYNCHRONIZATION SEQUENCE/CHANNEL WITH IMPROVED PAPR PERFORMANCE

This disclosure relates to a wireless communication system.

Sidelink (SL) communication is a communication scheme in which a direct link is established between User Equipments (UEs) and the UEs exchange voice and data directly with each other without intervention of a base station. SL communication is under consideration as a solution to the overhead of the base station caused by rapidly increasing data traffic. Vehicle-to-everything (V2X) refers to a communication technology through which a vehicle exchanges information with another vehicle, a pedestrian, an object having an infrastructure (or infra) established therein, and so on. The V2X may be divided into 4 types, such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2X communication may be provided via a PC5 interface and/or Uu interface.

Meanwhile, as a wider range of communication devices require larger communication capacities, the need for mobile broadband communication that is more enhanced than the existing Radio Access Technology (RAT) is rising. Accordingly, discussions are made on services and user equipment (UE) that are sensitive to reliability and latency. And, a next generation radio access technology that is based on the enhanced mobile broadband communication, massive Machine Type Communication (MTC), Ultra-Reliable and Low Latency Communication (URLLC), and so on, may be referred to as a new radio access technology (RAT) or new radio (NR). Herein, the NR may also support vehicle-to-everything (V2X) communication.

According to an embodiment of the present disclosure, a method for performing, by a first device, wireless communication may be proposed. For example, the method may comprise: generating N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining; mapping N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum, wherein time resources of the N transmission resources may be the same, and wherein the N transmission resources may be resources that are repeated N times in a frequency domain; performing channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and transmitting, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.

According to an embodiment of the present disclosure, a first device for performing wireless communication may be proposed. For example, the first device may comprise: at least one transceiver; at least one processor; and at least one memory operably connectable to the at least one processor and storing instructions. For example, the instructions may, based on being executed by the at least one processor, cause the first device to perform operations, wherein the operations may comprise: generating N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining; mapping N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum, wherein time resources of the N transmission resources may be the same, and wherein the N transmission resources may be resources that are repeated N times in a frequency domain; performing channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and transmitting, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.

According to an embodiment of the present disclosure, a device adapted to control a first user equipment (UE) may be proposed. For example, the device may comprise: at least one processor; and at least one memory operably connectable to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first UE to perform operations, wherein the operations may comprise: generating N inter-UE primary synchronization signals based on phase rotation and identifier (ID) combining; mapping N inter-UE synchronization signal blocks, each including one of the N inter-UE primary synchronization signals to N transmission resources in a shared spectrum, wherein time resources of the N transmission resources may be the same, and wherein the N transmission resources may be resources that are repeated N times in a frequency domain; performing channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and transmitting, to a second UE, the N inter-UE synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.

According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be proposed. For example, based on being executed, the instructions may cause a first device to: generate N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining; map N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum, wherein time resources of the N transmission resources may be the same, and wherein the N transmission resources may be resources that are repeated N times in a frequency domain; perform channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and transmit, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.

According to an embodiment of the present disclosure, a method for performing, by a second device, wireless communication may be proposed. For example, the method may comprise: receiving, from a first device, N inter-device synchronization signal blocks, each including one of N inter-device primary synchronization signals, based on N transmission resources in a shared spectrum, wherein the N inter-device synchronization signal blocks may be transmitted based on a result of channel sensing related to a channel access procedure, performed for a resource block (RB) set including the N transmission resources being IDLE and the N transmission resources, wherein time resources of the N transmission resources may be the same, wherein the N transmission resources may be resources that are repeated N times in a frequency domain, wherein the N inter-device synchronization signal blocks may be mapped one by one to the N transmission resources, and wherein the N inter-device primary synchronization signals may be generated based on phase rotation and identifier (ID) combining.

According to an embodiment of the present disclosure, a second device for performing wireless communication may be proposed. For example, the second device may comprise: at least one transceiver; at least one processor; and at least one memory operably connectable to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the second device to perform operations, wherein the operations may comprise: receiving, from a first device, N inter-device synchronization signal blocks, each including one of N inter-device primary synchronization signals, based on N transmission resources in a shared spectrum, wherein the N inter-device synchronization signal blocks may be transmitted based on a result of channel sensing related to a channel access procedure, performed for a resource block (RB) set including the N transmission resources being IDLE and the N transmission resources, wherein time resources of the N transmission resources may be the same, wherein the N transmission resources may be resources that are repeated N times in a frequency domain, wherein the N inter-device synchronization signal blocks may be mapped one by one to the N transmission resources, and wherein the N inter-device primary synchronization signals may be generated based on phase rotation and identifier (ID) combining.

FIG. 1 shows a structure of an NR system, based on an embodiment of the present disclosure.

FIG. 2 shows a radio protocol architecture, based on an embodiment of the present disclosure.

FIG. 3 shows a structure of a radio frame of an NR, based on an embodiment of the present disclosure.

FIG. 4 shows a structure of a slot of an NR frame, based on an embodiment of the present disclosure.

FIG. 5 shows an example of a BWP, based on an embodiment of the present disclosure.

FIG. 6 shows a procedure of performing V2X or SL communication by a UE based on a transmission mode, based on an embodiment of the present disclosure.

FIG. 7 shows three cast types, based on an embodiment of the present disclosure.

FIG. 8 shows a synchronization source or synchronization reference of V2X based on an embodiment of the present disclosure.

FIG. 9 shows an example of a wireless communication system supporting unlicensed bands, according to one embodiment of the present disclosure.

FIG. 10 shows a method for occupying a resource in an unlicensed band, according to one embodiment of the present disclosure.

FIG. 11 shows a plurality of LBT-SBs within an unlicensed band, according to one embodiment of the present disclosure.

FIG. 12 shows a CAP operation for a downlink signal transmission through an unlicensed band of a base station, according to one embodiment of the present disclosure.

FIG. 13 shows a Type 1 CAP operation of a UE for transmitting an uplink signal, according to one embodiment of the present disclosure.

FIGs. 14A to 14 C show a configuration of a new S-SSB design (config #1) with a different number of repetitions, based on an embodiment of the present disclosure.

FIG. 15 shows inter-UE synchronization signal block resources that are repeated in the frequency domain, according to one embodiment of the present disclosure.

FIG. 16 shows a method for generating related signals when inter-UE synchronization signal blocks are repeated, according to one embodiment of the present disclosure.

FIG. 17 shows a procedure for a first device to perform wireless communication, according to one embodiment of the present disclosure.

FIG. 18 shows a procedure for a second device to perform wireless communication, according to one embodiment of the present disclosure.

FIG. 19 shows a communication system 1, based on an embodiment of the present disclosure.

FIG. 20 shows wireless devices, based on an embodiment of the present disclosure.

FIG. 21 shows a signal process circuit for a transmission signal, based on an embodiment of the present disclosure.

FIG. 22 shows another example of a wireless device, based on an embodiment of the present disclosure.

FIG. 23 shows a hand-held device, based on an embodiment of the present disclosure.

FIG. 24 shows a vehicle or an autonomous vehicle, based on an embodiment of the present disclosure.

In the present disclosure, "A or B" may mean "only A", "only B" or "both A and B." In other words, in the present disclosure, "A or B" may be interpreted as "A and/or B". For example, in the present disclosure, "A, B, or C" may mean "only A", "only B", "only C", or "any combination of A, B, C"

A slash (/) or comma used in the present disclosure may mean "and/or". For example, "A/B" may mean "A and/or B". Accordingly, "A/B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C"

In the present disclosure, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, in the present disclosure, the expression "at least one of A or B" or "at least one of A and/or B" may be interpreted as "at least one of A and B"

In addition, in the present disclosure, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B, and/or C" may mean "at least one of A, B, and C"

In addition, a parenthesis used in the present disclosure may mean "for example". Specifically, when indicated as "control information (PDCCH)", it may mean that "PDCCH" is proposed as an example of the "control information". In other words, the "control information" of the present disclosure is not limited to "PDCCH", and "PDCCH" may be proposed as an example of the "control information". In addition, when indicated as "control information (i.e., PDCCH)", it may also mean that "PDCCH" is proposed as an example of the "control information"

In the following description, 'when, if, or in case of' may be replaced with 'based on'.

A technical feature described individually in one figure in the present disclosure may be individually implemented, or may be simultaneously implemented.

In the present disclosure, a higher layer parameter may be a parameter which is configured, pre-configured or pre-defined for a UE. For example, a base station or a network may transmit the higher layer parameter to the UE. For example, the higher layer parameter may be transmitted through radio resource control (RRC) signaling or medium access control (MAC) signaling.

The technology described below may be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and so on. The CDMA may be implemented with a radio technology, such as universal terrestrial radio access (UTRA) or CDMA-2000. The TDMA may be implemented with a radio technology, such as global system for mobile communications (GSM)/general packet ratio service (GPRS)/enhanced data rate for GSM evolution (EDGE). The OFDMA may be implemented with a radio technology, such as institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA (E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16e and provides backward compatibility with a system based on the IEEE 802.16e. The UTRA is part of a universal mobile telecommunication system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTE uses the OFDMA in a downlink and uses the SC-FDMA in an uplink. LTE-advanced (LTE-A) is an evolution of the LTE.

5G NR is a successive technology of LTE-A corresponding to a new Clean-slate type mobile communication system having the characteristics of high performance, low latency, high availability, and so on. 5G NR may use resources of all spectrum available for usage including low frequency bands of less than 1GHz, middle frequency bands ranging from 1GHz to 10GHz, high frequency (millimeter waves) of 24GHz or more, and so on.

For clarity in the description, the following description will mostly focus on LTE-A or 5G NR. However, technical features according to an embodiment of the present disclosure will not be limited only to this.

FIG. 1 shows a structure of an NR system, based on an embodiment of the present disclosure. The embodiment of FIG. 1 may be combined with various embodiments of the present disclosure.

Referring to FIG. 1, a next generation-radio access network (NG-RAN) may include a BS 20 providing a UE 10 with a user plane and control plane protocol termination. For example, the BS 20 may include a next generation-Node B (gNB) and/or an evolved-NodeB (eNB). For example, the UE 10 may be fixed or mobile and may be referred to as other terms, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), wireless device, and so on. For example, the BS may be referred to as a fixed station which communicates with the UE 10 and may be referred to as other terms, such as a base transceiver system (BTS), an access point (AP), and so on.

The embodiment of FIG. 1 exemplifies a case where only the gNB is included. The BSs 20 may be connected to one another via Xn interface. The BS 20 may be connected to one another via 5th generation (5G) core network (5GC) and NG interface. More specifically, the BSs 20 may be connected to an access and mobility management function (AMF) 30 via NG-C interface, and may be connected to a user plane function (UPF) 30 via NG-U interface.

Layers of a radio interface protocol between the UE and the network can be classified into a first layer (layer 1, L1), a second layer (layer 2, L2), and a third layer (layer 3, L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system. Among them, a physical (PHY) layer belonging to the first layer provides an information transfer service by using a physical channel, and a radio resource control (RRC) layer belonging to the third layer serves to control a radio resource between the UE and the network. For this, the RRC layer exchanges an RRC message between the UE and the BS.

FIG. 2 shows a radio protocol architecture, based on an embodiment of the present disclosure. The embodiment of FIG. 2 may be combined with various embodiments of the present disclosure. Specifically, (a) of FIG. 2 shows a radio protocol stack of a user plane for Uu communication, and (b) of FIG. 2 shows a radio protocol stack of a control plane for Uu communication. (c) of FIG. 2 shows a radio protocol stack of a user plane for SL communication, and (d) of FIG. 2 shows a radio protocol stack of a control plane for SL communication.

Referring to FIG. 2, a physical layer provides an upper layer with an information transfer service through a physical channel. The physical layer is connected to a medium access control (MAC) layer which is an upper layer of the physical layer through a transport channel. Data is transferred between the MAC layer and the physical layer through the transport channel. The transport channel is classified according to how and with what characteristics data is transmitted through a radio interface.

Between different physical layers, i.e., a physical layer of a transmitter and a physical layer of a receiver, data are transferred through the physical channel. The physical channel is modulated using an orthogonal frequency division multiplexing (OFDM) scheme, and utilizes time and frequency as a radio resource.

The MAC layer provides services to a radio link control (RLC) layer, which is a higher layer of the MAC layer, via a logical channel. The MAC layer provides a function of mapping multiple logical channels to multiple transport channels. The MAC layer also provides a function of logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC layer provides data transfer services over logical channels.

The RLC layer performs concatenation, segmentation, and reassembly of Radio Link Control Service Data Unit (RLC SDU). In order to ensure diverse quality of service (QoS) required by a radio bearer (RB), the RLC layer provides three types of operation modes, i.e., a transparent mode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM). An AM RLC provides error correction through an automatic repeat request (ARQ).

A radio resource control (RRC) layer is defined only in the control plane. The RRC layer serves to control the logical channel, the transport channel, and the physical channel in association with configuration, reconfiguration and release of RBs. The RB is a logical path provided by the first layer (i.e., the physical layer or the PHY layer) and the second layer (i.e., a MAC layer, an RLC layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer) for data delivery between the UE and the network.

Functions of a packet data convergence protocol (PDCP) layer in the user plane include user data delivery, header compression, and ciphering. Functions of a PDCP layer in the control plane include control-plane data delivery and ciphering/integrity protection.

A service data adaptation protocol (SDAP) layer is defined only in a user plane. The SDAP layer performs mapping between a Quality of Service (QoS) flow and a data radio bearer (DRB) and QoS flow ID (QFI) marking in both DL and UL packets.

The configuration of the RB implies a process for specifying a radio protocol layer and channel properties to provide a particular service and for determining respective detailed parameters and operations. The RB can be classified into two types, i.e., a signaling RB (SRB) and a data RB (DRB). The SRB is used as a path for transmitting an RRC message in the control plane. The DRB is used as a path for transmitting user data in the user plane.

When an RRC connection is established between an RRC layer of the UE and an RRC layer of the E-UTRAN, the UE is in an RRC_CONNECTED state, and, otherwise, the UE may be in an RRC_IDLE state. In case of the NR, an RRC_INACTIVE state is additionally defined, and a UE being in the RRC_INACTIVE state may maintain its connection with a core network whereas its connection with the BS is released.

Data is transmitted from the network to the UE through a downlink transport channel. Examples of the downlink transport channel include a broadcast channel (BCH) for transmitting system information and a downlink-shared channel (SCH) for transmitting user traffic or control messages. Traffic of downlink multicast or broadcast services or the control messages can be transmitted on the downlink-SCH or an additional downlink multicast channel (MCH). Data is transmitted from the UE to the network through an uplink transport channel. Examples of the uplink transport channel include a random access channel (RACH) for transmitting an initial control message and an uplink SCH for transmitting user traffic or control messages.

Examples of logical channels belonging to a higher channel of the transport channel and mapped onto the transport channels include a broadcast channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic channel (MTCH), etc.

FIG. 3 shows a structure of a radio frame of an NR, based on an embodiment of the present disclosure. The embodiment of FIG. 3 may be combined with various embodiments of the present disclosure.

Referring to FIG. 3, in the NR, a radio frame may be used for performing uplink and downlink transmission. A radio frame has a length of 10ms and may be defined to be configured of two half-frames (HFs). A half-frame may include five 1ms subframes (SFs). A subframe (SF) may be divided into one or more slots, and the number of slots within a subframe may be determined based on subcarrier spacing (SCS). Each slot may include 12 or 14 OFDM(A) symbols according to a cyclic prefix (CP).

In case of using a normal CP, each slot may include 14 symbols. In case of using an extended CP, each slot may include 12 symbols. Herein, a symbol may include an OFDM symbol (or CP-OFDM symbol) and a Single Carrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbol).

Table 1 shown below represents an example of a number of symbols per slot (N^slot _symb), a number slots per frame (N^frame,u _slot), and a number of slots per subframe (N^subframe,u _slot) based on an SCS configuration (u), in a case where a normal CP is used.

SCS (15*2^u)	N^slot _symb	N^frame,u _slot	N^subframe,u _slot
15KHz (u=0)	14	10	1
30KHz (u=1)	14	20	2
60KHz (u=2)	14	40	4
120KHz (u=3)	14	80	8
240KHz (u=4)	14	160	16

Table 2 shows an example of a number of symbols per slot, a number of slots per frame, and a number of slots per subframe based on the SCS, in a case where an extended CP is used.

SCS (15*2^u)	N^slot _symb	N^frame,u _slot	N^subframe,u _slot
60KHz (u=2)	12	40	4

In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, and so on) between multiple cells being integrate to one UE may be differently configured. Accordingly, a (absolute time) duration (or section) of a time resource (e.g., subframe, slot or TTI) (collectively referred to as a time unit (TU) for simplicity) being configured of the same number of symbols may be differently configured in the integrated cells.

In the NR, multiple numerologies or SCSs for supporting diverse 5G services may be supported. For example, in case an SCS is 15kHz, a wide area of the conventional cellular bands may be supported, and, in case an SCS is 30kHz/60kHz a dense-urban, lower latency, wider carrier bandwidth may be supported. In case the SCS is 60kHz or higher, a bandwidth that is greater than 24.25GHz may be used in order to overcome phase noise.

An NR frequency band may be defined as two different types of frequency ranges. The two different types of frequency ranges may be FR1 and FR2. The values of the frequency ranges may be changed (or varied), and, for example, the two different types of frequency ranges may be as shown below in Table 3. Among the frequency ranges that are used in an NR system, FR1 may mean a "sub 6GHz range", and FR2 may mean an "above 6GHz range" and may also be referred to as a millimeter wave (mmW).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing (SCS)
FR1	450MHz - 6000MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

As described above, the values of the frequency ranges in the NR system may be changed (or varied). For example, as shown below in Table 4, FR1 may include a band within a range of 410MHz to 7125MHz. More specifically, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, and so on) and higher. For example, a frequency band of 6GHz (or 5850, 5900, 5925 MHz, and so on) and higher being included in FR1 mat include an unlicensed band. The unlicensed band may be used for diverse purposes, e.g., the unlicensed band for vehicle-specific communication (e.g., automated driving).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing (SCS)
FR1	410MHz - 7125MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

FIG. 4 shows a structure of a slot of an NR frame, based on an embodiment of the present disclosure. The embodiment of FIG. 4 may be combined with various embodiments of the present disclosure.

Referring to FIG. 4, a slot includes a plurality of symbols in a time domain. For example, in case of a normal CP, one slot may include 14 symbols. However, in case of an extended CP, one slot may include 12 symbols. Alternatively, in case of a normal CP, one slot may include 7 symbols. However, in case of an extended CP, one slot may include 6 symbols.

A carrier includes a plurality of subcarriers in a frequency domain. A Resource Block (RB) may be defined as a plurality of consecutive subcarriers (e.g., 12 subcarriers) in the frequency domain. A Bandwidth Part (BWP) may be defined as a plurality of consecutive (Physical) Resource Blocks ((P)RBs) in the frequency domain, and the BWP may correspond to one numerology (e.g., SCS, CP length, and so on). A carrier may include a maximum of N number BWPs (e.g., 5 BWPs). Data communication may be performed via an activated BWP. Each element may be referred to as a Resource Element (RE) within a resource grid and one complex symbol may be mapped to each element.

Hereinafter, a bandwidth part (BWP) and a carrier will be described.

The BWP may be a set of consecutive physical resource blocks (PRBs) in a given numerology. The PRB may be selected from consecutive sub-sets of common resource blocks (CRBs) for the given numerology on a given carrier

For example, the BWP may be at least any one of an active BWP, an initial BWP, and/or a default BWP. For example, the UE may not monitor downlink radio link quality in a DL BWP other than an active DL BWP on a primary cell (PCell). For example, the UE may not receive PDCCH, physical downlink shared channel (PDSCH), or channel state information - reference signal (CSI-RS) (excluding RRM) outside the active DL BWP. For example, the UE may not trigger a channel state information (CSI) report for the inactive DL BWP. For example, the UE may not transmit physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) outside an active UL BWP. For example, in a downlink case, the initial BWP may be given as a consecutive RB set for a remaining minimum system information (RMSI) control resource set (CORESET) (configured by physical broadcast channel (PBCH)). For example, in an uplink case, the initial BWP may be given by system information block (SIB) for a random access procedure. For example, the default BWP may be configured by a higher layer. For example, an initial value of the default BWP may be an initial DL BWP. For energy saving, if the UE fails to detect downlink control information (DCI) during a specific period, the UE may switch the active BWP of the UE to the default BWP.

Meanwhile, the BWP may be defined for SL. The same SL BWP may be used in transmission and reception. For example, a transmitting UE may transmit a SL channel or a SL signal on a specific BWP, and a receiving UE may receive the SL channel or the SL signal on the specific BWP. In a licensed carrier, the SL BWP may be defined separately from a Uu BWP, and the SL BWP may have configuration signaling separate from the Uu BWP. For example, the UE may receive a configuration for the SL BWP from the BS/network. For example, the UE may receive a configuration for the Uu BWP from the BS/network. The SL BWP may be (pre-)configured in a carrier with respect to an out-of-coverage NR V2X UE and an RRC_IDLE UE. For the UE in the RRC_CONNECTED mode, at least one SL BWP may be activated in the carrier.

FIG. 5 shows an example of a BWP, based on an embodiment of the present disclosure. The embodiment of FIG. 5 may be combined with various embodiments of the present disclosure. It is assumed in the embodiment of FIG. 5 that the number of BWPs is 3.

Referring to FIG. 5, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other end thereof. In addition, the PRB may be a resource block numbered within each BWP. A point A may indicate a common reference point for a resource block grid.

The BWP may be configured by a point A, an offset NstartBWP from the point A, and a bandwidth NsizeBWP. For example, the point A may be an external reference point of a PRB of a carrier in which a subcarrier 0 of all numerologies (e.g., all numerologies supported by a network on that carrier) is aligned. For example, the offset may be a PRB interval between a lowest subcarrier and the point A in a given numerology. For example, the bandwidth may be the number of PRBs in the given numerology.

Hereinafter, V2X or SL communication will be described.

A sidelink synchronization signal (SLSS) may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS), as a SL-specific sequence. The PSSS may be referred to as a sidelink primary synchronization signal (S-PSS), and the SSSS may be referred to as a sidelink secondary synchronization signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 gold sequences may be used for the S-SSS. For example, a UE may use the S-PSS for initial signal detection and for synchronization acquisition. For example, the UE may use the S-PSS and the S-SSS for acquisition of detailed synchronization and for detection of a synchronization signal ID.

A physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel for transmitting default (system) information which must be first known by the UE before SL signal transmission/reception. For example, the default information may be information related to SLSS, a duplex mode (DM), a time division duplex (TDD) uplink/downlink (UL/DL) configuration, information related to a resource pool, a type of an application related to the SLSS, a subframe offset, broadcast information, or the like. For example, for evaluation of PSBCH performance, in NR V2X, a payload size of the PSBCH may be 56 bits including 24-bit cyclic redundancy check (CRC).

The S-PSS, the S-SSS, and the PSBCH may be included in a block format (e.g., SL synchronization signal (SS)/PSBCH block, hereinafter, sidelink-synchronization signal block (S-SSB)) supporting periodical transmission. The S-SSB may have the same numerology (i.e., SCS and CP length) as a physical sidelink control channel (PSCCH)/physical sidelink shared channel (PSSCH) in a carrier, and a transmission bandwidth may exist within a (pre-)configured sidelink (SL) BWP. For example, the S-SSB may have a bandwidth of 11 resource blocks (RBs). For example, the PSBCH may exist across 11 RBs. In addition, a frequency position of the S-SSB may be (pre-)configured. Accordingly, the UE does not have to perform hypothesis detection at frequency to discover the S-SSB in the carrier.

For example, based on Table 5 and Table 6, the UE may generate an S-SS/PSBCH block (i.e., S-SSB), and the UE may transmit the S-SS/PSBCH block (i.e., S-SSB) by mapping it on a physical resource.

FIG. 6 shows a procedure of performing V2X or SL communication by a UE based on a transmission mode, based on an embodiment of the present disclosure. The embodiment of FIG. 6 may be combined with various embodiments of the present disclosure.

In various embodiments of the present disclosure, the transmission mode may be called a mode or a resource allocation mode. Hereinafter, for convenience of explanation, in LTE, the transmission mode may be called an LTE transmission mode. In NR, the transmission mode may be called an NR resource allocation mode.

For example, (a) of FIG. 6 shows a UE operation related to an LTE transmission mode 1 or an LTE transmission mode 3. Alternatively, for example, (a) of FIG. 6 shows a UE operation related to an NR resource allocation mode 1. For example, the LTE transmission mode 1 may be applied to general SL communication, and the LTE transmission mode 3 may be applied to V2X communication.

For example, (b) of FIG. 6 shows a UE operation related to an LTE transmission mode 2 or an LTE transmission mode 4. Alternatively, for example, (b) of FIG. 6 shows a UE operation related to an NR resource allocation mode 2.

Referring to (a) of FIG. 6, in the LTE transmission mode 1, the LTE transmission mode 3, or the NR resource allocation mode 1, a base station may schedule SL resource(s) to be used by a UE for SL transmission. For example, in step S600, a base station may transmit information related to SL resource(s) and/or information related to UL resource(s) to a first UE. For example, the UL resource(s) may include PUCCH resource(s) and/or PUSCH resource(s). For example, the UL resource(s) may be resource(s) for reporting SL HARQ feedback to the base station.

For example, the first UE may receive information related to dynamic grant (DG) resource(s) and/or information related to configured grant (CG) resource(s) from the base station. For example, the CG resource(s) may include CG type 1 resource(s) or CG type 2 resource(s). In the present disclosure, the DG resource(s) may be resource(s) configured/allocated by the base station to the first UE through a downlink control information (DCI). In the present disclosure, the CG resource(s) may be (periodic) resource(s) configured/allocated by the base station to the first UE through a DCI and/or an RRC message. For example, in the case of the CG type 1 resource(s), the base station may transmit an RRC message including information related to CG resource(s) to the first UE. For example, in the case of the CG type 2 resource(s), the base station may transmit an RRC message including information related to CG resource(s) to the first UE, and the base station may transmit a DCI related to activation or release of the CG resource(s) to the first UE.

In step S610, the first UE may transmit a PSCCH (e.g., sidelink control information (SCI) or 1^st-stage SCI) to a second UE based on the resource scheduling. In step S620, the first UE may transmit a PSSCH (e.g., 2^nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S630, the first UE may receive a PSFCH related to the PSCCH/PSSCH from the second UE. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second UE through the PSFCH. In step S640, the first UE may transmit/report HARQ feedback information to the base station through the PUCCH or the PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on the HARQ feedback information received from the second UE. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on a pre-configured rule. For example, the DCI may be a DCI for SL scheduling. For example, a format of the DCI may be a DCI format 3_0 or a DCI format 3_1.

Hereinafter, an example of DCI format 3_0 will be described.

DCI format 3_0 is used for scheduling of NR PSCCH and NR PSSCH in one cell.

The following information is transmitted by means of the DCI format 3_0 with CRC scrambled by SL-RNTI or SL-CS-RNTI:

- Resource pool index - ceiling (log₂I) bits, where I is the number of resource pools for transmission configured by the higher layer parameter sl-TxPoolScheduling.

- Time gap - 3 bits determined by higher layer parameter sl-DCI-ToSL-Trans

- HARQ process number - 4 bits

- New data indicator - 1 bit

- Lowest index of the subchannel allocation to the initial transmission - ceiling (log₂(N^SL _subChannel)) bits

- SCI format 1-A fields: frequency resource assignment, time resource assignment

- PSFCH-to-HARQ feedback timing indicator - ceiling (log₂ N_{fb_timing}) bits, where N_{fb_timing} is the number of entries in the higher layer parameter sl-PSFCH-ToPUCCH.

- PUCCH resource indicator - 3 bits

- Configuration index - 0 bit if the UE is not configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI; otherwise 3 bits. If the UE is configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI, this field is reserved for DCI format 3_0 with CRC scrambled by SL-RNTI.

- Counter sidelink assignment index - 2 bits, 2 bits if the UE is configured with pdsch-HARQ-ACK-Codebook = dynamic, 2 bits if the UE is configured with pdsch-HARQ-ACK-Codebook = semi-static

- Padding bits, if required

Referring to (b) of FIG. 6, in the LTE transmission mode 2, the LTE transmission mode 4, or the NR resource allocation mode 2, a UE may determine SL transmission resource(s) within SL resource(s) configured by a base station/network or pre-configured SL resource(s). For example, the configured SL resource(s) or the pre-configured SL resource(s) may be a resource pool. For example, the UE may autonomously select or schedule resource(s) for SL transmission. For example, the UE may perform SL communication by autonomously selecting resource(s) within the configured resource pool. For example, the UE may autonomously select resource(s) within a selection window by performing a sensing procedure and a resource (re)selection procedure. For example, the sensing may be performed in a unit of subchannel(s). For example, in step S610, a first UE which has selected resource(s) from a resource pool by itself may transmit a PSCCH (e.g., sidelink control information (SCI) or 1^st-stage SCI) to a second UE by using the resource(s). In step S620, the first UE may transmit a PSSCH (e.g., 2^nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S630, the first UE may receive a PSFCH related to the PSCCH/PSSCH from the second UE.

Referring to (a) or (b) of FIG. 6, for example, the first UE may transmit a SCI to the second UE through the PSCCH. Alternatively, for example, the first UE may transmit two consecutive SCIs (e.g., 2-stage SCI) to the second UE through the PSCCH and/or the PSSCH. In this case, the second UE may decode two consecutive SCIs (e.g., 2-stage SCI) to receive the PSSCH from the first UE. In the present disclosure, a SCI transmitted through a PSCCH may be referred to as a 1^st SCI, a first SCI, a 1^st-stage SCI or a 1^st-stage SCI format, and a SCI transmitted through a PSSCH may be referred to as a 2^nd SCI, a second SCI, a 2^nd-stage SCI or a 2^nd-stage SCI format. For example, the 1^st-stage SCI format may include a SCI format 1-A, and the 2^nd-stage SCI format may include a SCI format 2-A and/or a SCI format 2-B.

Hereinafter, an example of SCI format 1-A will be described.

SCI format 1-A is used for the scheduling of PSSCH and 2nd-stage-SCI on PSSCH.

The following information is transmitted by means of the SCI format 1-A:

- Priority - 3 bits

- Frequency resource assignment - ceiling (log₂(N^SL _subChannel(N^SL _subChannel+1)/2)) bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 2; otherwise ceiling log₂(N^SL _subChannel(N^SL _subChannel+1)(2N^SL _subChannel+1)/6) bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 3

- Time resource assignment - 5 bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 2; otherwise 9 bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 3

- Resource reservation period - ceiling (log₂N_{rsv_period}) bits, where N_{rsv_period} is the number of entries in the higher layer parameter sl-ResourceReservePeriodList, if higher layer parameter sl-MultiReserveResource is configured; 0 bit otherwise

- DMRS pattern - ceiling (log₂N_pattern) bits, where N_pattern is the number of DMRS patterns configured by higher layer parameter sl-PSSCH-DMRS-TimePatternList

- 2^nd-stage SCI format - 2 bits as defined in Table 7

- Beta_offset indicator - 2 bits as provided by higher layer parameter sl-BetaOffsets2ndSCI

- Number of DMRS port - 1 bit as defined in Table 8

- Modulation and coding scheme - 5 bits

- Additional MCS table indicator - 1 bit if one MCS table is configured by higher layer parameter sl-Additional-MCS-Table; 2 bits if two MCS tables are configured by higher layer parameter sl- Additional-MCS-Table; 0 bit otherwise

- PSFCH overhead indication - 1 bit if higher layer parameter sl-PSFCH-Period = 2 or 4; 0 bit otherwise

- Reserved - a number of bits as determined by higher layer parameter sl-NumReservedBits, with value set to zero.

Value of 2nd-stage SCI format field	2nd-stage SCI format
00	SCI format 2-A
01	SCI format 2-B
10	Reserved
11	Reserved

Value of the Number of DMRS port field	Antenna ports
0	1000
1	1000 and 1001

Hereinafter, an example of SCI format 2-A will be described.

SCI format 2-A is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes ACK or NACK, when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.

The following information is transmitted by means of the SCI format 2-A:

- HARQ process number - 4 bits

- New data indicator - 1 bit

- Redundancy version - 2 bits

- Source ID - 8 bits

- Destination ID - 16 bits

- HARQ feedback enabled/disabled indicator - 1 bit

- Cast type indicator - 2 bits as defined in Table 9

- CSI request - 1 bit

Value of Cast type indicator	Cast type
00	Broadcast
01	Groupcast when HARQ-ACK information includes ACK or NACK
10	Unicast
11	Groupcast when HARQ-ACK information includes only NACK

Hereinafter, an example of SCI format 2-B will be described.

SCI format 2-B is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.

The following information is transmitted by means of the SCI format 2-B:

- HARQ process number - 4 bits

- New data indicator - 1 bit

- Redundancy version - 2 bits

- Source ID - 8 bits

- Destination ID - 16 bits

- HARQ feedback enabled/disabled indicator - 1 bit

- Zone ID - 12 bits

- Communication range requirement - 4 bits determined by higher layer parameter sl-ZoneConfigMCR-Index

Referring to (a) or (b) of FIG. 6, in step S630, the first UE may receive the PSFCH. For example, the first UE and the second UE may determine a PSFCH resource, and the second UE may transmit HARQ feedback to the first UE using the PSFCH resource.

Referring to (a) of FIG. 6, in step S640, the first UE may transmit SL HARQ feedback to the base station through the PUCCH and/or the PUSCH.

FIG. 7 shows three cast types, based on an embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure. Specifically, (a) of FIG. 7 shows broadcast-type SL communication, (b) of FIG. 7 shows unicast type-SL communication, and (c) of FIG. 7 shows groupcast-type SL communication. In case of the unicast-type SL communication, a UE may perform one-to-one communication with respect to another UE. In case of the groupcast-type SL transmission, the UE may perform SL communication with respect to one or more UEs in a group to which the UE belongs. In various embodiments of the present disclosure, SL groupcast communication may be replaced with SL multicast communication, SL one-to-many communication, or the like.

Hereinafter, synchronization acquisition of a SL UE will be described.

In time division multiple access (TDMA) and frequency division multiple access (FDMA) systems, accurate time and frequency synchronization is essential. If the time and frequency synchronization is not accurate, system performance may be degraded due to inter symbol interference (ISI) and inter carrier interference (ICI). The same is true for V2X. In V2X, for time/frequency synchronization, sidelink synchronization signal (SLSS) may be used in a physical layer, and master information block-sidelink-V2X (MIB-SL-V2X) may be used in a radio link control (RLC) layer.

FIG. 8 shows a synchronization source or synchronization reference of V2X based on an embodiment of the present disclosure. The embodiment of FIG. 8 may be combined with various embodiments of the present disclosure.

Referring to FIG. 8, in V2X, a UE may be directly synchronized with a global navigation satellite system (GNSS), or may be indirectly synchronized with the GNSS through a UE (inside network coverage or outside network coverage) directly synchronized with the GNSS. If the GNSS is configured as the synchronization source, the UE may calculate a DFN and a subframe number by using a coordinated universal time (UTC) and a (pre-)configured direct frame number (DFN) offset.

Alternatively, the UE may be directly synchronized with a BS, or may be synchronized with another UE which is time/frequency-synchronized with the BS. For example, the BS may be an eNB or a gNB. For example, if the UE is inside the network coverage, the UE may receive synchronization information provided by the BS, and may be directly synchronized with the BS. Thereafter, the UE may provide the synchronization information to adjacent another UE. If BS timing is configured based on synchronization, for synchronization and downlink measurement, the UE may be dependent on a cell related to a corresponding frequency (when it is inside the cell coverage at the frequency), or a primary cell or a serving cell (when it is outside the cell coverage at the frequency).

The BS (e.g., serving cell) may provide a synchronization configuration for a carrier used in V2X or SL communication. In this case, the UE may conform to the synchronization configuration received from the BS. If the UE fails to detect any cell in a carrier used in the V2X or SL communication and fails to receive the synchronization configuration from the serving cell, the UE may conform to a pre-configured synchronization configuration.

Alternatively, the UE may be synchronized with another UE which fails to obtain synchronization information directly or indirectly from the BS or the GNSS. A synchronization source or preference may be pre-configured to the UE. Alternatively, the synchronization source and preference may be configured through a control message provided by the BS.

An SL synchronization source may be associated/related with a synchronization priority. For example, a relation between the synchronization source and the synchronization priority may be defined as shown in Table 10 or Table 11. Table 10 or Table 11 are for exemplary purposes only, and the relation between the synchronization source and the synchronization priority may be defined in various forms.

Priority level	GNSS-based synchronization	eNB/gNB-based synchronization
P0	GNSS	BS
P1	All UEs directly synchronized with GNSS	All UEs directly synchronized with BS
P2	All UEs indirectly synchronized with GNSS	All UEs indirectly synchronized with BS
P3	All other UEs	GNSS
P4	N/A	All UEs directly synchronized with GNSS
P5	N/A	All UEs indirectly synchronized with GNSS
P6	N/A	All other UEs

Priority level	GNSS-based synchronization	eNB/gNB-based synchronization
P0	GNSS	BS
P1	All UEs directly synchronized with GNSS	All UEs directly synchronized with BS
P2	All UEs indirectly synchronized with GNSS	All UEs indirectly synchronized with BS
P3	BS	GNSS
P4	All UEs directly synchronized with BS	All UEs directly synchronized with GNSS
P5	All UEs indirectly synchronized with BS	All UEs indirectly synchronized with GNSS
P6	Remaining UE(s) having low priority	Remaining UE(s) having low priority

In Table 10 or Table 11, P0 may denote a highest priority, and P6 may denote a lowest priority. In Table 10 or Table 11, the BS may include at least one of a gNB and an eNB.

Whether to use GNSS-based synchronization or BS-based synchronization may be (pre-)configured. In a single-carrier operation, the UE may derive transmission timing of the UE from an available synchronization reference having the highest priority.

For example, the UE may (re)select a synchronization reference, and the UE may obtain synchronization from the synchronization reference. In addition, the UE may perform SL communication (e.g., PSCCH/PSSCH transmission/reception, physical sidelink feedback channel (PSFCH) transmission/reception, S-SSB transmission/reception, reference signal transmission/reception, etc.) based on the obtained synchronization.

On the other hand, the existing NR-U (unlicensed spectrum) supports communication methods between UEs and base stations in unlicensed bands. Rel-18 will also support a mechanism to support communication between sidelink UEs in unlicensed bands.

In the present disclosure, a channel may refer to a set of frequency domain resources over which a Listen-Before-Talk (LBT) is performed. In NR-U, a channel may refer to a 20 MHz LBT bandwidth, which may have the same meaning as an RB set. For example, a set of RBs may be defined in section 7 of 3GPP TS 38.214 V17.0.0.

In the present disclosure, channel occupancy (CO) may refer to the time/frequency domain resources obtained by a base station or UE after a successful LBT.

In the present disclosure, channel occupancy time (COT) may refer to a time domain resource obtained by a base station or UE after a successful LBT. It may be shared between the base station (or UE) and the UE (or base station) that has obtained the CO, which may be referred to as COT sharing. According to the initiating device, this may be referred to as gNB-initiated COT or UE-initiated COT.

The following describes a wireless communication system that supports unlicensed band/shared spectrum.

FIG. 9 shows an example of a wireless communication system supporting unlicensed bands, according to one embodiment of the present disclosure. For example, FIG. 9 may include an unlicensed spectrum (NR-U) wireless communication system. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure.

In the following description, a cell that operates in the licensed band (hereinafter referred to as L-band) may be defined as an LCell, and the carrier of an LCell may be defined as (DL/UL/SL) LCC. In addition, a cell that operates in the unlicensed band (hereinafter referred to as U-band) may be defined as a UCell, and the carrier of a UCell may be defined as (DL/UL/SL) UCC. The carrier/carrier-frequency of a cell may refer to the operation frequency (e.g., center frequency) of the cell. Cells/carriers (e.g., CC) are collectively referred to as cells.

When a UE and base station transmit and receive signals over a carrier aggregated LCC and UCC, as shown in (a) of Figure 9, the LCC may be set as a primary CC (PCC) and the UCC may be set as a secondary CC (SCC). As shown in (b) of FIG. 9, the UE and base station may transmit and receive signals over a single UCC or a plurality of carrier aggregated UCCs, i.e., the UE and base station may transmit and receive signals over the UCC(s) alone without an LCC. For standalone operation, the UCell may support PRACH, PUCCH, PUSCH, SRS transmission, etc.

In the embodiment of FIG. 9, the base station may be replaced by a UE. In this case, for example, PSCCH, PSSCH, PSFCH, S-SSB transmission may be supported in a UCell.

Unless otherwise noted, the following definitions may be applied to terms used herein. For example, unlicensed spectrum and shared spectrum in this disclosure may be mutually substituted/replaced. For example, channel sensing (on shared spectrum) in the present disclosure may refer to channel sensing related to a channel access procedure (CAP). The CAP may include a step of (channel) sensing for a resource (or, channel) over which a transmission is to be performed.

- Channel: A set of contiguous RBs in the shared spectrum over which a channel access procedure is performed, which may refer to a carrier or a portion of a carrier.

- Channel Access Procedure (CAP): Refers to a procedure for evaluating channel availability based on sensing, in order to determine whether a channel is available for use by other communication node(s) prior to signal transmission. The basic unit for sensing is a sensing slot with a duration of T_sl=9us. If a base station or UE senses a channel during the sensing slot interval, and the power detected within the sensing slot interval for at least 4us is less than the energy detection threshold X_Thresh, the sensing slot interval T_sl is considered to be IDLE. Otherwise, the sensing slot interval T_sl=9us is considered to be BUSY. CAP may be referred to as Listen-Before-Talk (LBT). For example, a channel access procedure (CAP) may include an LBT, and channel sensing that monitors the power of a channel for a specific time interval (channel sensing interval) may be performed for the CAP.

- Channel occupancy: Refers to the corresponding transmission(s) on the channel(s) by a base station/UE after performing the channel access procedure.

- Channel Occupancy Time (COT): After a base station/UE performs a channel access procedure, it refers to the total time that any base station/UE sharing channel occupancy with the base station/UE can perform transmission(s) on the channel. When determining a COT, if a transmission gap is 25us or less, the gap period is also counted in the COT. The COT may be shared for transmission between a base station and its corresponding UE(s).

- DL transmission burst: Defined as a set of transmissions from a base station with no gaps exceeding 16us. Transmissions from a base station that are separated by a gap of more than 16 us are considered to be separate DL transmission bursts. A base station may perform transmission(s) after a gap without sensing channel availability within a DL transmission burst.

- UL or SL transmission burst: Defined as a set of transmissions from a UE with no gap exceeding 16us. Transmissions from a UE that are separated by a gap exceeding 16us shall be considered as separate UL or SL transmission bursts. A UE may perform transmission(s) after a gap without sensing channel availability within a UL or SL transmission burst.

- Discovery Burst: Refers to a DL transmission burst including a set of signal(s) and/or channel(s), limited within a (time) window and related to a duty cycle. In LTE-based systems, a discovery burst is a transmission(s) initiated by a base station that includes PSS, SSS, and cell-specific RS (CRS), and may further include non-zero power CSI-RS. In NR-based systems, a discovery burst is a transmission(s) initiated by a base station, including at least an SS/PBCH block, and may further include a CORESET for a PDCCH scheduling a PDSCH with SIB1, a PDSCH carrying SIB1, and/or a non-zero power CSI-RS.

FIG. 10 shows a method for occupying a resource in an unlicensed band, according to one embodiment of the present disclosure. The embodiment of FIG. 10 may be combined with various embodiments of the present disclosure.

Referring to FIG. 10, a communication node (e.g., base station, UE) in an unlicensed band may need to determine whether another communication node(s) is using the channel before transmitting a signal. To do so, a communication node in an unlicensed band may perform a channel access procedure (CAP) to access channel(s) over which transmission(s) are to be performed. Channel access procedures may be performed based on sensing. For example, a communication node may first perform carrier sensing (CS) to determine whether another communication node(s) is transmitting a signal before transmitting a signal. A case where it is determined that the other communication node(s) are not transmitting a signal is defined as a case where a clear channel assessment (CCA) is confirmed. If there is a CCA threshold (e.g., X_Thresh) that is predefined or configured by a higher layer (e.g., RRC), the communication node may determine the channel state to be busy if energy higher than the CCA threshold is detected in the channel, and otherwise determine the channel state to be idle. If the channel state is determined to be idle, the communication node may start signal transmission in an unlicensed band. CAP may be replaced by LBT. For example, a channel access procedure (CAP) may include an LBT, and channel sensing may be performed to monitor the power of the channel for a specific time interval (channel sensing interval) for the CAP.

Table 12 shows examples of channel access procedures (CAPs) supported by NR-U.

	Type	Explanation
DL	Type
DL	1 CAP	CAP with random back-off - time duration spanned by the sensing slots that are sensed to be idle before a downlink transmission(s) is random
Type
2 CAP - Type 2A, 2B, 2C	CAP without random back-off - time duration spanned by sensing slots that are sensed to be idle before a downlink transmission(s) is deterministic
UL or SL	Type	1 CAP	CAP with random back-off - time duration spanned by the sensing slots that are sensed to be idle before an uplink or sidelink transmission(s) is random
UL or SL	Type
2 CAP - Type 2A, 2B, 2C	CAP without random back-off - time duration spanned by sensing slots that are sensed to be idle before an uplink or sidelink transmission(s) is deterministic

Referring to Table 12, LBT types or CAPs for DL/UL/SL transmissions may be defined. However, Table 12 is only an example, and new types or CAPs may be defined in a similar manner. For example, Type 1 (also referred to as Cat-4 LBT) may be a random back-off based channel access procedure. For example, in the case of Cat-4, the contention window may be variable. For example, Type 2 can be performed in case of COT sharing within COT acquired by gNB or UE.

In the following, we describe the LBT-SB (SubBand) (or RB set).

In a wireless communication system supporting unlicensed bands, a single cell (or carrier (e.g., CC)) or BWP configured to a UE may be configured as a wideband with a large bandwidth (BW) compared to conventional LTE; however, the BW requiring CCA based on independent LBT operation may be limited based on regulation or otherwise. By defining sub-bands (SBs) in which individual LBTs are performed as LBT-SBs, multiple LBT-SBs may be included within a single wideband cell/BWP. The set of RBs comprising an LBT-SB may be configured via higher layer (e.g., RRC) signaling. Thus, based on (i) the BW of the cell/BWP and (ii) the RB set allocation information, a cell/BWP may include one or more LBT-SBs.

FIG. 11 shows a plurality of LBT-SBs within an unlicensed band, according to one embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure.

Referring to FIG. 11, a plurality of LBT-SBs may be included in a BWP of a cell (or carrier). An LBT-SB may have a 20 MHz band, for example. An LBT-SB may be configured in the frequency domain as a plurality of continuous (P)RBs, which may be referred to as a set of (P)RBs. Although not shown, a guard band (GB) may be included between the LBT-SBs. Thus, a BWP may be configured in the form {LBT-SB #0 (RB set #0) + GB #0 + LBT-SB #1 (RB set #1 + GB #1) + ... + LBT-SB #(K-1) (RB set (#K-1))}. For convenience, an LBT-SB/RB index may be configured/defined to start at a lower frequency band and increase as it goes to a higher frequency band.

Hereinafter, channel access priority class (CAPC) is explained.

The CAPCs of MAC CEs and radio bearers are fixed or configurable to operate on FR1:

- Fixed to the lowest priority for padding buffer status report (BSR) and recommended bit rate MAC CEs;

- Fixed as the highest priority for SRB0, SRB1, SRB3, and other MAC CEs;

- Configured by a base station for SRB2 and DRB.

When selecting a CAPC for a DRB, a base station considers fairness among different traffic types and transmissions while considering the 5QI of all QoS flows multiplexed into the corresponding DRB. Table 13 shows which CAPCs should be used for standardized 5QI, i.e., which CAPCs should be used for a given QoS flow. For standardized 5QIs, the CAPCs are defined as shown in the table below, while for non-standardized 5QIs, the CAPC that best matches the QoS characteristics should be used.

CAPC	5QI
1	1, 3, 5, 65, 66, 67, 69, 70, 79, 80, 82, 83, 84, 85
2	2, 7, 71
3	4, 6, 8, 9, 72, 73, 74, 76
4	-
NOTE: A lower CAPC value means higher priority

Hereinafter, a method of transmitting a downlink signal through an unlicensed band is described. For example, the method of transmitting a downlink signal through an unlicensed band may be applicable to the method of transmitting a sidelink signal through an unlicensed band.

A base station may perform one of the following channel access procedures (CAP) for downlink signal transmission in an unlicensed band.

(1) Type 1 downlink (DL) CAP method

In a Type 1 DL CAP, the length of the time interval spanned by sensing slots that are sensed as idle prior to the transmission(s) is random. Type 1 DL CAP may be applied to the following transmission.

- Transmission(s) initiated by the base station, including (i) a unicast PDSCH with user plane data, or (ii) a unicast PDSCH with user plane data and a unicast PDCCH scheduling the user plane data, or,

- Transmission(s) initiated by a base station that (i) has a discovery burst only, or (ii) has non-unicast information and a multiplexed discovery burst.

FIG. 12 shows a CAP operation for a downlink signal transmission through an unlicensed band of a base station, according to one embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

Referring to FIG. 12, a base station may first sense whether the channel is idle during a sensing slot period of a defer duration T_d, and then, when the counter N becomes zero, perform a transmission (S134). At this time, the counter N is adjusted by sensing the channel during the additional sensing slot period(s) according to the procedure below:

Step 1) (S120) Set N=N_init. where N_init is a random value uniformly distributed between 0 and CW_p. Then go to Step 4.

Step 2) (S140) If N>0 and the base station chooses to decrement the counter, set N=N-1.

Step 3) (S150) Sense the channel for the duration of the additional sensing slot. If the additional sensing slot period is idle (Y), go to step 4. Otherwise (N), go to step 5.

Step 4) (S130) If N=0 (Y), end the CAP procedure (S132). Otherwise (N), go to step 2.

Step 5) (S160) Sense the channel until a busy sensing slot is detected within the additional defer duration T_d, or until all sensing slots within the additional defer duration T_d are detected as idle.

Step 6) (S170) If the channel is sensed as idle during all sensing slots of the additional defer duration T_d (Y), go to Step 4. Otherwise (N), go to step 5.

Table 14 shows how the m_p, minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes that are applied to CAP vary according to the channel access priority class.

Channel Access Priority Class (p)	m_p	CW_min,p	CW_max,p	T_mcot,p	allowed CW_p sizes
1	1	3	7	2 ms	{3,7}
2	1	7	15	3 ms	{7,15}
3	3	15	63	8 or 10 ms	{15,31,63}
4	7	15	1023	8 or 10 ms	{15,31,63,127,255,511,1023}

Referring to Table 14, the contention window size (CWS), maximum COT value, etc. may be defined for each CAPC. For example, T_d = T_f + m_p * T_sl.

The defer duration T_d is composed of a sequence of interval T_f (16us) + m_p consecutive sensing slot intervals T_sl (9us). T_f includes the sensing slot interval T_sl at the beginning of the 16us interval.

CW_min,p <= CW_p <= CW_max,p. CW_p is set to CW_p = CW_min,p, and may be updated (CW size update) prior to step 1 based on HARQ-ACK feedback (e.g., ACK or NACK ratio) for the previous DL burst (e.g., PDSCH). For example, CW_p may be initialized to CW_min,p, based on the HARQ-ACK feedback for the previous DL burst, or may be increased to the next highest allowed value, or may remain at its existing value.

(2) Type 2 DL CAP method

In a Type 2 DL CAP, the length of the time interval spanned by the sensing slots that are sensed as idle before the transmission(s) is deterministic. Type 2 DL CAPs are categorized as Type 2A/2B/2C DL CAPs.

Type 2A DL CAP may be applied to the following transmissions. In a Type 2A DL CAP, a base station may transmit a transmission immediately after the channel has been sensed as idle for at least a sensing interval T_{short_dl}=25us. Here, T_{short_dl} consists of a segment T_f (=16us) followed immediately by one sensing slot. T_f includes a sensing slot at the beginning of the interval.

- Transmission(s) initiated by a base station that (i) has a discovery burst only, or (ii) has non-unicast information and a multiplexed discovery burst; or

- The base station's transmission(s) after a 25us gap from the transmission(s) by a UE within the shared channel occupancy.

Type 2B DL CAP is applicable to the transmission(s) performed by a base station after a 16us gap from the transmission(s) by a UE within the shared channel occupancy time. In a Type 2B DL CAP, a base station may transmit a transmission immediately after the channel is sensed as idle during Tf=16us. Tf includes a sensing slot within the last 9 us of the interval. Type 2C DL CAP is applicable to the transmission(s) performed by a base station after a gap of up to 16us from the transmission(s) by a UE within the shared channel occupancy time. In Type 2C DL CAP, a base station does not sense the channel before performing a transmission.

Hereinafter, a method of transmitting an uplink signal over an unlicensed band is described. For example, the method of transmitting an uplink signal through an unlicensed band may be applicable to the method of transmitting a sidelink signal through an unlicensed band.

A UE performs Type 1 or Type 2 CAP for uplink signal transmission in the unlicensed band. In general, a UE may perform any CAP (e.g., Type 1 or Type 2) configured by a base station for uplink signal transmission. For example, CAP type indication information for a UE may be included within a UL grant (e.g., DCI format 0_0, 0_1) that schedules a PUSCH transmission.

(1) Type 1 uplink (UL) CAP method

The length of the time interval spanned by sensing slots that are sensed as idle prior to the transmission(s) in a Type 1 UL CAP is random. Type 1 UL CAP may be applied to the following transmissions

- Scheduled and/or configured PUSCH/SRS transmission(s) from a base station

- Scheduled and/or configured PUCCH transmission(s) from a base station

- Transmission(s) related to Random Access Procedure (RAP)

FIG. 13 shows a Type 1 CAP operation of a UE for transmitting an uplink signal, according to one embodiment of the present disclosure. The embodiment of FIG. 13 may be combined with various embodiments of the present disclosure.

Referring to FIG. 13, a UE may first sense whether the channel is idle during a sensing slot period of a defer duration T_d, and then, when the counter N becomes zero, perform a transmission (S234). At this time, the counter N is adjusted by sensing the channel during the additional sensing slot period(s) according to the procedure below:

Step 1) (S220) Set N=N_init. where N_init is a random value uniformly distributed between 0 and CW_p. Then go to Step 4.

Step 2) (S240) If N>0 and the UE chooses to decrement the counter, set N=N-1.

Step 3) (S250) Sense the channel for the duration of the additional sensing slot. If the additional sensing slot period is idle (Y), go to step 4. Otherwise (N), go to step 5.

Step 4) (S230) If N=0 (Y), end the CAP procedure (S232). Otherwise (N), go to step 2.

Step 5) (S260) Sense the channel until a busy sensing slot is detected within the additional defer duration T_d, or until all sensing slots within the additional defer duration T_d are detected as idle.

Step 6) (S270) If the channel is sensed as idle during all sensing slots of the additional defer duration T_d (Y), go to Step 4. Otherwise (N), go to step 5.

Table 15 shows how the m_p, minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes that are applied to CAP vary according to the channel access priority class.

Channel Access Priority Class (p)	mp	CWmin,p	CWmax,p	Tulmcot,p	allowed CWp sizes
1	2	3	7	2 ms	{3,7}
2	2	7	15	4 ms	{7,15}
3	3	15	1023	6 or 10 ms	{15,31,63,127,255,511,1023}
4	7	15	1023	6 or 10 ms	{15,31,63,127,255,511,1023}

Referring to Table 15, the contention window size (CWS), maximum COT value, etc. may be defined for each CAPC. For example, T_d = T_f + m_p * T_sl.

CW_min,p <= CW_p <= CW_max,p. CW_p is set to CW_p = CW_min,p, and may be updated (CW size update) prior to step 1 based on an implicit/explicit reception response for the previous UL burst (e.g., PUSCH). For example, CW_p may be initialized to CW_min,p, based on an implicit/explicit reception response for the previous UL burst, or may be increased to the next highest allowed value, or may remain at its existing value.

(2) Type 2 UL CAP method

In a Type 2 UL CAP, the length of the time interval spanned by the sensing slots that are sensed as idle before the transmission(s) is deterministic. Type 2 UL CAPs are categorized as Type 2A/2B/2C DL CAPs. In a Type 2A UL CAP, a UE may transmit a transmission immediately after the channel has been sensed as idle for at least a sensing interval T_{short_dl}=25us. Here, T_{short_dl} consists of a segment T_f (=16us) followed immediately by one sensing slot. In Type 2A UL CAP, T_f includes a sensing slot at the beginning of the interval. In Type 2B UL CAP, a UE may transmit immediately after the channel is sensed as idle during the sensing interval T_f=16us. In Type 2B UL CAP, T_f includes a sensing slot within the last 9 us of the interval. In Type 2C UL CAP, a UE does not sense the channel before performing a transmission.

For example, according to the Type 1 LBT based NR-U operation, a UE with uplink data to be transmitted may select a CAPC that is mapped to the 5QI of the data, and the UE may apply the parameters (e.g., minimum contention window size, max contention window size, m_p, etc.) of the corresponding CACP to perform the NR-U operation. For example, a UE may select a backoff counter (BC) after selecting a random value between the minimum CW and maximum CW that are mapped to a CAPC. In this case, for example, the BC may be a positive integer less than or equal to the random value. After sensing a channel, a UE decrements the BC by one when the channel is idle. When BC becomes zero and the UE detects that the channel is idle for a period of time T_d (T_d = T_f + m_p * T_sl), the UE may occupy the channel and attempt to transmit data. For example, T_sl (= 9 usec) is a basic sensing unit or sensing slot and may include a measurement duration of at least 4 usec. For example, the first 9 usec of T_f (= 16 usec) may comprise T_sl.

For example, according to the NR-U operation based on Type 2 LBT, a UE may perform a Type 2 LBT (e.g., Type 2A LBT, Type 2B LBT, Type 2C LBT) within the COT to perform data transmission.

For example, Type 2A (also referred to as Cat-2 LBT (one shot LBT) or one-shot LBT) may be a 25 usec one-shot LBT. In this case, a transmission may start immediately after idle sensing for at least a 25 usec gap. Type 2A may be used to initiate the transmission of SSB and non-unicast DL information. That is, a UE may sense the channel for 25 usec within a COT, and when the channel is idle, the UE may occupy the channel and attempt to transmit data.

For example, type 2B may be a 16 usec one-shot LBT. In this case, a transmission may start immediately after idle sensing for the 16 usec gap. That is, a UE may sense the channel for 16 usec within a COT, and when the channel is idle, the UE may occupy the channel and attempt to transmit data.

For example, in the case of Type 2C (also called Cat-1 LBT or No LBT), LTB may not be performed. In this case, a transmission may start immediately after a gap of up to 16 usec and the channel may not be sensed before the transmission. The duration of the transmission may be up to 584 usec. The UE may attempt to transmit after 16 usec without sensing, and the UE may perform the transmission for up to 584 usec.

In the sidelink unlicensed band, a UE may perform a listen before talk (LBT) based channel access operation. Before accessing a channel in the unlicensed band, a UE shall check whether the access channel is idle (i.e., the channel is not occupied by UEs and UEs can access the channel and transmit data) or busy (i.e., the channel is occupied and data transmission and reception operations are performed on the channel; a UE attempting to access the channel cannot transmit data while the channel is busy). That is, an operation in which a UE checks whether a channel is idle or busy may be referred to as a clear channel assessment (CCA), and the UE may check whether the channel is idle or busy during the CCA duration.

One of the next important features of the 5G NR specification is the introduction of the Sidelink protocol, intended to support mutual connectivity between UEs even without access to the NG-RAN coordination features. The similarity of the topology and usage models with the widely used Wi-Fi (IEEE 802.11) technologies may give the possibility to extend the 5G NR into the unlicensed bands, initially occupied by the Wi-Fi devices only.

For the coexistence purposes, the SL-U (sidelink unlicensed) devices should inherit both the contention-based protocols (listen-before-talk, LBT) and the 20 MHz channelization of the Wi-Fi devices.

However, synchronization block of the SL transmission occupy 127 (132 with guard bands) subcarriers only [3GPP TS 38.211 V17.4.0 (2022-12) Physical channels and modulation], which requires enhancement to satisfy OCB (Occupied Channel Bandwidth) requirement (i.e., the signal/channel should be transmitted occupying the bandwidth larger than 80% of single RB set), for example.

In this case, for example, it was proposed to replicate the initial S-SSB in frequency domain to satisfy the OCB requirement.

FIGs. 14A to 14C show a configuration of a new S-SSB design (config #1) with a different number of repetitions, based on an embodiment of the present disclosure.

Such solution allows re-using most of hardware and processing chains from the NR-bands SL in the SL-U.

However, the replication in frequency domain causes huge increase of the PAPR metric (peak-to average power ratio), which is generally lead to work in the power amplifier nonlinearity region, reducing of effective dynamic range and out-of-bands emission increase.

Thus, PAPR increase should be avoided by all means, and specific measures should be done to avoid this for the newly designed SL-U SSBs.

To solve the high PAPR problem in case of the sequence FD replications, currently two baseline methods are proposed and under consideration of the 3GPP standardization community:

(1) Phase adjustment

- For each of S-PSS/S-SSS/PSBCH sequence replication in FD (e.g., 2, 4, 8 repetitions for 60 / 30 /15 kHz SCS, see FIGS. 14A to 14C) some phase rotation per baseline sequence should be done.

- This will introduce certain grade of diversity in frequency domain and will decrease PAPR.

- At the same time, the same baseline sequences are used, and moreover, the same procedures for detection/demodulation/measurements can be applied with the non-coherent combinations over the different repetitions.

(2) Combination of sequences with different ID

- For each of S-PSS/S-SSS/PSBCH the baseline sequence (defined by the N^SL _ID parameter) is appended by the sequences from the same set, but corresponding to another parameter values.

- This also introduces diversity and reduces PAPR, and at the same time hardware/software processing may be similar to the baseline case.

The main task for practical implementation of the both approaches is finding the optimal phase values or sequences combinations that are meant to reduce the PAPR.

Typically, this can be done by exhaustive or optimized search over all possible variants.

For the S-PSS, the primary (first) synchronization sequence only two possible variants exist and the second approach provides limited enhancement. At the same time, phase adjustment also provides not very significant improvement. Thus, in present disclosure we propose joint phase/scrambling sequence modification for optimal PAPR reduction for the SL-U S-PSS design.

For the S-SSS (secondary synchronization sequence), there are 672 variants of the sequence, corresponding to different N_IDs. In this case, good PARP reduction can be achieved even with N_ID combinations, without phase changes. For example, in the present disclosure, N_ID may be the N^SL _ID parameter.

As discussed above, present disclosure proposes the new S-PSS design to satisfy the required bandwidth (e.g., defined by OCB requirement) based on simultaneous phase rotation and combination of existing PSS sequences.

Basically, we need to find the modifications that minimize PAPR for the case of 15 kHz SCS (e.g., 8 times replication). 30 kHz (e.g., 4 times replication) and 60 kHz (e.g., 2 times replications).

However, we will perform optimizations for the x2, x4, x6, x8, x10 repetitions, without specifying SCS values.

Note that the designs/schemes proposed in the present disclosure can be extended and applied to S-SSB transmissions with various SCS values and/or S-SSB transmissions on one or multiple RB sets. Also, the proposed rotation values and/or sequence combination for a specific case (with optimizing the individual S-PSS/S-SSS/PSBCH) can be extended and applied to other cases (with optimizing the average PAPR) as well.

This was done by using the optimized search that guarantees the final PAPR minimization values to be pretty close to the absolute minimums. It should be noted that exhaustive search, especially in the case of 8 replications become prohibitively complex. Table 16 shows PAPR comparison for different improvement methods for S-PSS sequence.

Signal	PAPR, dB for S-PSS #0 and #1
S-SSB configuration	Base	Phase adjustment	Sequences combination	Proposed joint approach
Legacy, 11RBs/132subc	5.43 / 5.94	N/A	N/A	N/A
2 repetitions 2x11RBs	7.45 / 8.7	7.45/7.44	5.4/5.41	5.34 /5.41
4 repetitions 4x11RBs	9.91 /11.72	6.6/7.01	8.22/8.23	4.95 / 4.58
6 repetitions 6x11RBs	11.65 / 13.47	7.29 / 7.39	9.32 / 9.33	5.15 / 4.98
8 repetitions 8x11RBs	12.87 / 14.71	6.6/6.77	10.34/10.35	5.1 / 4.82
10 repetitions 10x11RBs	13.81 / 15.67	6.91 / 7.29	11.52 / 11.53	5.11 / 5.21

It can be seen that PARP value for S-PSS (for 20MHz channels) can be significantly improved with the proposed method in comparison with the previously considered phase and combinations approaches, not saying about baseline replication without any modifications.

Proposed phase adjustments and sequences are for S-PSS are summarized in Table 17. Table 17 shows Proposed suboptimal phase adjustments and sequences orders.

S-SSB configuration	S-PSS #0 adjustments		S-PSS #1 adjustments
	Phases, radians	Sequences	Phases, radians	Sequences
2 repetitions 2x11RBs	[0, 3.14]	[0, 1]	[0, 0]	[1, 0]
4 repetitions 4x11RBs	[0, 0.26, 0.66, -2.24]	[0 0 1 1]	[0, 3.06, -3.04, -3.04]	[1 1 0 0]
6 repetitions 6x11RBs	[0, 2.71, 2.32, -1.58, 2.71, -2.36]	[0,0,0,1,1,1]	[0, 1.93, 0.37, 0.37, -2.36, -2.36]	[1,1,1,0,0,0]
8 repetitions 8x11RBs	[ 0, -1.58, 3.10, -1.58, 2.32, 0.76, 2.32, -2.36]	[0,0,0,0,1,1,1,1]	[ 0, -1.58, 2.32, -2.36, -1.58, -3.14, -2.36, 0.80]	[1,1,1,1,0,0,0,0]
10 repetitions 10x11RBs	[0, -0.02, -3.14, 3.1 -3.14, 3.1, -0.02, 3.1, -0.02, 3.1]	[0,0,1,1,0,1,0,0,1,1]	[0, 3.1, -3.14, -0.02, -0.02, -0.02, -0.02, -0.02, -0.02, -3.14]	[1,1,1,1,0,1,0,0,0,0]

Similar optimization is done for the 672 S-SSS and 672 PSBCH sequences.

The optimal PAPR values and corresponding sets on N_ID (and/or the optimal PAPR values and corresponding phase rotation values) for the S-SSS(/S-PSS) and PSBCH are included in the Tables 14-20. Specified phase adjustment and sequences replication order can be included in the SL-U specification as a baseline method for S-PSS generation (for 20 MHz channelization case).

For example, whether phase adjustment (and/or sequences combination and/or joint approach) is applied (and/or which one of the proposed schemes is applied) (optimizing the average PAPR) can be differently configured depending on at least one of parameters such as the number of repeated S-SSB transmissions on the frequency (and/or time) domain (e.g., within one RB set) (and/or the number of RB sets through which S-SSBs are transmitted), synchronization sequence type/order, SL channel type, SCS value, etc.

Despite provided combinations of sequences with specified N_ID will ensure sub-optimal PAPR minimization, it will require a serious modification of the existing software/firmware.

So, in another embodiment of present disclosure, we propose the set of phase rotations that will optimize the average PAPR for the whole set of sequences for the given repetition number. Table 18 summarized this optimal rotations for the x2, x4, x6, x8, x10 repetitions, showing the improvement in comparison with the baseline PAPR.

In the following, the trend of the phase rotation of S-SSS and PSBCH from #1 to #10 shows that the PAPR of phase rotation is higher than the PAPR of ID combining, so it is proposed that only ID combining is used to generate S-SSS and PSBCH signals.

In the following tables, the combinations listed after #10 for values involving S-SSS and PSBCH represent the lowest PAPR. Table 18 shows Phase rotations that optimize the Average PAPR. Table 19 shows 2 repetitions. Table 20 shows 4 repetitions. Table 21 shows 6 repetitions. Tables 22 and 23 show 8 repetitions. Tables 24 and 25 show 10 repetitions.

Signal	PAPR base, dB	Phases, radians	PAPR base, dB
2 repetitions
S-PSS	8.12	[0,-3.14]	7.88
S-SSS	10.11	[0,-3.14]	10.08
PSBCH	10.49	[0,0]	10.49
4 repetitions
S-PSS	10.9	[0,-0.34,-2.64,-0.24]	7.14
S-SSS	13	[0,-1.84,-1.84,-0.04]	9.38
PSBCH	13.36	[0,1.96,-0.54,-1.24]	9.75
6 repetitions
S-PSS	12.65	[0,-0.8,2.32,-0.8,2.32,-3.14]	7.48
S-SSS	14.66	[0,-0.8,2.32,-0.8,2.32,-3.14]	9.74
PSBCH	15.02	[0,3.1,-2.36,-0.8,-0.8,-1.58 ]	10.09
8 repetitions
S-PSS	13.89	[0,-1.58,-1.7,2.32,-0.8,1.48,1.66,-3.08]	6.33
S-SSS	15.79	[0,-1.58,-1.58,2.32,-0.8,1.54,1.54,-3.14]	8.75
PSBCH	16.16	[0,-1.58,-1.58,2.32,-0.8,1.54,1.54,-3.14]	8.8
10 repetitions
S-PSS	14.84	[0,-1.58,-1.58,1.54,-1.58,1.54,3.1,3.1,-1.58,-3.14]	7.47
S-SSS	16.63	[0,-1.58,-0.02,-1.58,-1.58,3.1,-0.02,-0.02,1.54,3.1]	9.81
PSBCH	17	[0,3.1,-0.02,-0.02,1.54,1.54,1.54,-0.02,-1.58,-1.58]	10.14

		Phase adjust.			Use different NSLID
Signal	PAPR value w/o adjus.	Phases, radians		PAPR, dB	ID combination		PAPR, dB
S-PSS #0	7.45	0	0	7.45	0	1	5.4
S-PSS #1	8.71	0	-3.14	7.44	1	0	5.41
S-SSS #0	10.74	0	-3.14	8.78	0	533	6.05
S-SSS #1	9.98	0	0	9.98	1	523	6.17
S-SSS #2	10.81	0	-3.14	9.27	2	436	6.26
S-SSS #3	8.76	0	0	8.76	3	314	6.15
S-SSS #4	9.13	0	0	9.13	4	404	6.01
S-SSS #5	11.19	0	0	11.19	5	46	5.96
S-SSS #6	10.96	0	-3.14	10.49	6	588	6.27
S-SSS #7	10.33	0	-1.52	9.95	7	298	6.03
S-SSS #8	9.67	0	-3.14	8.98	8	100	5.91
S-SSS #9	8.68	0	0	8.68	9	437	6.09
S-SSS #10	10.57	0	-3.14	10.37	10	372	6.06
S-SSS #533	9.94	0	-3.14	9.37	533	176	5.52
PSBCH #0	12.41	0	-1.41	11.81	0	185	7.45
PSBCH #1	11.89	0	-0.59	10.92	1	22	7.27
PSBCH #2	10.28	0	-2.57	9.61	2	197	6.77
PSBCH #3	10.5	0	1.09	9.56	3	545	6.5
PSBCH #4	10.79	0	-2.48	9.24	4	217	6.74
PSBCH #5	10.42	0	-0.91	10.14	5	452	6.7
PSBCH #6	11.86	0	-2.62	10.67	6	162	7.1
PSBCH #7	10.96	0	1.87	9.88	7	42	6.67
PSBCH #8	11.47	0	3.06	9.89	8	282	6.67
PSBCH #9	9.54	0	2.74	8.66	9	40	6.6
PSBCH #10	11.66	0	1.85	9.85	10	76	6.89
PSBCH #297	9.61	0	-2.29	9.01	297	582	6.15

		Phase adjust.					Use different NSLID
Signal	PAPR value w/o adjus.	Phases, radians				PAPR, dB	ID combination				PAPR, dB
S-PSS #0	9.91	0	2.26	0.63	0.41	6.6	0	0	1	0	8.22
S-PSS #1	11.71	0	-0.3	-2.59	-0.17	7.01	1	0	0	0	8.23
S-SSS #0	13.74	0	0.08	-2.44	0.48	8.29	0	512	17	185	6
S-SSS #1	12.74	0	2.36	0.59	0.42	9.09	1	650	200	412	5.95
S-SSS #2	13.8	0	1.57	-1.47	-2.98	8.82	2	362	285	583	6.09
S-SSS #3	11.72	0	-0.14	1.03	-1.9	7.79	3	574	649	662	6.07
S-SSS #4	11.91	0	-1.64	-1.6	0.07	8.56	4	351	46	155	6.2
S-SSS #5	14.14	0	-1.77	-1.77	0.01	10.16	5	285	21	345	6.27
S-SSS #6	13.68	0	-2.96	1.82	2.58	9.7	6	445	594	314	6.16
S-SSS #7	13.34	0	-1.04	2.24	-2.47	8.85	7	512	253	278	6.2
S-SSS #8	12.68	0	-1.55	1.42	2.68	8.16	8	155	36	316	6.12
S-SSS #9	11.43	0	-1.43	-1.39	0.36	8.52	9	197	338	15	6.1
S-SSS #10	13.37	0	2.98	-1.92	-2.71	9.49	10	540	407	430	6.16
S-SSS #222	12.06	0	-1.72	-1.71	0.02	8.33	222	96	666	548	5.61
PSBCH #0	15.41	0	-1.5	1.5	2.52	10.85	0	507	523	191	6.96
PSBCH #1	14.39	0	1.03	0.48	-1.43	10.76	1	385	642	391	6.83
PSBCH #2	13.1	0	-1.13	2.72	-1.79	8.77	2	211	452	294	6.81
PSBCH #3	13.41	0	2.64	-2.55	2.95	8.76	3	255	31	93	6.96
PSBCH #4	13.56	0	-2.14	-3.15	-1.55	8.71	4	293	438	545	6.72
PSBCH #5	13.31	0	-0.61	0.55	-2.75	8.89	5	96	394	516	6.73
PSBCH #6	14.85	0	1.93	-0.57	-1.69	10.1	6	31	128	651	6.61
PSBCH #7	13.68	0	-1.24	-0.16	2.17	9.1	7	421	358	154	6.92
PSBCH #8	14.48	0	-2.32	0.55	1.05	9.19	8	635	630	381	6.72
PSBCH #9	12.4	0	2.95	0.93	1.42	8.01	9	369	210	135	6.82
PSBCH #10	14.52	0	0.17	2.04	-0.98	9.47	10	220	81	22	6.86
PSBCH #228	12.17	0	-0.14	-1.1	1.7	8.41	228	182	428	16	6.26

		Phase adjust.							Use different NSLID
Signal	PAPR value w/o adjus.	Phases, radians						PAPR, dB	ID combination						PAPR, dB
S-PSS #0	11.65	0	-3.14	3.1	2.32	1.54	-3.14	7.29	0	0	1	1	0	0	9.32
S-PSS #1	13.47	0	-0.8	2.32	-0.8	2.32	-3.14	7.39	1	0	0	1	0	0	9.33
S-SSS #0	15.5	0	-0.8	2.32	-0.8	2.32	-3.14	8.48	0	194	361	293	569	431	6.41
S-SSS #1	14.36	0	-2.36	2.32	2.32	-2.36	-0.02	9.58	1	533	587	546	530	60	6.36
S-SSS #2	15.52	0	-1.58	2.32	-0.8	1.54	-3.14	9.35	2	288	584	162	12	47	6.45
S-SSS #3	13.39	0	2.32	2.32	2.32	2.32	-0.02	8.06	3	542	485	639	222	260	6.44
S-SSS #4	13.48	0	2.32	2.32	2.32	2.32	-0.02	8.98	4	297	455	57	10	202	6.47
S-SSS #5	15.79	0	-2.36	2.32	2.32	-2.36	-0.02	10.54	5	202	442	659	92	252	6.56
S-SSS #6	15.16	0	3.1	-3.14	-3.14	-1.58	2.32	10.07	6	193	153	463	388	488	6.39
S-SSS #7	15.1	0	-1.58	-0.02	0.76	1.54	-1.58	9.43	7	255	93	395	52	328	6.51
S-SSS #8	14.44	0	-0.8	2.32	-0.8	2.32	-3.14	8.57	8	39	332	145	641	222	6.38
S-SSS #9	13.01	0	2.32	2.32	2.32	2.32	-0.02	8.89	9	363	396	326	256	635	6.48
S-SSS #10	14.88	0	0.76	2.32	-0.8	-2.36	-3.14	9.99	10	364	521	163	312	144	6.26
S-SSS #551	13.73	0	2.32	2.32	3.1	2.32	0.76	8.77	551	268	263	71	223	224	6.03
PSBCH #0	17.17	0	3.1	3.1	-1.58	-0.8	-2.36	11.41	0	647	466	473	397	638	7.28
PSBCH #1	15.75	0	3.1	0.76	-0.02	-0.8	-0.8	11.12	1	214	15	414	532	368	7.09
PSBCH #2	14.61	0	-0.8	2.32	-0.8	-3.14	-2.36	9.15	2	586	497	455	565	404	7.02
PSBCH #3	15.16	0	-3.14	-2.36	-1.58	-0.02	-1.58	9.07	3	255	65	429	570	238	7.14
PSBCH #4	15.05	0	3.1	1.54	-3.14	0.76	0.76	9.16	4	267	250	128	395	88	7.07
PSBCH #5	14.89	0	2.32	2.32	2.32	2.32	-0.02	9.41	5	649	313	211	664	206	7.05
PSBCH #6	16.59	0	-2.36	-1.58	-0.8	1.54	-0.02	10.55	6	404	256	273	122	53	7.13
PSBCH #7	15.27	0	-2.36	-0.8	0.76	3.1	2.32	9.43	7	34	197	289	225	261	6.96
PSBCH #8	16.23	0	2.32	0.76	-0.8	3.1	-2.36	9.51	8	575	389	450	52	320	6.9
PSBCH #9	14.16	0	-0.02	1.54	-2.36	-0.02	-2.36	8.55	9	364	284	419	488	554	7.07
PSBCH #10	16.03	0	3.1	-1.58	-0.02	0.76	-0.02	9.93	10	140	125	546	578	230	7.08
PSBCH #73	13.37	0	2.32	-3.14	3.1	-3.14	1.54	8.83	73	64	68	44	189	4	6.61

		Phase adjust.
Signal	PAPR value w/o adjus.	Phases, radians								PAPR, dB
S-PSS #0	12.88	0	-1.34	-1.7	2.14	-0.92	1.3	1.54	-3.32	5.96
S-PSS #1	14.71	0	2.92	-0.92	-3.26	1.42	0.58	1.36	2.14	6.47
S-SSS #0	16.74	0	2.86	-0.2	1.54	2.38	3.04	1.42	-0.14	7.86
S-SSS #1	15.43	0	-1.46	-1.58	2.44	-0.8	1.48	1.54	-3.02	8.58
S-SSS #2	16.71	0	2.86	-0.8	-2.96	1.66	0.82	1.42	2.38	8.44
S-SSS #3	14.52	0	1.66	0.88	2.14	1.6	-0.62	-0.62	3.1	7.23
S-SSS #4	14.47	0	-0.86	-3.14	2.98	-2.42	-0.92	-3.38	-1.46	8.11
S-SSS #5	16.88	0	-1.7	-1.7	2.32	-0.74	1.48	1.6	-3.08	9.59
S-SSS #6	16.19	0	1.36	3.28	2.98	2.32	0.7	-2.9	1	8.98
S-SSS #7	16.35	0	0.1	-2.48	3.28	0.88	-2.9	1.66	-3.02	8.38
S-SSS #8	15.68	0	-1.52	-1.82	2.08	-1.04	1.3	1.6	-3.2	7.3
S-SSS #9	14.15	0	-2.12	0.04	-1.58	-2.48	-2.54	-0.62	0.04	8.01
S-SSS #10	15.77	0	1.42	-1.7	-0.86	-0.74	-1.64	1.6	-0.02	8.97
PSBCH #0	18.41	0	2.26	1.6	3.16	-2.96	1.36	1.6	-0.8	10.35
PSBCH #1	16.42	0	3.04	2.32	-0.26	-0.92	-0.62	-1.82	-0.8	10.25
PSBCH #2	15.5	0	-3.38	2.08	-0.74	-2.3	-1.64	3.1	-2.3	8.2
PSBCH #3	16.4	0	-0.68	-2.96	-2.96	-2.12	-0.56	3.16	-0.74	8.11
PSBCH #4	16	0	-0.02	-0.68	0.94	-3.14	-0.2	-1.64	2.14	8.16
PSBCH #5	15.88	0	-0.62	-2.96	3.28	-2.36	-0.98	2.56	-0.98	8.23
PSBCH #6	17.8	0	-2.36	2.56	-0.68	1.78	-2.96	2.98	3.22	9.57
PSBCH #7	16.29	0	3.16	-2.96	0.76	-0.02	1.36	0.04	1.48	8.78
PSBCH #8	17.46	0	-0.2	-3.14	2.26	-0.26	2.14	-0.26	1.36	8.62
PSBCH #9	15.4	0	0.7	1.72	0.88	-0.74	-3.02	-1.04	2.2	7.44
PSBCH #10	16.93	0	2.26	-2.42	0.76	-1.46	-2.9	-2.18	-2.24	9.08

		Use different NSLID
Signal	PAPR value w/o adjust.	ID combination								PAPR, dB
S-PSS #0	12.88	0	0	0	0	0	1	1	1	10.34
S-PSS #1	14.71	1	0	0	0	0	0	1	1	10.35
S-SSS #0	16.74	0	628	475	554	121	160	231	459	6.5
S-SSS #1	15.43	1	109	294	55	29	495	87	414	6.3
S-SSS #2	16.71	2	568	244	436	223	663	382	359	6.49
S-SSS #3	14.52	3	238	154	474	252	587	36	247	6.5
S-SSS #4	14.47	4	237	146	443	612	427	44	653	6.63
S-SSS #5	16.88	5	194	592	169	578	122	135	632	6.41
S-SSS #6	16.19	6	226	24	312	115	297	495	193	6.47
S-SSS #7	16.35	7	564	327	129	335	128	308	68	6.44
S-SSS #8	15.68	8	47	527	227	501	201	511	441	6.69
S-SSS #9	14.15	9	10	659	143	68	439	481	90	6.42
S-SSS #10	15.77	10	511	577	147	112	422	387	266	6.55
S-SSS #241	16.19	241	361	516	82	156	566	125	97	6.16
PSBCH #0	18.41	0	253	298	344	381	454	373	313	7.33
PSBCH #1	16.42	1	229	196	9	362	339	156	155	7.28
PSBCH #2	15.5	2	101	145	364	246	319	605	17	7.18
PSBCH #3	16.4	3	1	238	157	196	78	11	400	7.16
PSBCH #4	16	4	348	665	164	345	389	151	375	7.27
PSBCH #5	15.88	5	483	278	333	78	231	622	337	7.17
PSBCH #6	17.8	6	522	243	227	568	37	229	631	7.24
PSBCH #7	16.29	7	471	499	609	225	161	478	220	7.13
PSBCH #8	17.46	8	334	484	588	310	133	298	541	7.19
PSBCH #9	15.4	9	550	112	199	316	138	341	433	7.24
PSBCH #10	16.93	10	615	236	372	146	561	69	163	7.12
PSBCH #642	16.72	642	413	621	233	14	127	189	564	6.82

		Phase adjust.
Signal	PAPR value w/o adjus.	Phases, radians										PAPR, dB
S-PSS #0	13.81	0	-3.14	-0.02	-3.14	3.1	3.1	-1.58	-1.58	3.1	3.1	6.91
S-PSS #1	15.67	0	-0.02	-0.02	-0.02	3.1	3.1	-0.02	-3.14	-0.02	3.1	7.29
S-SSS #0	17.71	0	-1.58	1.54	-1.58	1.54	-0.02	-0.02	-3.14	-1.58	-0.02	8.54
S-SSS #1	16.15	0	-0.02	-3.14	3.1	-0.02	3.1	-0.02	3.1	-3.14	-3.14	8.78
S-SSS #2	17.61	0	-0.02	-1.58	3.1	-0.02	3.1	-0.02	-3.14	-1.58	-0.02	9.19
S-SSS #3	15.33	0	-1.58	-0.02	-1.58	-1.58	3.1	-0.02	-0.02	1.54	-3.14	7.98
S-SSS #4	15.11	0	-1.58	3.1	3.1	-0.02	1.54	1.54	1.54	1.54	-3.14	8.81
S-SSS #5	17.65	0	-3.14	-0.02	1.54	3.1	-3.14	-3.14	1.54	-0.02	3.1	10.03
S-SSS #6	16.87	0	-0.02	-1.58	-1.58	1.54	-1.58	1.54	1.54	-3.14	3.1	9.74
S-SSS #7	17.32	0	1.54	-3.14	-0.02	3.1	-0.02	-1.58	-3.14	-3.14	3.1	9.32
S-SSS #8	16.64	0	1.54	-0.02	-1.58	-1.58	1.54	-1.58	1.54	1.54	3.1	8.39
S-SSS #9	15.1	0	-0.02	-0.02	-0.02	-0.02	3.1	-3.14	-0.02	-3.14	-0.02	8.67
S-SSS #10	16.28	0	-3.14	-3.14	3.1	-1.58	1.54	3.1	1.54	-0.02	-3.14	9.47
PSBCH #0	19.38	0	-1.58	3.1	-3.14	-0.02	1.54	-3.14	1.54	3.1	3.1	11.17
PSBCH #1	16.77	0	1.54	3.1	1.54	-1.58	-3.14	-3.14	3.1	1.54	1.54	10.69
PSBCH #2	16.01	0	-3.14	-3.14	3.1	1.54	-1.58	-3.14	-1.58	-0.02	-3.14	8.73
PSBCH #3	17.35	0	1.54	3.1	3.1	-0.02	-1.58	3.1	-1.58	-3.14	-3.14	9.04
PSBCH #4	16.57	0	-1.58	-3.14	3.1	3.1	-1.58	-0.02	-3.14	-0.02	-1.58	8.85
PSBCH #5	16.5	0	3.1	3.1	-0.02	-1.58	1.54	3.1	1.54	1.54	1.54	9.16
PSBCH #6	18.72	0	-3.14	1.54	-1.58	-3.14	-1.58	-0.02	-0.02	-1.58	-1.58	10.42
PSBCH #7	16.97	0	-1.58	-1.58	-3.14	-0.02	-3.14	-0.02	1.54	3.1	-1.58	9.31
PSBCH #8	18.42	0	3.1	-0.02	3.1	-0.02	-0.02	-3.14	3.1	-3.14	3.1	9.52
PSBCH #9	16.37	0	1.54	-1.58	-3.14	3.1	1.54	-1.58	1.54	1.54	-3.14	8.18
PSBCH #10	17.43	0	-0.02	-0.02	-3.14	1.54	-1.58	-0.02	1.54	-1.58	-0.02	9.58

		Use different NSLID
Signal	PAPR value w/o adjus.	ID combination										PAPR, dB
S-PSS #0	13.81	0	0	0	0	0	0	1	1	1	1	11.52
S-PSS #1	15.67	1	0	0	0	0	0	0	1	1	1	11.53
S-SSS #0	17.71	0	601	431	7	460	530	9	669	218	124	6.53
S-SSS #1	16.15	1	82	432	33	649	151	206	497	264	660	6.72
S-SSS #2	17.61	2	533	414	357	629	612	446	489	125	77	6.63
S-SSS #3	15.33	3	45	463	61	244	406	357	580	639	511	6.58
S-SSS #4	15.11	4	319	478	384	627	558	421	438	569	184	6.57
S-SSS #5	17.65	5	158	204	220	488	125	606	429	113	538	6.62
S-SSS #6	16.87	6	483	362	283	186	206	545	52	302	226	6.69
S-SSS #7	17.32	7	180	265	371	121	591	458	556	227	350	6.3
S-SSS #8	16.64	8	103	615	437	499	567	167	93	314	603	6.67
S-SSS #9	15.1	9	206	273	352	506	217	66	206	99	600	6.72
S-SSS #10	16.28	10	162	386	582	577	501	331	65	275	648	6.52
S-SSS #72	17.01	72	219	519	588	577	217	373	205	567	78	6.21
PSBCH #0	19.38	0	558	33	223	414	443	495	465	17	67	7.22
PSBCH #1	16.77	1	510	664	349	455	219	269	162	236	503	7.2
PSBCH #2	16.01	2	423	154	38	284	449	526	645	58	595	7.13
PSBCH #3	17.35	3	485	465	58	376	477	47	31	417	529	7.22
PSBCH #4	16.57	4	644	39	303	482	187	529	318	256	354	7.27
PSBCH #5	16.5	5	597	468	366	93	434	164	368	212	341	7.25
PSBCH #6	18.72	6	535	315	632	90	187	600	619	147	596	7.24
PSBCH #7	16.97	7	491	537	351	388	194	666	566	670	170	7.35
PSBCH #8	18.42	8	452	609	205	131	213	654	69	63	336	7.22
PSBCH #9	16.37	9	265	64	528	636	53	250	42	497	131	7.26
PSBCH #10	17.43	10	375	429	250	342	419	602	447	524	502	7.27
PSBCH #543	16.09	543	620	192	665	427	270	663	593	622	60	6.89

In the present disclosure, the S-SSB may be mapped to resources and transmitted to other devices based on Table 26. Specific procedures are described in 3GPP TS 38.211 V17.5.0.

FIG. 15 shows inter-UE synchronization signal block resources that are repeated in the frequency domain, according to one embodiment of the present disclosure. The embodiment of FIG. 15 may be combined with various embodiments of the present disclosure.

Referring now to FIG. 15, inter-UE synchronization signal block resources 1 to 3 are shown. These three resources may be repeated resources in the frequency domain, and may be repeated resources in an increasing frequency direction. For example, although not shown in FIG. 15, a guard band may exist between two of the inter-UE synchronization signal block resources. The repeated inter-UE synchronization signal block resources may be included in one resource block set (e.g., RB set).

FIG. 16 shows a method for generating related signals when inter-UE synchronization signal blocks are repeated, according to one embodiment of the present disclosure. The embodiment of FIG. 16 may be combined with various embodiments of the present disclosure.

Referring to FIG. 16, inter-UE synchronization signal blocks (e.g., S-SSBs) to be transmitted on resources that are repeated in the frequency domain are shown. For example, the inter-UE synchronization signal blocks may each include an inter-UE primary synchronization signal (e.g., S-PSS), an inter-UE secondary synchronization signal (e.g., S-SSS), and an inter-UE physical broadcast channel signal (e.g., PSBCH). The repeated inter-UE synchronization signal blocks (e.g., S-SSBs) may be included in one resource block set (e.g., RB set).

For example, each inter-UE primary synchronization signal (e.g., S-PSS) may be generated based on phase rotation and ID combining, which may result in the lowest PAPR on the receiving UE side.

Further, for example, each inter-UE secondary synchronization signal (e.g., S-SSS) and inter-UE physical broadcast channel signal (e.g., PSBCH) may be generated based on ID combining, which may result in the lowest PAPR on the receiving UE side.

For example, a phase rotation operation may refer to an operation of mapping signals with phases rotated by specific values with respect to the phase of the signal (e.g., S-PSS, S-SSS, or PSBCH) included in the inter-UE synchronization signal block (e.g., S-SSB 1) transmitted from a resource at the lowest frequency among the inter-UE synchronization signal blocks to inter-UE synchronization signal blocks in a direction that increases the frequency at which the inter-UE synchronization signal block is transmitted, and transmitting.

For example, an ID combining operation may mean an operation of generating signals (e.g., S-PSS, S-SSS, or PSBCH) that are to be included in each of inter-UE synchronization signal blocks and mapping them to the inter-UE synchronization signal blocks in such a way that the frequency at which the inter-UE synchronization signal blocks are transmitted is increased based on the combination of IDs involved in generating the signals that are to be mapped to inter-UE synchronization signal blocks, and transmitting.

In order to secure transmission opportunities in an unlicensed band, an LBT operation (or channel sensing operation for CAP) may be performed. A transmission may be performed only if, after performing channel sensing on the channel sensing window from a time point earlier than the length of the channel sensing window at the time point of the transmission resource, the result is IDLE. For inter-UE communication (e.g., SL communication) operations in an unlicensed band, the occupied channel bandwidth (OCB) requirement may need to be satisfied. To achieve this, inter-UE synchronization signal block (e.g., S-SSB) transmission may be performed repeatedly in the frequency domain. However, this approach may suffer from PAPR degradation (i.e., reduced performance/coverage of the synchronization signal/channel), which may require a solution to address.

For transmissions of inter-UE synchronization signal blocks (e.g., S-SSBs), transmissions may be performed using multiple non-contiguous resource block sets (e.g., RB sets). That is, for example, when channel sensing related to channel access procedure is performed for resource block sets (e.g., RB sets) in the shared spectrum and the results includes at least one "BUSY" for at least one resource block sets (e.g., RB sets) among the resource block sets (e.g., RB sets), even if not all of the channel sensing results are "IDLE", at least one transmission for a resource block set (e.g., RB set) with the result of "IDLE" may be performed. That is, for example, when a transmission of inter-UE synchronization signal blocks (e.g., S-SSBs) using resource block sets (e.g., RB sets) is to be performed, if the channel sensing results for some of the resource block sets (e.g., RB sets) are "BUSY", since the transmission of the inter-UE synchronization signal blocks (e.g., S-SSBs) may be performed using the remaining resource block sets (e.g., S-SSBs) except for the resource block set (e.g., RB sets) with the sensing result "BUSY", the transmission of the inter-UE synchronization signal blocks (e.g., S-SSBs) using the resource block sets (e.g., RB sets) may eventually be performed using multiple non-contiguous resource block sets (e.g., RB sets).

When inter-UE synchronization signal blocks (e.g., S-SSB) are transmitted repeatedly in the frequency domain, the phase rotation scheme (for repeatedly transmitted inter-UE primary synchronization signals (e.g., S-PSS)) and the ID combination scheme (for repeatedly transmitted inter-UE secondary synchronization signals (e.g., S-PSS)) may be applied simultaneously for an inter-UE primary synchronization signal (e.g., S-PSS) (i.e., the phase rotation scheme and the ID combination scheme are applied together to optimize the PAPR performance because the total number of ID candidates that can be applied for the inter-UE primary synchronization signals (e.g., S-PSS) is two), and the phase rotation scheme and/or the ID combination scheme may be applied for an inter-UE secondary synchronization signal (e.g., S-SSS) and/or an inter-UE physical broadcast channel (e.g., PSBCH) (signal). Here, for example, the phase rotation values and/or ID combination values used for the repeated transmission of inter-UE synchronization signal blocks may be different according to parameters such as the repetition number of inter-UE synchronization signal blocks (e.g., S-SSBs) (in the frequency domain), inter-UE subcarrier spacing (e.g., SL SCS) value, the number of RB sets used in the transmissions of inter-UE synchronization signal blocks (e.g., S-SSBs), etc.

In shared spectrum, PAPR can be reduced as much as possible while still meeting OCB requirements. That is, repeated transmission of inter-UE synchronization signal blocks (e.g., S-SSBs) may be performed in a form that optimizes PAPR performance.

FIG. 17 shows a procedure for a first device to perform wireless communication, according to one embodiment of the present disclosure. The embodiment of FIG. 17 may be combined with various embodiments of the present disclosure.

Referring to FIG. 17, in step S1710, a first device may generate N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining. In step S1720, the first device may map N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum. For example, time resources of the N transmission resources may be the same, and the N transmission resources may be resources that are repeated N times in a frequency domain. In step S1730, the first device may perform channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources. In step S1740, the first device may transmit, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.

For example, the N may be 2, IDs related to the generation of the N inter-device primary synchronization signals may be 0, 1, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and phase values related to the generation of the N inter-device primary synchronization signals may be 0 rad, 3.14 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.

For example, the N may be 4, IDs related to the generation of the N inter-device primary synchronization signals may be 1, 1, 0, 0, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and phase values related to the generation of the N inter-device primary synchronization signals may be 0 rad, 3.06 rad, -3.04 rad, -3.04 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.

For example, the N may be 8, IDs related to the generation of the N inter-device primary synchronization signals may be 1, 1, 1, 1, 0, 0, 0, 0, in a direction of increasing frequency of the transmission resources over which the inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and phase values related to the generation of the N inter-device primary synchronization signals may be 0 rad, -1.58 rad, 2.32 rad, -2.36 rad, -1.58 rad, -3.14 rad, -2.36 rad, 0.80 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.

For example, additionally, the first device may generate N inter-device secondary synchronization signals based on ID combining. For example, each of the N inter-device secondary synchronization signals may be included in one of the N inter-device synchronization signal blocks, and parameters other than IDs, used in the generation of the N inter-device secondary synchronization signals may be the same.

For example, the N may be 2, and IDs related to the generation of the N inter-device secondary synchronization signals may be 533, 176, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device secondary synchronization signals are transmitted.

For example, the N may be 4, and IDs related to the generation of the N inter-device secondary synchronization signals may be 222, 96, 666, 548, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device secondary synchronization signals are transmitted.

For example, the N may be 8, and IDs related to the generation of the N inter-device secondary synchronization signals may be 241, 361, 516, 82, 156, 566, 125, 97, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device secondary synchronization signals are transmitted.

For example, additionally, the first device may generate N inter-device physical broadcast channel signals based on ID combining. For example, each of the N inter-device physical broadcast channel signals may be included in one of the N inter-device synchronization signal blocks, and parameters other than IDs, used in the generation of the N inter-device physical broadcast channel signals may be the same.

For example, the N may be 2, and IDs related to the generation of the N inter-device physical broadcast channel signals may be 297, 582, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device physical broadcast channel signals are transmitted.

For example, the N may be 4, and IDs related to the generation of the N inter-device physical broadcast channel signals may be 228, 182, 428, 16, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device physical broadcast channel signals are transmitted.

For example, the N may be 8, and IDs related to the generation of the N inter-device physical broadcast channel signals may be 642, 413, 621, 233, 14, 127, 189, 564, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device physical broadcast channel signals are transmitted.

For example, additionally, the first device may generate N inter-device secondary synchronization signals and N inter-device physical broadcast channel signals, based on ID combining. For example, phase values related to the generation of the N inter-device primary synchronization signals and IDs related to the generation of the N inter-device primary synchronization signals, the generation of the N inter-device secondary synchronization signals, and the generation of the N inter-device physical broadcast channel signals may be determined based on at least one of the N, a value of inter-device subcarrier spacing, or a number of resource block sets used in a transmission of inter-device synchronization signal blocks including the N inter-device synchronization signal blocks.

The embodiments described above may be applied to various devices described below. For example, a processor 102 of a first device 100 may generate N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining. And, the processor 102 of the first device 100 may map N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum. For example, time resources of the N transmission resources may be the same, and the N transmission resources may be resources that are repeated N times in a frequency domain. And, the processor 102 of the first device 100 may perform channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources. And, the processor 102 of the first device 100 may control a transceiver 106 to transmit, to a second device 200, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.

For example, additionally, the instructions may further comprise: generating N inter-device secondary synchronization signals based on ID combining. For example, each of the N inter-device secondary synchronization signals may be included in one of the N inter-device synchronization signal blocks, and parameters other than IDs, used in the generation of the N inter-device secondary synchronization signals may be the same.

For example, additionally, the instructions may further comprise: generating N inter-device physical broadcast channel signals based on ID combining. For example, each of the N inter-device physical broadcast channel signals may be included in one of the N inter-device synchronization signal blocks, and parameters other than IDs, used in the generation of the N inter-device physical broadcast channel signals may be the same.

For example, additionally, the operations may further comprise: generating N inter-device secondary synchronization signals and N inter-device physical broadcast channel signals, based on ID combining. For example, phase values related to the generation of the N inter-device primary synchronization signals and IDs related to the generation of the N inter-device primary synchronization signals, the generation of the N inter-device secondary synchronization signals, and the generation of the N inter-device physical broadcast channel signals may be determined based on at least one of the N, a value of inter-device subcarrier spacing, or a number of resource block sets used in a transmission of inter-device synchronization signal blocks including the N inter-device synchronization signal blocks.

FIG. 18 shows a procedure for a second device to perform wireless communication, according to one embodiment of the present disclosure. The embodiment of FIG. 18 may be combined with various embodiments of the present disclosure.

Referring to FIG. 18, in step S1810, a second device may receive, from a first device, N inter-device synchronization signal blocks, each including one of N inter-device primary synchronization signals, based on N transmission resources in a shared spectrum. For example, the N inter-device synchronization signal blocks may be transmitted based on a result of channel sensing related to a channel access procedure, performed for a resource block (RB) set including the N transmission resources being IDLE and the N transmission resources, time resources of the N transmission resources may be the same, the N transmission resources may be resources that are repeated N times in a frequency domain, the N inter-device synchronization signal blocks may be mapped one by one to the N transmission resources, and the N inter-device primary synchronization signals may be generated based on phase rotation and identifier (ID) combining.

The embodiments described above may be applied to various devices described below. For example, a processor 202 of a second device 200 may control a transceiver 206 to receive, from a first device 100, N inter-device synchronization signal blocks, each including one of N inter-device primary synchronization signals, based on N transmission resources in a shared spectrum. For example, the N inter-device synchronization signal blocks may be transmitted based on a result of channel sensing related to a channel access procedure, performed for a resource block (RB) set including the N transmission resources being IDLE and the N transmission resources, time resources of the N transmission resources may be the same, the N transmission resources may be resources that are repeated N times in a frequency domain, the N inter-device synchronization signal blocks may be mapped one by one to the N transmission resources, and the N inter-device primary synchronization signals may be generated based on phase rotation and identifier (ID) combining.

Various embodiments of the present disclosure may be combined with each other.

Hereinafter, device(s) to which various embodiments of the present disclosure can be applied will be described.

The various descriptions, functions, procedures, proposals, methods, and/or operational flowcharts of the present disclosure described in this document may be applied to, without being limited to, a variety of fields requiring wireless communication/connection (e.g., 5G) between devices.

Hereinafter, a description will be given in more detail with reference to the drawings. In the following drawings/description, the same reference symbols may denote the same or corresponding hardware blocks, software blocks, or functional blocks unless described otherwise.

FIG. 19 shows a communication system 1, based on an embodiment of the present disclosure. The embodiment of FIG. 19 may be combined with various embodiments of the present disclosure.

Referring to FIG. 19, a communication system 1 to which various embodiments of the present disclosure are applied includes wireless devices, Base Stations (BSs), and a network. Herein, the wireless devices represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE)) and may be referred to as communication/radio/5G devices. The wireless devices may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an Artificial Intelligence (AI) device/server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous vehicle, and a vehicle capable of performing communication between vehicles. Herein, the vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter. For example, the BSs and the network may be implemented as wireless devices and a specific wireless device 200a may operate as a BS/network node with respect to other wireless devices.

Here, wireless communication technology implemented in wireless devices 100a to 100f of the present disclosure may include Narrowband Internet of Things for low-power communication in addition to LTE, NR, and 6G. In this case, for example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology and may be implemented as standards such as LTE Cat NB1, and/or LTE Cat NB2, and is not limited to the name described above. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may perform communication based on LTE-M technology. In this case, as an example, the LTE-M technology may be an example of the LPWAN and may be called by various names including enhanced Machine Type Communication (eMTC), and the like. For example, the LTE-M technology may be implemented as at least any one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-Bandwidth Limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the name described above. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may include at least one of Bluetooth, Low Power Wide Area Network (LPWAN), and ZigBee considering the low-power communication, and is not limited to the name described above. As an example, the ZigBee technology may generate personal area networks (PAN) related to small/low-power digital communication based on various standards including IEEE 802.15.4, and the like, and may be called by various names.

The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200/network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs/network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g. Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

Wireless communication/

connections

150a, 150b, or 150c may be established between the wireless devices 100a to 100f/BS 200, or BS 200/BS 200. Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150a, sidelink communication 150b (or, D2D communication), or inter BS communication (e.g. relay, Integrated Access Backhaul (IAB)). The wireless devices and the BSs/the wireless devices may transmit/receive radio signals to/from each other through the wireless communication/

connections

150a and 150b. For example, the wireless communication/

connections

150a and 150b may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.

FIG. 20 shows wireless devices, based on an embodiment of the present disclosure. The embodiment of FIG. 20 may be combined with various embodiments of the present disclosure.

Referring to FIG. 20, a first wireless device 100 and a second wireless device 200 may transmit radio signals through a variety of RATs (e.g., LTE and NR). Herein, {the first wireless device 100 and the second wireless device 200} may correspond to {the wireless device 100x and the BS 200} and/or {the wireless device 100x and the wireless device 100x} of FIG. 19.

The first wireless device 100 may include one or more processors 102 and one or more memories 104 and additionally further include one or more transceivers 106 and/or one or more antennas 108. The processor(s) 102 may control the memory(s) 104 and/or the transceiver(s) 106 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 102 may process information within the memory(s) 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver(s) 106. The processor(s) 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory(s) 104. The memory(s) 104 may be connected to the processor(s) 102 and may store a variety of information related to operations of the processor(s) 102. For example, the memory(s) 104 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 102 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 102 and the memory(s) 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 106 may be connected to the processor(s) 102 and transmit and/or receive radio signals through one or more antennas 108. Each of the transceiver(s) 106 may include a transmitter and/or a receiver. The transceiver(s) 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202 and one or more memories 204 and additionally further include one or more transceivers 206 and/or one or more antennas 208. The processor(s) 202 may control the memory(s) 204 and/or the transceiver(s) 206 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 202 may process information within the memory(s) 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver(s) 206. The processor(s) 202 may receive radio signals including fourth information/signals through the transceiver(s) 106 and then store information obtained by processing the fourth information/signals in the memory(s) 204. The memory(s) 204 may be connected to the processor(s) 202 and may store a variety of information related to operations of the processor(s) 202. For example, the memory(s) 204 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 202 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 202 and the memory(s) 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 206 may be connected to the processor(s) 202 and transmit and/or receive radio signals through one or more antennas 208. Each of the transceiver(s) 206 may include a transmitter and/or a receiver. The transceiver(s) 206 may be interchangeably used with RF unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.

Hereinafter, hardware elements of the

wireless devices

100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or

more processors

102 and 202. For example, the one or

more processors

102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or

more processors

102 and 202 may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Unit (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or

more processors

102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or

more processors

102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document and provide the generated signals to the one or

more transceivers

106 and 206. The one or

more processors

102 and 202 may receive the signals (e.g., baseband signals) from the one or

more transceivers

106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document.

The one or

more processors

102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or

more processors

102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or

more processors

102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software and the firmware or software may be configured to include the modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be included in the one or

more processors

102 and 202 or stored in the one or

more memories

104 and 204 so as to be driven by the one or

more processors

102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of code, commands, and/or a set of commands.

The one or

more memories

104 and 204 may be connected to the one or

more processors

102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or

more memories

104 and 204 may be configured by Read-Only Memories (ROMs), Random Access Memories (RAMs), Electrically Erasable Programmable Read-Only Memories (EPROMs), flash memories, hard drives, registers, cash memories, computer-readable storage media, and/or combinations thereof. The one or

more memories

104 and 204 may be located at the interior and/or exterior of the one or

more processors

102 and 202. The one or

more memories

104 and 204 may be connected to the one or

more processors

102 and 202 through various technologies such as wired or wireless connection.

The one or

more transceivers

106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the methods and/or operational flowcharts of this document, to one or more other devices. The one or

more transceivers

106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, from one or more other devices. For example, the one or

more transceivers

106 and 206 may be connected to the one or

more processors

102 and 202 and transmit and receive radio signals. For example, the one or

more processors

102 and 202 may perform control so that the one or

more transceivers

106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or

more processors

102 and 202 may perform control so that the one or

more transceivers

106 and 206 may receive user data, control information, or radio signals from one or more other devices. The one or

more transceivers

106 and 206 may be connected to the one or

more antennas

108 and 208 and the one or

more transceivers

106 and 206 may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, through the one or

more antennas

108 and 208. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or

more transceivers

106 and 206 may convert received radio signals/channels etc. from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc. using the one or

more processors

102 and 202. The one or

more transceivers

106 and 206 may convert the user data, control information, radio signals/channels, etc. processed using the one or

more processors

102 and 202 from the base band signals into the RF band signals. To this end, the one or

more transceivers

106 and 206 may include (analog) oscillators and/or filters.

FIG. 21 shows a signal process circuit for a transmission signal, based on an embodiment of the present disclosure. The embodiment of FIG. 21 may be combined with various embodiments of the present disclosure.

Referring to FIG. 21, a signal processing circuit 1000 may include scramblers 1010, modulators 1020, a layer mapper 1030, a precoder 1040, resource mappers 1050, and signal generators 1060. An operation/function of FIG. 21 may be performed, without being limited to, the

processors

102 and 202 and/or the

transceivers

106 and 206 of FIG. 20. Hardware elements of FIG. 21 may be implemented by the

processors

102 and 202 and/or the

transceivers

106 and 206 of FIG. 20. For example, blocks 1010 to 1060 may be implemented by the

processors

102 and 202 of FIG. 20. Alternatively, the blocks 1010 to 1050 may be implemented by the

processors

102 and 202 of FIG. 20 and the block 1060 may be implemented by the

transceivers

106 and 206 of FIG. 20.

Codewords may be converted into radio signals via the signal processing circuit 1000 of FIG. 21. Herein, the codewords are encoded bit sequences of information blocks. The information blocks may include transport blocks (e.g., a UL-SCH transport block, a DL-SCH transport block). The radio signals may be transmitted through various physical channels (e.g., a PUSCH and a PDSCH).

Specifically, the codewords may be converted into scrambled bit sequences by the scramblers 1010. Scramble sequences used for scrambling may be generated based on an initialization value, and the initialization value may include ID information of a wireless device. The scrambled bit sequences may be modulated to modulation symbol sequences by the modulators 1020. A modulation scheme may include pi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complex modulation symbol sequences may be mapped to one or more transport layers by the layer mapper 1030. Modulation symbols of each transport layer may be mapped (precoded) to corresponding antenna port(s) by the precoder 1040. Outputs z of the precoder 1040 may be obtained by multiplying outputs y of the layer mapper 1030 by an N*M precoding matrix W. Herein, N is the number of antenna ports and M is the number of transport layers. The precoder 1040 may perform precoding after performing transform precoding (e.g., DFT) for complex modulation symbols. Alternatively, the precoder 1040 may perform precoding without performing transform precoding.

The resource mappers 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMA symbols) in the time domain and a plurality of subcarriers in the frequency domain. The signal generators 1060 may generate radio signals from the mapped modulation symbols and the generated radio signals may be transmitted to other devices through each antenna. For this purpose, the signal generators 1060 may include Inverse Fast Fourier Transform (IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-Analog Converters (DACs), and frequency up-converters.

Signal processing procedures for a signal received in the wireless device may be configured in a reverse manner of the signal processing procedures 1010 to 1060 of FIG. 21. For example, the wireless devices (e.g., 100 and 200 of FIG. 20) may receive radio signals from the exterior through the antenna ports/transceivers. The received radio signals may be converted into baseband signals through signal restorers. To this end, the signal restorers may include frequency downlink converters, Analog-to-Digital Converters (ADCs), CP remover, and Fast Fourier Transform (FFT) modules. Next, the baseband signals may be restored to codewords through a resource demapping procedure, a postcoding procedure, a demodulation processor, and a descrambling procedure. The codewords may be restored to original information blocks through decoding. Therefore, a signal processing circuit (not illustrated) for a reception signal may include signal restorers, resource demappers, a postcoder, demodulators, descramblers, and decoders.

FIG. 22 shows another example of a wireless device, based on an embodiment of the present disclosure. The wireless device may be implemented in various forms according to a use-case/service (refer to FIG. 19). The embodiment of FIG. 22 may be combined with various embodiments of the present disclosure.

Referring to FIG. 22,

wireless devices

100 and 200 may correspond to the

wireless devices

100 and 200 of FIG. 20 and may be configured by various elements, components, units/portions, and/or modules. For example, each of the

wireless devices

100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional components 140. The communication unit may include a communication circuit 112 and transceiver(s) 114. For example, the communication circuit 112 may include the one or

more processors

102 and 202 and/or the one or

more memories

104 and 204 of FIG. 20. For example, the transceiver(s) 114 may include the one or

more transceivers

106 and 206 and/or the one or

more antennas

108 and 208 of FIG. 20. The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140 and controls overall operation of the wireless devices. For example, the control unit 120 may control an electric/mechanical operation of the wireless device based on programs/code/commands/information stored in the memory unit 130. The control unit 120 may transmit the information stored in the memory unit 130 to the exterior (e.g., other communication devices) via the communication unit 110 through a wireless/wired interface or store, in the memory unit 130, information received through the wireless/wired interface from the exterior (e.g., other communication devices) via the communication unit 110.

The additional components 140 may be variously configured according to types of wireless devices. For example, the additional components 140 may include at least one of a power unit/battery, input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented in the form of, without being limited to, the robot (100a of FIG. 19), the vehicles (100b-1 and 100b-2 of FIG. 19), the XR device (100c of FIG. 19), the hand-held device (100d of FIG. 19), the home appliance (100e of FIG. 19), the IoT device (100f of FIG. 19), a digital broadcast terminal, a hologram device, a public safety device, an MTC device, a medicine device, a fintech device (or a finance device), a security device, a climate/environment device, the AI server/device (400 of FIG. 19), the BSs (200 of FIG. 19), a network node, etc. The wireless device may be used in a mobile or fixed place according to a use-example/service.

In FIG. 22, the entirety of the various elements, components, units/portions, and/or modules in the

wireless devices

100 and 200 may be connected to each other through a wired interface or at least a part thereof may be wirelessly connected through the communication unit 110. For example, in each of the

wireless devices

100 and 200, the control unit 120 and the communication unit 110 may be connected by wire and the control unit 120 and first units (e.g., 130 and 140) may be wirelessly connected through the communication unit 110. Each element, component, unit/portion, and/or module within the

wireless devices

100 and 200 may further include one or more elements. For example, the control unit 120 may be configured by a set of one or more processors. As an example, the control unit 120 may be configured by a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphical processing unit, and a memory control processor. As another example, the memory 130 may be configured by a Random Access Memory (RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory, a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 22 will be described in detail with reference to the drawings.

FIG. 23 shows a hand-held device, based on an embodiment of the present disclosure. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), or a portable computer (e.g., a notebook). The hand-held device may be referred to as a mobile station (MS), a user terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT). The embodiment of FIG. 23 may be combined with various embodiments of the present disclosure.

Referring to FIG. 23, a hand-held device 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a memory unit 130, a power supply unit 140a, an interface unit 140b, and an I/O unit 140c. The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110 to 130/140a to140c correspond to the blocks 110 to 130/140 of FIG. 22, respectively.

The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from other wireless devices or BSs. The control unit 120 may perform various operations by controlling constituent elements of the hand-held device 100. The control unit 120 may include an Application Processor (AP). The memory unit 130 may store data/parameters/programs/code/commands needed to drive the hand-held device 100. The memory unit 130 may store input/output data/information. The power supply unit 140a may supply power to the hand-held device 100 and include a wired/wireless charging circuit, a battery, etc. The interface unit 140b may support connection of the hand-held device 100 to other external devices. The interface unit 140b may include various ports (e.g., an audio I/O port and a video I/O port) for connection with external devices. The I/O unit 140c may input or output video information/signals, audio information/signals, data, and/or information input by a user. The I/O unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker, and/or a haptic module.

As an example, in the case of data communication, the I/O unit 140c may acquire information/signals (e.g., touch, text, voice, images, or video) input by a user and the acquired information/signals may be stored in the memory unit 130. The communication unit 110 may convert the information/signals stored in the memory into radio signals and transmit the converted radio signals to other wireless devices directly or to a BS. The communication unit 110 may receive radio signals from other wireless devices or the BS and then restore the received radio signals into original information/signals. The restored information/signals may be stored in the memory unit 130 and may be output as various types (e.g., text, voice, images, video, or haptic) through the I/O unit 140c.

FIG. 24 shows a vehicle or an autonomous vehicle, based on an embodiment of the present disclosure. The vehicle or autonomous vehicle may be implemented by a mobile robot, a car, a train, a manned/unmanned Aerial Vehicle (AV), a ship, etc. The embodiment of FIG. 24 may be combined with various embodiments of the present disclosure.

Referring to FIG. 24, a vehicle or autonomous vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 may be configured as a part of the communication unit 110. The blocks 110/130/140a to 140d correspond to the blocks 110/130/140 of FIG. 22, respectively.

The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and road side units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The control unit 120 may include an Electronic Control Unit (ECU). The driving unit 140a may cause the vehicle or the autonomous vehicle 100 to drive on a road. The driving unit 140a may include an engine, a motor, a powertrain, a wheel, a brake, a steering device, etc. The power supply unit 140b may supply power to the vehicle or the autonomous vehicle 100 and include a wired/wireless charging circuit, a battery, etc. The sensor unit 140c may acquire a vehicle state, ambient environment information, user information, etc. The sensor unit 140c may include an Inertial Measurement Unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement technology for maintaining a lane on which a vehicle is driving, technology for automatically adjusting speed, such as adaptive cruise control, technology for autonomously driving along a determined path, technology for driving by automatically setting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the obtained data. The control unit 120 may control the driving unit 140a such that the vehicle or the autonomous vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed/direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically/periodically acquire recent traffic information data from the external server and acquire surrounding traffic information data from neighboring vehicles. In the middle of autonomous driving, the sensor unit 140c may obtain a vehicle state and/or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and the driving plan based on the newly obtained data/information. The communication unit 110 may transfer information about a vehicle position, the autonomous driving path, and/or the driving plan to the external server. The external server may predict traffic information data using AI technology, etc., based on the information collected from vehicles or autonomous vehicles and provide the predicted traffic information data to the vehicles or the autonomous vehicles.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method.

Claims

A method for performing, by a first device, wireless communication, the method comprising:

generating N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining;

mapping N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum,

wherein time resources of the N transmission resources are the same, and

wherein the N transmission resources are resources that are repeated N times in a frequency domain;

performing channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and

transmitting, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.
The method of claim 1,

wherein the N is 2,

wherein IDs related to the generation of the N inter-device primary synchronization signals are 0, 1, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and

wherein phase values related to the generation of the N inter-device primary synchronization signals are 0 rad, 3.14 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.
The method of claim 1,

wherein the N is 4,

wherein IDs related to the generation of the N inter-device primary synchronization signals are 1, 1, 0, 0, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and

wherein phase values related to the generation of the N inter-device primary synchronization signals are 0 rad, 3.06 rad, -3.04 rad, -3.04 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.
The method of claim 1,

wherein the N is 8,

wherein IDs related to the generation of the N inter-device primary synchronization signals are 1, 1, 1, 1, 0, 0, 0, 0, in a direction of increasing frequency of the transmission resources over which the inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and

wherein phase values related to the generation of the N inter-device primary synchronization signals are 0 rad, -1.58 rad, 2.32 rad, -2.36 rad, -1.58 rad, -3.14 rad, -2.36 rad, 0.80 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.
The method of claim 1, further comprising:

generating N inter-device secondary synchronization signals based on ID combining,

wherein each of the N inter-device secondary synchronization signals is included in one of the N inter-device synchronization signal blocks, and

wherein parameters other than IDs, used in the generation of the N inter-device secondary synchronization signals are the same.
The method of claim 5, wherein the N is 2, and

wherein IDs related to the generation of the N inter-device secondary synchronization signals are 533, 176, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device secondary synchronization signals are transmitted.
The method of claim 5, wherein the N is 4, and

wherein IDs related to the generation of the N inter-device secondary synchronization signals are 222, 96, 666, 548, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device secondary synchronization signals are transmitted.
The method of claim 5, wherein the N is 8, and

wherein IDs related to the generation of the N inter-device secondary synchronization signals are 241, 361, 516, 82, 156, 566, 125, 97, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device secondary synchronization signals are transmitted.
The method of claim 1, further comprising:

generating N inter-device physical broadcast channel signals based on ID combining,

wherein each of the N inter-device physical broadcast channel signals is included in one of the N inter-device synchronization signal blocks, and

wherein parameters other than IDs, used in the generation of the N inter-device physical broadcast channel signals are the same.
The method of claim 9, wherein the N is 2, and

wherein IDs related to the generation of the N inter-device physical broadcast channel signals are 297, 582, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device physical broadcast channel signals are transmitted.
The method of claim 9, wherein the N is 4, and

wherein IDs related to the generation of the N inter-device physical broadcast channel signals are 228, 182, 428, 16, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device physical broadcast channel signals are transmitted.
The method of claim 9, wherein the N is 8, and

wherein IDs related to the generation of the N inter-device physical broadcast channel signals are 642, 413, 621, 233, 14, 127, 189, 564, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device physical broadcast channel signals are transmitted.
The method of claim 1, further comprising:

generating N inter-device secondary synchronization signals and N inter-device physical broadcast channel signals, based on ID combining,

wherein phase values related to the generation of the N inter-device primary synchronization signals and IDs related to the generation of the N inter-device primary synchronization signals, the generation of the N inter-device secondary synchronization signals, and the generation of the N inter-device physical broadcast channel signals are determined based on at least one of the N, a value of inter-device subcarrier spacing, or a number of resource block sets used in a transmission of inter-device synchronization signal blocks including the N inter-device synchronization signal blocks.
A first device for performing wireless communication, the first device comprising:

at least one transceiver;

at least one processor; and

at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the first device to perform operations,

wherein the operations comprise:

generating N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining;

mapping N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum,

wherein time resources of the N transmission resources are the same, and

wherein the N transmission resources are resources that are repeated N times in a frequency domain;

performing channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and

transmitting, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.
A device adapted to control a first user equipment (UE), the device comprising:

at least one processor; and

at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the first UE to perform operations,

wherein the operations comprise:

generating N inter-UE primary synchronization signals based on phase rotation and identifier (ID) combining;

mapping N inter-UE synchronization signal blocks, each including one of the N inter-UE primary synchronization signals to N transmission resources in a shared spectrum,

wherein time resources of the N transmission resources are the same, and

wherein the N transmission resources are resources that are repeated N times in a frequency domain;

performing channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and

transmitting, to a second UE, the N inter-UE synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.
A non-transitory computer-readable storage medium storing instructions that, based on being executed, cause a first device to:

generate N inter-device primary synchronization signals based on phase rotation and identifier (ID) combining;

map N inter-device synchronization signal blocks, each including one of the N inter-device primary synchronization signals to N transmission resources in a shared spectrum,

wherein time resources of the N transmission resources are the same, and

wherein the N transmission resources are resources that are repeated N times in a frequency domain;

perform channel sensing related to a channel access procedure for a resource block (RB) set including the N transmission resources; and

transmit, to a second device, the N inter-device synchronization signal blocks, based on a result of the channel sensing being IDLE and the N transmission resources.
A method for performing, by a second device, wireless communication, the method comprising:

receiving, from a first device, N inter-device synchronization signal blocks, each including one of N inter-device primary synchronization signals, based on N transmission resources in a shared spectrum,

wherein the N inter-device synchronization signal blocks are transmitted based on a result of channel sensing related to a channel access procedure, performed for a resource block (RB) set including the N transmission resources being IDLE and the N transmission resources,

wherein time resources of the N transmission resources are the same,

wherein the N transmission resources are resources that are repeated N times in a frequency domain,

wherein the N inter-device synchronization signal blocks are mapped one by one to the N transmission resources, and

wherein the N inter-device primary synchronization signals are generated based on phase rotation and identifier (ID) combining.
The method of claim 17,

wherein the N is 2,

wherein IDs related to the generation of the N inter-device primary synchronization signals are 0, 1, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and

wherein phase values related to the generation of the N inter-device primary synchronization signals are 0 rad, 3.14 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.
A second device for performing wireless communication, the second device comprising:

at least one transceiver;

at least one processor; and

at least one memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the second device to perform operations,

wherein the operations comprise:

receiving, from a first device, N inter-device synchronization signal blocks, each including one of N inter-device primary synchronization signals, based on N transmission resources in a shared spectrum,

wherein the N inter-device synchronization signal blocks are transmitted based on a result of channel sensing related to a channel access procedure, performed for a resource block (RB) set including the N transmission resources being IDLE and the N transmission resources,

wherein time resources of the N transmission resources are the same,

wherein the N transmission resources are resources that are repeated N times in a frequency domain,

wherein the N inter-device synchronization signal blocks are mapped one by one to the N transmission resources, and

wherein the N inter-device primary synchronization signals are generated based on phase rotation and identifier (ID) combining.
The second device of claim 19,

wherein the N is 2,

wherein IDs related to the generation of the N inter-device primary synchronization signals are 0, 1, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted, and

wherein phase values related to the generation of the N inter-device primary synchronization signals are 0 rad, 3.14 rad, in a direction of increasing frequency of the transmission resources over which the N inter-device synchronization signal blocks each including one of the N inter-device primary synchronization signals are transmitted.