Method and device for operation on basis of physical sidelink feedback channel (PSFCH) occasion in sidelink communication

Abstract

The present specification proposes a sidelink communication method and device. A terminal according to one disclosure in the present specification: configures at least one physical sidelink feedback channel (PSFCH) occasion; and performs a PSFCH transmission on the basis of the at least one configured PSFCH occasion, wherein the at least one PSFCH occasion is configured for each resource pool (RP) and the PSFCH transmission is performed within a channel occupancy time (COT).

Description

Method and device for operating based on PSFCH (PHYSICAL SIDELINK FEEDBACK CHANNEL) opportunity in sidelink communication

[0001] This specification relates to 3GPP 5G sidelink communications.

[0002] As more and more communication devices demand ever-increasing communication traffic, the need for next-generation 5G systems, which offer enhanced wireless broadband communication capabilities over existing LTE systems, is growing. This next-generation 5G system, known as NewRAT, differentiates communication scenarios into Enhanced Mobile BroadBand (eMBB), Ultra-reliability and low-latency communication (URLLC), and Massive Machine-Type Communications (mMTC).

[0003] Here, eMBB is a next-generation mobile communication scenario with characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate; URLLC is a next-generation mobile communication scenario with characteristics such as Ultra Reliable, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, and Remote Control); and mMTC is a next-generation mobile communication scenario with characteristics such as Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT).

[0004] The disclosure of the present specification is intended to provide a method and apparatus for operating based on a physical sidelink feedback channel (PSFCH) occasion in sidelink communication.

[0005] One embodiment of the present specification provides a method in which, in sidelink (SL) communication, a terminal sets at least one physical sidelink feedback channel (PSFCH) opportunity, and performs transmission of the PSFCH based on the set at least one PSFCH opportunity, wherein at least one PSFCH opportunity is set for each resource pool (RP), and transmission of the PSFCH is performed within a channel occupancy time (COT).

[0006] In addition, one embodiment of the present specification provides a terminal including, in sidelink (SL) communication, a control unit and a memory unit storing instructions and being operably electrically connectable to the control unit, wherein an operation performed based on the instructions being executed by the control unit is: setting at least one physical sidelink feedback channel (PSFCH) occasion, and performing transmission of the PSFCH based on the set at least one PSFCH occasion, wherein the at least one PSFCH occasion is set per resource pool (RP), and the transmission of the PSFCH is performed within a channel occupancy time (COT).

[0007] Meanwhile, the at least one PSFCH opportunity may be allocated to at least one slot. Here, the at least one slot includes a plurality of slots, and transmission of the PSFCH may be performed through one of the plurality of slots.

[0008] Additionally, PSFCH transmission attempts may be sequentially performed for the plurality of slots, and at least one slot in which a PSFCH transmission attempt failed may exist prior to one slot in which a PSFCH transmission is performed.

[0009] The period of at least one PSFCH opportunity preceding may be one of slot 1, slot 2, and slot 4.

[0010] Channel occupancy sharing information can be received from other terminals, and PSFCH transmission can be performed using this.

[0011] According to the disclosure of this specification, the operation of PSFCH for sidelink communication can be efficiently performed.

[0012] Figure 1 is a diagram illustrating an NR wireless communication system.

[0013] Figure 2 illustrates the structure of a radio frame used in NR.

[0014] Figure 3 illustrates the slot structure of an NR frame.

[0015] Figure 4 is an example showing an NG-RAN architecture supporting the PC5 interface.

[0016] Figures 5a and 5b illustrate a procedure for performing sidelink communication according to a sidelink resource allocation mode.

[0017] FIGS. 6A to 6C are diagrams illustrating a first method for setting a PSFCH opportunity within a COT according to the disclosure of the present specification.

[0018] FIGS. 7A to 7D are diagrams illustrating a second method for setting a PSFCH opportunity within a COT according to the disclosure of the present specification.

[0019] FIGS. 8A and 8B are diagrams illustrating a third method for setting a PSFCH opportunity within a COT according to the disclosure of the present specification.

[0020] Figure 9 illustrates an operation method of a terminal according to one embodiment of the present specification.

[0021] Fig. 10 illustrates an operation method of a terminal according to another embodiment of the present specification.

[0022] FIG. 11 illustrates a wireless communication device according to one embodiment of the present specification.

[0023] Although this specification describes embodiments using LTE systems, LTE-A systems, and NR systems, these embodiments may be applied to any communication system falling within the above definitions.

[0024] Additionally, the name of the base station in this specification may be used as a comprehensive term including RRH (remote radio head), eNB, TP (transmission point), RP (reception point), relay, etc.

[0025] 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from higher layers, and downlink physical signals corresponding to resource elements that are used by the physical layer but do not carry information originating from higher layers. For example, the physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), physical multicast channel (PMCH), physical control format indicator channel (PCFICH), physical downlink control channel (PDCCH), and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, is a signal with a predefined special waveform known to the gNB and the UE. For example, cell specific RS, UE-specific RS (UE-RS), positioning RS (PRS), and channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE / LTE-A standard defines uplink physical channels corresponding to resource elements carrying information originating from higher layers, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers.For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are defined as uplink physical channels, and a demodulation reference signal (DMRS) for uplink control / data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

[0026] In this specification, PDCCH (Physical Downlink Control CHannel) / PCFICH (Physical Control Format Indicator CHannel) / PHICH ((Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel) mean a set of time-frequency resources or a set of resource elements that carry DCI (Downlink Control Information) / CFI (Control Format Indicator) / downlink ACK / NACK (ACKnowlegement / Negative ACK) / downlink data, respectively. In addition, PUCCH (Physical Uplink Control CHannel) / PUSCH (Physical Uplink Shared CHannel) / PRACH (Physical Random Access CHannel) mean a set of time-frequency resources or a set of resource elements that carry UCI (Uplink Control Information) / uplink data / random access signals, respectively.

[0027] Meanwhile, the NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges (FR1, FR2) can be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the “sub 6 GHz range”, and FR2 can mean the “above 6 GHz range” and can be called millimeter wave (mmW).

[0028] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0029] The numerical value of the frequency range of the NR system can be changed. For example, FR1 can include a band from 410 MHz to 7125 MHz, as shown in Table 1. That is, FR1 can include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 can include unlicensed bands. Unlicensed bands can be used for various purposes, such as for vehicle communications (e.g., autonomous driving).

[0030] Figure 1 is a diagram illustrating an NR wireless communication system.

[0031] Referring to FIG. 1, the NR wireless communication system can be divided into a 5G core network (5GC) and a next generation-radio access network (NG-RAN), and the NG-RAN can include a base station (gNB and / or ng-eNB) that provides user plane and control plane protocol termination to user equipment (UE). The gNB (next generation-Node B) provides NR user plane and control plane protocol termination to the UE, and the ng-eNB (next generation-evolved Node B) provides evolved-universal terrestrial radio access (E-UTRA) user plane and control plane protocol termination to the UE. The UE can be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), or a wireless device. A base station (gNB and / or ng-eNB) may be a fixed station that communicates with a terminal (UE) and may be called by other terms such as base transceiver system (BTS), access point, etc.

[0032] Base stations (gNB and / or ng-eNB) can be connected to each other via Xn interfaces and can be connected to 5GC (5G core network) via NG interfaces. Specifically, base stations (gNB and / or ng-eNB) can be connected to AMF (access and mobility management function) via NG-C interfaces and can be connected to UPF (user plane function) via NG-U interfaces.

[0033] Figure 2 illustrates the structure of a radio frame used in NR.

[0034] In NR, uplink and downlink transmissions are structured as frames. A radio frame is 10ms long and is defined by two 5ms half-frames (HF). Each half-frame is defined by five 1ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols, depending on the cyclic prefix (CP). When a regular CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or DFT-s-OFDM symbols).

[0035] Table 2 illustrates that when CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0036] SCS(15*2 u )N slot symb N frame,u slot N subframe,u slot 15 KHz(u =0)1410130 KHz(u=1)1420260 KHz(u=2)14404120 KHz(u=3)14808240 KHz(u=4)1416016

[0037] N slot symb : Number of symbols in the slot

[0038] N frame,u slot : Number of slots in the frame

[0039] ​​N subframe,u slot : Number of slots in a subframe

[0040] Table 3 illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0041] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0042] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0043] Figure 3 illustrates the slot structure of an NR frame.

[0044] ​​A slot contains multiple symbols in the time domain. For example, a slot contains 14 symbols for a regular CP, but 12 symbols for an extended CP. A carrier contains multiple subcarriers in the frequency domain. A resource block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) is defined as multiple consecutive (P)RBs in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 4) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a resource element (RE), to which one complex symbol can be mapped.

[0045] Figure 4 is an example showing an NG-RAN architecture supporting the PC5 interface.

[0046] Referring to Figure 4, the NG-RAN (next generation-radio access network) architecture supports the PC5 interface. Sidelink transmission and reception via the PC5 interface are supported when the UE is inside NG-RAN coverage and when the UE is outside NG-RAN coverage, regardless of the RRC (radio resource control) state the UE is in.

[0047] Support for V2X (Vehicle-to-Everything) services via the PC5 interface can be provided by NR sidelink communications and / or V2X sidelink communications. NR sidelink communications can also be used to support services other than V2X services.

[0048] NR sidelink communication can support one of the following transmission modes: unicast, groupcast, and broadcast. In the case of unicast sidelink communication, a terminal can perform one-to-one communication with another terminal, and in the case of groupcast sidelink communication, a terminal can perform sidelink communication with one or more terminals within the group to which it belongs.

[0049] Figures 5a and 5b illustrate a procedure for performing sidelink communication according to a sidelink resource allocation mode.

[0050] Figure 5a shows terminal operation related to NR resource allocation mode 1, and Figure 5b shows terminal operation related to NR resource allocation mode 2.

[0051] Referring to FIG. 5A, in NR resource allocation mode 1, a base station can schedule sidelink (SL) resources to be used by a terminal (UE) for sidelink (SL) transmission. For example, the base station can perform resource scheduling using downlink control information (DCI) transmitted to terminal 1 (UE1) via a physical downlink control channel (PDCCH), and UE1 can perform V2X or SL communication with terminal 2 (UE2) according to the resource scheduling. For example, UE1 can transmit sidelink control information (SCI) to UE2 via a physical sidelink control channel (PSCCH), and then transmit SL data based on the SCI to UE2 via a physical sidelink shared channel (PSSCH).

[0052] Referring to FIG. 5b, in NR resource allocation mode 2, a terminal can determine an SL transmission resource within the SL resources configured by the base station or within preset SL resources. For example, the configured SL resources or preset SL resources may be an SL resource pool (sidelink resource pool). For example, the terminal can autonomously select or schedule resources for SL transmission. That is, the terminal can perform SL communication by selecting resources within the configured resource pool. In addition, the terminal can perform sensing and resource (re)selection procedures to select resources within a selection window. For example, the sensing can be performed on a sub-channel basis. As illustrated in FIG. 5b, UE1, which has selected a resource within the resource pool, can transmit SCI to UE2 via PSCCH and then transmit data based on the SCI to UE2 via PSSCH.

[0053] Discussions are underway on PSFCH transmission methods using PSFCH occasions and channel access in SL-U (sidelink-unlicensed), and development of relevant PSFCH transmission methods and operations is needed. Therefore, this specification proposes solutions related to the above.

[0054] Disclosure 1: A Scheme for Establishing PSFCH Occasions within the Coordinated Transmission Control System

[0055] Based on the NR sidelink (SL), the PSFCH (transmission) opportunity (occasion) for each resource pool (RP) is set to 1, 2, or 4 slot cycles and is operated, and RP configuration without PSFCH occasion is possible. Therefore, the configuration for PSFCH occasion in SL-U can be applied using the contents of the initiation method as follows.

[0056] Method 1

[0057] FIGS. 6A to 6C are diagrams illustrating a first method for setting a PSFCH opportunity within a COT according to the disclosure of the present specification.

[0058] The PSFCH setting values ​​set for each RP are also applied within the COT section. In this case, the PSFCH occasion setting within the COT initiated by SL-U will have a PSFCH occasion in the slot of the 1, 2, or 4 slot cycle set by the RP.

[0059] Fig. 6a is an example of an SL slot format with a PSFCH occasion where PSCCH is allocated for 3 symbols, Fig. 6b is an example of an SL slot format without a PSFCH occasion where PSCCH is allocated for 3 symbols, and Fig. 6c is an example of an allocation of slots with a PSFCH occasion when a PSFCH occasion is set for a 2-slot period in an RP. Slots capable of sending a PSFCH occasion as in Fig. 6a can be allocated for 2-slot periods, such as Slots #0, #2, and #4. SL slots without a PSFCH occasion as in Fig. 6b can be allocated for the remaining Slots #1, #3, etc. In Fig. 6c, a case is indicated where a specific UE successfully initiates a COT through a channel access attempt, and the COT starts from SL slot #3. In this case, the first occasion where PSFCH can actually be transmitted can be PSFCH transmission from SL slot #4 according to the PSFCH occasion set in the RP. That is, the first PSFCH occasion starts from SL slot#4.

[0060] Method 2

[0061] FIGS. 7A to 7D are diagrams illustrating a second method for setting a PSFCH opportunity within a COT according to the disclosure of the present specification.

[0062] Based on the PSFCH occasion settings set for each RP, the PSFCH occasions used within the COT can be configured through COT-SI (sharing information). At this time, it is possible to operate so that additional PSFCH occasions other than the PSFCH occasions set for each RP cannot be configured within the COT. In other words, among the PSFCH occasions set for each RP, the PSFCH occasions to be used within the COT can be reconfigured and operated through COT-SI.

[0063] When resetting a PSFCH occasion through COT-SI, COT-SI includes periodic information about the PSFCH occasion within the COT, and PSFCH operation can be performed based on this.

[0064] Fig. 7a illustrates a case where the PSFCH occasion setting in the RP is set to a 1-slot cycle. That is, there is a PSFCH occasion in every slot. In this case, if the COT-SI indicates a 2-slot cycle for the PSFCH occasion setting within the COT, the PSFCH occasions available within the COT, such as SL slot#1, SL slot#3, and SL slot#5, can be reset, as shown in Fig. 7b.

[0065] Meanwhile, FIG. 7c illustrates a case where the PSFCH occasion setting in the RP is set to a 2-slot cycle. That is, there is one PSFCH occasion every 2 slots. In this case, if the COT-SI indicates the PSFCH occasion setting in the COT again to a 2-slot cycle, only one slot out of every two slots can be set and operated as a PSFCH occasion in the COT within the preset PSFCH occasion. That is, if the PSFCH occasion based on the PSFCH occasion set in the RP is allocated in the form of the previous PSFCH occasion slot index +2, such as SL slot#2, SL slot#4, SL slot#6, etc., it can be allocated in the form of the previous PSFCH occasion slot index +4, such as SL slot#2, SL slot#6, etc. within the COT, as shown in FIG. 7d.

[0066] In the example of the above method, it was described as including additional period information used within COT-SI based on slot period information for PSFCH occasion set in RP, but the period to be used within COT can be directly included and operated.

[0067] For example, in the case of FIGS. 7a and 7b, the PSFCH occasion slot period information in COT-SI can be set to 2 and operated. In addition, in the case of FIGS. 7c and 7d, the PSFCH occasion slot period information can be set to 4 and operated.

[0068] At this time, the starting point of the PSFCH occasion can be indicated through the COT-SI depending on the starting point of the COT. For example, in FIG. 7d, the PSFCH occasion slot period is 4, but in order to operate within the PSFCH occasion set in the RP, the PSFCH occasion within the COT must start from SL slot #2. In this case, the slot location where the PSFCH occasion starts within the COT can be additionally indicated through the COT-SI. The location of the corresponding slot can be relative location information within the COT.

[0069] Alternatively, the location information of the slot where the COT starts may be indicated through COT-SI to enable the terminal to know the location where the PSFCH occasion starts within the COT based on the PSFCH occasion slot period information set for each RP. The location of the slot may be relative location information within the COT.

[0070] Unlike the above methods, PSFCH occasions that can be used within a COT can be allocated in the form of a bit map through COT-SI. COT-SI can indicate a bit map for PSFCH occasions to be used within a COT based on the entire SL slot of the COT. For example, assuming that the COT is from SL slot#1 to SL slot#5 in the examples of FIGS. 7a and 7b, the bit map can be indicated in the form of "10101."

[0071] In the examples of FIGS. 7c and 7d, assuming that COT is from SL slot#1 to SL slot#6, the bit map can be indicated in the form of "010001".

[0072] Alternatively, to reduce the size of the bit map, the bit map can be set based on the PSFCH occasion slots set in the RP. In the examples of FIGS. 7c and 7d, assuming that the COT is from SL slot#1 to SL slot#6, only SL slots #2 and #6 are set and used within the COT based on SL slots#2, #4, and #6 set by the RP, so the bit map can be indicated in the form of "101". In this case, the starting point of the PSFCH occasion can be indicated through COT-SI according to the starting point of the COT suggested above. Alternatively, the location information of the slot where the COT starts can be indicated through COT-SI.

[0073] Third method

[0074] FIGS. 8A and 8B are diagrams illustrating a third method for setting a PSFCH opportunity within a COT according to the disclosure of the present specification.

[0075] Based on the PSFCH occasion settings set for each RP, additional PSFCH occasions to be used within the COT can be configured through COT-SI (sharing information). That is, in addition to the PSFCH occasions set for each RP, additional PSFCH occasions to be used within the COT can be reconfigured and operated through COT-SI.

[0076] An additional PSFCH occasion slot period can be indicated via COT-SI to additionally configure PSFCH occasions within the COT. Alternatively, an additional PSFCH slot period can be configured via an indication in the form of a bit map.

[0077] When indicating an additional PSFCH occasion slot period within the COT-SI, a lower period value than the PSFCH slot period set for the existing RP can be set to configure the PSFCH occasion set for each RP and the additional PSFCH occasion within the COT. For example, if the PSFCH occasion slot period for each RP is set to 4 and the PSFCH occasion slot period is indicated as 2 through the COT-SI, a PSFCH occasion is set every 2 slots within the COT, so that PSFCH occasion settings including the PSFCH occasion set for each RP are possible.

[0078] When indicating an additional PSFCH occasion slot period within the COT-SI, the period value can be set based on the remaining slots excluding the PSFCH occasion set for each RP within the COT. Fig. 8a is an example in which the PSFCH occasion slot period set for each RP is set to 4 and the setting is applied as is within the COT section. When indicating an additional PSFCH occasion slot period of 2 through the COT-SI, additional PSFCH occasion allocation is possible as shown in Fig. 8b. Based on Fig. 8a, slots without PSFCH occasions are SL slots #1, #2, #3, #5, #6, and #7, and an example in which a PSFCH occasion slot period of 2 is applied to SL slots #1, #3, and #6 to additionally allocate PSFCH occasions.

[0079] In FIGS. 8A and 8B, the starting position of the PSFCH occasion is fixed to the first slot of the COT. However, the starting position of the PSFCH occasion can be indicated through the COT-SI, and the location can be set and operated so that it can be changed. At this time, in order to indicate the starting position of the PSFCH occasion in the COT-SI, an indication of the COT starting position or the starting slot position within the COT can be directly indicated. In this case, the position of the corresponding slot can be relative position information within the COT.

[0080] Unlike the indication method using the period value, a bit map-type indication method can be used to additionally set a PSFCH occasion within the COT through the COT-SI. If a bit map is configured based on the entire COT slot, it can be indicated in the form of '11011010' based on FIG. 8b. To reduce the size of the bit map, the bit map can be configured based on the remaining slots other than the PSFCH occasion configured for each RP. In this case, a 6-bit bit map can be configured based on slots SL slot#1, SL slot#2, SL slot#3, SL slot#5, SL slot#6, and SL slot#7, which are slots within the COT without a PSFCH occasion configured for each RP based on FIG. 8a. Since the additionally used slots in FIG. 8b are SL slots #1, #3, and #6, the bit map can be configured as '101010'.

[0081] Method 4

[0082] Regardless of the RP setting, PSFCH occasions can be set and operated by COT-SI. To this end, the PSFCH occasion slot cycle can be set based on all slots within the COT through COT-SI. Alternatively, a bit map can be configured and indicated for setting PSFCH occasion slots within the COT.

[0083] In the above method, the PSFCH occasion in COT-SI can be indicated based on or in conjunction with the configuration information values ​​such as the PSFCH occasion slot cycle set for each RP. That is, the indication method(s) in COT-SI proposed in the second or third method described above can be applied, and also can be applied in a simple, modified, combined, and / or extended form of the method(s).

[0084] In the case of the 4th method, it can be operated to be used for PSFCH occasion settings within the COT only when there is no PSFCH occasion setting for each RP.

[0085] The contents of the first to fourth methods for setting up PSFCH occasions within the COT can be operated in simple, modified, combined and / or extended forms.

[0086] In the third and fourth methods, in addition to the PSFCH occasions set for each RP within the COT, channel access can be performed on the PSFCH occasion only for the COT initiating UE, responding UE, or UE that has received COT-SI information. This can be utilized as a configuration and operation method for COT-specific PSFCH occasions. Here, the COT initiating UE is the UE that initiated the COT, and the responding UE is the target UE of the COT initiating UE, i.e., the UE to which the COT initiating UE wishes to transmit data / signal.

[0087] Therefore, in the case of a PSFCH occasion configured COT-specifically within a COT, if neither the COT initiating UE nor the responding UE transmits PSFCH at the specific PSFCH occasion, the COT initiating UE or the responding UE need not transmit signals such as a PSFCH like signal or PSSCH at the occasion to prevent any user from accessing the corresponding resource area or to prevent COT interruption. However, in the case of a PSFCH occasion within a COT configured by an RP, if neither the COT initiating UE nor the responding UE transmits PSFCH at the specific PSFCH occasion, the COT initiating UE or the responding UE can transmit a PSSCH or a PSFCH like signal at the occasion to prevent COT interruption.

[0088] Second Disclosure: A Scheme for Occasional Operation of N PSFCHs Associated with One PSCCH / PSSCH

[0089] Within a COT, N PSFCHs associated with one PSCCH / PSSCH can be configured. At this time, the N value can be configured RP-specifically or COT-specifically. For configuration, one or a combination of RRC (radio resource control), MAC-CE (medium access control-control element), and SCI (sidelink control information) can be configured. When configured COT-specifically, it can be indicated in COT-SI. COT-SI can be configured with one or a combination of RRC, MAC-CE, and SCI, and at least SCI can be included for COT-SI configuration.

[0090] The maximum number of PSFCH transmission attempts for a PSCCH / PSSCH within the COT or in the COT and subsequent sections can be set and operated to N. For example, in an environment where there are N PSFCH occasions associated with a PSCCH / PSSCH, if LBT fails at the nearest PSFCH occasion, PSFCH transmission through LBT can be attempted sequentially at the configured PSFCH occasions.

[0091] In the above operation, if HARQ feedback RTT (round trip time) restriction is set, that is, if ACK / NACK for one PSCCH / PSSCH is set to be fed back within a specific time, the maximum number of times that PSFCH can be transmitted may be restricted. For convenience of explanation, let us assume that a specific time duration within which the HARQ feedback must arrive is T based on the time point at which one PSCCH / PSSCH is transmitted. That is, among N PSFCH occasions, PSFCH transmission cannot be attempted in a PSFCH occasion that exceeds time point T. Therefore, the maximum number of PSFCH transmission attempts corresponding to one PSCCH / PSSCH in SL-U can be determined to be a value less than or equal to N based on the time point at which the PSCCH / PSSCH is transmitted, the N value, and the T value.

[0092] Third Disclosure: A Scheme for PSFCH Occasional Operations within the COT

[0093] The operation of allowing PSFCH transmission to a UE other than the COT initiating UE by using the PSFCH occasion set within the COT can be performed in the following manner.

[0094] Through COT-SI, a responding UE within a COT can operate by including indication information on whether or not to allow PSFCH transmission to UEs other than the COT initiating UE. For example, this can be indicated through a 1-bit field within the COT-SI. In this case, if PSFCH transmission is allowed according to the indication, the responding UE can perform PSFCH transmission to UEs other than the COT initiating UE. Conversely, if PSFCH transmission is not allowed, the responding UE can attempt PSFCH transmission to other UEs through a PSFCH occasion configured for each RP in a resource section other than the COT resource region.

[0095] Figure 9 illustrates an operation method of a terminal according to one embodiment of the present specification.

[0096] Referring to FIG. 9, a terminal sets at least one first physical sidelink feedback channel (PSFCH) opportunity within a channel occupancy time (COT) (S901). Thereafter, sidelink communication is performed based on the set at least one first PSFCH opportunity (S902).

[0097] The period of at least one first PSFCH opportunity set above may be 1 slot, 2 slots or 4 slots.

[0098] The period of at least one of the first PSFCH opportunities may be set per resource pool (RP).

[0099] Resetting the cycle of at least one of the first PSFCH opportunities may utilize COT-SI (sharing information).

[0100] Meanwhile, at least one second PSFCH opportunity may be set in addition to the at least one first PSFCH opportunity. Furthermore, COT-SI (sharing information) may be used to set the cycle of the at least one second PSFCH opportunity.

[0101] Fig. 10 illustrates an operation method of a terminal according to another embodiment of the present specification.

[0102] Referring to FIG. 10, a terminal sets at least one PSFCH (physical sidelink feedback channel) opportunity (S1001). Thereafter, based on the set at least one PSFCH opportunity, PSFCH transmission is performed (S1002). Here, at least one PSFCH opportunity is set for each resource pool (RP), and PSFCH transmission can be performed within the channel occupancy time (COT).

[0103] Meanwhile, the at least one PSFCH opportunity may be allocated to at least one slot. Here, the at least one slot includes a plurality of slots, and transmission of the PSFCH may be performed through one of the plurality of slots.

[0104] Additionally, PSFCH transmission attempts may be sequentially performed for the plurality of slots, and at least one slot in which a PSFCH transmission attempt failed may exist prior to one slot in which a PSFCH transmission is performed.

[0105] The period of at least one PSFCH opportunity preceding may be one of slot 1, slot 2, and slot 4.

[0106] Channel occupancy sharing information can be received from other terminals, and PSFCH transmission can be performed using this.

[0107] Below, a description is given of a device to which this specification can be applied.

[0108] FIG. 11 illustrates a wireless communication device according to one embodiment of the present specification.

[0109] Referring to FIG. 11, a wireless communication system may include a first device (100) and a second device (200).

[0110] The first device (100) may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or any other device related to the 4th industrial revolution field.

[0111] The second device (200) may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or a device related to other fields of the 4th industrial revolution.

[0112] The first device (100) may include at least one processor, such as a control unit (1020), at least one memory, such as a memory unit (1030), and at least one transceiver, such as a transceiver unit (1010). In addition, the first device (100) may further include a power supply unit (1040) that supplies and controls power to the control unit (1020), the memory unit (1030), and / or the transceiver unit (1010). The control unit (1020) may perform the functions, procedures, and / or methods described above. The control unit (1020) may perform one or more protocols. For example, the control unit (1020) may perform one or more layers of a wireless interface protocol. The memory unit (1030) may be connected to the control unit (1020) and may store various types of information and / or commands. The above transmitting and receiving unit (1010) is connected to the control unit (1020) and can be controlled to transmit and receive wireless signals.

[0113] The second device (200) may include at least one processor, such as a control unit (2020), at least one memory, such as a memory unit (2030), and at least one transceiver, such as a transceiver unit (2010). In addition, the second device (200) may further include a power supply unit (2040) that supplies and controls power to the control unit (2020), the memory unit (2030), and / or the transceiver unit (2010). The control unit (2020) may perform the functions, procedures, and / or methods described above. The control unit (2020) may perform one or more protocols. For example, the control unit (2020) may perform one or more layers of a wireless interface protocol. The memory unit (2030) may be connected to the control unit (2020) and may store various types of information and / or commands. The above transmitting and receiving unit (2010) is connected to the control unit (2020) and can be controlled to transmit and receive wireless signals.

[0114] The memory unit (1030) and / or the memory unit (2030) may be connected to the control unit (1020) and / or the control unit (2020) either internally or externally, respectively, and may be connected to other control units via various technologies such as wired or wireless connections.

[0115] The first device (100) and / or the second device (200) may have one or more antennas. For example, the antenna (1050) and / or the antenna (2050) may be configured to transmit and receive wireless signals.

[0116] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various forms within the scope described in the spirit and claims of this specification.

Claims

1. In a method for a terminal to perform sidelink communication, A step of establishing at least one physical sidelink feedback channel (PSFCH) occasion; and A step of performing transmission of a PSFCH based on at least one PSFCH opportunity set above, At least one PSFCH opportunity is set per resource pool (RP), A method in which the transmission of the above PSFCH is performed within a channel occupancy time (COT).

2. In paragraph 1, A method wherein at least one PSFCH opportunity is allocated to at least one slot.

3. In paragraph 2, A method wherein at least one slot includes a plurality of slots, and transmission of the PSFCH is performed through one of the plurality of slots.

4. In paragraph 3, A method further comprising the step of sequentially performing PSFCH transmission attempts for the plurality of slots.

5. In paragraph 4, A method wherein, prior to the one slot in which the transmission of the PSFCH is performed, there exists at least one slot in which the transmission attempt of the PSFCH failed.

6. In paragraph 1, A method wherein the period of at least one PSFCH opportunity is one of 1 slot, 2 slots and 4 slots.

7. In paragraph 1, A method further comprising the step of receiving channel occupancy sharing information from another terminal.

8. As a terminal performing sidelink communication, control unit; and A memory unit storing instructions and being operably electrically connectable to the control unit, wherein the operations performed based on the instructions being executed by the control unit are: A step of establishing at least one PSFCH (physical sidelink feedback channel) occasion, and A step of performing transmission of a PSFCH based on at least one PSFCH opportunity set above, At least one PSFCH opportunity is set per resource pool (RP), The transmission of the above PSFCH is performed within the channel occupancy time (COT).

9. In paragraph 8, A terminal wherein at least one PSFCH opportunity is allocated to at least one slot.

10. In paragraph 9, A terminal, wherein at least one slot includes a plurality of slots, and transmission of the PSFCH is performed through one of the plurality of slots.

11. In paragraph 8, Based on the above command being executed by the above control unit, the operations performed are: A terminal further comprising a step of sequentially performing PSFCH transmission attempts for the plurality of slots.

12. In paragraph 11, A terminal, wherein, prior to the one slot in which the transmission of the PSFCH is performed, there exists at least one slot in which the transmission attempt of the PSFCH failed.

13. In paragraph 8, The terminal, wherein the period of at least one PSFCH opportunity is one of 1 slot, 2 slots and 4 slots.

14. In paragraph 8, Based on the above command being executed by the above control unit, the operations performed are: A terminal further comprising a step of receiving channel occupancy sharing information from another terminal.

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