Method and apparatus for performing communication based on cot in nr v2x

Abstract

A method for a first device to perform wireless communication and a device supporting the same are provided. The method may include: determining a channel occupancy time (COT) based on sensing for channel access; transmitting information related to the COT to a second device; transmitting a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) through a physical sidelink control channel (PSCCH) within the COT; transmitting the second SCI and a medium access control (MAC) protocol data unit (PDU) through the PSSCH within the COT; determining to stop using the COT; and transmitting information related to the COT cessation to the second device based on the determination.

Description

Technology Field

[0001] The present disclosure relates to a wireless communication system. Background Technology

[0002] Sidelink (SL) refers to a communication method that establishes a direct link between User Equipment (UE) units, allowing them to directly exchange voice or data without passing through a Base Station (BS). SL is being considered as a solution to address the burden on base stations caused by rapidly increasing data traffic. V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-equipped objects via wired or wireless communication. V2X can be classified into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or the Uu interface.

[0003] Meanwhile, as more communication devices require larger communication capacities, the need for improved mobile broadband communication compared to existing Radio Access Technology (RAT) is emerging. Accordingly, communication systems considering services or terminals sensitive to reliability and latency are being discussed; next-generation radio access technology that incorporates improved mobile broadband communication, Massive Machine Type Communication (MTC), and Ultra-Reliable and Low Latency Communication (URLC) can be referred to as new radio access technology (new RAT) or new radio (NR). Vehicle-to-everything (V2X) communication can also be supported in NR. The problem to be solved

[0004] Meanwhile, even when channel occupancy time (COT) is generated and / or shared, SL communication performed within the COT may fail (continuously) due to transmission by other devices in the unlicensed band, interference, etc. If the terminal attempts SL communication (continuously) within the COT despite the failure of SL communication due to non-periodic transmission by other devices or transmission of high-importance traffic within the COT, unnecessary resource waste may occur and the reliability of SL communication may not be guaranteed. means of solving the problem

[0005] In one embodiment, a method is provided in which a first device performs wireless communication. The method may include: determining a channel occupancy time (COT) based on sensing for channel access; transmitting information related to the COT to a second device; transmitting a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) through a physical sidelink control channel (PSCCH) within the COT; transmitting the second SCI and a medium access control (MAC) protocol data unit (PDU) through the PSSCH within the COT; determining to stop using the COT; and transmitting information related to the COT cessation to the second device based on the determination.

[0006] In one embodiment, a first device configured to perform wireless communication is provided. The first device comprises at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor and cause the first device to: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) within the COT via a physical sidelink control channel (PSCCH); transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH; decide to stop using the COT; and transmit information related to the COT cessation to the second device based on the decision.

[0007] In one embodiment, a processing device configured to control a first device is provided. The processing device comprises at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor and cause the first device to: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second SCI (sidelink control information) via a physical sidelink control channel (PSCCH) within the COT; transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) via the PSSCH within the COT; decide to stop using the COT; and transmit information related to the COT cessation to the second device based on the decision. Effects of the invention

[0008] The terminal can efficiently perform SL communication in the unlicensed band. Brief explanation of the drawing

[0009] FIG. 1 shows the structure of an NR system according to one embodiment of the present disclosure. FIG. 2 shows a radio protocol architecture according to one embodiment of the present disclosure. FIG. 3 shows the structure of a wireless frame of NR according to one embodiment of the present disclosure. FIG. 4 shows a slot structure of an NR frame according to one embodiment of the present disclosure. FIG. 5 shows an example of a BWP according to one embodiment of the present disclosure. FIG. 6 illustrates a procedure in which a terminal performs V2X or SL communication according to a transmission mode, according to one embodiment of the present disclosure. FIG. 7 shows three cast types according to one embodiment of the present disclosure. FIG. 8 shows an example of a wireless communication system that supports an unlicensed band according to one embodiment of the present disclosure. FIG. 9 illustrates a method of occupying resources within an unlicensed band according to one embodiment of the present disclosure. FIG. 10 illustrates a case in which a plurality of LBT-SBs are included within an unlicensed band according to one embodiment of the present disclosure. FIG. 11 illustrates a CAP operation for downlink signal transmission through an unlicensed band of a base station according to one embodiment of the present disclosure. FIG. 12 illustrates a Type 1 CAP operation of a terminal for uplink signal transmission according to one embodiment of the present disclosure. FIGS. 13 to 15 illustrate a procedure in which a terminal performs SL communication in an unlicensed band based on COT according to one embodiment of the present disclosure. FIG. 16 illustrates a method in which a first device performs wireless communication according to one embodiment of the present disclosure. FIG. 17 illustrates a method in which a second device performs wireless communication according to one embodiment of the present disclosure. FIG. 18 shows a communication system (1) according to one embodiment of the present disclosure. FIG. 19 shows a wireless device according to one embodiment of the present disclosure. FIG. 20 shows a signal processing circuit for a transmission signal according to one embodiment of the present disclosure. FIG. 21 shows a wireless device according to one embodiment of the present disclosure. FIG. 22 shows a portable device according to one embodiment of the present disclosure. FIG. 23 shows a vehicle or an autonomous vehicle according to one embodiment of the present disclosure. Specific details for implementing the invention

[0010] In this specification, "A or B" may mean "only A," "only B," or "both A and B." Alternatively, in this specification, "A or B" may be interpreted as "A and / or B." For example, in this specification, "A, B or C" may mean "only A," "only B," "only C," or "any combination of A, B and C."

[0011] A slash ( / ) or a comma used in this specification 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."

[0012] In this specification, "at least one of A and B" may mean "only A," "only B," or "both A and B." Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted as synonymous with "at least one of A and B."

[0013] Additionally, in this specification, "at least one of A, B and C" may mean "only A," "only B," "only C," or "any combination of A, B and C." Also, "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."

[0014] Additionally, parentheses used in this specification may mean "for example." Specifically, when indicated as "control information (PDCCH)," "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)," "PDCCH" may be proposed as an example of "control information."

[0015] In the following explanation, 'when, if, in case of' can be replaced with 'based on'.

[0016] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0017] In this specification, a higher layer parameter may be a parameter that is set for the terminal, pre-set, or pre-defined. For example, a base station or a network may transmit the higher layer parameter to the terminal. For example, the higher layer parameter may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0018] The following technologies can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented using wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (global system for mobile communications), GPRS (general packet radio service), and EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented using wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) which uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0019] 5G NR is a successor technology to LTE-A and is a new clean-slate type mobile communication system with characteristics such as high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, ranging from low frequency bands below 1 GHz to mid-frequency bands from 1 GHz to 10 GHz, and high frequency (millimeter wave) bands above 24 GHz.

[0020] For clarity of explanation, the description focuses on 5G NR, but the technical concept according to one embodiment of the present disclosure is not limited thereto.

[0021] FIG. 1 shows the structure of an NR system according to one embodiment of the present disclosure. The embodiment of FIG. 1 can be combined with various embodiments of the present disclosure.

[0022] Referring to FIG. 1, the NG-RAN (Next Generation - Radio Access Network) may include a base station (20) that provides user plane and control plane protocol termination to a terminal (10). For example, the base station (20) may include a gNB (next generation-Node B) and / or an eNB (evolved-Node B). For example, the terminal (10) may be fixed or mobile and may be referred to by other terms such as MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), MT (Mobile Terminal), or Wireless Device. For example, the base station may be a fixed station communicating with the terminal (10) and may be referred to by other terms such as BTS (Base Transceiver System) or Access Point.

[0023] The embodiment of FIG. 1 illustrates a case including only gNB. Base stations (20) may be connected to each other via an Xn interface. Base stations (20) may be connected to a 5th generation core network (5G Core Network: 5GC) via an NG interface. More specifically, base stations (20) may be connected to an access and mobility management function (AMF) (30) via an NG-C interface and to a user plane function (UPF) (30) via an NG-U interface.

[0024] The layers of the Radio Interface Protocol between a terminal and a network can be classified into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in communication systems. Among these, the Physical Layer, belonging to Layer 1, provides Information Transfer Services using a physical channel, while the Radio Resource Control (RRC) layer, located at Layer 3, performs the role of controlling radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0025] FIG. 2 illustrates a radio protocol architecture according to one embodiment of the present disclosure. The embodiment of FIG. 2 may be combined with various embodiments of the present disclosure. Specifically, FIG. 2(a) illustrates a radio protocol stack of the user plane for Uu communication, and FIG. 2(b) illustrates a radio protocol stack of the control plane for Uu communication. FIG. 2(c) illustrates a radio protocol stack of the user plane for SL communication, and FIG. 2(d) illustrates a radio protocol stack of the control plane for SL communication.

[0026] Referring to Fig. 2, the physical layer provides information transmission services to the upper layer using a physical channel. The physical layer is connected to the upper layer, the MAC (Medium Access Control) layer, through a transport channel. Data travels between the MAC layer and the physical layer through the transport channel. Transport channels are classified according to how and with what characteristics data is transmitted through a wireless interface.

[0027] Data travels between different physical layers, specifically between the physical layers of the transmitter and the receiver, through a physical channel. This physical channel can be modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilizes time and frequency as wireless resources.

[0028] The MAC layer provides services to the upper layer, the RLC (radio link control) layer, through logical channels. The MAC layer provides mapping functions from multiple logical channels to multiple transmission channels. Additionally, the MAC layer provides logical channel multiplexing functions through mapping from multiple logical channels to a single transmission channel. The MAC sublayer provides data transmission services over logical channels.

[0029] The RLC layer performs the concatenation, segmentation, and reassembly of RLC Service Data Units (SDUs). To guarantee the various Quality of Service (QoS) required by the Radio Bearer (RB), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through Automatic Repeat Requests (ARQ).

[0030] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmission channels, and physical channels in relation to the configuration, reconfiguration, and release of wireless bearers. RB refers to the logical path provided by Layer 1 (physical layer or PHY layer) and Layer 2 (MAC layer, RLC layer, PDCP (Packet Data Convergence Protocol) layer, SDAP (Service Data Adaptation Protocol) layer) for data transmission between a terminal and a network.

[0031] The functions of the PDCP layer in the user plane include the delivery of user data, header compression, and ciphering. The functions of the PDCP layer in the control plane include the delivery of control plane data and encryption / integrity protection.

[0032] The SDAP (Service Data Adaptation Protocol) layer is defined only in the user plane. The SDAP layer performs tasks such as mapping QoS flows between data radio bearers and marking QoS flow identifiers (IDs) within downlink and uplink packets.

[0033] The establishment of an RB refers to the process of defining the characteristics of the wireless protocol layer and channel to provide specific services, and setting their respective specific parameters and operating methods. RBs can be further divided into two types: SRBs (Signaling Radio Bearers) and DRBs (Data Radio Bearers). SRBs are used as a channel for transmitting RRC messages in the control plane, while DRBs are used as a channel for transmitting user data in the user plane.

[0034] When an RRC connection is established between the RRC layer of the terminal and the RRC layer of the base station, the terminal is in the RRC_CONNECTED state; otherwise, it is in the RRC_IDLE state. For NR, the RRC_INACTIVE state is additionally defined, and a terminal in the RRC_INACTIVE state maintains a connection with the core network while being able to release the connection with the base station.

[0035] Downlink transmission channels for transmitting data from a network to a terminal include a Broadcast Channel (BCH) for transmitting system information and a Shared Channel (SCH) for transmitting user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted via the Shared Channel (SCH) or via a separate Multicast Channel (MCH). Meanwhile, uplink transmission channels for transmitting data from a terminal to a network include a Random Access Channel (RACH) for transmitting initial control messages and a Shared Channel (SCH) for transmitting user traffic or control messages.

[0036] Logical channels that are above the transmission channel and mapped to the transmission channel include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0037] FIG. 3 shows the structure of a wireless frame of NR according to one embodiment of the present disclosure. The embodiment of FIG. 3 can be combined with various embodiments of the present disclosure.

[0038] Referring to FIG. 3, radio frames can be used for uplink and downlink transmission in NR. The radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (HF). A half-frame may contain five 1 ms subframes (SF). A subframe may be divided into one or more slots, and the number of slots within a subframe may be determined by the subcarrier spacing (SCS). Each slot may contain 12 or 14 OFDM(A) symbols according to the cyclic prefix (CP).

[0039] When normal CP is used, each slot may contain 14 symbols. When extended CP is used, each slot may contain 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) and SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0040] Table 1 below shows the number of symbols per slot (N) according to the SCS setting (u) when normal CP is used. slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot ) exemplifies.

[0041] 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

[0042] Table 2 shows the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to the SCS when an extended CP is used.

[0043] SCS (15*2 u ) N slot symb N frame,u slot N subframe,u slot 60KHz (u=2) 12 40 4

[0044] In an NR system, the OFDM(A) numerology (e.g., SCS, CP length, etc.) can be configured differently among multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols can be configured differently among the merged cells.

[0045] In NR, multiple numerologies or SCSs may be supported to support various 5G services. For example, if the SCS is 15 kHz, a wide area in traditional cellular bands may be supported, and if the SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth may be supported. If the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

[0046] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges may be FR1 and FR2. The numerical values ​​of the frequency ranges may change, for example, as shown in Table 3 below. Among the frequency ranges used in an NR system, FR1 may mean "sub 6GHz range" and FR2 may mean "above 6GHz range" and may be referred to as millimeter wave (mmW).

[0047] Frequency Range designation Corresponding frequency range Subcarrier Spacing (SCS) FR1 450MHz - 6000MHz 15, 30, 60kHz FR2 24250MHz - 52600MHz 60, 120, 240kHz

[0048] As described above, the numerical value of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0049] Frequency Range designation Corresponding frequency range Subcarrier Spacing (SCS) FR1 410MHz - 7125MHz 15, 30, 60kHz FR2 24250MHz - 52600MHz 60, 120, 240kHz

[0050] FIG. 4 shows a slot structure of an NR frame according to one embodiment of the present disclosure. The embodiment of FIG. 4 can be combined with various embodiments of the present disclosure.

[0051] Referring to FIG. 4, a slot contains multiple symbols in the time domain. For example, in the case of a normal CP, one slot may contain 14 symbols, but in the case of an extended CP, one slot may contain 12 symbols. Alternatively, in the case of a normal CP, one slot may contain 7 symbols, but in the case of an extended CP, one slot may contain 6 symbols.

[0052] A carrier includes multiple subcarriers in the frequency domain. A Resource Block (RB) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through the active BWPs. Each element can be referred to as a Resource Element (RE) in a resource grid and can be mapped to a single complex symbol.

[0053] The Bandwidth Part (BWP) and Carrier are described below.

[0054] A Bandwidth Part (BWP) may be a continuous set of Physical Resource Blocks (PRB) in a given Numenology. A PRB may be selected from a continuous subset of Common Resource Blocks (CRB) for a given Numenology on a given carrier.

[0055] For example, the BWP may be at least one of an active BWP, an initial BWP, and / or a default BWP. For example, the terminal may not monitor downlink radio link quality on DL BWPs other than the active DL BWP on the PCell (primary cell). For example, the terminal may not receive PDCCH, PDSCH (physical downlink shared channel), or CSI-RS (reference signal) (except RRM) outside of the active DL BWP. For example, the terminal may not trigger Channel State Information (CSI) reporting for inactive DL BWPs. For example, the terminal may not transmit PUCCH (physical uplink control channel) or PUSCH (physical uplink shared channel) outside of the active UL BWP. For example, in the case of a downlink, the initial BWP may be given as a successive set of RBs for the RMSI (remaining minimum system information) CORESET (control resource set) (set by the PBCH (physical broadcast channel)). For example, in the case of an uplink, the initial BWP may be given by the SIB (system information block) for the random access procedure. For example, the default BWP may be set by the upper layer. For example, the initial value of the default BWP may be the initial DL BWP. For energy saving, if the terminal does not detect DCI (downlink control information) for a certain period, the terminal may switch the terminal's active BWP to the default BWP.

[0056] Meanwhile, a BWP may be defined for an SL. The same SL BWP may be used for transmission and reception. For example, a transmitting terminal may transmit an SL channel or an SL signal on a specific BWP, and a receiving terminal may receive an SL channel or an SL signal on said specific BWP. In a licensed carrier, an SL BWP may be defined separately from a Uu BWP, and the SL BWP may have separate configuration signaling from the Uu BWP. For example, a terminal may receive a configuration for an SL BWP from a base station / network. For example, a terminal may receive a configuration for a Uu BWP from a base station / network. An SL BWP may be (pre-)configured within the carrier for out-of-coverage NR V2X terminals and RRC_IDLE terminals. For a terminal in RRC_CONNECTED mode, at least one SL BWP may be activated within the carrier.

[0057] FIG. 5 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 5 may be combined with various embodiments of the present disclosure. In the embodiment of FIG. 5, it is assumed that there are three BWPs.

[0058] Referring to FIG. 5, the common resource block (CRB) may be a numbered carrier resource block extending from one end of the carrier band to the other. And, the PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0059] BWP is point A, offset from point A (N start BWP ) and bandwidth (N sizeBWP It can be set by ). For example, point A may be an external reference point of the PRB of a carrier where the subcarrier 0 of all numerologies (e.g., all numerologies supported by the network in that carrier) is aligned. For example, offset may be the PRB interval between the lowest subcarrier in a given numerology and point A. For example, bandwidth may be the number of PRBs in a given numerology.

[0060] V2X or SL communication will be explained below.

[0061] SLSS (Sidelink Synchronization Signal) is an SL-specific sequence that may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS, and length-127 Gold sequences may be used for S-SSS. For example, a terminal may use S-PSS to detect the initial signal and obtain synchronization. For example, a terminal may use S-PSS and S-SSSS to obtain detailed synchronization and detect the synchronization signal ID.

[0062] The PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that the terminal must know first is transmitted before transmitting or receiving SL signals. For example, the basic information may include information related to SLSS, Duplex Mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pools, types of applications related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate PSBCH performance, in NR V2X, the payload size of the PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

[0063] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may span 11 RB. Additionally, the frequency position of the S-SSB may be (pre-)set. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0064] FIG. 6 illustrates a procedure in which a terminal performs V2X or SL communication according to a transmission mode, according to one 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 referred to as a mode or a resource allocation mode. Hereinafter, for convenience of explanation, the transmission mode in LTE may be referred to as an LTE transmission mode, and the transmission mode in NR may be referred to as an NR resource allocation mode.

[0065] For example, FIG. 6(a) illustrates a terminal operation associated with LTE transmission mode 1 or LTE transmission mode 3. Or, for example, FIG. 6(a) illustrates a terminal operation associated with NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0066] For example, FIG. 6(b) illustrates a terminal operation associated with LTE transmission mode 2 or LTE transmission mode 4. Or, for example, FIG. 6(b) illustrates a terminal operation associated with NR resource allocation mode 2.

[0067] Referring to FIG. 6(a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S600, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0068] For example, the first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from the base station. For example, the CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, the DG resource may be a resource that the base station sets / assigns to the first terminal via downlink control information (DCI). In this specification, the CG resource may be a (periodic) resource that the base station sets / assigns to the first terminal via DCI and / or RRC messages. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal, and the base station may transmit DCI related to the activation or release of the CG resource to the first terminal.

[0069] In step S610, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S620, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S630, the first terminal may receive a PSFCH associated with the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S640, the first terminal may transmit / report the HARQ feedback information to the base station via a PUCCH or PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a pre-set rule. For example, the DCI may be a DCI for scheduling SL. For example, the format of the DCI may be DCI format 3_0 or DCI format 3_1.

[0070] Referring to FIG. 6(b), in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the terminal can determine an SL transmission resource within an SL resource set by the base station / network or a preset SL resource. For example, the set SL resource or the preset SL resource may be a resource pool. For example, the terminal may autonomously select or schedule a resource for SL transmission. For example, the terminal may perform SL communication by independently selecting a resource within the set resource pool. For example, the terminal may independently select a resource within a selection window by performing a sensing and resource (re)selection procedure. For example, the sensing may be performed on a subchannel basis. For example, in step S610, the first terminal, which independently selected a resource within the resource pool, uses the resource to [transmit] PSCCH (e.g., SCI (Sidelink Control Information) or 1 st -stage SCI) can be transmitted to the second terminal. In step S620, the first terminal transmits the PSSCH associated with the PSCCH (e.g., 2 nd -stage SCI, MAC PDU, data, etc.) can be transmitted to the second terminal. In step S630, the first terminal can receive PSFCH associated with PSCCH / PSSCH from the second terminal.

[0071] Referring to FIG. 6(a) or (b), for example, the first terminal may transmit an SCI to the second terminal over the PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal over the PSCCH and / or PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, the SCI transmitted over the PSCCH is 1 st SCI, 1st SCI, 1 st -stage SCI or 1 st It can be called a -stage SCI format, and the SCI transmitted over PSSCH is 2 nd SCI, 2nd SCI, 2 nd -stage SCI or 2 nd It can be called a -stage SCI format. For example, 1 st -stage SCI formats may include SCI format 1-A, and 2 nd -stage SCI format may include SCI format 2-A and / or SCI format 2-B.

[0072] Below, an example of SCI format 1-A is described.

[0073] SCI Format 1-A is PSSCH and 2 on PSSCH nd - It is used for scheduling stage SCI.

[0074] The following information is transmitted using SCI format 1-A.

[0075] - Priority - 3 bits

[0076] - Frequency resource allocation - If the value of the upper layer parameter sl-MaxNumPerReserve is set to 2, ceiling (log2(N SL subChannel (N SLsubChannel +1) / 2)) bits; otherwise, if the value of the upper layer parameter sl-MaxNumPerReserve is set to 3, ceiling log2(N SL subChannel (N SL subChannel +1)(2N SL subChannel +1) / 6) bits

[0077] - Time resource allocation - 5 bits if the value of the upper tier parameter sl-MaxNumPerReserve is set to 2; otherwise, 9 bits if the value of the upper tier parameter sl-MaxNumPerReserve is set to 3.

[0078] - Resource reservation cycle - ceiling (log2N) rsv_period ) bits, here N rsv_period is the number of entries in the upper-level parameter sl-ResourceReservePeriodList if the upper-level parameter sl-MultiReserveResource is set; otherwise, 0 bit

[0079] - DMRS pattern - ceiling (log2N pattern ) bits, here N pattern is the number of DMRS patterns set by the upper layer parameter sl-PSSCH-DMRS-TimePatternList

[0080] - 2 nd -stage SCI format - 2 bits as defined in Table 5

[0081] - Beta_Offset Indicator - 2 bits as provided by the upper layer parameter sl-BetaOffsets2ndSCI

[0082] - Number of DMRS ports - 1 bit as defined in Table 6

[0083] - Modulation and Coding Method - 5 bits

[0084] - Additional MCS Table Indicator - 1 bit if one MCS table is set by the upper layer parameter sl-Additional-MCS-Table; 2 bits if two MCS tables are set by the upper layer parameter sl-Additional-MCS-Table; otherwise, 0 bits

[0085] - PSFCH Overhead Indicator - Upper layer parameter sl-PSFCH-Period = 1 bit if 2 or 4; otherwise 0 bit

[0086] - Reserved bits - The number of bits determined by the upper layer parameter sl-NumReservedBits, and the value is set to 0.

[0087] 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

[0088] Value of the Number of DMRS port field Antenna ports 0 1000 1 1000 and 1001

[0089] Below, an example of SCI format 2-A is explained.

[0090] In a HARQ operation, if the HARQ-ACK information contains ACK or NACK, or if the HARQ-ACK information contains only NACK, or if there is no feedback of the HARQ-ACK information, SCI format 2-A is used for decoding PSSCH.

[0091] The following information is transmitted via SCI format 2-A.

[0092] - HARQ Process Number - 4 bits

[0093] - New data indicator - 1 bit

[0094] - Redundancy version - 2 bits

[0095] - Source ID - 8 bits

[0096] - Destination ID - 16 bits

[0097] - HARQ Feedback Enable / Disable Indicator - 1 bit

[0098] - Cast type specifier - 2 bits as defined in Table 7

[0099] - CSI Request - 1 bit

[0100] 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

[0101] Below, an example of SCI format 2-B is explained.

[0102] In HARQ operations, when HARQ-ACK information contains only NACK, or when there is no feedback of HARQ-ACK information, SCI format 2-B is used for decoding PSSCH.

[0103] The following information is transmitted via SCI format 2-B.

[0104] - HARQ Process Number - 4 bits

[0105] - New data indicator - 1 bit

[0106] - Redundancy version - 2 bits

[0107] - Source ID - 8 bits

[0108] - Destination ID - 16 bits

[0109] - HARQ Feedback Enable / Disable Indicator - 1 bit

[0110] - Zone ID - 12 bits

[0111] - Communication range requirements - 4 bits determined by the upper layer parameter sl-ZoneConfigMCR-Index

[0112] Referring to FIG. 6 (a) or (b), in step S630, the first terminal can receive PSFCH. For example, the first terminal and the second terminal can determine a PSFCH resource, and the second terminal can use the PSFCH resource to transmit HARQ feedback to the first terminal.

[0113] Referring to FIG. 6(a), in step S640, the first terminal can transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0114] FIG. 7 illustrates three cast types according to one embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure. Specifically, FIG. 7(a) illustrates a broadcast type SL communication, FIG. 7(b) illustrates a unicast type SL communication, and FIG. 7(c) illustrates a group cast type SL communication. In the case of a unicast type SL communication, a terminal may perform one-to-one communication with another terminal. In the case of a group cast type SL communication, a terminal may perform SL communication with one or more terminals within the group to which it belongs. In various embodiments of the present disclosure, SL group cast communication may be replaced with SL multicast communication, SL one-to-many communication, etc.

[0115] The HARQ (Hybrid Automatic Repeat Request) procedure is described below.

[0116] For example, SL HARQ feedback may be enabled for unicast. In this case, in a non-Code Block Group (non-CBG) operation, if the receiving terminal decodes the PSCCH targeting the receiving terminal and the receiving terminal successfully decodes the transmission block associated with the PSCCH, the receiving terminal may generate a HARQ-ACK. The receiving terminal may then transmit the HARQ-ACK to the transmitting terminal. On the other hand, if the receiving terminal fails to successfully decode the transmission block associated with the PSCCH after decoding the PSCCH targeting the receiving terminal, the receiving terminal may generate a HARQ-NACK. The receiving terminal may then transmit the HARQ-NACK to the transmitting terminal.

[0117] For example, SL HARQ feedback can be enabled for group casts. For example, in non-CBG operation, two HARQ feedback options can be supported for group casts.

[0118] (1) Group Cast Option 1: After the receiving terminal has decoded the PSCCH targeting the receiving terminal, if the receiving terminal fails to decode the transmission block associated with the PSCCH, the receiving terminal may send a HARQ-NACK to the transmitting terminal via the PSFCH. On the other hand, if the receiving terminal has decoded the PSCCH targeting the receiving terminal and the receiving terminal has successfully decoded the transmission block associated with the PSCCH, the receiving terminal may not send a HARQ-ACK to the transmitting terminal.

[0119] (2) Group Cast Option 2: After the receiving terminal has decoded the PSCCH targeting the receiving terminal, if the receiving terminal fails to decode the transmission block associated with the PSCCH, the receiving terminal may send a HARQ-NACK to the transmitting terminal via PSFCH. And, if the receiving terminal has decoded the PSCCH targeting the receiving terminal and the receiving terminal has successfully decoded the transmission block associated with the PSCCH, the receiving terminal may send a HARQ-ACK to the transmitting terminal via PSFCH.

[0120] For example, if groupcast option 1 is used for SL HARQ feedback, all terminals performing groupcast communication can share PSFCH resources. For example, terminals belonging to the same group can transmit HARQ feedback using the same PSFCH resources.

[0121] For example, if groupcast option 2 is used for SL HARQ feedback, each terminal performing groupcast communication may use different PSFCH resources to transmit HARQ feedback. For example, terminals belonging to the same group may transmit HARQ feedback using different PSFCH resources.

[0122] In this specification, HARQ-ACK may be referred to as ACK, ACK information or positive-ACK information, and HARQ-NACK may be referred to as NACK, NACK information or negative-ACK information.

[0123] In various embodiments of the present disclosure, the TX UE and / or RX UE may obtain a Discontinuous Reception (DRX) setting. For example, the DRX setting may include a Uu DRX setting and / or an SL DRX setting. For example, the TX UE may receive the DRX setting from a base station, and the RX UE may receive the DRX setting from the TX UE. For example, the DRX setting may be set for or pre-set for the TX UE and / or RX UE.

[0124] For example, the above Uu DRX configuration may include information related to drx-HARQ-RTT-Timer-SL and / or information related to drx-RetransmissionTimer-SL. For example, the timer may be used for the following purposes.

[0125] (1) (Per HARQ process) drx-HARQ-RTT-Timer-SL: drx-HARQ-RTT-Timer-SL may be the minimum duration before a sidelink HARQ retransmission grant is expected by the MAC entity. drx-HARQ-RTT-Timer-SL may refer to the minimum time required for resources to be prepared for SL mode 1 retransmission. That is, resources for sidelink retransmission cannot be prepared until the drx-HARQ-RTT-Timer-SL timer. Therefore, the TX UE may transition to sleep mode during the drx-HARQ-RTT-Timer-SL timer to reduce power consumption. Alternatively, the TX UE may not perform monitoring operations of the base station's mode 1 DCI. When the drx-HARQ-RTT-Timer-SL timer expires, the TX UE can determine that a resource for SL retransmission may be ready. Therefore, the TX UE can start the drx-RetransmissionTimer-SL timer and monitor whether a resource for SL HARQ retransmission is received. Since the SL HARQ retransmission resource may or may not be received immediately upon the expiration of the drx-HARQ-RTT-Timer-SL timer, the TX UE can start the drx-RetransmissionTimer-SL timer and monitor the base station's Mode 1 DCI to receive the resource for SL HARQ retransmission. For example, the drx-HARQ-RTT-Timer-SL timer may be a period during which a TX UE (e.g., a UE supporting Uu DRX operation) performing sidelink communication based on sidelink resource allocation mode 1 does not perform PDCCH (or DCI) monitoring for sidelink mode 1 resource allocation from the base station.

[0126] (2) (Per HARQ process) drx-RetransmissionTimer-SL: drx-RetransmissionTimer-SL may be the maximum duration until a grant for sidelink retransmission is received. That is, the drx-RetransmissionTimer-SL timer is a timer that starts when the drx-HARQ-RTT-Timer-SL timer expires, and may be a timer that causes the TX UE to transition to an active state for SL retransmission. Alternatively, while the timer is running, the TX UE may monitor the base station's SL Mode 1 DCI. The TX UE may start monitoring the base station's SL Mode 1 DCI from the start of drx-RetransmissionTimer-SL to check whether retransmission resources (i.e., a grant for sidelink retransmission) to the RX UE are ready. Then, when the retransmission resource is ready, the TX UE can perform a sidelink HARQ retransmission to the RX UE. When the HARQ retransmission packet is transmitted to the RX UE, the TX UE can stop the drx-RetransmissionTimer-SL timer. While the drx-RetransmissionTimer-SL timer is running, the UE can maintain an active state. For example, the drx-RetransmissionTimer-SL timer may be a period during which a TX UE (e.g., a UE supporting Uu DRX operation) performing sidelink communication based on sidelink resource allocation mode 1 performs PDCCH (or DCI) monitoring for sidelink mode 1 resource allocation from the base station.

[0127] For example, the above SL DRX setting may include at least one parameter / information among the parameters / information described below.

[0128] (1) SL drx-onDurationTimer: the duration at the beginning of a SL DRX Cycle

[0129] (2) SL drx-SlotOffset: the delay before starting the sl drx-onDurationTimer

[0130] (3) SL drx-InactivityTimer: the duration after the PSCCH occasion in which a PSCCH indicates a new SL transmission for the MAC entity

[0131] (4) (Per HARQ process or per sidelink process) SL drx-RetransmissionTimer: the maximum duration until a retransmission is received

[0132] (5) (Per HARQ process or per sidelink process) SL drx-HARQ-RTT-Timer: the minimum duration before PSCCH (Sidelink Control Information) & PSSCH for SL HARQ retransmission is expected by the MAC entity

[0133] (6) SL drx-LongCycleStartOffset: the Long DRX cycle and drx-StartOffset which defines the subframe where the Long and Short DRX Cycle starts

[0134] (7) SL drx-ShortCycle (optional): the Short DRX cycle

[0135] (8) SL drx-ShortCycleTimer (optional): the duration the UE shall follow the Short DRX cycle

[0136] (9) (Per sidelink process) SL drx-HARQ-RTT-Timer: the minimum duration before an assignment for HARQ retransmission is expected by the MAC entity

[0137] (10) SL drx-StartOffset: the subframe where the SL DRX cycle starts

[0138] (11) SL drx-Cycle: SL DRX Cycle

[0139] The SL DRX timer mentioned in the present disclosure below can be used for the following purposes.

[0140] (1) SL DRX Onduration Timer: The period during which a UE performing an SL DRX operation must operate in an active time by default to receive PSCCH / PSSCH from a counterpart UE.

[0141] (2) SL DRX Inactivity Timer: A period that extends the SL DRX onduration period, which is the interval during which a UE performing an SL DRX operation must operate as an active time by default to receive PSCCH / PSSCH from a counterpart UE.

[0142] For example, the UE can extend the SL DRX onduration timer by the duration of the SL DRX inactivity timer. Additionally, when the UE receives a new packet (e.g., a new PSSCH transmission) from the other UE, the UE can extend the SL DRX onduration timer by starting the SL DRX inactivity timer.

[0143] For example, the SL DRX inactivity timer can be used to extend the SL DRX onduration timer interval, which is the interval during which the RX UE performing the SL DRX operation must operate as an active time by default to receive PSCCH / PSSCH from the counterpart TX UE. That is, the SL DRX onduration timer can be extended by the duration of the SL DRX inactivity timer interval. Additionally, when the RX UE receives a new packet (e.g., a new PSSCH transmission) from the counterpart TX UE, the RX UE can start the SL DRX inactivity timer to extend the SL DRX onduration timer.

[0144] (3) SL DRX HARQ RTT Timer: The period during which the UE performing the SL DRX operation operates in sleep mode until it receives a retransmission packet (or PSSCH assignment) transmitted by the other UE.

[0145] For example, if a UE starts an SL DRX HARQ RTT timer, the UE may determine that the other UE will not send sidelink retransmission packets to it until the SL DRX HARQ RTT timer expires, and may operate in sleep mode while the timer is running. For example, if a UE starts an SL DRX HARQ RTT timer, the UE may not monitor for sidelink retransmission packets from the other UE until the SL DRX HARQ RTT timer expires. For example, if an RX UE receives a PSCCH / PSSCH sent by a TX UE and sends SL HARQ NACK feedback, the RX UE may start an SL DRX HARQ RTT timer. In this case, the RX UE may determine that the other TX UE will not send sidelink retransmission packets to it until the SL DRX HARQ RTT timer expires, and the RX UE may operate in sleep mode while the timer is running.

[0146] (4) SL DRX retransmission timer: A timer that starts when the SL DRX HARQ RTT timer expires, and a period during which the UE performing the SL DRX operation operates as an active time to receive a retransmission packet (or PSSCH assignment) transmitted by the counterpart UE.

[0147] For example, during the timer interval, the UE can receive or monitor retransmission sidelink packets (or PSSCH assignments) transmitted by the counterpart UE. For example, the RX UE can receive or monitor retransmission sidelink packets (or PSSCH assignments) transmitted by the counterpart TX UE while the SL DRX retransmission timer is operating.

[0148] In the present disclosure, the names of the timers (drx-HARQ-RTT-Timer-SL, drx-RetransmissionTimer-SL, Sidelink DRX Onduration Timer, Sidelink DRX Inactivity Timer, Sidelink DRX HARQ RTT Timer, Sidelink DRX Retransmission Timer, etc.) are exemplary, and timers performing the same or similar functions based on the description of each timer may be considered the same or similar timers regardless of their names.

[0149] A UE operating a sidelink DRX may operate in an active mode during the DRX active time (e.g., onduration timer, inactivity timer, retransmission timer, or a period of operation in active mode) to perform PSCCH / PSSCH monitoring. However, the UE may operate in a sleep mode during the sidelink DRX inactive time period and may not perform PSCCH / PSSCH monitoring for receiving SL data.

[0150] In sidelink unicast, a terminal can negotiate / determine sidelink DRX settings (SL DRX settings to be used during sidelink unicast communication) with a counterpart terminal that has established a unicast connection. If there is a connection (RRC connection) between the transmitting terminal and the base station, the base station of the transmitting terminal can set the SL DRX settings to be used by the receiving terminal that has established a unicast connection with the transmitting terminal and notify the transmitting terminal, and the transmitting terminal can transmit the SL DRX settings to be used by the receiving terminal received from the base station to the receiving terminal via a PC5 RRC message. If there is no connection (RRC connection) between the transmitting terminal and the base station, the transmitting terminal can directly set the SL DRX settings to be used by the receiving terminal that has established a unicast connection with the transmitting terminal and transmit them to the receiving terminal via a PC5 RRC message.

[0151] Although SL DRX is an operation for the receiving terminal, the transmitting terminal must also be aware of the receiving terminal's SL DRX operation status (active mode or sleep mode, or the start time of DRX onduration / inactivity / HARQ RTT / retransmission timer, the expiration time of DRX onduration / inactivity / HARQ RTT / retransmission timer, etc.). For example, during resource allocation and transmission, the transmitting terminal must be able to determine whether the receiving terminal is operating in active mode or sleep mode. Therefore, the transmitting terminal can apply SL DRX settings in the same way as the receiving terminal to maintain the same operation status as the receiving terminal, such as SL DRX timers.

[0152] The AS layer of a UE (RX UE or TX UE) that supports SL DRX operations may receive a Tx profile mapped to an available sidelink service from an upper layer (e.g., V2X layer). The Tx profile may include information distinguishing whether an available sidelink service or a sidelink service of interest is a sidelink service that must perform SL DRX operations. Thus, when the UE's AS layer receives available sidelink data (or a sidelink service of interest) and a Tx profile from an upper layer, the UE can determine (or decide) whether or not to support SL DRX operations for the available sidelink data (or a sidelink service of interest).

[0153] A TX UE performing SL transmission (or resource (re)selection operation) based on sidelink mode 2 resource allocation operation may perform a process of reselecting transmission resources reserved for previous SL data (or previous SL TB). For example, the TX UE may perform an operation of reselecting transmission resources reserved for previous SL data (or previous SL TB) due to preemption, SL dropping due to UL / SL prioritization, NR SL dropping due to NR SL / LTE SL prioritization, congestion control, etc.

[0154] The transmitting terminal may include information regarding up to three resources in the SCI, including information regarding resources related to the PSSCH currently being transmitted and information regarding two retransmission resources, and transmit it to the receiving terminal.

[0155] When a transmitting terminal transmits a HARQ Feedback Disabled MAC PDU to a receiving terminal, and the receiving terminal checks a HARQ feedback mode indicator set to HARQ Feedback Disabled included in the SCI, the receiving terminal that receives the PSCCH / PSSCH may not transmit SL HARQ feedback to the transmitting terminal, and the receiving terminal may monitor additional PSCCH / PSSCH transmitted by the transmitting terminal. The transmitting terminal may also perform additional PSCCH / PSSCH transmission (blind transmission) without receiving HARQ feedback (ACK or NACK) from the receiving terminal when transmitting the HARQ Feedback Disabled MAC PDU.

[0156] Meanwhile, conventional NR-U (unlicensed spectrum) supports a method of communication between a terminal and a base station in the unlicensed band. In addition, Rel-18 is scheduled to support a mechanism that enables communication between sidelink terminals in the unlicensed band.

[0157] In the present disclosure, a channel may refer to a set of frequency-axis resources that perform Listen-Before-Talk (LBT). In NR-U, a channel may mean a 20 MHz LBT bandwidth and may have the same meaning as an RB set. For example, an RB set may be defined in Section 7 of 3GPP TS 38.214 V17.0.0.

[0158] In the present disclosure, CO (channel occupancy) may refer to time / frequency axis resources acquired by a base station or terminal after a successful LBT.

[0159] In the present disclosure, channel occupancy time (COT) may refer to a time-axis resource acquired by a base station or terminal after a successful LBT. The CO may be shared between the base station (or terminal) that acquired the CO and the terminal (or base station), and this may be referred to as COT sharing. Depending on the initiating device, this may be referred to as gNB-initiated COT or UE-initiated COT.

[0160] Below, a wireless communication system that supports the unlicensed band (shared spectrum) is described.

[0161] FIG. 8 illustrates an example of a wireless communication system supporting an unlicensed band according to one embodiment of the present disclosure. For example, FIG. 8 may include an NR-U (unlicensed spectrum) wireless communication system. An embodiment of FIG. 8 may be combined with various embodiments of the present disclosure.

[0162] In the following description, a cell operating in the licensed band (hereinafter, L-band) may be defined as LCell, and the carrier of the LCell may be defined as (DL / UL / SL) LCC. Additionally, a cell operating in the unlicensed band (hereinafter, U-band) may be defined as UCell, and the carrier of the UCell may be defined as (DL / UL / SL) UCC. The cell's carrier / carrier-frequency may refer to the cell's operating frequency (e.g., center frequency). The cell / carrier (e.g., CC) is collectively referred to as the cell.

[0163] As shown in FIG. 8(a), when a terminal and a base station transmit and receive signals through carrier-coupled LCCs and UCCs, the LCC may be set as PCC (Primary CC) and the UCC may be set as SCC (Secondary CC). As shown in FIG. 8(b), the terminal and the base station may transmit and receive signals through a single UCC or multiple carrier-coupled UCCs. That is, the terminal and the base station may transmit and receive signals through only UCC(s) without LCC. For standalone operation, PRACH, PUCCH, PUSCH, SRS transmission, etc. may be supported in the UCELL.

[0164] In the embodiment of FIG. 8, the base station may be replaced with a terminal. In this case, for example, PSCCH, PSSCH, PSFCH, S-SSB transmission, etc. may be supported in the UCELL.

[0165] Unless otherwise noted, the following definitions may apply to terms used in this specification.

[0166] - Channel: Consists of a series of RBs in which channel access procedures are performed in the shared spectrum, and may refer to a carrier or a part of a carrier.

[0167] - Channel Access Procedure (CAP): Represents a procedure for evaluating channel availability based on sensing to determine whether other communication node(s) are using the channel before signal transmission. The basic unit for sensing is T sl = It is a sensing slot with a duration of 9us. A base station or terminal senses the channel during the sensing slot period, and the power detected for at least 4us within the sensing slot period is the energy detection threshold X Thresh If smaller, sensing slot interval T sl is considered to be in an idle state. Otherwise, the sensing slot interval T sl=9us is considered a busy state. CAP can be referred to as LBT (Listen-Before-Talk).

[0168] - Channel occupancy: Refers to the corresponding transmission(s) on the channel(s) by the base station / terminal after performing the channel access procedure.

[0169] - Channel Occupancy Time (COT): Refers to the total time during which any base station / terminal(s) sharing channel occupancy with said base station / terminal can perform transmission(s) on the channel after the base station / terminal has performed the channel access procedure. When determining the COT, if the transmission gap is 25 µs or less, the gap period is also counted in the COT. The COT may be shared for transmission between the base station and the corresponding terminal(s).

[0170] - DL transmission burst: Defined as a set of transmissions from a base station without gaps exceeding 16us. Transmissions from a base station separated by gaps exceeding 16us are considered as separate DL transmission bursts. The base station can perform transmission(s) after the gap without sensing channel availability within the DL transmission burst.

[0171] - UL or SL transmission burst: Defined as a set of transmissions from a terminal without gaps exceeding 16us. Transmissions from a terminal separated by gaps exceeding 16us are considered as distinct UL or SL transmission bursts. The terminal may perform transmission(s) after the gap without sensing channel availability within the UL or SL transmission burst.

[0172] - Discovery burst: Refers to a DL transmission burst comprising a set of signal(s) and / or channel(s) that is limited within a (time) window and associated with a duty cycle. In an LTE-based system, the discovery burst is a transmission(s) initiated by a base station, comprising PSS, SSS, and CRS (cell-specific RS), and may further comprise a non-zero power CSI-RS. In an NR-based system, the discovery burst is a transmission(s) initiated by a base station, comprising at least an SS / PBCH block, and may further comprise a CORESET for a PDCCH scheduling a PDSCH having SIB1, a PDSCH carrying SIB1, and / or a non-zero power CSI-RS.

[0173] FIG. 9 illustrates a method of occupying resources within an unlicensed band according to one embodiment of the present disclosure. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure.

[0174] Referring to FIG. 9, a communication node (e.g., base station, terminal) within an unlicensed band must determine whether other communication node(s) are using the channel before transmitting a signal. To this end, the communication node within the unlicensed band may perform a Channel Access Procedure (CAP) to access the channel(s) where the transmission(s) are to be performed. The Channel Access Procedure may be performed based on sensing. For example, the communication node may first perform Carrier Sensing (CS) before transmitting a signal to check whether other communication node(s) are transmitting a signal. The case where it is determined that other communication node(s) are not transmitting a signal is defined as having confirmed Clear Channel Assessment (CCA). A predefined or upper layer (e.g., RRC) CCA threshold (e.g., X) ThreshIf ) is present, the communication node may determine the channel state as busy if energy higher than the CCA threshold is detected in the channel, and as idle otherwise. If the channel state is determined to be idle, the communication node may start signal transmission in the unlicensed band. CAP can be replaced with LBT.

[0175] Table 8 illustrates the channel access procedures (CAP) supported in NR-U.

[0176] Type Explanation DL Type 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 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

[0177] Referring to Table 8, LBT types or CAPs for DL / UL / SL transmissions may be defined. However, Table 8 is merely an example, and new types or CAPs may be defined in a similar manner. For example, Type 1 (also called 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 vary. For example, Type 2 can be performed in case of COT sharing within COT acquired by gNB or UE.

[0178] The LBT-SB (SubBand) (or RB set) will be explained below.

[0179] In a wireless communication system supporting an unlicensed band, a single cell (or carrier (e.g., CC)) or BWP configured for a terminal may be configured as a wideband with a Bandwidth (BW) larger than that of existing LTE; however, based on regulations, etc., the BW that requires CCA based on independent LBT operation may be limited. If the sub-band (SB) where individual LBT is performed is defined as an LBT-SB, multiple LBT-SBs may be included within a single wideband cell / BWP. The RB set constituting the LBT-SB may be configured through upper layer (e.g., RRC) signaling. Therefore, based on (i) the BW of the cell / BWP and (ii) RB set allocation information, one or more LBT-SBs may be included in a single cell / BWP.

[0180] FIG. 10 illustrates a case in which a plurality of LBT-SBs are included within 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.

[0181] Referring to FIG. 10, a plurality of LBT-SBs may be included in the BWP of a cell (or carrier). The LBT-SBs may have a band of, for example, 20 MHz. The LBT-SBs consist of a plurality of consecutive (P)RBs in the frequency domain and may be referred to as (P)RB sets. Although not illustrated, a guard band (GB) may be included between the LBT-SBs. Thus, the BWP may be configured in the form of {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, the LBT-SB / RB index may be set / defined to increase as it goes from a low frequency band to a high frequency band.

[0182] The following describes CAPC (channel access priority class).

[0183] The CAPCs of MAC CEs and wireless bearers can be fixed or configured to operate in FR1:

[0184] - Padding BSR (buffer status report) and recommended bit rate MAC CE are fixed to the lowest priority;

[0185] - Fixed to highest priority for SRB0, SRB1, SRB3, and other MAC CEs;

[0186] - Configured by the base station for SRB2 and DRB.

[0187] When selecting a CAPC for a DRB, the base station considers the 5QIs of all QoS flows multiplexed to the DRB, while also considering fairness between different traffic types and transmissions. Table 9 indicates which CAPC should be used for standardized 5QIs, that is, the CAPC to be used for a given QoS flow. For standardized 5QIs, CAPCs are defined as shown in the table below, and for non-standardized 5QIs, the CAPC that best matches the QoS characteristics should be used.

[0188] 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: CAPC 값이 낮을수록 우선 순위가 높음을 의미한다

[0189] The following describes a method for transmitting downlink signals through an unlicensed band. For example, the method for transmitting downlink signals through an unlicensed band can be applied to a method for transmitting sidelink signals through an unlicensed band.

[0190] A base station may perform one of the following channel access procedures (CAP) for downlink signal transmission in the unlicensed band.

[0191] (1) Type 1 Downlink (DL) CAP method

[0192] In a Type 1 DL CAP, the length of the time interval spanned by the sensing slot sensed idle before the transmission(s) is random. A Type 1 DL CAP can be applied to the following transmissions.

[0193] - (i) a unicast PDSCH having user plane data, or (ii) a unicast PDSCH having user plane data and a unicast PDCCH scheduling user plane data, or, transmission(s) initiated by a base station, comprising,

[0194] - Transmission(s) initiated by a base station having only a discovery burst, or (ii) a discovery burst multiplexed with non-unicast information.

[0195] FIG. 11 illustrates a CAP operation for downlink signal transmission through an unlicensed band of a base station according to one embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure.

[0196] Referring to Fig. 11, the base station first has a deferred duration T d During the sensing slot interval, it is sensed whether the channel is in an idle state, and then when counter N becomes 0, transmission can be performed (S134). At this time, counter N is adjusted by sensing the channel during additional sensing slot interval(s) according to the procedure below:

[0197] Step 1)(S120) N=N init Set to. Here, N init It starts from 0 and goes up to CW p It is a random value evenly distributed between. Then proceed to Step 4.

[0198] Step 2)(S140) If N>0 and the base station chooses to decrease the counter, set N=N-1.

[0199] Step 3) (S150) Sensing the channel during the additional sensing slot interval. At this time, if the additional sensing slot interval is idle (Y), move to Step 4. If not (N), move to Step 5.

[0200] Step 4) (S130) If N=0 (Y), terminate the CAP procedure (S132). Otherwise (N), proceed to Step 2.

[0201] Step 5)(S160) Additional delay interval T d If a busy sensing slot is detected within, or an additional delay interval T d Sensing the channel until all sensing slots within are detected as idle.

[0202] Step 6)(S170) Additional delay interval T d If the channel is sensed as idle during all sensing slot intervals (Y), proceed to Step 4. Otherwise (N), proceed to Step 5.

[0203] Table 10 shows the m applied to the CAP according to the channel access priority class. p , examples of changes in the minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes.

[0204] 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}

[0205] Referring to Table 10, the contention window size (CWS), maximum COT value, etc., can be defined for each CAPC. For example, T d = T f + m p * T sl It could be.

[0206] Delay interval T d is interval T f (16us) + m p T consecutive sensing slot intervals sl It consists of the sequence (9us). T f is the sensing slot interval T at the start of the 16us interval. sl Includes

[0207] CW min,p <= CW p <= CW max,p is. CW p is CW p = CW min,p It is set to and can be updated prior to Step 1 based on HARQ-ACK feedback (e.g., ACK or NACK ratio) for the previous DL burst (e.g., PDSCH) (CW size update). For example, CW p Based on HARQ-ACK feedback for the previous DL burst, CW min,p It can be initialized to, increased to the next highest allowed value, or the existing value can be kept.

[0208] (2) Type 2 Downlink (DL) CAP method

[0209] In a Type 2 DL CAP, the length of the time interval spanned by the sensing slot that is sensed idle before the transmission(s) is deterministic. Type 2 DL CAPs are classified into Type 2A / 2B / 2C DL CAPs.

[0210] Type 2A DL CAP can be applied to the following transmissions. In Type 2A DL CAP, the base station at least has a sensing interval T short_dl A transmission can be sent immediately after the channel is sensed as idle for 25us. Here, T short_dl is interval T f It consists of (=16us) and a single sensing slot interval immediately following it. T fIt includes a sensing slot at the start point of the interval.

[0211] - (i) having only a discovery burst, or (ii) having a discovery burst multiplexed with non-unicast information, transmission(s) initiated by a base station, or,

[0212] - Base station transmission(s) after a 25us gap from transmission(s) by the terminal within shared channel occupancy.

[0213] Type 2B DL ​​CAP is applicable to transmission(s) performed by the base station after a 16 µs gap from transmission(s) by the terminal within the shared channel occupancy time. In Type 2B DL ​​CAP, the base station T f A transmission can be sent immediately after the channel is sensed as idle for 16us. T f It includes a sensing slot within the last 9us of the interval. Type 2C DL CAP is applicable to transmission(s) performed by the base station after a gap of up to 16us from transmission(s) by the terminal within the shared channel occupancy time. In Type 2C DL CAP, the base station does not sense the channel before performing the transmission.

[0214] The following describes a method for transmitting uplink signals through an unlicensed band. For example, the method for transmitting uplink signals through an unlicensed band can be applied to a method for transmitting sidelink signals through an unlicensed band.

[0215] The terminal performs a Type 1 or Type 2 CAP for uplink signal transmission in an unlicensed band. Generally, the terminal can perform a CAP (e.g., Type 1 or Type 2) set by the base station for uplink signal transmission. For example, the terminal may include CAP type indication information within a UL grant (e.g., DCI format 0_0, 0_1) that schedules a PUSCH transmission.

[0216] (1) Type 1 Uplink (UL) Cap Method

[0217] In a Type 1 UL CAP, the length of the time interval spanned by the sensing slot sensed idle before the transmission(s) is random. A Type 1 UL CAP can be applied to the following transmissions.

[0218] - Scheduled and / or configured PUSCH / SRS transmission(s) from the base station

[0219] - Scheduled and / or configured PUCCH transmission(s) from the base station

[0220] - Transmission(s) related to RAP (Random Access Procedure)

[0221] FIG. 12 illustrates a Type 1 CAP operation of a terminal for uplink signal transmission according to one embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0222] Referring to FIG. 12, the terminal first has a deferred duration T d During the sensing slot interval, it is sensed whether the channel is in an idle state, and then when counter N becomes 0, transmission can be performed (S234). At this time, counter N is adjusted by sensing the channel during additional sensing slot interval(s) according to the procedure below:

[0223] Step 1)(S220) N=N init Set to. Here, N init It starts from 0 and goes up to CW p It is a random value evenly distributed between. Then proceed to Step 4.

[0224] Step 2)(S240) If N>0 and the terminal chooses to decrease the counter, set N=N-1.

[0225] Step 3) (S250) Sensing the channel during the additional sensing slot interval. At this time, if the additional sensing slot interval is idle (Y), move to Step 4. If not (N), move to Step 5.

[0226] Step 4) (S230) If N=0 (Y), terminate the CAP procedure (S232). Otherwise (N), proceed to Step 2.

[0227] Step 5)(S260) Additional delay interval T d If a busy sensing slot is detected within, or an additional delay interval T d Sensing the channel until all sensing slots within are detected as idle.

[0228] Step 6)(S270) Additional delay interval T d If the channel is sensed as idle during all sensing slot intervals (Y), proceed to Step 4. Otherwise (N), proceed to Step 5.

[0229] Table 11 shows the m applied to the CAP according to the channel access priority class. p , examples of changes in minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes.

[0230] Channel Access Priority Class (p) m p CW min,p CW max,p T ulmcot,p allowed CW p 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}

[0231] Referring to Table 11, the contention window size (CWS), maximum COT value, etc., can be defined for each CAPC. For example, T d = T f + m p * T sl It could be.

[0232] Delay interval T d is interval T f (16us) + m p T consecutive sensing slot intervals slIt consists of the sequence (9us). T f is the sensing slot interval T at the start of the 16us interval. sl Includes

[0233] CW min,p <= CW p <= CW max,p is. CW p is CW p = CW min,p It is set to and can be updated prior to Step 1 based on explicit / implicit reception responses to the previous UL burst (e.g., PUSCH) (CW size update). For example, CW p is based on explicit / implicit reception responses to previous UL bursts, CW min,p It can be initialized to, increased to the next highest allowed value, or the existing value can be kept.

[0234] (2) Type 2 Uplink (UL) Cap Method

[0235] In a Type 2 UL CAP, the length of the time interval spanned by the sensing slot sensed idle prior to the transmission(s) is deterministic. Type 2 UL CAPs are classified into Type 2A / 2B / 2C UL CAPs. In a Type 2A UL CAP, the terminal has at least the sensing interval T short_dl A transmission can be sent immediately after the channel is sensed as idle for 25us. Here, T short_dl is interval T f It consists of (=16us) and a single sensing slot section immediately following it. In Type 2A UL CAP, T f It includes a sensing slot at the start point of the interval. In a Type 2B UL CAP, the terminal has a sensing interval T f Transmission can be sent immediately after the channel is sensed as idle for 16us. In Type 2B UL CAP, T fIt includes a sensing slot within the last 9us of the interval. In Type 2C UL CAP, the terminal does not sense the channel before performing transmission.

[0236] For example, according to Type 1 LBT-based NR-U operation, a terminal having uplink data to transmit can select a CAPC mapped to the 5QI of the data, and the terminal [can] select the parameters of the corresponding CAPC (e.g., minimum contention window size, maximum contention window size), m p NR-U operation can be performed by applying (etc.). For example, the terminal may select a Backoff Counter (BC) after selecting a random value between the minimum CW and maximum CW mapped to the CAPC. In this case, for example, BC may be a positive integer less than or equal to the random value. The terminal sensing the channel decreases BC by 1 when the channel is idle. When BC becomes zero and the terminal T d (T d = T f + m p * T sl If the terminal detects that the channel is idle for a period of time, it can 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, T f The first 9 usec of (= 16 usec) is T sl It can be composed of.

[0237] For example, according to the Type 2 LBT-based NR-U operation, the terminal can perform data transmission by performing Type 2 LBT (e.g., Type 2A LBT, Type 2B LBT, Type 2C LBT) within the COT.

[0238] For example, Type 2A (also called Cat-2 LBT (one shot LBT) or one-shot LBT) can be a 25 usec one-shot LBT. In this case, transmission can begin immediately after idle sensing for at least a 25 usec gap. Type 2A can be used to initiate SSB and non-unicast DL information transmission. That is, the terminal can sense the channel for 25 usec within the COT, and the terminal can occupy the channel and attempt to transmit data when the channel is idle.

[0239] For example, Type 2B can be a 16 usec one-shot LBT. In this case, transmission can begin immediately after idle sensing for a 16 usec gap. That is, the terminal can sense the channel for 16 usec within the COT, and when the channel is idle, the terminal can occupy the channel and attempt to transmit data.

[0240] For example, in the case of Type 2C (also called Cat-1 LBT or No LBT), LBT may not be performed. In this case, transmission may begin immediately after a gap of up to 16 usec and may not sense the channel prior to said transmission. The duration of said transmission may be up to 584 usec. The terminal may attempt transmission after 16 usec without sensing, and the terminal may perform transmission for up to 584 usec.

[0241] Meanwhile, even when channel occupancy time (COT) is generated and / or shared, SL communication performed within the COT may fail (continuously) due to transmission by other devices in the unlicensed band, interference, etc. If the terminal attempts SL communication (continuously) within the COT despite the failure of SL communication due to non-periodic transmission by other devices or transmission of high-importance traffic within the COT, unnecessary resource waste may occur and the reliability of SL communication may not be guaranteed.

[0242] According to various embodiments of the present disclosure, a method and device supporting the same are proposed for a terminal that generates a channel occupancy time (COT) in a sidelink unlicensed spectrum to perform a COT return operation.

[0243] FIGS. 13 to 15 illustrate a procedure in which a terminal performs SL communication in an unlicensed band based on COT according to one embodiment of the present disclosure. The embodiment of FIGS. 13 to 15 may be combined with various embodiments of the present disclosure.

[0244] Referring to FIG. 13, in step S1310, the terminal can generate a COT. In step S1320, the terminal can share the COT with the counterpart terminal. For example, the terminal generating the COT can share the COT it has secured with the counterpart terminal as in the embodiment of FIG. 14. For example, the terminal that generated / secured the COT can transmit the COT secured via SCI to the counterpart terminal. For example, the terminal that generated / secured the COT can transmit the COT secured via MAC CE to the counterpart terminal. For example, the terminal that generated / secured the COT can transmit the COT secured via PC5-RRC message to the counterpart terminal. When transmitting a COT obtained via SCI, the terminal may transmit the obtained COT to a destination UE (pair of L1 source ID and L1 destination ID) on a unicast link, and / or the terminal may transmit the obtained COT to a groupcast / broadcast destination UE (groupcast / broadcast L1 destination ID). When transmitting a COT obtained via MAC CE, the terminal may transmit the obtained COT to a destination UE (pair of L1 / L2 source ID and L1 / L2 destination ID) on a unicast link, and / or the terminal may transmit the obtained COT to a groupcast / broadcast destination UE (groupcast / broadcast L1 / L2 destination ID). A terminal that has received a shared COT from a terminal that created the COT may perform a Type 2 LBT operation within the shared COT after the transmission by the terminal that created the COT is completed. For example, the above type 2 LBT may include type 2A LBT, type 2B LBT, or type 2C LBT.For example, in the case of Type 2A LBT or Type 2B LBT, if a terminal that has performed a sensing operation confirms that the channel has been idle for a certain period of time, the terminal can transmit SL data to be transmitted within the shared COT. For example, in the case of Type 2C LBT, the terminal can transmit SL data immediately without sensing for a certain period of time.

[0245] In step S1330, the terminal that generated the COT may return the COT it has acquired. The terminal that generated and / or acquired the COT and shared the COT with the counterpart terminal may send a COT END MAC CE to the counterpart terminal to return the acquired COT. The COT END MAC CE may be sent to a destination UE (pair of L1 / L2 source ID and L1 / L2 destination ID) for a unicast link, and / or the COT END MAC CE may be sent to a groupcast / broadcast destination UE (groupcast / broadcast L1 / L2 destination ID). Referring to FIG. 15, the terminal that receives the COT END MAC CE may transmit SL data by performing a Type 1 LBT from the time it receives the COT END MAC CE until the expiration time of the previously shared COT. Until it receives the COT END MAC CE, the terminal that received the COT can transmit SL data by performing Type 2 LBT within the shared COT until the COT expires.

[0246] COT release can be performed not only via MAC CE but also via SCI or PC5-RRC messages. Information for COT release / termination can be transmitted via SCI to a destination UE (pair of L1 source ID and L1 destination ID) on a unicast link, and / or to a groupcast / broadcast destination UE (groupcast / broadcast L1 destination ID).

[0247] For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically to the resource pool (or differently or independently). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically to the congestion level (or differently or independently). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically to the service priority (or differently or independently). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically to the service type (or differently or independently). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically to QoS requirements (e.g., latency, reliability) (or differently or independently). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) to PQI (5QI (5G QoS identifier) ​​for PC5). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) to traffic types (e.g., periodic generation or non-periodic generation). For example, the applicability of (some) proposed methods / rules of the present disclosure and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) to SL transmission resource allocation modes (e.g., Mode 1 or Mode 2).For example, whether the (some) proposed methods / rules of the present disclosure apply and / or related parameters (e.g., thresholds) may be specifically (or differently or independently) set to a Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not support sidelink DRX operation).

[0248] For example, the applicability of the proposed rules of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set depending on whether PUCCH setting is supported (e.g., when a PUCCH resource is set or when a PUCCH resource is not set). For example, the applicability of the proposed rules of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set for a resource pool (e.g., a resource pool where PSFCH is set or a resource pool where PSFCH is not set). For example, the applicability of the proposed rules of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set for the type of service / packet. For example, the applicability of the proposed rules of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set for the priority of the service / packet. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be set specifically (or differently or independently) to a QoS profile or QoS requirements (e.g., URLLC / EMBB traffic, reliability, latency). For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be set specifically (or differently or independently) to a PQI. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be set specifically (or differently or independently) to a PFI. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be set specifically (or differently or independently) to a cast type (e.g., unicast, groupcast, broadcast). For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be set specifically (or differently or independently) to a (resource pool) congestion level (e.g., CBR).For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting value may be set specifically (or differently or independently) to an SL HARQ feedback method (e.g., NACK-only feedback, ACK / NACK feedback). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting value may be set specifically (or differently or independently) to HARQ Feedback Enabled MAC PDU transmission. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting value may be set specifically (or differently or independently) to HARQ Feedback Disabled MAC PDU transmission. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting value may be set specifically (or differently or independently) depending on whether a PUCCH-based SL HARQ feedback reporting operation is enabled. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set depending on whether pre-emption or pre-emption-based resource reselection is performed. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set depending on whether re-evaluation or re-evaluation-based resource reselection is performed. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set to the (L2 or L1) (source and / or destination) identifier. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting values ​​may be specifically (or differently or independently) set to the (L2 or L1) (combination of source ID and destination ID) identifier.For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting value may be set specifically (or differently or independently) to the identifier (L2 or L1) (combination of the pair of source ID and destination ID and cast type). For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting value may be set specifically (or differently or independently) to the direction of the pair of source layer ID and destination layer ID. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting value may be set specifically (or differently or independently) to the PC5 RRC connection / link. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting value may be set specifically (or differently or independently) depending on whether SL DRX is performed. For example, the applicability of the proposal rule of the present disclosure and / or the related parameter setting value may be set specifically (or differently or independently) depending on whether SL DRX is supported. For example, whether the proposed rules of the present disclosure apply and / or the related parameter setting values ​​may be set specifically (or differently or independently) to an SL mode type (e.g., resource allocation mode 1 or resource allocation mode 2). For example, whether the proposed rules of the present disclosure apply and / or the related parameter setting values ​​may be set specifically (or differently or independently) to cases where (non)periodic resource reservation is performed. For example, whether the proposed rules of the present disclosure apply and / or the related parameter setting values ​​may be set specifically (or differently or independently) to a Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not support sidelink DRX operation).

[0249] The applicability of the proposals and proposal rules of the present disclosure (and / or related parameter setting values) may also apply to mmWave SL operations.

[0250] According to various embodiments of the present disclosure, if a terminal sharing a COT determines that it needs to terminate or return the COT due to transmission or interference by another device in an unlicensed band, the terminal may transmit information related to the termination or return of the COT. Through this, unnecessary waste of resources may not occur, and the reliability of SL communication may be guaranteed.

[0251] FIG. 16 illustrates a method in which a first device performs wireless communication according to one embodiment of the present disclosure. The embodiment of FIG. 16 may be combined with various embodiments of the present disclosure.

[0252] Referring to FIG. 16, at step S1610, the first device may determine a channel occupancy time (COT) based on sensing for channel access. At step S1620, the first device may transmit information related to the COT to the second device. At step S1630, the first device may transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) within the COT via a physical sidelink control channel (PSCCH). At step S1640, the first device may transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH. At step S1650, the first device may decide to stop using the COT. In step S1660, the first device may transmit information related to the suspension of COT to the second device based on the above decision.

[0253] For example, information related to the above COT interruption can be transmitted through the MAC CE (control element).

[0254] For example, information related to the above COT suspension can be transmitted via SCI.

[0255] For example, information related to the above COT interruption can be transmitted via a PC5 RRC (radio resource control) message.

[0256] For example, the COT may include a first time before the second device receives information related to the interruption of the COT and a second time after the second device receives information related to the interruption of the COT.

[0257] For example, within the second time included in the above COT, SL communication may be performed based on a first type LBT (listen before talk). For example, the first type LBT may be a channel access procedure based on random back-off.

[0258] For example, within the first time included in the above COT, SL communication may be performed based on a second type LBT (listen before talk). For example, the second type LBT may be a channel sensing procedure performed during a predefined time. For example, the predefined time may be 25 microseconds, 16 microseconds, or zero.

[0259] For example, information related to the above COT can be transmitted via SCI, MAC CE (control element), or PC5 RRC (radio resource control) messages.

[0260] For example, based on the fact that the above COT is shared for unicast, information related to the above COT or information related to the above COT interruption may be transmitted by pair of destination ID and source ID.

[0261] For example, based on the fact that the above COT is shared for group cast or broadcast, information related to the above COT or information related to the interruption of the above COT may be transmitted by destination ID.

[0262] The proposed method above may be applied to a device according to various embodiments of the present disclosure. First, a processor (102) of a first device (100) may determine a channel occupancy time (COT) based on sensing for channel access. Then, the processor (102) of the first device (100) may control a transceiver (106) to transmit information related to the COT to a second device. Then, the processor (102) of the first device (100) may control the transceiver (106) to transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) through a physical sidelink control channel (PSCCH) within the COT. And, the processor (102) of the first device (100) can control the transceiver (106) to transmit the second SCI and MAC (medium access control) PDU (protocol data unit) through the PSSCH within the COT. And, the processor (102) of the first device (100) can decide to stop using the COT. And, based on the decision, the processor (102) of the first device (100) can control the transceiver (106) to transmit information related to the COT discontinuation to the second device.

[0263] According to one embodiment of the present disclosure, a first device configured to perform wireless communication may be provided. For example, the first device may include at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions, based on execution by the at least one processor, cause the first device to: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) within the COT via a physical sidelink control channel (PSCCH); transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH; and decide to stop using the COT. And based on the above decision, information related to the interruption of COT can be transmitted to the second device.

[0264] According to one embodiment of the present disclosure, a processing device configured to control a first device may be provided. For example, the processing device may include at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, based on the instructions executed by the at least one processor, the first device may: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second SCI (sidelink control information) within the COT via a physical sidelink control channel (PSCCH); transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH; and decide to stop using the COT. And based on the above decision, information related to the interruption of COT can be transmitted to the second device.

[0265] According to one embodiment of the present disclosure, a non-transient computer-readable storage medium recording instructions may be provided. For example, when the instructions are executed, the first device may: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second SCI (sidelink control information) within the COT via a physical sidelink control channel (PSCCH); transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH; determine to stop using the COT; and transmit information related to the COT cessation based on the determination to the second device.

[0266] FIG. 17 illustrates a method in which a second device performs 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.

[0267] Referring to FIG. 17, in step S1710, the second device may receive information related to channel occupancy time (COT) from the first device. In step S1720, the second device may receive information related to COT interruption from the first device.

[0268] For example, information related to the above COT interruption can be received through the MAC CE (control element).

[0269] For example, information related to the above COT interruption can be received through SCI (sidelink control information).

[0270] For example, information related to the above COT interruption can be received through a PC5 RRC (radio resource control) message.

[0271] For example, the COT may include a first time before the second device receives information related to the interruption of the COT and a second time after the second device receives information related to the interruption of the COT.

[0272] For example, within the second time included in the above COT, SL communication may be performed based on a first type LBT (listen before talk). For example, the first type LBT may be a channel access procedure based on random back-off.

[0273] For example, within the first time included in the above COT, SL communication may be performed based on a second type LBT (listen before talk). For example, the second type LBT may be a channel sensing procedure performed during a predefined time. For example, the predefined time may be 25 microseconds, 16 microseconds, or zero.

[0274] For example, information related to the above COT can be received through SCI (sidelink control information), MAC CE (control element), or PC5 RRC (radio resource control) messages.

[0275] For example, based on the fact that the above COT is shared for unicast, information related to the above COT or information related to the above COT interruption may be received by pair of destination ID and source ID.

[0276] For example, based on the fact that the above COT is shared for group cast or broadcast, information related to the above COT or information related to the interruption of the above COT may be received by destination ID.

[0277] The proposed method above may be applied to a device according to various embodiments of the present disclosure. First, the processor (202) of the second device (200) may control the transceiver (206) to receive information related to channel occupancy time (COT) from the first device. Then, the processor (202) of the second device (200) may control the transceiver (206) to receive information related to COT interruption from the first device.

[0278] According to one embodiment of the present disclosure, a second device configured to perform wireless communication may be provided. For example, the second device may include at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, the instructions may cause the second device to: receive information related to channel occupancy time (COT) from the first device; and receive information related to COT interruption from the first device, based on execution by the at least one processor.

[0279] According to one embodiment of the present disclosure, a processing device configured to control a second device may be provided. For example, the processing device may include at least one processor; and at least one memory connected to the at least one processor and storing instructions. For example, based on the instructions executed by the at least one processor, the second device may: receive information related to channel occupancy time (COT) from a first device; and receive information related to COT interruption from the first device.

[0280] According to one embodiment of the present disclosure, a non-transient computer-readable storage medium recording instructions may be provided. For example, when the instructions are executed, the second device may: receive information related to a channel occupancy time (COT) from the first device; and receive information related to a interruption of the COT from the first device.

[0281] Various embodiments of the present disclosure may be combined with one another.

[0282] The following describes an apparatus to which various embodiments of the present disclosure may be applied.

[0283] Although not limited to this, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0284] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0285] FIG. 18 shows a communication system (1) according to one embodiment of the present disclosure. The embodiment of FIG. 18 can be combined with various embodiments of the present disclosure.

[0286] Referring to FIG. 18, a communication system (1) to which various embodiments of the present disclosure are applied includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0287] Here, the wireless communication technology implemented in the wireless devices (100a to 100f) of this specification may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally, or generally, the wireless communication technology implemented in the wireless devices (100a to 100f) of this specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the names mentioned above. Additionally or generally, wireless communication technology implemented in the wireless devices (100a to 100f) of this specification may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) for low-power communication, and is not limited to the names mentioned above. As an example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

[0288] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0289] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and inter-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present disclosure, at least some of the following may be performed: various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc.

[0290] FIG. 19 shows a wireless device according to one embodiment of the present disclosure. The embodiment of FIG. 19 may be combined with various embodiments of the present disclosure.

[0291] Referring to FIG. 19, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), base station (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 18.

[0292] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0293] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). Memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In this disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0294] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0295] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For 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 one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be contained in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0296] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0297] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0298] FIG. 20 shows a signal processing circuit for a transmission signal according to one embodiment of the present disclosure. The embodiment of FIG. 20 can be combined with various embodiments of the present disclosure.

[0299] Referring to FIG. 20, the signal processing circuit (1000) may include a scrambler (1010), a modulator (1020), a layer mapper (1030), a precoder (1040), a resource mapper (1050), and a signal generator (1060). Although not limited thereto, the operation / function of FIG. 20 may be performed in the processor (102, 202) and / or transceiver (106, 206) of FIG. 19. The hardware elements of FIG. 20 may be implemented in the processor (102, 202) and / or transceiver (106, 206) of FIG. 19. For example, blocks 1010 through 1060 may be implemented in the processor (102, 202) of FIG. 19. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 19, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 19.

[0300] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 20. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transmission block (e.g., UL-SCH transmission block, DL-SCH transmission block). The wireless signal can be transmitted through various physical channels (e.g., PUSCH, PDSCH).

[0301] Specifically, a codeword can be converted into a scrambled bit sequence by a scrambler (1010). The scrambled sequence used for scrambling is generated based on an initialization value, which may include ID information of a wireless device, etc. The scrambled bit sequence can be modulated into a modulation symbol sequence by a modulator (1020). The modulation method may include pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), m-QAM (m-Quadrature Amplitude Modulation), etc. The complex modulation symbol sequence can be mapped to one or more transmission layers by a layer mapper (1030). The modulation symbols of each transmission layer can be mapped to the corresponding antenna port(s) by a precoder (1040) (precoding). The output z of the precoder (1040) can be obtained by multiplying the output y of the layer mapper (1030) by an N*M precoding matrix W. Here, N is the number of antenna ports and M is the number of transmission layers. Here, the precoder (1040) can perform precoding after performing transform precoding (e.g., DFT transform) on the complex modulation symbols. Additionally, the precoder (1040) can perform precoding without performing transform precoding.

[0302] A resource mapper (1050) can map the modulation symbols of each antenna port to a time-frequency resource. The time-frequency resource may include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. A signal generator (1060) generates a radio signal from the mapped modulation symbols, and the generated radio signal can be transmitted to another device through each antenna. To this end, the signal generator (1060) may include an Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0303] The signal processing process for a received signal in a wireless device can be configured as the inverse of the signal processing process (1010–1060) of FIG. 20. For example, a wireless device (e.g., 100, 200 in FIG. 19) can receive a wireless signal from the outside through an antenna port / transceiver. The received wireless signal can be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a Fast Fourier Transform (FFT) module. Subsequently, the baseband signal can be restored into a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scrambling process. The codeword can be restored into the original information block through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler, and a decoder.

[0304] FIG. 21 shows a wireless device according to one embodiment of the present disclosure. The wireless device may be implemented in various forms depending on the use-example / service (see FIG. 18). The embodiment of FIG. 21 may be combined with various embodiments of the present disclosure.

[0305] Referring to FIG. 21, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 19 and may be composed of various elements, components, units / parts, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 19. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 19. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and additional elements (140) and controls the general operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (130). Additionally, the control unit (120) may transmit information stored in the memory unit (130) to an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110) in the memory unit (130).

[0306] The additional element (140) can be configured in various ways depending on the type of wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 18, 100a), a vehicle (Fig. 18, 100b-1, 100b-2), an XR device (Fig. 18, 100c), a portable device (Fig. 18, 100d), a home appliance (Fig. 18, 100e), an IoT device (Fig. 18, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 18, 400), a base station (Fig. 18, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0307] In FIG. 21, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least a portion may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and the first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). Additionally, each element, component, unit / part, and / or module within the wireless device (100, 200) may include one or more additional elements. For example, the control unit (120) may be composed of one or more sets of processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0308] Hereinafter, an implementation example of FIG. 21 will be described in more detail with reference to the drawings.

[0309] FIG. 22 illustrates a portable device according to one embodiment of the present disclosure. The portable device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch, smart glasses), a portable computer (e.g., a laptop, etc.). The portable device may be referred to as an MS (Mobile Station), UT (User Terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), or WT (Wireless Terminal). The embodiment of FIG. 22 may be combined with various embodiments of the present disclosure.

[0310] Referring to FIG. 22, the portable 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 input / output unit (140c). The antenna unit (108) may be configured as part of the communication unit (110). Blocks 110 to 130 / 140a to 140c each correspond to blocks 110 to 130 / 140 of FIG. 21.

[0311] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (120) can control the components of the portable device (100) to perform various operations. The control unit (120) may include an AP (Application Processor). The memory unit (130) can store data / parameters / programs / code / commands required for the operation of the portable device (100). Additionally, the memory unit (130) can store input / output data / information, etc. The power supply unit (140a) supplies power to the portable device (100) and may include wired / wireless charging circuits, batteries, etc. The interface unit (140b) can support the connection between the portable device (100) and other external devices. The interface unit (140b) may include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (140c) can receive or output video information / signals, audio information / signals, data, and / or information input by a user. The input / output unit (140c) may include a camera, a microphone, a user input unit, a display unit (140d), a speaker and / or a haptic module, etc.

[0312] For example, in the case of data communication, the input / output unit (140c) acquires information / signals (e.g., touch, text, voice, image, video) input from the user, and the acquired information / signals can be stored in the memory unit (130). The communication unit (110) converts the information / signals stored in the memory into wireless signals and can directly transmit the converted wireless signals to another wireless device or to a base station. Additionally, the communication unit (110) can receive wireless signals from another wireless device or base station and then restore the received wireless signals to their original information / signals. The restored information / signals can be stored in the memory unit (130) and then output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (140c).

[0313] FIG. 23 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc. The embodiment of FIG. 23 may be combined with various embodiments of the present disclosure.

[0314] Referring to FIG. 23, 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 part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 21, respectively.

[0315] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (Roadside units), etc.), and servers. The control unit (120) can perform various operations by controlling elements of the vehicle or autonomous vehicle (100). The control unit (120) may include an Electronic Control Unit (ECU). The driving unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The driving unit (140a) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and may include wired / wireless charging circuits, batteries, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0316] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving path and a driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or the autonomous vehicle (100) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving path and the driving plan based on the newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles.

[0317] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

Claim 1 A method comprising: a first device determining a channel occupancy time (COT) based on sensing for channel access; the first device transmitting information related to the COT to a second device; the first device transmitting a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second sidelink control information (SCI) through a physical sidelink control channel (PSCCH) within the COT; the first device transmitting the second SCI and a medium access control (MAC) protocol data unit (PDU) through the PSSCH within the COT; the first device determining to stop using the COT; and the first device transmitting information related to the COT interruption to the second device based on the decision to interrupt. Claim 2 A method according to claim 1, wherein information related to the interruption of the COT is transmitted through a MAC CE (control element). Claim 3 In claim 1, the method wherein information related to the suspension of the COT is transmitted via SCI. Claim 4 A method according to claim 1, wherein information related to the interruption of the COT is transmitted via a PC5 RRC (radio resource control) message. Claim 5 A method according to claim 1, wherein the COT includes a first time before the second device receives information related to the interruption of the COT and a second time after the second device receives information related to the interruption of the COT. Claim 6 In claim 5, the method wherein SL communication within the second time included in the COT is performed based on a first type LBT (listen before talk). Claim 7 In claim 6, the first type LBT is a method that is a random back-off based channel access procedure. Claim 8 In claim 5, the method wherein SL communication within the first time included in the COT is performed based on a second type LBT (listen before talk). Claim 9 In claim 8, the method wherein the second type LBT is a channel sensing procedure performed for a predefined period of time. Claim 10 In claim 9, the above-mentioned prior-defined time is 25 microseconds, 16 microseconds, or zero, method. Claim 11 A method according to claim 1, wherein information related to the COT is transmitted via SCI, MAC CE (control element) or PC5 RRC (radio resource control) messages. Claim 12 A method according to claim 1, wherein information related to the COT or information related to the interruption of the COT is transmitted per pair of destination ID and source ID, based on the fact that the COT is shared for unicast. Claim 13 A method according to claim 1, wherein information related to the COT or information related to the interruption of the COT is transmitted per destination ID, based on the fact that the COT is shared for group cast or broadcast. Claim 14 A first device comprising: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor, and the first device is configured to: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second SCI (sidelink control information) within the COT via a physical sidelink control channel (PSCCH); transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH; determine to stop using the COT; and transmit information related to the COT cessation to the second device based on the decision to cease. Claim 15 A processing device comprising: at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor, and the first device is configured to: determine a channel occupancy time (COT) based on sensing for channel access; transmit information related to the COT to a second device; transmit a first SCI for scheduling a physical sidelink shared channel (PSSCH) and a second SCI (sidelink control information) within the COT via a physical sidelink control channel (PSCCH); transmit the second SCI and a medium access control (MAC) protocol data unit (PDU) within the COT via the PSSCH; determine to stop using the COT; and transmit information related to the COT cessation to the second device based on the decision to cease.

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