Terminal and communication method

Abstract

A terminal is provided with: a control unit that, when a first signal pertaining to direct communication between terminals is transmitted in an unlicensed band, executes listen before talk (LBT) for transmitting a second signal transmitted after the first signal; and a transmission unit that transmits at least the second signal when the LBT is successful, and that does not execute LBT in a time interval in which the first signal is transmitted when the period of the LBT overlaps with the first signal in a time domain.

Description

Technical Field

[0001] The present invention relates to a terminal and a communication method in a wireless communication system. Background Art

[0002] In LTE (Long Term Evolution) and LTE's successor systems (e.g., LTE-A (LTE Advanced), NR (New Radio) (also known as 5G)), D2D (Device to Device) technology is being studied, in which terminals communicate directly with each other without going through a base station (e.g., non-patent document 1).

[0003] D2D reduces the traffic between the terminal and the base station, and enables communication between the terminals even when the base station cannot communicate during disasters. In addition, in 3GPP (registered trademark) (3rd Generation Partnership Project: Third Generation Partnership Project), D2D is called "sidelink", but in this specification, a more common term, D2D, is used. However, in the description of the implementation method described later, the sidelink is also used as needed.

[0004] D2D communication is roughly divided into D2D discovery (also called D2D discovery) for discovering other terminals that can communicate, and D2D communication (also called D2D direct communication, D2D communication, direct communication between terminals, etc.) for communicating directly between terminals. Hereinafter, when D2D communication (D2D communication), D2D discovery (D2D discovery), etc. are not specifically distinguished, they are referred to as D2D for short. In addition, the signal sent and received via D2D is called a D2D signal. Various use cases for services related to V2X (Vehicle to Everything) in NR are being studied (for example, non-patent document 2).

[0005] In addition, in NR version 17 (e.g., non-patent document 3), research is being conducted on the use of higher frequency bands than in previous versions. For example, applicable parameter sets including subcarrier spacing, channel bandwidth, etc., the design of the physical layer, and obstacles envisioned in actual wireless communications in the frequency band of 52.6 GHz to 71 GHz are being studied.

[0006] Prior art literature

[0007] Non-patent literature

[0008] Non-patent document 1: 3GPP TS 38.211 V17.1.0 (2022-03)

[0009] Non-patent document 2: 3GPP TR22.886V15.1.0 (2017-03)

[0010] Non-patent document 3: 3GPP TS 38.306 V17.0.0 (2022-03)

[0011] Non-patent document 4: 3GPP TS 37.213 V17.1.0 (2022-03)

[0012] Non-patent document 5: 3GPP TS 38.214 V17.1.0 (2022-03) Summary of the invention

[0013] Problems to be solved by the invention

[0014] In a newly used frequency band that uses a higher frequency than before, an unlicensed band is defined. In the unlicensed band, various rules are defined, for example, LBT (Listen before talk) is performed when accessing a channel. When D2D communication is performed in this high frequency band, an action that conforms to the rules in the unlicensed band is required. Here, if the conventional LBT is applied when a terminal performs multiple D2D transmissions, it is sometimes required to perform LBT in the transmission of the own device.

[0015] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to perform LBT (Listen before talk) suitable for direct communication between terminals in an unlicensed band.

[0016] Means for solving problems

[0017] According to the disclosed technology, a terminal is provided, comprising: a control unit, which performs LBT, i.e., listen before conversation, when sending a first signal related to direct communication between terminals in an unlicensed band, and the LBT is used to send a second signal sent after the first signal; and a sending unit, which sends at least the second signal when the LBT is successful, and when the period of the LBT overlaps with the first signal in the time domain, the control unit does not perform LBT during the time interval when the first signal is sent.

[0018] Effects of the Invention

[0019] According to the disclosed technology, it is possible to perform LBT (Listen before talk) suitable for direct communication between terminals in an unlicensed band. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram for explaining V2X.

[0021] Figure 2 This is a timing diagram showing an operation example (1) of V2X.

[0022] Figure 3 This is a timing diagram showing an operation example (2) of V2X.

[0023] Figure 4 This is a timing diagram showing an operation example (3) of V2X.

[0024] Figure 5 This is a timing diagram showing an operation example (4) of V2X.

[0025] Figure 6 It is a diagram showing an example of a monitoring (sensing) operation.

[0026] Figure 7 is a flowchart for explaining an example of a preemption action.

[0027] Figure 8 is a diagram showing an example of a preemption action.

[0028] Fig. 9 It is a diagram showing an example of a partial monitoring operation.

[0029] Fig.10 It is a diagram for explaining an example of periodic partial monitoring.

[0030] Fig.11 It is a diagram for explaining an example of continuous partial monitoring.

[0031] Fig.12 This is a diagram showing an example of the frequency range in the embodiment of the present invention.

[0032] Fig.13 This is a diagram for explaining example (1) of LBT.

[0033] Fig.14 This is a diagram for explaining example (2) of LBT.

[0034] Fig.15 This is a diagram for explaining example (3) of LBT.

[0035] Fig.16 This is a diagram for explaining an example of direct communication between terminals.

[0036] Fig.17 This is a diagram for explaining example (1) of inter-terminal direct communication in an embodiment of the present invention.

[0037] Fig.18This is a diagram for explaining example (2) of direct communication between terminals in an embodiment of the present invention.

[0038] Fig.19 This is a diagram for explaining example (3) of direct communication between terminals in an embodiment of the present invention.

[0039] Fig. 20 This is a diagram for explaining example (4) of direct communication between terminals in an embodiment of the present invention.

[0040] Fig.21 This is a diagram for explaining example (5) of direct communication between terminals in an embodiment of the present invention.

[0041] Fig. 22 It is a diagram showing an example of the functional configuration of the base station 10 in the embodiment of the present invention.

[0042] Fig.23 This is a diagram showing an example of the functional configuration of the terminal 20 in the embodiment of the present invention.

[0043] Fig.24 This is a diagram showing an example of the hardware configuration of the base station 10 or the terminal 20 in the embodiment of the present invention.

[0044] Fig.25 1 is a diagram showing an example of the structure of a vehicle 2001 in the embodiment of the present invention. DETAILED DESCRIPTION

[0045] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0046] In the operation of the wireless communication system of the embodiment of the present invention, existing technologies are appropriately used. The existing technologies are, for example, existing LTE, but are not limited to existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and methods after LTE-Advanced (for example, NR) or wireless LAN (Local Area Network: local area network).

[0047] Furthermore, in the embodiments of the present invention, the duplexing method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, Flexible Duplex, etc.).

[0048] In addition, in the embodiment of the present invention, “configuring” wireless parameters and the like may be pre-configuring predetermined values, or may be configuring wireless parameters notified from the base station 10 or the terminal 20 .

[0049] Figure 1 This is a diagram for explaining V2X. In 3GPP, the technology to realize V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functions is being studied and standardized. Figure 1 As shown, V2X is a part of ITS (Intelligent Transport Systems), which is a general term for V2V (Vehicle to Vehicle) which represents the communication between vehicles, V2I (Vehicle to Infrastructure) which represents the communication between vehicles and roadside units (RSU: Road-Side Unit) installed next to the road, V2N (Vehicle to Network) which represents the communication between vehicles and ITS servers, and V2P (Vehicle to Pedestrian) which represents the communication between vehicles and mobile terminals held by pedestrians.

[0050] In addition, 3GPP is studying V2X using cellular communication and terminal-to-terminal communication using LTE or NR. V2X using cellular communication is also called cellular V2X. In NR's V2X, research is being promoted to achieve large capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0051] Regarding LTE or NR V2X, it is envisioned that research will be conducted in the future that is not limited to 3GPP specifications. For example, it is envisioned to study the guarantee of interoperability, cost reduction using high-level implementations, the use or switching methods of multiple RATs (Radio Access Technology), regulatory support in various countries, and data acquisition, publication, database management, and usage methods of LTE or NR V2X platforms.

[0052] In the embodiments of the present invention, the communication device is mainly assumed to be mounted on a vehicle, but the embodiments of the present invention are not limited to this form. For example, the communication device may be a terminal held by a person, or a device mounted on a drone or an aircraft, or a base station, an RSU, a relay station (Relay Node), a terminal with scheduling capabilities, etc.

[0053] In addition, SL (Sidelink) can also be distinguished based on UL (Uplink) or DL ​​(Downlink) and any one or a combination of the following 1)-4). In addition, SL can also be other names.

[0054] 1) Resource allocation in the time domain

[0055] 2) Resource allocation in frequency domain

[0056] 3) Reference synchronization signal (including SLSS (Sidelink Synchronization Signal))

[0057] 4) Reference signal used for path loss measurement for transmit power control

[0058] In addition, for OFDM (Orthogonal Frequency Division Multiplexing) of SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, and OFDM with transform precoding can also be applied.

[0059] In the SL of LTE, Mode 3 and Mode 4 are defined for resource allocation of the SL to the terminal 20. In Mode 3, transmission resources are dynamically allocated using DCI (Downlink Control Information) sent from the base station 10 to the terminal 20. In addition, in Mode 3, SPS (SemiPersistent Scheduling) can also be performed. In Mode 4, the terminal 20 autonomously selects transmission resources from a resource pool.

[0060] In addition, the time slot in the embodiment of the present invention may also be replaced by a symbol, a mini-time slot, a subframe, a radio frame, or a TTI (Transmission Time Interval). In addition, the cell in the embodiment of the present invention may also be replaced by a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), etc.

[0061] In addition, in the embodiment of the present invention, the terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a terminal held by a user such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0062] In addition, in NR-SL, it is envisaged to support HARQ (Hybrid automatic repeat request) in unicast and multicast of the side link. And in NR-V2X, SFCI (Sidelink Feedback Control Information) including HARQ response is defined. And, the transmission of SFCI via PSFCH (Physical Sidelink Feedback Channel) is being studied.

[0063] In addition, in the following description, it is assumed that PSFCH is used in the transmission of HARQ-ACK based on the side link, but this is an example. For example, PSCCH can be used to transmit HARQ-ACK in the side link, PSSCH can be used to transmit HARQ-ACK in the side link, and other channels can be used to transmit HARQ-ACK in the side link.

[0064] In the following, for convenience of explanation, all information reported by the terminal 20 in HARQ is referred to as HARQ-ACK. The HARQ-ACK may also be referred to as HARQ-ACK information. In addition, more specifically, the codebook for the HARQ-ACK information reported from the terminal 20 to the base station 10, etc. is referred to as the HARQ-ACK codebook. The HARQ-ACK codebook specifies the bit string of the HARQ-ACK information. In addition, using "HARQ-ACK", NACK is also sent in addition to ACK.

[0065] Figure 2 is a timing diagram showing an operation example (1) of V2X. Figure 2 As shown in FIG. 1 , the wireless communication system according to the embodiment of the present invention may include a terminal 20A and a terminal 20B. In addition, there are actually a plurality of user devices. Figure 2 The terminal 20A and the terminal 20B are shown as examples.

[0066] Hereinafter, when the terminals 20A, 20B, etc. are not particularly distinguished, they are simply referred to as "terminal 20" or "user device". Figure 2 In the figure, as an example, the case where both the terminal 20A and the terminal 20B are within the coverage of the cell is shown, but the actions in the embodiment of the present invention can also be applied to the case where the terminal 20B is outside the coverage.

[0067] As described above, in this embodiment, the terminal 20 is, for example, a device mounted on a vehicle such as a car, and has a cellular communication function as a UE in LTE or NR and a side link function. The terminal 20 may also be a conventional portable terminal (smartphone, etc.). In addition, the terminal 20 may also be an RSU. The RSU may be a UE type RSU (UE type RSU) having the function of a UE, or a gNB type RSU (gNB type RSU) having the function of a base station device.

[0068] In addition, the terminal 20 does not need to be a device having a single housing. For example, even when various sensors are dispersedly arranged in a vehicle, the terminal 20 may be a device including the various sensors.

[0069] In addition, the processing content of the transmission data of the side link of the terminal 20 is basically the same as the processing content of the UL transmission in LTE or NR. For example, the terminal 20 scrambles and modulates the codeword of the transmission data to generate complex-valued symbols, maps the complex-valued symbols (transmission signal) to layer 1 or layer 2, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate a transmission signal (for example, a complex-valued time-domain SC-FDMA signal), and transmitted from each antenna port.

[0070] In addition, the base station 10 has a function of cellular communication as a base station in LTE or NR, and a function for enabling the terminal 20 in this embodiment to communicate (for example, resource pool setting, resource allocation, etc.). In addition, the base station 10 can also be an RSU (gNB type RSU).

[0071] In addition, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 in the SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.

[0072] As a synchronization signal in SL, the terminal 20 sends a sidelink synchronization signal block (Sidelink Synchronization Signal Block) (S-SSB). S-SSB may include S-PSS (Sidelink Primary Synchronization Signal), S-SSS (Sidelink Secondary Synchronization Signal), and PSBCH (Physical Sidelink Broadcast Channel). In addition, the names of S-SSB, S-PSS, S-SSS, etc. are examples, and may also be names other than S-SSB, S-PSS, S-SSS, etc.

[0073] The terminal 20 sends S-SSB to other terminals 20 based on a signal received from the base station device 10 or a GNSS (Global Navigation Satellite System) signal or a signal received from other terminals 20. In addition, when the terminal 20 cannot send S-SSB based on any signal from the base station device 10, GNSS, or other terminals 20, the terminal 20 may also send an autonomously determined S-SSB to other terminals 20. The resources that can be used by S-SSB may be periodic time slots, which may be referred to as S-SSB opportunities.

[0074] In step S101, the terminal 20A autonomously selects resources used by the PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window may also be set by the base station 10 for the terminal 20. Here, the predetermined period of the resource selection window may be specified based on the implementation conditions of the terminal such as the processing time or the maximum allowable delay time of the packet, or may be specified in advance based on the specification, and the predetermined period may also be referred to as an interval in the time domain.

[0075] In step S102 and step S103, the terminal 20A uses the resources independently selected in step S101 to send SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and sends SL data using PSSCH. For example, the terminal 20A can send PSCCH using frequency resources that are adjacent or non-adjacent to the frequency resources of PSSCH in the same time resources as at least a portion of the time resources of PSSCH.

[0076] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from terminal 20A. The received SCI may include resource information of PSFCH for terminal 20B to send HARQ-ACK for the data reception. Terminal 20A may include the resource information selected autonomously in SCI and send it. In addition, the resources that can be used by PSFCH may be periodic time slots and the symbols at the end (except the final symbol) of the time slot, which may also be called PSFCH opportunities.

[0077] In step S104, the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the PSFCH resources specified by the received SCI.

[0078] If the HARQ-ACK received in step S104 indicates a request for retransmission, that is, NACK (negative acknowledgement), in step S105, the terminal 20A retransmits the PSCCH and PSSCH to the terminal 20B. The terminal 20A can retransmit the PSCCH and PSSCH using the autonomously selected resources.

[0079] In addition, when HARQ control accompanied by HARQ feedback is not performed, step S104 and step S105 may not be performed.

[0080] Figure 3 This is a timing diagram showing an example of V2X operation (2). Blind retransmission may be performed regardless of HARQ control for improving the transmission success rate or the reach distance.

[0081] In step S201 , the terminal 20A autonomously selects resources used by the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0082] In step S202 and step S203, terminal 20A uses the resources independently selected in step S201 to send SCI using PSCCH and / or PSSCH, and sends SL data using PSSCH. For example, terminal 20A can send PSCCH using frequency resources adjacent to the frequency resources of PSSCH in the same time resources as at least a portion of the time resources of PSSCH.

[0083] In step S204, the terminal 20A retransmits the SCI based on the PSCCH and / or PSSCH and the SL data based on the PSSCH to the terminal 20B using the resources autonomously selected in step S201. The retransmission in step S204 may also be performed multiple times.

[0084] In addition, when blind retransmission is not performed, step S204 may not be performed.

[0085] Figure 4 is a timing diagram showing an action example (3) of V2X. The base station 10 can perform scheduling of the side link. That is, the base station 10 can determine the resources of the side link used by the terminal 20 and send information indicating the resources to the terminal 20. Furthermore, when HARQ control accompanied by HARQ feedback is applied, the base station 10 can send information indicating the resources of the PSFCH to the terminal 20.

[0086] In step S301, the base station 10 transmits DCI (Downlink Control Information) to the terminal 20A using the PDCCH, thereby performing SL scheduling. Hereinafter, for convenience of description, DCI for SL scheduling is referred to as SL scheduling DCI (SL scheduling DCI).

[0087] In addition, the following situation is assumed: in step S301, the base station 10 also sends DCI for DL ​​scheduling (also referred to as DL allocation) to the terminal 20A using the PDCCH. Hereinafter, for the convenience of explanation, the DCI for DL ​​scheduling is referred to as DL scheduling DCI. The terminal 20A that receives the DL scheduling DCI uses the resources specified by the DL scheduling DCI to receive DL data using the PDSCH.

[0088] In step S302 and step S303, the terminal 20A uses the resources specified by the SL scheduling DCI to send SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and sends SL data using PSSCH. In addition, in the SL scheduling DCI, only the resources of PSSCH can be specified. In this case, for example, the terminal 20A can send PSCCH using frequency resources adjacent to the frequency resources of PSSCH in the same time resources as at least a part of the time resources of PSSCH.

[0089] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The SCI received using PSCCH and / or PSSCH includes information on PSFCH resources for terminal 20B to transmit HARQ-ACK for the received data.

[0090] The resource information is included in the DL scheduling DCI or SL scheduling DCI sent from the base station 10 in step S301, and the terminal 20A obtains the resource information from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, the DCI sent from the base station 10 does not include the resource information, and the terminal 20A autonomously includes the resource information in the SCI and sends it.

[0091] In step S304, the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the resources of the PSFCH specified by the received SCI.

[0092] In step S305, the terminal 20A, for example, sends HARQ-ACK at a timing (e.g., timing in time slots) specified by the DL scheduling DCI (or the SL scheduling DCI) using the PUCCH (Physical uplink control channel) resources specified by the DL scheduling DCI (or the SL scheduling DCI), and the base station 10 receives the HARQ-ACK. The codebook of the HARQ-ACK may include the HARQ-ACK received from the terminal 20B or the HARQ-ACK generated based on the unreceived PSFCH, as well as the HARQ-ACK for the DL data. However, in the case where there is no allocation of DL data, etc., the HARQ-ACK for the DL data is not included. In version 16 of NR, the codebook of the HARQ-ACK does not include the HARQ-ACK for the DL data.

[0093] In addition, when HARQ control accompanied by HARQ feedback is not performed, step S304 and / or step S305 may not be performed.

[0094] Figure 5 It is a timing diagram showing an action example (4) of V2X. As described above, in the side link of NR, HARQ response is supported to be sent via PSFCH. In addition, the format of PSFCH can use, for example, the same format as PUCCH (Physical Uplink Control Channel) format 0. That is, regarding the format of PSFCH, it can be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified based on the difference in sequence and / or cyclic shift. The format of PSFCH is not limited to this. The resources of PSFCH can be configured in the codeword at the end of the time slot or multiple codewords at the end. In addition, it is predetermined whether to set the period N for the PSFCH resources. For the period N, it can be predetermined whether to set it in units of time slots.

[0095] exist Figure 5 In , the vertical axis corresponds to the frequency domain, and the horizontal axis corresponds to the time domain. PSCCH can be configured in one codeword at the start of the time slot, or in multiple codewords starting from the start, or in multiple codewords starting from a codeword other than the start. PSFCH can be configured in one codeword at the end of the time slot, or in multiple codewords at the end of the time slot. In addition, the above-mentioned "start of the time slot" and "end of the time slot" can also omit the consideration of the codewords used for AGC (Automatic Gain Control) and the codewords used for sending / receiving switching. That is, for example, in the case where one time slot is composed of 14 codewords, "the start of the time slot" and "the end of the time slot" can also refer to the start and end codewords respectively among the 12 codewords excluding the start and end codewords. In Figure 5 In the example shown, three subchannels are set in the resource pool, and two PSFCHs are arranged three slots after the slot in which the PSSCH is arranged. The arrow from the PSSCH to the PSFCH shows an example of the PSFCH associated with the PSSCH.

[0096] In the case where the HARQ response in the NR-V2X multicast is multicast option 2 of sending ACK or NACK, it is necessary to determine the resources used for the transmission and reception of the PSFCH. Figure 5As shown, in step S401, terminal 20A as the transmitting terminal 20 performs multicast to terminal 20B, terminal 20C and terminal 20D as the receiving terminal 20 via SL-SCH. In the next step S402, terminal 20B uses PSFCH#B, terminal 20C uses PSFCH#C, and terminal 20D uses PSFCH#D to send a HARQ response to terminal 20A. Figure 5 As shown in the example of , when the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to decide how to allocate PSFCH resources. In addition, the transmitting terminal 20 can also grasp the number of receiving terminals 20 in the multicast. In addition, in multicast option 1, as a HARQ response, only NACK is sent, and ACK is not sent.

[0097] Figure 6 is a diagram showing an example of monitoring action in NR. In resource allocation mode 2, the terminal 20 selects resources for transmission. Figure 6 As shown, the terminal 20 performs monitoring in the monitoring window in the resource pool. Through monitoring, the terminal 20 receives the resource reservation field or resource assignment field contained in the SCI sent from other terminals 20, and based on the field, identifies the available resource candidates in the resource selection window in the resource pool. Then, the terminal 20 randomly selects a resource from the available resource candidates.

[0098] In addition, if Figure 6 As shown, the resource pool setting may have a period. For example, the period may be a period of 10240 milliseconds. Figure 6 is the time slot t 0 SL To time slot t Tmax-1 SL An example of being set as a resource pool. The area of ​​the resource pool in each cycle can be set by, for example, a bitmap.

[0099] In addition, if Figure 6 As shown, assuming that the transmission trigger in terminal 20 occurs in time slot n, the priority of the transmission is p TX In the time slot nT 0 To time slot nT proc,0 In the monitoring window up to the time slot immediately before the time slot, the terminal 20 can detect that, for example, another terminal 20 is performing a priority p RXWhen SCI is detected in the monitoring window and RSRP (Reference Signal Received Power) exceeds the threshold, the resources in the resource selection window corresponding to the SCI are excluded. In addition, when SCI is detected in the monitoring window and RSRP is less than the threshold, the resources in the resource selection window corresponding to the SCI are not excluded. The threshold can also be based on the priority p TX and priority p RX The threshold value Th is set or defined for each resource in the monitoring window. pTX，pRX .

[0100] In addition, if Figure 6 The time slot t m SL In this way, for example, for transmission, resources within the resource selection window are excluded as candidates for resource reservation information corresponding to resources within the monitoring window that are not monitored.

[0101] like Figure 6 As shown, in time slot n+T 1 To time slot n+T 2 In the resource selection window, the resources occupied by other UEs are identified, and the resources after the resources are excluded become the available resource candidates. When the set of available resource candidates is set to S A When S A If the resource selection window is less than 20%, the threshold value Th set for each resource in the monitoring window can be set to pTX，pRX The resource identification is performed again by increasing the threshold Th by 3 dB. pTX，pRX The resource identification is performed again, so that the number of resources that are not excluded due to RSRP being less than the threshold increases, so that the set of resource candidates S A Become more than 20% of the resource selection window. A If the threshold value Th is less than 20% of the resource selection window, the threshold value Th set for each resource in the monitoring window can be repeatedly increased. pTX，pRX Increase by 3dB and perform resource identification again.

[0102] The lower layer of terminal 20 can A The upper layer of terminal 20 can report to S A The random selection is performed to determine the resource to be used. The terminal 20 can use the determined resource to perform side link transmission. For example, the high layer may be a MAC layer, and the low layer may be a PHY layer or a physical layer.

[0103] In the above Figure 6In the description, the operation of the transmitting terminal 20 is described, but the receiving terminal 20 may detect data transmission from another terminal 20 based on the result of monitoring or partial monitoring and receive data from the other terminal 20.

[0104] Figure 7 is a flowchart showing an example of preemption in NR. Figure 8 is a diagram showing an example of preemption in NR. In step S501, the terminal 20 performs monitoring in the monitoring window. When the terminal 20 performs power saving operation, the monitoring may be performed during a predetermined limited period. Next, the terminal 20 identifies each resource in the resource selection window based on the monitoring result and determines a set S of resource candidates. A , select the resource to be used in the transmission (S502). Next, the terminal 20 selects the resource candidate set S A A resource set (r_0, r_1, ...) for determining preemption is selected (S503). The resource set can be notified from the higher layer to the PHY layer as a resource for determining whether to be preempted.

[0105] In step S504, the terminal 20 Figure 8 The T(r_0)-T 3 Based on the monitoring results, the resources in the resource selection window are re-identified to determine the set of resource candidates S A , and then based on the priority, determine the preemption for the resource set (r_0, r_1, ...). For example, Figure 8 The r_1 shown in the figure is detected by monitoring again, and the SCI sent from the other terminal 20 is not included in the S A In the case where preemption is effective, when the value prio_RX indicating the priority of the SCI sent from another terminal 20 is lower than the value prio_TX indicating the priority of the transport block sent from the terminal itself, the terminal 20 determines that the resource r_1 is preempted. In addition, the lower the value indicating the priority, the higher the priority. That is, when the value prio_RX indicating the priority of the SCI sent from another terminal 20 is higher than the value prio_TX indicating the priority of the transport block sent from the terminal itself, the terminal 20 does not preempt the resource r_1 from the SCI. A Resource r_1 is excluded. Alternatively, when preemption is valid only in a specific priority (for example, sl-PreemptionEnable is any one of pl1, pl2, ..., pl8), the priority is set to prio_pre. At this time, when the value prio_RX indicating the priority of the SCI sent from the other terminal 20 is lower than prio_pre and prio_RX is lower than the value prio_TX indicating the priority of the transport block sent from the terminal itself, the terminal 20 determines that the resource r_1 is preempted.

[0106] In step S505, when the terminal 20 determines that the preemption has occurred in step S504, the terminal 20 notifies the upper layer of the preemption, reselects resources in the upper layer, and ends the preemption check.

[0107] In addition, when re-evaluation is performed instead of the preemption check, in the above step S504, a set S of resource candidates is determined. A After that, in S A If a resource in a resource set (r_0, r_1, ...) is not included in the resource set, the resource is not used and a resource reselection is performed in a higher layer.

[0108] Fig. 9 FIG. 1 is a diagram showing an example of partial monitoring operation in LTE. In the case where partial monitoring is set from a high layer in the LTE side link, as shown in FIG. Fig. 9 As shown, terminal 20 selects and sends resources. Fig. 9 As shown, the terminal 20 partially monitors a portion of the monitoring window in the resource pool, i.e., the monitoring target. Through partial monitoring, the terminal 20 receives the resource reservation field included in the SCI sent from other terminals 20, and based on the field, identifies the available resource candidates in the resource selection window in the resource pool. Then, the terminal 20 randomly selects a resource from the available resource candidates.

[0109] Fig. 9 is subframe t 0 SL To subframe t Tmax-1 SL The object area of ​​the resource pool can be set by a bitmap, for example. Fig. 9 As shown, it is assumed that the transmission trigger in the terminal 20 occurs in subframe n. Fig. 9 As shown, subframe n+T 1 To subframe n+T 2 In subframe t y1 SL To subframe t yY SL The Y subframes are set as the resource selection window.

[0110] In the subframe t which becomes the length of Y subframe y1-k×Pstep SL To subframe t yY-k×Pstep SL In one or more monitoring targets, the terminal 20 can detect that, for example, other terminals 20 are transmitting. k can be determined, for example, by a 10-bit bitmap. Fig. 9 , an example is shown in which the 3rd and 6th bits of the bitmap are set to "1" to indicate partial monitoring. Fig. 9 In subframe t y1-6×Pstep SL To subframe t yY-6×Pstep SL And from subframe t y1-3×Pstep SL To subframe t yY-3×Pstep SL As described above, the kth bit of the bitmap may correspond to the number of bits from subframe t y1-k×Pstep SL To subframe t yY-k×Pstep SL In addition, y i Corresponding to the index (1...Y) within the Y subframe.

[0111] In addition, k is set or specified in advance through a 10-bit bitmap. step However, in the case of SL communication via DL and UL carriers, P step It may also be set to (U / (D+S+U))*100ms, where U corresponds to the number of UL subframes, D corresponds to the number of DL subframes, and S corresponds to the number of special subframes.

[0112] When SCI is detected at the monitoring target and RSRP exceeds the threshold, resources in the resource selection window corresponding to the resource reservation field of the SCI are excluded. In addition, when SCI is detected at the monitoring target and RSRP is less than the threshold, resources in the resource selection window corresponding to the resource reservation field of the SCI are not excluded. The threshold can be based on the sending side priority p TX and the receiving side priority p RX , a threshold value Th is set or defined for each resource within the monitoring target pTX，pRX .

[0113] like Fig. 9 As shown, in the interval [n+T 1 , n+T 2 In the resource selection window set as the Y subframe in ], the terminal 20 identifies the resources occupied by other UEs, and the resources after excluding the resources become the available resource candidates. In addition, the Y subframes may also be discontinuous. When the set of available resource candidates is set to S A When S A If the resource selection window is less than 20%, the threshold value Th set for each resource of the monitoring target can be set to pTX，pRX The resource identification is performed again with the frequency increased by 3 dB.

[0114] That is, the threshold Th pTX，pRXThe resource identification is performed again when the RSRP is lower than the threshold, so that the number of resources that are not excluded due to RSRP being lower than the threshold is increased. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to the set S B You can also repeat the process of A The RSSI contained in is the smallest resource appended to S B The actions in the above table are as follows: B Until it becomes 20% or more of the resource selection window.

[0115] The lower layer of terminal 20 can B The upper layer of terminal 20 can report to S B The terminal 20 may use the determined resources to perform sidelink transmission. In addition, once the resources are secured, the terminal 20 may not use the resources at a predetermined number of times (e.g., C resel times) for monitoring but rather uses resources periodically.

[0116] In the NR side link, power saving based on random resource selection and partial sensing is being standardized. The terminal 20 to which partial monitoring is applied performs reception and monitoring only in a specific time slot within the monitoring window. That is, the terminal 20 may also perform resource identification by monitoring only limited resources compared to full monitoring, and perform partial monitoring for resource selection from the identified resource set. In addition, the terminal 20 may also not exclude resources from the resources in the resource selection window, but may use the resources in the resource selection window as the identified resource set and perform random selection for resource selection from the identified resource set.

[0117] In addition, the method of performing random selection at the time point of resource selection and using monitoring information during re-evaluation or preemption check can be processed as partial monitoring or as random selection.

[0118] In addition, as the action in monitoring, the following 1) and 2) may also be applied. In addition, monitoring (sensing) and monitoring (monitoring) may be interchangeable, and the action may include at least one of measurement of received RSRP, acquisition of reserved resource information, and acquisition of priority information.

[0119] 1) Periodic-based partial sensing

[0120] In the mechanism of monitoring only a part of the time slots, the action of monitoring the time slots is determined based on the reservation periodicity. In addition, the reservation periodicity is a value associated with the resource reservation period field. In addition, the period can also be replaced by periodicity.

[0121] 2) Contiguous partial sensing

[0122] In the mechanism of monitoring only a part of the time slots, the action of monitoring the time slots is determined based on aperiodic reservation. In addition, aperiodic reservation is a value associated with the time resource assignment field.

[0123] In addition, multiple resource allocation methods can be set for a resource pool. In addition, as one of the power saving functions, SL-DRX (Discontinuous reception) is supported. That is, reception is performed only in a predetermined time interval.

[0124] As described above, partial monitoring is supported as one of the power saving functions. In a resource pool with partial monitoring set, the terminal 20 can perform the above-mentioned periodic partial monitoring. The terminal 20 can receive information for setting a resource pool from the base station 10, wherein the resource pool is set with partial monitoring and the periodic reservation is set to be valid.

[0125] Fig.10 is a diagram for explaining an example of periodic partial monitoring. Fig.10 As shown, from the resource selection window [n+T 1 , n+T 2 ] select Y candidate time slots for resource selection.

[0126] You can also use t y SL As a time slot included in the Y candidate time slots, t y-k×Preserve SL The monitoring is performed as the target time slot for periodic partial monitoring.

[0127] P reserve It can correspond to all values ​​included in the set or predefined sl-ResouceReservePeriodList. Alternatively, it can correspond to P limited to a subset of sl-ResouceReservePeriodList. reserve The value of P may also be set or predefined. reservesl-ResouceReservePeriodList and sl-ResouceReservePeriodList may be set for each transmission resource pool of resource allocation mode 2. In addition, as a UE implementation, the period included in sl-ResouceReservePeriodList other than the limited subset may be monitored. For example, the terminal 20 may additionally monitor the opportunity corresponding to P_RSVP_Tx.

[0128] Regarding the k value, the terminal 20 may monitor the latest monitoring opportunity in a certain reserved period before the time slot n of the resource selection trigger or before the starting time slot of the Y candidate time slots subject to the processing time limit. In addition, the terminal 20 may also additionally monitor the periodic monitoring opportunities corresponding to the set of one or more k values. For example, as the k value, a value corresponding to the latest monitoring opportunity in a certain reserved period before the time slot n of the resource selection trigger or before the starting time slot of the Y candidate time slots subject to the processing time limit, and a value corresponding to the monitoring opportunity immediately before the latest monitoring opportunity in the certain reserved period may also be set.

[0129] As described above, partial monitoring is supported as one of the power saving functions. In a resource pool with partial monitoring set, the terminal 20 can perform the above-mentioned continuous partial monitoring. The terminal 20 can receive information for setting a resource pool from the base station 10, wherein the resource pool is set with partial monitoring and the non-periodic reservation is set to be valid.

[0130] Fig.11 is a diagram for explaining an example of continuous partial monitoring. Fig.11 As shown, when the terminal 20 sets the trigger of resource selection to time slot n, it selects the resource from the resource selection window [n+T 1 , n+T 2 ] select Y candidate time slots for resource selection. Fig.11 This is an example of the case where Y=7. Fig.11 As shown, the start of Y candidate time slots is recorded as time slot t y1 , and the next time slot is recorded as t y2 , ..., the end of the Y candidate time slots is recorded as time slot t yY .

[0131] Terminal 20 is in the interval [n+T A , n+T B ] to monitor, at n+T B or n+T B Later (set to n+T C ) performs resource selection. In addition, the above periodic partial monitoring can also be performed additionally. In addition, the interval [n+T A , n+T B ] A and TB It can be any value. In addition, n can also be replaced by the index of any time slot among the Y candidate time slots.

[0132] In addition, the symbol [ can be replaced by the symbol (, the symbol] can be replaced by the symbol. In addition, for example, the interval [a, b] is the interval from time slot a to time slot b, including time slot a and time slot b. For example, the interval (a, b) is the interval from time slot a to time slot b, excluding time slot a and time slot b.

[0133] In addition, the candidate resources to be selected as the resource are recorded as Y candidate time slots, but it can be an interval [n+T 1 , n+T 2 ] All time slots are candidate time slots, or part of the time slots can be candidate time slots.

[0134] As a method for improving reliability and delay performance, terminal coordination is being standardized. For example, terminal coordination method 1 and terminal coordination method 2 shown below are being standardized. Hereinafter, the terminal 20 that sends coordination information is recorded as UE-A, and the terminal 20 that receives coordination information is recorded as UE-B.

[0135] Inter-UE coordination scheme 1) UE-A sends to UE-B a preferred resource set and / or a non-preferred resource set for UE-B's transmission. Hereinafter, the inter-UE coordination scheme 1 is also referred to as IUC scheme 1 (Inter-UE coordination scheme 1).

[0136] Inter-UE coordination method 2) UE-A sends information to UE-B indicating resources that are expected to conflict with other transmissions or receptions and / or detected to conflict among the resources indicated by the SCI received from UE-B. This information can be sent via PSFCH. Hereinafter, inter-UE coordination method 2 is also recorded as IUC scheme 2 (Inter-UE coordination scheme 2).

[0137] The 3GPP Release 16 or Release 17 side link standardizes the following 1) and 2) as objects.

[0138] 1) In an environment where only 3GPP terminals exist in the ITS (Intelligent Transport Systems) band

[0139] 2) Environments where UL resources can be used for SL in the authorized bands of FR1 (Frequency range 1) and FR2 defined by NR

[0140] As the side link after 3GPP Release 18, unlicensed bands are being studied as new targets, for example, unlicensed bands such as 5 GHz-7 GHz band and 60 GHz band.

[0141] Fig.12 3GPP Release 15 and Release 16 NR specifications have studied the use of frequency bands above 52.6 GHz. Fig.12 As shown, the currently used FR (Frequency range) 1 is defined as a frequency band from 410 MHz to 7.125 GHz, the SCS (Sub carrier spacing) is 15, 30 or 60 kHz, and the bandwidth is from 5 MHz to 100 MHz.

[0142] FR2-1 is the frequency band from 24.25 GHz to 52.6 GHz, SCS uses 60, 120 or 240 kHz, and the bandwidth is from 50 MHz to 400 MHz. Fig.12 As shown, FR2-2 can also be assumed to support 52.6 GHz to 71 GHz. Furthermore, it is also conceivable to support frequency bands exceeding 71 GHz.

[0143] When using a frequency band exceeding 52.6 GHz, CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) / DFT-S-OFDM (Discrete Fourier Transform-Spread OFDM) with a larger sub-carrier spacing (SCS) can be applied.

[0144] In addition, in high frequency bands such as FR2-2, the increase in phase noise between carriers becomes a problem. Therefore, it may be necessary to apply a larger (wider) SCS or a single carrier waveform.

[0145] For example, as examples of unlicensed bands in the 5 GHz-7 GHz band, 5.15 GHz to 5.35 GHz, 5.47 GHz to 5.725 GHz, and 5.925 GHz and above are conceivable.

[0146] For example, as examples of unlicensed bands in the 60 GHz band, 59 GHz to 66 GHz, 57 GHz to 64 GHz, or 66 GHz, 59.4 GHz to 62.9 GHz, etc. are envisioned.

[0147] In the unlicensed band, various rules are stipulated to avoid affecting other systems or other devices.

[0148] For example, in the 5GHz-7GHz frequency band, LBT (Listen before talk) is performed when accessing the channel. The base station 10 or the terminal 20 performs power detection in a predetermined period before transmission, and terminates the transmission when the power exceeds a certain value, that is, when the transmission of other devices is detected (also known as LBT failure). In addition, the maximum channel occupancy time (MCOT) is specified. MCOT is the maximum time interval allowed for continuous transmission when transmission is started after LBT, for example, 4ms in Japan.

[0149] In addition, as an occupied channel bandwidth (OCB) requirement, when a certain carrier bandwidth is used for transmission, more than X% of the band must be used. For example, in Europe, 80% to 100% of the NCB (Nominal channel bandwidth) is required. The purpose of the OCB requirement is to correctly perform power detection for channel access.

[0150] In addition, regarding the maximum transmission power and the maximum power spectral density, it is stipulated that transmission is performed below a predetermined transmission power to avoid excessive interference. For example, in Europe, the maximum transmission power is 23dBm in the 5150MHz-5350MHz band. In addition, for example, in Europe, the maximum power spectral density is 10dBm / MHz in the 5150MHz-5350MHz band.

[0151] For example, in the 60 GHz band, LBT is performed during channel access. The base station 10 or the terminal 20 performs power detection in a predetermined period immediately before transmission, and stops transmission when the power exceeds a certain value, that is, when the transmission of other devices is detected. In addition, regarding the maximum transmission power and the maximum power spectrum density, it is stipulated that transmission is performed below the predetermined transmission power. In addition, it is stipulated that the ability to meet the OCB requirements is met.

[0152] In NR, based on the difference in the behavior of LBT in the time direction (the period of monitoring), the following four types of channel access procedures are specified. In addition, this monitoring is different from the above-mentioned side link monitoring, and is described as LBT monitoring for the sake of distinction.

[0153] Type 1) performs variable time LBT monitoring before transmission. Also called Category 4 LBT.

[0154] Type 2A) performs 25μs LBT monitoring before transmitting. Also called Category 2 LBT.

[0155] Type 2B) performs 16μs of LBT monitoring before transmitting. Also called Category 2 LBT.

[0156] Type 2C) Start sending without LBT. Same as sending in the authorized band.

[0157] Fig.13 This is a diagram for explaining example (1) of LBT. Fig.13 This is an example of a channel access procedure of type 1. Type 1 is further classified into four levels representing channel access priority classes (CAPC) based on the difference in LBT monitoring length. LBT monitoring is performed in the following two periods.

[0158] The first period is the prioritization period or the deferment period, which has 16+9×m p Length [μs]. m p A fixed value is defined for each channel access priority level.

[0159] The second period is a backoff process, which has a length of 9×N [μs]. The value of N is randomly determined from a certain range (refer to the CWS adjustment process of non-patent document 4). N is the initial value of the backoff counter, and the value of the backoff counter is reduced by 1 each time the power of the signal of the other device is not detected during the period of 9 [μs].

[0160] In the above description, the LBT monitoring period of 9 μs may also be referred to as an LBT monitoring time slot period.

[0161] exist Fig.13 In the example, m p =3, the retention period is 43μs. Fig.13 As shown, the backoff counter is fixed when the channel is busy. Fig.13 As shown, when an error is detected due to a transmission conflict between the NR-U gNB and the wireless LAN node #2, the contention window size (CWS: Contention Window Size) in the NR-U gNB is expanded from 3 to 13.

[0162] Fig.14 This is a diagram for explaining example (2) of LBT. Fig.14This is an example of a channel access procedure of type 2A or type 2B without random backoff. Type 2A sets a 25 μs gap for power detection before transmission, and type 2B sets a 16 μs gap for power detection before transmission.

[0163] Fig.15 This is a diagram for explaining example (3) of LBT. Fig.15 is an example of a Type 2C channel access procedure. Fig.15 As shown, no power detection is performed before transmission, and transmission is performed immediately after a gap of no more than 16 μs. The maximum transmission period can be 584 μs.

[0164] As described above, multiple LBT types are supported in NR-U. In the above type 1, the initial value N of the backoff counter is set from 0 to CW. p The random number in the interval from 1 to 1 is used to determine the CW based on the channel access priority level p. p Table 1 shows the range of values ​​of m specified for each channel access priority level p in UL p , CW p Minimum CW p,min , CW p Maximum CW p,max Example.

[0165] [Table 1]

[0166] Level p <![CDATA[m p ]]> <![CDATA[CW min，p ]]> <![CDATA[CW max，p ]]> 1 2 3 7 2 2 7 15 3 3 15 1023 4 7 15 1023

[0167] As shown in Table 1, m is determined according to the channel access priority level p. p , CW p，min , CW p，max . When p is 1, if the LBT period is calculated according to Table 1, the minimum is 34μs and the maximum is 88μs. When p is 2, if the LBT period is calculated according to Table 1, the minimum is 34μs and the maximum is 160μs. When p is 3, if the LBT period is calculated according to Table 1, the minimum is 43μs and the maximum is 9286μs. When p is 4, if the LBT period is calculated according to Table 1, the minimum is 79μs and the maximum is 9286μs. In addition, Table 1 is a table for UL.

[0168] The LBT type and the channel access priority level may be determined based on a notification from the base station 10 , the channel type, etc. The 25 μs or 16 μs gap may be set according to the scheduling of the base station 10 , taking into account TA (Timing Advance) and CP extension.

[0169] Fig.16 FIG. 1 is a diagram for explaining an example of direct communication between terminals. Fig.16 As shown in FIG. 1 , when UE-X transmits in time slot n, it is necessary to perform LBT type 1 immediately before time slot n and continue to detect idleness until the backoff counter becomes zero. That is, UE-X can transmit in time slot n without detecting the signal of other devices in LBT. Fig.16 In the example shown, no other transmission from the own device is performed in LBT.

[0170] On the other hand, consider a case where other transmissions are performed by the own device in LBT. Fig.17 1 is a diagram for explaining example (1) of direct communication between terminals in an embodiment of the present invention. Fig.17 As shown, there is a possibility that the UE performs multiple SL transmissions in a short period of time. If the previous backoff counter mechanism of type 1 LBT is applied to a certain SL resource, when the LBT opportunity performs other SL transmissions of its own device, LBT cannot be performed during the SL transmission interval due to half-duplex. It is necessary to determine the UE action under this communication condition. For example, the limitation based on the half-duplex may occur in any of the following 1) and 2).

[0171] 1) Transmission using resources allocated according to SL resource allocation mode 1 (resource allocation based on a control signal from a base station)

[0172] 2) Transmission using resources selected according to SL resource allocation mode 2 (autonomous resource allocation based on resource reservation information of other UEs)

[0173] Therefore, the UE can perform predetermined actions on the 2nd SL transmission (UE-X TX2) related to the Type 1 LBT and other 1st SL transmissions (UE-X TX1) of its own device before this transmission.

[0174] Fig.18 2 is a diagram for explaining example (2) of direct communication between terminals in an embodiment of the present invention. Fig.18 As shown in the LBT skipping, the UE may not perform LBT during the time interval of the first SL transmission. That is, when the LBT period for the second SL transmission overlaps with the period of the first SL transmission, the UE may not perform LBT during the period of the first SL transmission.

[0175] In addition, after the first SL is sent, the UE can perform LBT while continuing to count the backoff counter immediately without setting a reservation interval.

[0176] In addition, the first SL transmission may be performed or not performed. In the case where the first SL transmission is not performed, the UE may not apply the embodiments of the present invention.

[0177] Through the above-mentioned actions, within the time interval of the first SL transmission, it is assumed that collision avoidance is performed through the LBT related to the transmission, and the type 1 LBT can continue to be executed to be suitable for the next transmission.

[0178] In addition, when the first SL transmission is performed during the LBT period of the second SL transmission, the UE can stop counting the backoff counter. The backoff counter can be stopped just before the first SL transmission or at the time point when the first SL transmission is decided.

[0179] In addition, after the first SL transmission in which the backoff counter is stopped, the UE can restart the counting from the backoff counter value at the time of the stop and perform LBT. In addition, the second SL transmission can be performed when the backoff counter immediately before the second SL transmission becomes zero. That is, the start timing of the LBT corresponding to the second SL transmission can be the timing obtained by considering the stopping of the backoff counter during the execution of the first SL transmission.

[0180] In addition, in resource allocation mode 2, when the UE performs resource reselection for the 2nd SL transmission and applies type 1 LBT to the transmission in the newly selected resources, it can perform LBT by restarting the counting from the backoff counter value at the time of stopping after the 1st SL transmission in which the backoff counter is stopped is completed.

[0181] The resource reselection may be performed as shown in 1)-4) below.

[0182] 1) It can be executed at a timing associated with the first SL transmission. For example, it can be executed immediately before the first SL transmission.

[0183] 2) It can be executed at the time when it is decided to execute the 1st SL sending or after the time when it is decided to execute the 1st SL sending.

[0184] 3) It can be executed at the time point when the LBT period involved in the second SL transmission is determined to overlap with the first SL transmission or after the time point when the LBT period involved in the second SL transmission is determined to overlap with the first SL transmission.

[0185] 4) It can be executed at a time point when the backoff counter of the LBT involved in determining the second SL transmission does not become zero immediately before the second time point or after a time point when the backoff counter of the LBT involved in determining the second SL transmission does not become zero immediately before the second time point.

[0186] The resource reselection candidate may be determined based on the backoff counter's value when counting stops. For example, a resource that cannot perform LBT by restarting the backoff counter from the backoff counter's value when counting stops may not be a resource reselection candidate or may be excluded.

[0187] Furthermore, in resource allocation mode 2, when the UE performs resource reselection for the second SL transmission and applies type 1 LBT to the transmission in the newly selected resource, the action of performing LBT by restarting the counting from the backoff counter value at the time of stopping after the first SL transmission for which the backoff counter is stopped ends can be performed in association with the action related to the re-evaluation or preemption check. For example, the resource reselection can be performed when the re-evaluation or preemption is notified from the physical layer to the MAC layer.

[0188] Through the above-mentioned actions, the rules related to LBT can be complied with, and actions related to subsequent transmission can be performed based on the actions.

[0189] In resource allocation mode 2, the UE can determine the resources for SL transmission based on the LBT period. For example, it is possible to exclude resources from resource candidates based on the LBT period. In addition, the following description describes actions related to resource identification / selection in a state where there is a resource Z that has been determined to be transmitted, but is not limited to this. For example, it can also be applied as an action related to resource identification / selection in the case of performing more than two resource selections.

[0190] Fig.19 This is a diagram for explaining example (3) of direct communication between terminals in an embodiment of the present invention. Fig. 20 This is a diagram for explaining example (4) of direct communication between terminals in an embodiment of the present invention. In a resource identification action in a physical layer, or a resource selection action in a MAC layer, or a timing before the action, X1 can be determined as an LBT period in a type 1 LBT, and resource exclusion can be performed from resource candidates based on period X1. X1 includes a period corresponding to a backoff counter.

[0191] For example, Fig.19 As shown, the resource exclusion object may be the following time slot or resource, that is, the value determined based on X1 is set to Y1, and the time slot or resource corresponding to the time from the timing based on the resource Z that has been determined to perform transmission to the time Y1. Y1 may be the same as X1, or may be specified in milliseconds, or may be a value converted to the minimum number of slots with a time width greater than the LBT period, or may be added with an offset (e.g., +1 time slot). However, as Fig. 20 As shown, the resource immediately behind the resource Z may not be excluded, and it is also conceivable to apply COT sharing based on LBT 2A / 2B / 2C.

[0192] In addition, for example, Fig.19As shown, X2 may be determined as the LBT period for the resource that has been determined to be transmitted, and resource exclusion may be performed from resource candidates based on the period X2. X2 includes a period corresponding to the backoff counter.

[0193] For example, Fig.19 As shown in FIG. 1 , the resource exclusion object may be the following time slot or resource, that is, the value determined based on X2 is set to Y2, and the time slot or resource corresponding to the time slot or resource that is reversed by Y2 from the timing based on the resource Z that has been determined to perform transmission. Y2 may be the same as X2, or may be specified in milliseconds, or may be a value converted to the minimum number of slots with a time width greater than the LBT period, or may be offset (e.g., +1 time slot). However, as Fig. 20 As shown, the resource immediately in front of the resource Z may not be excluded, and it is also conceivable to apply COT sharing based on LBT 2A / 2B / 2C.

[0194] Fig.19 and Fig. 20 The resource exclusion action shown can, for example, be in the physical layer, during the loop processing involving the RSRP threshold change in the resource identification process (refer to Section 8.1.4 Step 4-Step 7 of non-patent document 5) or after the loop processing (refer to Section 8.1.4 Step 7 of non-patent document 5), to exclude the resources in the time slot immediately following the PSFCH opportunity and / or S-SSB opportunity from the resource candidates.

[0195] Fig.19 and Fig. 20 The resource exclusion action shown may, for example, exclude resources of time slots corresponding to Y1 and / or Y2 from resource candidates reported by the physical layer based on full monitoring or partial monitoring, or resource candidates determined in the MAC layer for random selection, in the MAC layer. Fig. 20 It is shown in FIG. 2 that the resources immediately before and after the resource Z are not excluded.

[0196] Resource exclusion in the MAC layer may refer to performing resource selection actions to ensure a gap above the time gap referred to by X1, Y1, X2 or Y2.

[0197] Through the above-mentioned actions, it is possible to control so that other SL transmissions of the own device do not occur during the LBT period related to a certain SL transmission.

[0198] In addition, in resource allocation mode 2, the UE can decide the resources for SL transmission based on the parameter P associated with LBT.

[0199] The parameter P may be determined based on the LBT period, may be defined by the specification, or may be given by setting or presetting. For example, P may be the maximum value during the LBT period. For example, P may be a parameter for each priority level sent by the SL, or a parameter for each CAPC, or may be based on the CW. min,p , CW p and The CW max,p is determined by at least one of the following.

[0200] You can also Fig.19 and Fig. 20 In the resource exclusion action shown, Y1, X1, Y2 or X2 is replaced by P, and the resource exclusion action is performed.

[0201] Through the above-mentioned actions, it is possible to control so that other SL transmissions of the own device do not occur during the LBT period related to a certain SL transmission.

[0202] In addition, in resource allocation mode 1, the UE can suspend Fig.18 The 1st SL transmission or the 2nd SL transmission as shown in the figure, and NACK is sent as HARQ-ACK for the suspended transmission to the base station 10. For example, the UE can perform any one or more of the actions shown in the following 1)-5).

[0203] 1) The UE may abort the SL transmission that starts at the previous or later timing.

[0204] 2) The UE may abort the SL transmission scheduled at the previous or later timing.

[0205] 3) The UE may terminate the transmission of SLs with low SL priority (indicating a large value of priority) related to the transmission.

[0206] 4) The UE can terminate the SL sending of DG (Dynamic grant) or CG (Configured grant).

[0207] 5) The priority of NACK transmission may be a priority related to the aborted SL transmission, a priority defined by setting, presetting or specification, or the lowest or highest priority among the priorities applicable to the aborted SL transmission.

[0208] Through the above actions, it is possible to comply with the LBT rules and request resources for retransmission from the network.

[0209] In addition, in resource allocation mode 1, the UE can send information related to the LBT period to the base station 10.

[0210] The UE may send information related to the LBT period to the base station 10 in association with SR (Scheduling Request) transmission in the physical layer. For example, part or all of the LBT period, LBT type, CAPC, backoff counter, CW, and other LBT-related parameters may be associated with SR resources.

[0211] The UE can send information related to the LBT period to the base station 10 in association with CSI (Channel state information) transmission in the physical layer. For example, the information related to the LBT period can be defined as a type of CSI. For example, the information can be sent in a specific CSI transmission type, and it can also be imagined that the information cannot be sent in a specific CSI transmission type. The specific CSI transmission type can be any one of aperiodic CSI transmission on PUSCH (Aperiodic-CSI on PUSCH), semi-persistent CSI transmission on PUSCH (Semi-persistent-CSI on PUSCH), semi-persistent CSI transmission on PUCCH (Semi-persistent-CSI on PUCCH), and periodic CSI transmission on PUCCH (Periodic-CSI on PUCCH), but is not limited to this.

[0212] The UE may send information related to the LBT period in association with the BSR (Buffer status report) in the MAC layer to the base station 10. For example, the UE may send information related to the LBT period as information included in the BSR, or may send information separate from the BSR when the BSR is sent.

[0213] The above-mentioned action of sending the information related to the LBT period to the base station 10 can be started or executed based on any one of the timings shown in the following 1)-4).

[0214] 1) Timing of generating packets

[0215] 2) Timing of packet arrival from upper layer

[0216] 3) Timing of sending SR or BSR

[0217] 4) Determine the timing of the LBT period

[0218] The information sent related to the LBT period may be any one of the LBT period, LBT type, CAPC, backoff counter, CW, and other parameters related to the LBT.

[0219] In addition, for the purpose of proper scheduling between the transmission of its own device and the transmission of other SL-UEs, the UE may also send information related to the above-mentioned LBT period to the base station 10.

[0220] Through the above-mentioned actions, it is possible to share the information required by the base station 10 for scheduling that complies with the LBT rule.

[0221] Fig.21 1 is a diagram for explaining example (5) of direct communication between terminals in an embodiment of the present invention. Fig.21 As shown, the UE may decide actions involved in LBT based on resource selection. For example, after performing resource selection, the backoff counter N may be determined based on the selected resource.

[0222] For example, when the first SL transmission of the own device has been scheduled to be executed and resources for the second SL transmission after the first SL transmission have been selected, the backoff counter N can be determined based on the resources.

[0223] For example, when the second SL transmission of the own device has been scheduled to be executed and the resources for the first SL transmission before the second SL transmission have been selected, the backoff counter N can be determined based on the resources.

[0224] For example, when resources for transmission to the first SL and resources for transmission to the second SL are selected at the same time, the backoff counter N can be determined based on the resources.

[0225] For example, Fig.21 As shown, the backoff counter value corresponding to the time gap between the end timing t1 of the first SL transmission and the second SL transmission timing t2 can be set to N max , the backoff counter N for the LBT involved in the second SL transmission is determined to be greater than 0 and N max The following values ​​(for example, random values ​​selected with equal probability) are used. This action can also be applied to the decision action of N involving the resource that has already been selected. Even when N has already been determined, N can be determined again when it is decided to perform another SL transmission (first SL transmission).

[0226] In addition, the "resource selection" in the above-mentioned resource allocation mode 2 can be replaced by the "resource scheduling and reception" in resource allocation mode 1, or can be replaced by the "transmission execution decision" of, for example, PSFCH, S-SSB, SL-PRS (Positioning RS: Positioning RS), etc.

[0227] Through the above-mentioned operation, it is possible to perform reuse without changing the resource allocation operation.

[0228] In addition, in the above-mentioned embodiment, the conventional SL channel and SL signal structure are used, but the present invention is not limited to this. For example, when an interlaced channel is used as a structure for satisfying the OCB requirement, this embodiment can also be applied.

[0229] In addition, the above-mentioned embodiments may also be limited to applications where predetermined conditions are met. For example, it may also be applied in association with a predetermined SL channel or SL signal. For example, the present embodiment may be applied to any one of PSCCH / PSSCH, PSFCH, S-SSB, and SL positioning RS. For example, it may also be applied based on a predetermined setting or a pre-setting. For example, in a resource pool, the present embodiment may also be applied when the present embodiment is "validated" by setting or pre-setting. For example, the present embodiment may not be applied when the LBT method involved in the second SL transmission is not type 1 or is no longer type 1.

[0230] In addition, in order to apply LBT type 2A, 2B or 2C, additional transmission (additional TX) such as CP extension may be performed immediately before transmission P.

[0231] In addition, the UE capabilities involved in the application and actions of this embodiment can be defined and can be reported to the base station 10 and / or the terminal 20 or not.

[0232] In addition, the first SL transmission and the second SL transmission can be any one of PSCCH, PSSCH, PSFCH, S-SSB and SL-PRS, and different channels or signals can be applied in each action of this embodiment.

[0233] In addition, at least one of the first SL transmission and the second SL transmission may be UL transmission.

[0234] This embodiment can be applied to any one of resource selection, resource reselection, re-evaluation, and preemption check.

[0235] In addition, the method in the embodiment of the present invention is not limited to the above-mentioned situation of direct communication between terminals, and can also be applied to other similar situations.

[0236] In addition, this embodiment may be limited to the case where the first SL transmission is executed, and may not be applied when the first SL transmission is not executed (for example, LBT, priority-based processing, transmission termination based on preemption, etc.).

[0237] The above embodiments are not limited to application to V2X terminals, but may also be applied to terminals performing D2D communication.

[0238] According to the above-described embodiment, when the own device performs multiple side link transmissions, appropriate LBT can be performed.

[0239] That is, LBT (Listen before talk) suitable for direct communication between terminals in an unlicensed band can be performed.

[0240] (Device Structure)

[0241] Next, the functional configuration examples of the base station 10 and the terminal 20 that execute the above-described processing and operation are described. The base station 10 and the terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions in the embodiments.

[0242] <Base station 10>

[0243] Fig. 22 1 is a diagram showing an example of the functional configuration of the base station 10. Fig. 22 As shown, the base station 10 includes a transmission unit 110 , a reception unit 120 , a setting unit 130 , and a control unit 140 . Fig. 22 The functional configuration shown is only an example, and any functional division and name of the functional unit may be used as long as the operation involved in the embodiment of the present invention can be performed.

[0244] The transmitting unit 110 includes a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The receiving unit 120 includes a function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher layer information from the received signals. In addition, the transmitting unit 110 has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0245] The setting unit 130 stores the preset setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads the setting information from the storage device as needed. The content of the setting information is, for example, information related to the setting of the D2D communication.

[0246] As described in the embodiment, the control unit 140 performs processing related to the setting for the terminal 20 to perform D2D communication. In addition, the control unit 140 sends the scheduling of D2D communication and DL communication to the terminal 20 via the transmission unit 110. In addition, the control unit 140 receives information related to the HARQ response of the D2D communication and DL communication from the terminal 20 via the reception unit 120. The functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the reception unit 120.

[0247] <Terminal 20>

[0248] Fig.23 2 is a diagram showing an example of the functional structure of the terminal 20. Fig.23 As shown, the terminal 20 includes a transmitting unit 210 , a receiving unit 220 , a setting unit 230 , and a control unit 240 . Fig.23 The functional configuration shown is only an example, and any functional division and name of the functional unit may be used as long as the operation involved in the embodiment of the present invention can be performed.

[0249] The transmitting unit 210 generates a transmission signal according to the transmission data, and transmits the transmission signal wirelessly. The receiving unit 220 receives various signals wirelessly, and obtains a higher layer signal from the received physical layer signal. In addition, the receiving unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals, etc. transmitted from the base station 10. And, for example, as D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0250] The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or the terminal 20 in the storage device, and reads it from the storage device as needed. In addition, the setting unit 230 also stores pre-set setting information. The content of the setting information is, for example, information related to the setting of D2D communication.

[0251] As described in the embodiment, the control unit 240 controls the D2D communication for establishing the RRC connection with the other terminal 20. In addition, the control unit 240 performs processing related to power saving action. In addition, the control unit 240 performs processing related to HARQ of D2D communication and DL communication. In addition, the control unit 240 sends information related to HARQ responses of D2D communication and DL communication scheduled from the base station 10 to other terminals 20. In addition, the control unit 240 can also schedule D2D communication for other terminals 20. In addition, the control unit 240 can autonomously select resources used for D2D communication from the resource selection window based on the results of side link monitoring, and can also perform re-evaluation or preemption. In addition, the control unit 240 performs processing related to power saving in the transmission and reception of D2D communication. In addition, the control unit 240 performs processing related to coordination between terminals in D2D communication. In addition, the control unit 240 performs processing related to LBT in D2D communication. The functional unit related to signal transmission in the control unit 240 may be included in the transmission unit 210 , and the functional unit related to signal reception in the control unit 240 may be included in the reception unit 220 .

[0252] (Hardware Structure)

[0253] The block diagram used in the description of the above embodiment ( Fig. 22 and Fig.23 ) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using one device that is physically or logically combined, or it can be implemented by connecting two or more physically or logically separated devices directly or indirectly (for example, using wires, wirelessly, etc.) and using these multiple devices. The functional blocks can also be implemented by combining software in the above-mentioned one device or the above-mentioned multiple devices.

[0254] Functions include judging, determining, judging, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, solving, selecting, selecting, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but are not limited to these. For example, a functional block (structural unit) that performs a sending function is called a transmitting unit or a transmitter. In short, as mentioned above, there is no particular limitation on the implementation method.

[0255] For example, the base station 10 , the terminal 20 , and the like in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig.24 1 is a diagram showing an example of the hardware structure of a base station 10 and a terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 may be configured as a computer device that physically includes a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

[0256] In the following description, the word "device" may be replaced by "circuit", "device", "unit", etc. The hardware configuration of the base station 10 and the terminal 20 may include one or more of the devices shown in the figure, or may exclude some of the devices.

[0257] Each function in the base station 10 and the terminal 20 is implemented by the following method: predetermined software (program) is read into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs calculations and controls the communication of the communication device 1004 or controls at least one of the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0258] The processor 1001 controls the entire computer by, for example, operating an operating system. The processor 1001 may also be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, a computing device, registers, etc. For example, the control unit 140, the control unit 240, etc. may also be implemented by the processor 1001.

[0259] In addition, the processor 1001 reads a program (program code), a software module, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and performs various processes accordingly. As a program, a program that causes the computer to execute at least a part of the actions described in the above embodiments is used. For example, Fig. 22 The control unit 140 of the base station 10 shown may also be implemented by a control program stored in the storage device 1002 and executed in the processor 1001. In addition, for example, Fig.23 The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and operated in the processor 1001. Although it is described that the above-mentioned various processes are performed by one processor 1001, the above-mentioned various processes can also be performed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be implemented by one or more chips. In addition, the program can also be sent from the network via a telecommunication line.

[0260] The storage device 1002 is a computer-readable recording medium, and may be composed of at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be referred to as a register, a cache, a main memory (main storage device), etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing the communication method involved in one embodiment of the present disclosure.

[0261] The auxiliary storage device 1003 is a computer-readable recording medium, and may be composed of at least one of an optical disk such as a CD-ROM (CompactDisc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk, a smart card, a flash memory (e.g., a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, and other appropriate media including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0262] The communication device 1004 is hardware (transceiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also called a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., to implement at least one of frequency division duplex (FDD: Frequency Division Duplex) and time division duplex (TDD: Time Division Duplex). For example, a transceiver antenna, an amplifier, a transceiver, a transmission path interface, etc. may also be implemented by the communication device 1004. The transceiver may also be implemented by physically or logically separating the transmitter and the receiver.

[0263] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1006 is an output device that implements output to the outside (e.g., a display, a speaker, an LED light, etc.). In addition, the input device 1005 and the output device 1006 may also be integrally formed (e.g., a touch panel).

[0264] In addition, the processor 1001 and the storage device 1002 and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or different buses may be used between the devices.

[0265] In addition, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array), and a part or all of each functional block may be implemented by the hardware. For example, the processor 1001 may also be implemented using at least one of these hardware.

[0266] Fig.25 FIG. 2 shows a structural example of a vehicle 2001. Fig.25As shown, the vehicle 2001 includes a driving unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each form / embodiment described in the present disclosure may also be applied to a communication device mounted on the vehicle 2001, for example, may also be applied to the communication module 2013.

[0267] The driving unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also referred to as a steering wheel), and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by a user.

[0268] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals from various sensors 2021 to 2029 provided in the vehicle 2001 are input to the electronic control unit 2010. The electronic control unit 2010 may also be referred to as an ECU (Electronic Control Unit).

[0269] As signals from various sensors 2021~2029, there are current signals from the current sensor 2021 that senses the current of the motor, speed signals of the front wheels and rear wheels obtained by the speed sensor 2022, air pressure signals of the front wheels and rear wheels obtained by the air pressure sensor 2023, vehicle speed signals obtained by the vehicle speed sensor 2024, acceleration signals obtained by the acceleration sensor 2025, accelerator pedal depression amount signals obtained by the accelerator pedal sensor 2029, brake pedal depression amount signals obtained by the brake pedal sensor 2026, shift lever operation signals obtained by the shift lever sensor 2027, detection signals for detecting obstacles, vehicles, pedestrians, etc. obtained by the object detection sensor 2028, and the like.

[0270] The information service unit 2012 is composed of various devices such as a car navigation system, an audio system, a speaker, a television, and a radio for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information obtained from an external device via the communication module 2013 and the like to provide various multimedia information and multimedia services to passengers of the vehicle 2001. The information service unit 2012 may include an input device for accepting input from the outside (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.), and may also include an output device for implementing output to the outside (for example, a display, a speaker, an LED light, a touch panel, etc.).

[0271] The driving assistance system unit 2030 is composed of various devices for preventing accidents or reducing the driver's driving load, such as millimeter wave radar, LiDAR (Light Detection and Ranging), camera, positioning device (such as GNSS, etc.), map information (such as high-definition (HD) map, autonomous driving vehicle (AV) map, etc.), gyroscope system (such as IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chip, AI processor, and one or more ECUs that control these devices. In addition, the driving assistance system unit 2030 sends and receives various information via the communication module 2013 to realize the driving assistance function or the autonomous driving function.

[0272] The communication module 2013 can communicate with the microprocessor 2031 and the components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data with the drive unit 2002, the steering unit 2003, the accelerator pedal 2004, the brake pedal 2005, the shift lever 2006, the front wheel 2007, the rear wheel 2008, the axle 2009, the microprocessor 2031 in the electronic control unit 2010, the memory (ROM, RAM) 2032, and the sensors 2021 to 2029 via the communication port 2033.

[0273] The communication module 2013 can be controlled by the microprocessor 2031 of the electronic control unit 2010, and is a communication device that can communicate with an external device. For example, various information can be sent and received with the external device via wireless communication. The communication module 2013 can be located inside or outside the electronic control unit 2010. The external device can also be, for example, a base station, a mobile station, etc.

[0274] The communication module 2013 may transmit at least one of the signals from the various sensors 2021 to 2028 input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012 to an external device via wireless communication. The electronic control unit 2010, the various sensors 2021 to 2028, the information service unit 2012, etc. may also be referred to as an input unit that receives input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above input.

[0275] The communication module 2013 receives various information (traffic information, signal information, vehicle-to-vehicle information, etc.) sent from an external device and displays it on the information service unit 2012 of the vehicle 2001. The information service unit 2012 may also be referred to as an output unit that outputs information (for example, outputs information to a display, a speaker, etc. based on the PDSCH received by the communication module 2013 (or data / information decoded from the PDSCH)). In addition, the communication module 2013 stores various information received from the external device in the memory 2032 that can be used by the microprocessor 2031. The microprocessor 2031 may also control the drive unit 2002, the steering unit 2003, the accelerator pedal 2004, the brake pedal 2005, the gear lever 2006, the front wheel 2007, the rear wheel 2008, the axle 2009, the sensors 2021 to 2029, etc. of the vehicle 2001 based on the information stored in the memory 2032.

[0276] (Summary of Implementation Methods)

[0277] As described above, according to an embodiment of the present invention, there is provided a terminal comprising: a control unit, which performs LBT, i.e., listen before conversation, when sending a first signal related to direct communication between terminals in an unlicensed band, wherein the LBT is used to send a second signal sent after the first signal; and a sending unit, which sends at least the second signal when the LBT is successful, and when the period of the LBT overlaps with the first signal in the time domain, the control unit does not perform the LBT during the time interval when the first signal is sent.

[0278] According to the above configuration, when the own device performs side link transmission multiple times, appropriate LBT can be performed. In other words, LBT (Listen before talk) suitable for inter-terminal direct communication in an unlicensed band can be performed.

[0279] Alternatively, the control unit stops counting of the backoff counter immediately before transmitting the first signal, and restarts counting of the backoff counter at the time when the transmission of the first signal is completed. According to this configuration, when the own device performs multiple sidelink transmissions, appropriate LBT can be performed.

[0280] Alternatively, when the control unit reselects a resource used for transmission of the second signal immediately before the first signal is transmitted, the backoff counter that stopped counting immediately before the first signal is transmitted may restart counting for LBT for performing transmission in the newly selected resource to perform LBT. According to this configuration, when the own device performs multiple sidelink transmissions, an appropriate LBT can be performed.

[0281] In addition, according to an embodiment of the present invention, a terminal is provided, comprising: a control unit, which performs LBT, i.e., listen before conversation, when sending a first signal related to direct communication between terminals in an unlicensed band, and the LBT is used to send a second signal sent after the first signal; and a sending unit, which sends at least the second signal when the LBT is successful, and the control unit determines the resources used in sending the first signal or the second signal based on the LBT period.

[0282] According to the above configuration, when the own device performs side link transmission multiple times, appropriate LBT can be performed. In other words, LBT (Listen before talk) suitable for inter-terminal direct communication in an unlicensed band can be performed.

[0283] Alternatively, the control unit may exclude resources corresponding to a certain period from the first signal or a certain period from the second signal from the resource candidates. According to this configuration, when the own device performs multiple sidelink transmissions, appropriate LBT can be performed.

[0284] In addition, according to an embodiment of the present invention, a communication method is provided, in which a terminal executes the following steps: a control step, when sending a first signal related to direct communication between terminals in an unlicensed band, performing LBT, i.e., listening before talking, and the LBT is used to send a second signal sent after the first signal; a sending step, when the LBT is successful, at least sending the second signal; and a step of not performing LBT during the time interval when the first signal is sent when the period of the LBT overlaps with the first signal in the time domain.

[0285] According to the above configuration, when the own device performs side link transmission multiple times, appropriate LBT can be performed. In other words, LBT (Listen before talk) suitable for inter-terminal direct communication in an unlicensed band can be performed.

[0286] (Supplementary Implementation Methods)

[0287] The above describes the embodiments of the present invention, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, alternatives, replacements, etc. In order to promote the understanding of the invention, specific numerical examples are used for description, but unless otherwise specified, these numerical values ​​are only examples, and any appropriate value can be used. The item distinction in the above description is not essential to the present invention. The items recorded in more than two items can be combined and used as needed, and the items recorded in a certain item can be applied to the items recorded in another item (as long as there is no contradiction). The boundaries of the functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of the physical components. The actions of multiple functional units can be performed by one physical component, or the actions of one functional unit can be performed by multiple physical components. Regarding the processing process described in the embodiment, the order of processing can be swapped without contradiction. In order to facilitate the description of the processing, the base station 10 and the terminal 20 are described using a functional block diagram, but such a device can also be implemented by hardware, software, or a combination thereof. The software that operates according to the implementation mode of the present invention through the processor of the base station 10 and the software that operates according to the implementation mode of the present invention through the processor of the terminal 20 can also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server and any other appropriate storage medium.

[0288] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information may be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), high-level signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals or a combination thereof. In addition, RRC signaling may be referred to as an RRC message, for example, it may also be an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0289] Each form / embodiment described in the present disclosure may also be applied to a mobile communication system using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or a decimal)), FRA (Future Radio Access), NR (New Radio), New Radio Access (NX), Future Generation Radio Access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE At least one of 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), other appropriate systems, and next-generation systems that are expanded, modified, created, and specified based on these systems. In addition, a combination of multiple systems (for example, a combination of at least one of LTE and LTE-A and 5G, etc.) may also be applied.

[0290] The processing procedures, timings, and flows of each form / implementation described in this specification may be reversed in order if there is no contradiction. For example, the methods described in this disclosure use the order in which the elements of various steps are presented, but are not limited to the specific order presented.

[0291] In this specification, specific actions performed by the base station 10 are sometimes also performed by its upper node according to the situation. In a network composed of one or more network nodes having the base station 10, various actions performed for communicating with the terminal 20 can be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, MME or S-GW, etc., but not limited to these). In the above, the case where there is one other network node other than the base station 10 is illustrated, but the other network node may also be a combination of multiple other network nodes (for example, MME and S-GW).

[0292] The information or signals described in the present disclosure can be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), and can also be input or output via a plurality of network nodes.

[0293] The input or output information can be stored in a specific location (e.g., a memory) or managed using a management table. The input or output information can be rewritten, updated, or appended. The output information can also be deleted. The input information can also be sent to other devices.

[0294] The determination in the present disclosure may be performed by a value represented by 1 bit (0 or 1), by a Boolean value (Boolean: true or false), or by comparison of numerical values ​​(for example, comparison with a predetermined value).

[0295] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to commands, sets of commands, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0296] In addition, software, commands, information, etc. can be sent and received via a transmission medium. For example, when software is sent from a web page, server, or other remote source using at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.), at least one of these wired technology and wireless technology is included in the definition of transmission medium.

[0297] The information, signals, etc. described in the present disclosure may also be represented by any of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the above description as a whole may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0298] In addition, the terms described in the present disclosure and the terms required for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may also be a signal (signaling). In addition, a signal may also be a message. In addition, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0299] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0300] In addition, the information, parameters, etc. described in the present disclosure may be represented by absolute values, relative values ​​to predetermined values, or other corresponding information. For example, a wireless resource may be indicated by an index.

[0301] The names used for the above parameters are non-restrictive in any respect. Furthermore, the formulas etc. using these parameters may sometimes differ from those explicitly disclosed in the present disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by all appropriate names, and therefore the various names assigned to these various channels and information elements are non-restrictive in any respect.

[0302] In the present disclosure, the terms "base station (BS)," "wireless base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier" and the like are used interchangeably. Sometimes, the base station is also referred to as macro cell, small cell, micro-micro cell, micro-micro cell and the like.

[0303] A base station can accommodate one or more (for example, 3) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services through a base station subsystem (for example, a small base station for indoor use (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a part or the entirety of the coverage area of ​​at least one of a base station and a base station subsystem that provide communication services within the coverage area.

[0304] In the present disclosure, the base station sending information to the terminal may be replaced by the base station instructing the terminal to perform control / action based on the information.

[0305] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0306] For mobile stations, those skilled in the art sometimes also use the following terms: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terms.

[0307] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to an object that can move, and the moving speed is arbitrary. In addition, of course, it also includes the situation where the mobile body stops. The mobile body includes, for example, vehicles, transport vehicles, cars, motorcycles, bicycles, networked cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, two-wheel trailers (rear car), rickshaws, ships (ships and other watercraft: ships and other ships), airplanes, rockets, artificial satellites, Drone (registered trademark), multi-rotor helicopters, quadcopters, balloons and objects mounted on them, and is not limited to this. In addition, the mobile body may also be a mobile body that drives autonomously based on an operation instruction. It can be a means of transportation (such as a car, an airplane, etc.), a mobile body that moves in an unmanned manner (such as a drone, an automatic driving car, etc.), or a robot (man-powered or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0308] In addition, the base station in the present disclosure may also be replaced by a user terminal. For example, a structure in which the communication between a base station and a user terminal is replaced by the communication between multiple terminals 20 (for example, it may also be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.) may also apply various forms / implementations of the present disclosure. In this case, it may also be configured that the terminal 20 has the functions possessed by the above-mentioned base station 10. In addition, terms such as "uplink" and "downlink" may also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. may also be replaced by side channels.

[0309] Likewise, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station may have the functions of the user terminal.

[0310] The terms "determining" and "determining" used in the present disclosure sometimes include a variety of actions. "Determining" and "determining" may include, for example, considering matters that have been judged, calculated, calculated, processed, derived, investigated, searched (for example, searched in a table, database or other data structure), confirmed (ascertaining) as matters that have been "determined", "determined", etc. In addition, "determining" and "determining" may include matters that have been received (for example, receiving information), transmitted (for example, transmitting information), input, output, accessed (for example, accessed data in memory) as matters that have been "determined", "determined", etc. In addition, "determining" and "determining" may include matters that have been resolved (resolving), selected (selecting), chosen (choosing), established (establishing), compared (comparing), etc. as matters that have been "determined", "determined", etc. That is, "judgment" and "decision" may include certain actions that are considered to be "judged" or "decided". In addition, "judgment (decision)" may also be replaced by "assuming", "expecting", "considering", etc.

[0311] The terms "connected", "coupled" or all variations of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include the situation where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used to replace "connection". In the context of the present disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the wireless frequency domain, microwave region, and light (including both visible and invisible) region may be used to "connect" or "couple" to each other.

[0312] The reference signal may be referred to as RS (Reference Signal) for short, or may be referred to as a pilot signal (Pilot) according to the applied standard.

[0313] The phrase “based on” used in the present disclosure does not mean “based only on” unless otherwise explicitly stated. In other words, the phrase “based on” means both “based only on” and “based at least on”.

[0314] Any reference to an element using the designations "first", "second", etc. used in this disclosure does not necessarily limit the number or order of these elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Therefore, a reference to a first element and a second element does not mean that only two elements can be used or that the first element must precede the second element in any form.

[0315] The “unit” in the configuration of each of the above-mentioned devices may be replaced with a “section”, “circuit”, “device” or the like.

[0316] When the terms "include", "including" and their variations are used in the present disclosure, these terms are intended to be inclusive, just like the term "comprising". Furthermore, the term "or" used in the present disclosure does not mean an exclusive or.

[0317] A radio frame may be composed of one or more frames in the time domain. In the time domain, one or more frames may be referred to as a subframe. A subframe may also be composed of one or more time slots in the time domain. A subframe may be a fixed time length (e.g., 1 ms) that is independent of a numerology.

[0318] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a certain signal or channel. The parameter set may, for example, represent at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transceiver in the frequency domain, specific windowing processing performed by the transceiver in the time domain, and the like.

[0319] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0320] A time slot may contain multiple mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. In addition, a mini-slot may also be referred to as a sub-slot. A mini-slot may be composed of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in units of time greater than a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type B.

[0321] A radio frame, a subframe, a time slot, a mini-time slot, and a symbol all represent time units for transmitting signals. A radio frame, a subframe, a time slot, a mini-time slot, and a symbol may be referred to by other corresponding names.

[0322] For example, one subframe may be referred to as a transmission time interval (TTI), multiple consecutive subframes may be referred to as a TTI, and one time slot or one mini time slot may be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. In addition, the unit representing a TTI may not be referred to as a subframe, but as a time slot, a mini time slot, or the like.

[0323] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate wireless resources (frequency bandwidth, transmission power, etc. that can be used in each terminal 20) to each terminal 20 in units of TTI. In addition, the definition of TTI is not limited to this.

[0324] TTI can be a transmission time unit of data packets (transport blocks), code blocks, code words, etc. after channel coding, or a processing unit such as scheduling and link adaptation. In addition, when TTI is given, the time interval (e.g., the number of symbols) to which the transport block, code block, code word, etc. is actually mapped can be shorter than the TTI.

[0325] In addition, when one time slot or one mini time slot is called TTI, one or more TTIs (i.e., one or more time slots or one or more mini time slots) can be the minimum time unit for scheduling. In addition, the number of time slots (mini time slots) constituting the minimum time unit for scheduling can be controlled.

[0326] A TTI having a time length of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may also be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini-time slot, a sub-time slot, a time slot, etc.

[0327] In addition, for a long TTI (longTTI) (for example, a normal TTI, a subframe, etc.), it can be replaced with a TTI having a time length exceeding 1ms, and for a short TTI (short TTI) (for example, a shortened TTI, etc.), it can be replaced with a TTI having a TTI length smaller than the long TTI (longTTI) and greater than 1ms.

[0328] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain. In the frequency domain, it may include one or more consecutive subcarriers. The number of subcarriers included in an RB may be the same regardless of the parameter set, for example, it may be 12. The number of subcarriers included in an RB may also be determined based on the parameter set.

[0329] In addition, the time domain of an RB may include one or more symbols, and may be the length of one slot, one mini slot, one subframe, or one TTI. One TTI, one subframe, etc. may be composed of one or more resource blocks, respectively.

[0330] In addition, one or more RBs may also be referred to as a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, etc.

[0331] In addition, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0332] A bandwidth part (BWP) (also referred to as partial bandwidth, etc.) may also represent a subset of contiguous common RBs (common resource blocks) for a parameter set in a carrier. Here, the common RBs may be identified by the index of the RBs relative to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0333] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for the terminal 20 within one carrier.

[0334] At least one of the set BWPs may be active, and it is not assumed that the terminal 20 transmits and receives a predetermined signal / channel outside the activated BWP. In addition, "cell", "carrier" and the like in the present disclosure may be replaced with "BWP".

[0335] The above structures of radio frames, subframes, time slots, mini-time slots, and symbols are merely examples. For example, the number of subframes included in a radio frame, the number of time slots per subframe or radio frame, the number of mini-time slots included in a time slot, the number of symbols and RBs included in a time slot or mini-time slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, and the cyclic prefix (CP) length may be changed in various ways.

[0336] In the present disclosure, when an article is added by translation, such as a, an, and the in English, for example, the present disclosure also includes a case where the noun following the article is in a plural form.

[0337] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". In addition, the term may mean "A and B are different from C, respectively". The terms "separate" and "combined" may also be interpreted in the same way as "different".

[0338] Each form / implementation described in the present disclosure may be used alone or in combination, and may be switched depending on the execution. In addition, notification of predetermined information (e.g., notification of "yes X") is not limited to being performed explicitly, but may also be performed implicitly (e.g., not notifying the predetermined information).

[0339] The present disclosure is described in detail above, but it should be clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as a modification and variation without departing from the subject matter and scope of the present disclosure as determined by the claims. Therefore, the purpose of the description of the present disclosure is to illustrate and not to have any limiting meaning on the present disclosure.

[0340] Description of symbols

[0341] 10: Base Station

[0342] 110: Sending Department

[0343] 120: Receiving Department

[0344] 130: Setting department

[0345] 140: Control Department

[0346] 20: Terminal

[0347] 210: Sending Department

[0348] 220: Receiving Department

[0349] 230: Setting department

[0350] 240: Control Department

[0351] 1001: Processor

[0352] 1002: Storage device

[0353] 1003: Auxiliary storage device

[0354] 1004: Communication device

[0355] 1005: Input device

[0356] 1006: Output device

[0357] 2001: Vehicles

[0358] 2002: Drive Department

[0359] 2003: Steering

[0360] 2004: Accelerator pedal

[0361] 2005: Brake pedal

[0362] 2006: Gear Lever

[0363] 2007: Front wheel

[0364] 2008: Rear wheel

[0365] 2009: Axles

[0366] 2010: Electronic Control Department

[0367] 2012: Information Services Department

[0368] 2013: Communication Module

[0369] 2021: Current Sensors

[0370] 2022: Speed ​​Sensor

[0371] 2023: Barometric pressure sensor

[0372] 2024: Vehicle speed sensor

[0373] 2025: Accelerometers

[0374] 2026: Brake pedal sensor

[0375] 2027: Gearshift sensor

[0376] 2028: Object detection sensors

[0377] 2029: Accelerator pedal sensor

[0378] 2030: Driving Assistance Systems Division

[0379] 2031: Microprocessors

[0380] 2032: Memory (ROM, RAM)

[0381] 2033: Communication port (IO port)

Claims

1. A terminal comprising: a control unit that, when transmitting a first signal related to inter-terminal direct communication in an unlicensed band, performs LBT (Listen Before Talk), wherein the LBT is used to transmit a second signal transmitted after the first signal; and a sending unit, which sends at least the second signal when the LBT is successful, When a period of the LBT overlaps with the first signal in the time domain, the control unit does not perform the LBT in the time interval when the first signal is transmitted.

2. The terminal according to claim 1, wherein: The control unit stops counting of the back-off counter immediately before transmitting the first signal, and restarts counting of the back-off counter at a time point when transmission of the first signal is completed.

3. The terminal according to claim 2, wherein: When the control unit reselects a resource used for transmitting the second signal immediately before transmitting the first signal, the backoff counter that stopped counting immediately before transmitting the first signal restarts counting for performing LBT in the newly selected resource to perform LBT.

4. A terminal comprising: a control unit that, when transmitting a first signal related to inter-terminal direct communication in an unlicensed band, performs LBT (Listen Before Talk), wherein the LBT is used to transmit a second signal transmitted after the first signal; and a sending unit, which sends at least the second signal when the LBT is successful, The control unit determines resources used for transmitting the first signal or the second signal based on the LBT period.

5. The terminal according to claim 4, wherein: The control unit excludes, from resource candidates, resources corresponding to a period of time after the first signal or a period of time after the second signal.

6. A communication method, wherein a terminal performs the following steps: A control step of performing LBT (Listen Before Talk) when a first signal related to inter-terminal direct communication is sent in an unlicensed band, wherein the LBT is used to send a second signal sent after the first signal; A sending step, in the case where the LBT is successful, at least sending the second signal; as well as When the period of the LBT overlaps with the first signal in the time domain, the LBT step is not performed during the time interval when the first signal is transmitted.

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