Terminal and communication method

Abstract

A terminal has a transmission section that transmits information on resource selection to another terminal via a resource related to a HARQ (Hybrid automatic repeat request) feedback channel, and a reception section that receives data from the other terminal via a resource decided based on the information on resource selection, the information on resource selection including at least one of a listening result, information indicating a resource decided based on listening, an instruction to reevaluate or reselect, and a sidelink grant.

Description

Technical Field

[0001] This invention relates to a terminal and a communication method in a wireless communication system. Background Technology

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

[0003] D2D reduces the traffic load between terminals and base stations, enabling communication between terminals even when base stations cannot communicate, such as during disasters. Furthermore, in 3GPP (3rd Generation Partnership Project), D2D is referred to as a "sidelink," but in this specification, the more general term D2D is used. However, in the description of the implementation methods described later, "sidelink" may also be used as needed.

[0004] D2D communication is broadly divided into D2D discovery (also known as D2D discovery), used to discover other terminals capable of communication, and D2D communication (also known as D2D direct communication, D2D communication, direct communication between terminals, etc.), used for direct communication between terminals. Hereinafter, without specifically distinguishing between D2D communication, D2D discovery, etc., it will be simply referred to as D2D. Furthermore, signals transmitted and received via D2D are referred to as D2D signals. Various use cases for services related to V2X (Vehicle to Everything) in NR are being investigated (e.g., Non-Patent Document 2).

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent document 1: 3GPP TS 38.211V16.2.0 (2020-06)

[0008] Non-patent document 2: 3GPP TR 22.886V15.1.0 (2017-03) Summary of the Invention

[0009] The problem the invention aims to solve

[0010] As an enhancement to the NR sidelink, eURLLC (enhanced Ultra Reliable Low Latency Communication) was investigated. For example, it is envisioned that by leveraging cooperation between terminals, information related to the resources to be used can be received from other terminals, and resource selection can be performed based on that information, thereby improving communication quality. However, specific methods for sharing any information with other terminals have not yet been specified.

[0011] The present invention was made in view of the above circumstances, and its purpose is to improve the efficiency of communication by enabling cooperative actions between terminals in direct communication between terminals.

[0012] means for solving problems

[0013] According to the disclosed technology, a terminal is provided, comprising: a transmitting unit that transmits information related to resource selection to other terminals via resources associated with a HARQ (Hybrid Automatic Repeat Request) feedback channel; and a receiving unit that receives data from the other terminals via resources determined based on the information related to resource selection, wherein the information related to resource selection includes at least one of monitoring results, information indicating resources determined based on monitoring, an indication of re-evaluation or re-selection, and sidelink authorization.

[0014] Invention Effects

[0015] According to the disclosed technology, it is possible to perform collaborative actions between terminals during direct communication, thereby improving communication efficiency. Attached Figure Description

[0016] Figure 1 This is a diagram used to illustrate V2X.

[0017] Figure 2 This is a diagram (1) used to illustrate the transmission mode of V2X.

[0018] Figure 3 This is a diagram (2) used to illustrate the transmission mode of V2X.

[0019] Figure 4 This is a diagram (3) used to illustrate the transmission mode of V2X.

[0020] Figure 5 This is a diagram (4) used to illustrate the transmission mode of V2X.

[0021] Figure 6 This is a diagram (5) used to illustrate the transmission mode of V2X.

[0022] Figure 7 This is a diagram (1) used to illustrate the communication types of V2X.

[0023] Figure 8 This is a diagram (2) used to illustrate the communication types of V2X.

[0024] Figure 9 This is a diagram (3) used to illustrate the communication types of V2X.

[0025] Figure 10 This is a timing diagram showing the action example (1) of V2X.

[0026] Figure 11 This is a timing diagram showing the action example (2) of V2X.

[0027] Figure 12 This is a timing diagram showing the action example (3) of V2X.

[0028] Figure 13 This is a timing diagram showing the action example (4) of V2X.

[0029] Figure 14 This is a diagram illustrating an example of a listening action.

[0030] Figure 15 This is a diagram illustrating an example of some listening actions.

[0031] Figure 16 This is a timing diagram illustrating an example of inter-terminal collaboration in an embodiment of the present invention.

[0032] Figure 17 This is a diagram illustrating an example (1) of resources used in inter-terminal collaboration in an embodiment of the present invention.

[0033] Figure 18 This is a diagram illustrating an example (2) of resources used in inter-terminal collaboration in an embodiment of the present invention.

[0034] Figure 19 This is a diagram illustrating an example (3) of resources used in inter-terminal collaboration in an embodiment of the present invention.

[0035] Figure 20 This is a diagram illustrating an example (4) of resources used in inter-terminal collaboration in an embodiment of the present invention.

[0036] Figure 21 This is a diagram illustrating an example (5) of resources used in inter-terminal collaboration in an embodiment of the present invention.

[0037] Figure 22 This is a diagram illustrating an example of the functional structure of a base station 10 in an embodiment of the present invention.

[0038] Figure 23 This is a diagram illustrating an example of the functional structure of terminal 20 in an embodiment of the present invention.

[0039] Figure 24 The figure shown is an example of the hardware structure of the base station 10 or terminal 20 in an embodiment of the present invention. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are merely examples, and the application of the present invention is not limited to the embodiments described below.

[0041] When the wireless communication system according to the embodiments of the present invention is in operation, existing technologies may be appropriately used. However, such existing technologies include, but are not limited to, existing LTE. Furthermore, unless otherwise stated, the term "LTE" as used in this specification has a broad meaning that includes LTE-Advanced and subsequent modes (such as NR) or wireless LAN (Local Area Network).

[0042] Furthermore, in embodiments of the present invention, the duplex mode can be TDD (Time Division Duplex), FDD (Frequency Division Duplex), or other modes (e.g., Flexible Duplex).

[0043] Furthermore, in embodiments of the present invention, the "configure" wireless parameters can be pre-configured predetermined values, or wireless parameters notified from the base station 10 or the terminal 20 can be set.

[0044] Figure 1 This diagram illustrates V2X. Within 3GPP, technologies for implementing V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality are being researched and standardized. Figure 1As shown, V2X is a part of ITS (Intelligent Transport Systems). It is a collective term for V2V (Vehicle to Vehicle), V2I (Vehicle to Infrastructure), V2N (Vehicle to Network), and V2P (Vehicle to Pedestrian), which are communication forms between vehicles and roadside units (RSUs) located beside the road.

[0045] Furthermore, 3GPP is researching V2X using LTE or NR cellular communication and inter-terminal communication. V2X using cellular communication is also referred to as cellular V2X. In NR V2X, research is underway to achieve high capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0046] Regarding V2X for LTE or NR, future research is envisioned to extend beyond 3GPP specifications. For example, research is envisioned to ensure interoperability, reduce costs associated with high-level installations, methods for the concurrent use or switching of multiple RATs (Radio Access Technologies), regulatory support in various countries, and methods for data acquisition, distribution, database management, and usage on LTE or NR V2X platforms.

[0047] In the embodiments of the present invention, the communication device is primarily envisioned as being mounted on a vehicle, but the embodiments of the present invention are not limited to this method. For example, the communication device can be a terminal held by a person, a device mounted on a drone or aircraft, or a base station, RSU, relay station, terminal with scheduling capabilities, etc.

[0048] Additionally, SL (Sidelink) can be distinguished based on UL (Uplink) or DL ​​(Downlink) and any one or a combination of 1) to 4) below. Furthermore, SL can also be other names.

[0049] 1) Resource allocation in the time domain

[0050] 2) Frequency domain resource allocation

[0051] 3) Reference synchronization signals (including SLSS (Sidelink Synchronization Signal))

[0052] 4) Reference signal used in path-loss measurement for transmit power control

[0053] Furthermore, for SL or UL OFDM (Orthogonal Frequency Division Multiplexing), any of the following can be applied: CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding.

[0054] In LTE's SL (Send-On) architecture, two modes, Mode 3 and Mode 4, are specified for resource allocation for terminal 20. In Mode 3, transmission resources are dynamically allocated using the DCI (Downlink Control Information) sent from base station 10 to terminal 20. Furthermore, SPS (Semi-Persistent Scheduling) is also possible in Mode 3. In Mode 4, terminal 20 autonomously selects transmission resources from the resource pool.

[0055] In addition, the time slot in the embodiments of the present invention can also be replaced by symbol, mini time slot, subframe, radio frame, TTI (Transmission Time Interval). Furthermore, the cell in the embodiments of the present invention can also be replaced by cell group, carrier component, BWP, resource pool, resource, RAT (Radio Access Technology), system (including wireless LAN), etc.

[0056] Furthermore, in embodiments of the present invention, terminal 20 is not limited to a V2X terminal, but can be any type of terminal performing D2D communication. For example, terminal 20 can be a user-owned terminal such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0057] Figure 2 This is a diagram illustrating an example (1) of V2X transmission modes. In Figure 2 In the sidelink communication transmission mode shown, in step 1, base station 10 sends a sidelink schedule to terminal 20A. Then, terminal 20A, based on the received schedule, sends PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to terminal 20B (step 2). Alternatively... Figure 2 The sidelink communication transmission mode shown is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, sidelink scheduling is performed based on Uu. Uu refers to the radio interface between the UTRAN (Universal Terrestrial Radio Access Network) and the UE (User Equipment). Alternatively, it can also be... Figure 2 The sidelink communication transmission mode shown is called sidelink transmission mode 1 in NR.

[0058] Figure 3 This is a diagram illustrating example (2) of V2X transmission modes. Figure 3 In the side-link communication transmission mode shown, in step 1, terminal 20A uses autonomously selected resources to send PSCCH and PSSCH to terminal 20B. Alternatively... Figure 3 The sidelink communication transmission mode shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0059] Figure 4 This is a diagram illustrating example (3) of V2X transmission modes. Figure 4 In the side-link communication transmission mode shown, in step 1, terminal 20A uses autonomously selected resources to send PSCCH and PSSCH to terminal 20B. Similarly, terminal 20B uses autonomously selected resources to send PSCCH and PSSCH to terminal 20A (step 1). Alternatively... Figure 4 The sidelink communication transmission mode shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2a in NR, terminal 20 performs resource selection itself.

[0060] Figure 5 This is a diagram illustrating an example (4) of V2X transmission modes. Figure 5In the sidelink communication transmission mode shown, in step 0, base station 10 grants sidelink transmission permission to terminal 20A via RRC (Radio Resource Control). Then, terminal 20A sends PSSCH to terminal 20B according to the received resource mode (step 1). Alternatively... Figure 5 The sidelink communication transmission mode shown is called sidelink transmission mode 2c in NR.

[0061] Figure 6 This is a diagram (5) used to illustrate the transmission modes of V2X. In Figure 6 In the sidelink communication transmission mode shown, in step 1, terminal 20A sends a sidelink schedule to terminal 20B via PSCCH. Then, terminal 20B sends a PSSCH to terminal 20A according to the received schedule (step 2). Alternatively... Figure 6 The sidelink communication transmission mode shown is called sidelink transmission mode 2d in NR.

[0062] Figure 7 This is a diagram (1) used to illustrate the communication types of V2X. Figure 7 The communication type of the side link shown is unicast. Terminal 20A sends PSCCH and PSSCH to terminal 20. Figure 7 In the example shown, terminal 20A unicasts to terminal 20B and unicasts to terminal 20C.

[0063] Figure 8 This is a diagram (2) used to illustrate the communication types of V2X. Figure 8 The communication type of the side link shown is multicast. Terminal 20A sends PSCCH and PSSCH to one or more groups to which terminals 20 belong. Figure 8 In the example shown, the group includes terminals 20B and 20C, and terminal 20A multicasts to the group.

[0064] Figure 9 This is a diagram (3) used to illustrate the communication types of V2X. Figure 9 The communication type of the side link shown is broadcast. Terminal 20A sends PSCCH and PSSCH to one or more terminals 20. Figure 9 In the example shown, terminal 20A broadcasts to terminals 20B, 20C, and 20D. Additionally, it can be... Figures 7-9 The terminal 20A shown is called the header UE.

[0065] Furthermore, NR-V2X envisions supporting HARQ (Hybrid Automatic Repeat Request) in unicast and multicast on sidelinks. Additionally, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Furthermore, the transmission of SFCI via PSFCH (PhysicalSidelink Feedback Channel) is under investigation.

[0066] Furthermore, in the following explanation, it is assumed that PSFCH is used for HARQ-ACK transmission in the side link, but this is only one example. For example, PSCCH, PSSCH, and other channels can be used for HARQ-ACK transmission in the side link.

[0067] For ease of explanation, the entire message reported by terminal 20 in HARQ will be referred to as HARQ-ACK. This HARQ-ACK can also be called HARQ-ACK information. More specifically, the codebook used in the HARQ-ACK information reported by terminal 20 to base station 10, etc., is called the HARQ-ACK codebook. The HARQ-ACK codebook defines the bit string of the HARQ-ACK information. In addition to ACK, NACK is also sent via HARQ-ACK.

[0068] Figure 10 This is a timing diagram illustrating the action example (1) of V2X. For example... Figure 10 As shown, the wireless communication system according to the embodiments of the present invention may have terminal 20A and terminal 20B. Furthermore, multiple user devices are actually present, but... Figure 10 Terminals 20A and 20B are shown as examples.

[0069] Unless otherwise specified, terminals 20A, 20B, etc., will be referred to as "Terminal 20" or "User Equipment". Figure 10 As an example, the example shows a situation where both terminal 20A and terminal 20B are within the coverage area, but the operation in the embodiments of the present invention can also be applied to a situation where terminal 20B is outside the coverage area.

[0070] As described above, in this embodiment, the terminal 20 is, for example, a device mounted in a vehicle such as an automobile, and has cellular communication functions as a UE in LTE or NR, as well as sidelink functions. Alternatively, the terminal 20 can also be a general portable terminal (such as a smartphone). Furthermore, the terminal 20 can also be an RSU. This RSU can be a UE-type RSU with UE functions, or a gNB-type RSU with base station functions.

[0071] In addition, the terminal 20 does not need to be a housing device. For example, even if various sensors are distributed throughout the vehicle, the device containing these various sensors is also the terminal 20.

[0072] Furthermore, the processing of data transmitted via the sidelink of terminal 20 is essentially the same as that of UL transmission in LTE or NR. For example, terminal 20 scrambles and modulates the codewords of the transmitted data to generate complex-valued symbols, maps these complex-valued symbols (transmitted signals) to layer 1 or layer 2, and performs precoding. Then, it maps the precoded complex-valued symbols to resource elements to generate a transmitted signal (e.g., a complex-valued time-domain SC-FDMA signal) and transmits it from each antenna port.

[0073] Furthermore, regarding base station 10, it has cellular communication functions as a base station in LTE or NR, and functions for enabling terminal 20 in this embodiment to communicate (e.g., resource pool setting, resource allocation, etc.). Additionally, base station 10 can be an RSU (gNB type RSU).

[0074] Furthermore, in the wireless communication system according to the embodiments of the present invention, the signal waveform used by the terminal 20 in SL or UL can be OFDMA, SC-FDMA, or other signal waveforms.

[0075] In step S101, terminal 20A autonomously selects resources used in PSCCH and PSSCH from a resource selection window with a predetermined period. The resource selection window can be set by base station 10 for terminal 20.

[0076] In steps S102 and S103, terminal 20A uses the resources autonomously selected in step S101 to send SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and also sends SL data using PSSCH. For example, terminal 20A can use frequency resources adjacent to the frequency resources of PSSCH in at least a portion of the time resources that are the same as the time resources of PSSCH to send PSCCH.

[0077] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from terminal 20A. The received SCI may contain information about the resources used by terminal 20B to send a HARQ-ACK for the received data via PSFCH. Terminal 20A may include information about resources it has autonomously selected in the SCI before sending it.

[0078] In step S104, terminal 20B uses the resources of PSFCH determined according to the received SCI to send HARQ-ACK for the received data to terminal 20A.

[0079] If the HARQ-ACK received in step S104 is a NACK (negative acknowledgment) indicating a request for retransmission, then in step S105, terminal 20A retransmits the PSCCH and PSSCH to terminal 20B. Terminal 20A may use resources it autonomously selects to retransmit the PSCCH and PSSCH.

[0080] Alternatively, steps S104 and S105 can be omitted if HARQ control is not performed.

[0081] Figure 11 This is a timing diagram illustrating a V2X action example (2). Blind retransmission can be performed without relying on HARQ control used to improve transmission success rate or arrival distance.

[0082] In step S201, terminal 20A autonomously selects resources used in PSCCH and PSSCH from a resource selection window with a predetermined period. The resource selection window can be set by base station 10 for terminal 20.

[0083] In steps S202 and S203, terminal 20A uses the resources autonomously selected in step S201 to transmit SCI via PSCCH and / or PSSCH, and transmit SL data via PSSCH. For example, terminal 20A can use 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 to transmit PSCCH.

[0084] In step S204, terminal 20A uses the resources autonomously selected in step S201 to retransmit SCI data based on PSCCH and / or PSSCH and SL data based on PSSCH to terminal 20B. This retransmission in step S204 can be performed multiple times.

[0085] Alternatively, step S204 can be omitted if blind retransmission is not performed.

[0086] Figure 12 This is a timing diagram illustrating an example of V2X operation (3). Base station 10 can perform sidelink scheduling. That is, base station 10 can determine the resources of the sidelink that terminal 20 will use and send information indicating those resources to terminal 20. In addition, when HARQ control is applied, base station 10 can send information indicating the resources of HSFCH to terminal 20.

[0087] In step S301, base station 10 sends DCI (Downlink Control Information) to terminal 20A via PDCCH to perform SL scheduling. For ease of explanation, the DCI used for SL scheduling will be referred to as SL scheduling DCI.

[0088] Furthermore, in step S301, it is envisioned that base station 10 also sends a DCI for DL ​​scheduling (also known as DL allocation) to terminal 20A via PDCCH. For ease of explanation, the DCI for DL ​​scheduling will be referred to as DL scheduling DCI. Terminal 20A, upon receiving the DL scheduling DCI, uses the resources specified by the DL scheduling DCI to receive DL data via PDSCH.

[0089] In steps S302 and S303, terminal 20A uses the resources specified by the SL scheduling DCI to transmit SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and also transmits SL data using PSSCH. Alternatively, in the SL scheduling DCI, only the PSSCH resources can be specified. In this case, for example, terminal 20A can use frequency resources adjacent to the PSSCH frequency resources in the same time resources as at least a portion of the PSSCH time resources to transmit the PSCCH.

[0090] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from terminal 20A. The SCI received via PSCCH and / or PSSCH contains information about the resources of the PSFCH used by terminal 20B to send a HARQ-ACK for the reception of the data.

[0091] The information about the resource is included in the DL scheduling DCI or SL scheduling DCI sent from base station 10 in step S301. Terminal 20A obtains the information about the resource from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, the DCI sent from base station 10 may not contain the information about the resource, and terminal 20A may autonomously include the information about the resource in the SCI before sending it.

[0092] In step S304, terminal 20B uses the resources of PSFCH determined according to the received SCI to send HARQ-ACK for the received data to terminal 20A.

[0093] In step S305, terminal 20A, for example, at a timing specified by the DL scheduling DCI (or SL scheduling DCI) (e.g., timing in time slots), uses the PUCCH (Physical uplink control channel) resources specified by the DL scheduling DCI (or the SL scheduling DCI) to send a HARQ-ACK, which is received by base station 10. The codebook of this HARQ-ACK may include the HARQ-ACK received from terminal 20B, or an HARQ-ACK generated based on an unreceived PSFCH, as well as HARQ-ACKs for DL ​​data. However, in cases where no DL data allocation exists, etc., the codebook does not include HARQ-ACKs for DL ​​data. In NR Rel.16, the codebook of this HARQ-ACK does not include HARQ-ACKs for DL ​​data.

[0094] Alternatively, steps S304 and S305 can be omitted if HARQ control is not performed.

[0095] Figure 13This is a timing diagram illustrating a V2X operation example (4). As described above, in the NR side link, HARQ responses are supported via PSFCH. Furthermore, the PSFCH format can, for example, use the same format as PUCCH (Physical Uplink Control Channel) format 0. That is, the PSFCH format can be a sequence-based format with a PRB (Physical Resource Block) size of 1, identifying ACK and NACK through differences in sequence and / or cyclic shifts. The PSFCH format is not limited to this. PSFCH resources can be configured at the end of a time slot or multiple symbols at the end. Additionally, a period N is set or predefined for the PSFCH resources. The period N can be set or predefined in units of time slots.

[0096] exist Figure 13 In the diagram, the vertical axis corresponds to the frequency domain, and the horizontal axis corresponds to the time domain. The PSCCH can be configured with one symbol at the beginning of a time slot, or with multiple symbols starting from the beginning, or with multiple symbols starting from symbols other than the beginning. The PSFCH can be configured with one symbol at the end of a time slot, or with multiple symbols at the end of a time slot. Figure 13 In the example shown, three sub-channels are configured in the resource pool, and two PSFCHs are configured after the three time slots configured with PSSCHs. The arrows from PSSCHs toward PSFCHs indicate examples of PSFCHs associated with PSSCHs.

[0097] In NR-V2X multicast, when the HARQ response is either ACK or NACK (multicast option 2), it is necessary to determine the resources used for sending and receiving the PSFCH. For example... Figure 13 As shown, in step S401, terminal 20A, acting as the transmitting terminal 20, performs multicast to terminals 20B, 20C, and 20D, acting as the receiving terminal 20, via SL-SCH. In the following 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. Wherein, as... Figure 13 As shown in the example, 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 the PSFCH resources. Additionally, the sending terminal 20 can know the number of receiving terminals 20 in the multicast. Furthermore, in multicast option 1, only NACK is sent as a HARQ response; ACK is not sent.

[0098] Figure 14This diagram illustrates an example of a listening action. It shows an example where partial sensing is not configured from higher layers in the LTE sidelink, such as... Figure 14 As shown, terminal 20 selects resources for transmission. Figure 14 As shown, terminal 20 performs listening within a listening window of the resource pool. Through listening, terminal 20 receives the resource reservation field contained in the SCI sent from other terminals 20, and identifies usable resource candidates within the resource selection window of the resource pool based on this field. Then, terminal 20 randomly selects a resource from the usable resource candidates. Listening to all resources within the listening window can be called full sensing.

[0099] In addition, such as Figure 14 As shown, the resource pool can be configured with a period. For example, the period could be a duration of 10240 milliseconds. Figure 14 It is subframe t0 SL To t Tmax SL An example of something set up as a resource pool. For a resource pool within a period, a region can be set, for example, using a bitmap.

[0100] In addition, such as Figure 14 As shown, a transmission trigger occurred in terminal 20 in subframe n. Let the priority of this transmission be p. TX Terminal 20 is able to [operate in] subframe t n-10×Pstep SL To subframe t n-1 SL In the listening window, for example, detecting other terminals 20 performing priority p RX The transmission status is as follows: When an SCI is detected within the listening window and the RSRP exceeds a threshold, the resource in the resource selection window corresponding to that SCI is excluded. Conversely, when an SCI is detected within the listening window and the RSRP is less than a threshold, the resource in the resource selection window corresponding to that SCI is not excluded. This threshold could, for example, be based on priority p. TX and priority p RX According to the threshold Th set or defined for each resource within the listening window pTX，pRX .

[0101] In addition, such as Figure 14 The subframe t shown Z SL In this way, for example, resources in the resource selection window that are candidates for resource reservation information, corresponding to resources in the listening window used for sending but not monitored, are excluded.

[0102] like Figure 14As shown, in the resource selection window from subframe n+T1 to subframe n+T2, resources occupied by other UEs are identified, and the resources excluded from this selection become available resource candidates. If the set of available resource candidates is set as S... A Then in S A If the number of resources is less than 20% of the resources in the resource selection window, the threshold Th can be set for each resource in the listening window. pTX，pRX Increase by 3dB, and then perform resource identification again. That is, by making the threshold Th pTX，pRX The resource identification process is repeated upon raising the threshold, increasing the number of resources that were not excluded due to RSRP being below the threshold. Additionally, S can be measured. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to set S. B In the middle. S can be repeatedly... A The minimum resource contained in RSSI is added to S B The actions in the process, up to the set S of resource candidates. B More than 20% of the resource selection window.

[0103] The lower layer of terminal 20 can report S to the higher layer. B The higher levels of terminal 20 can access S. B A random selection process is performed to determine the resources to be used. Terminal 20 can use the determined resources to perform sidelink transmissions. Additionally, once resources are secured, terminal 20 can transmit a predetermined number of times (e.g., C). resel (times), using resources periodically without monitoring.

[0104] Figure 15 This diagram illustrates an example of partial listening operations. When partial listening is configured from a higher layer in the LTE sidelink, such as... Figure 15 As shown, terminal 20 selects resources for transmission. Figure 15 As shown, terminal 20 performs listening on a portion of the listening window within the resource pool. Through partial listening, terminal 20 receives the resource reservation field contained in the SCI sent from other terminals 20, and identifies usable resource candidates within the resource selection window of the resource pool based on this field. Then, terminal 20 randomly selects a resource from the usable resource candidates.

[0105] In addition, such as Figure 15 As shown, the resource pool can be configured with a period. For example, the period could be a duration of 10240 milliseconds. Figure 15 It is subframe t0 SL To subframe t Tmax SL An example of something set up as a resource pool. For a resource pool within a period, a region can be set, for example, using a bitmap.

[0106] like Figure 15 As shown, a transmission trigger occurred in terminal 20 within subframe n. Let the priority of this transmission be p. TX .like Figure 15 As shown, subframes t in subframes n+T1 to n+T2 y SL To subframe t y+Y SL The Y-frame can be set as a resource selection window. Additionally, as... Figure 15 As shown, a transmission trigger occurred in terminal 20 in subframe n, and the priority of this transmission is set to p. TX .

[0107] Terminal 20 can be in subframe t that constitutes the Y-subframe length y-k×Pstep SL To subframe t y+Y-k×Pstep SL In one or more listening windows, for example, detecting other terminals 20 performing priority p RX The transmission scenario. k could be, for example, a 10-bit bitmap. In Figure 15 The image shows an example where the third and sixth bits of bitmap k are set to "1" to indicate partial listening. That is, in Figure 15 In the middle, subframe t y-6×Pstep SL To subframe t y+Y-6×Pstep SL and subframe t y-3×Pstep SL To subframe t y+Y-3×Pstep SL It is set as the listening window. As mentioned above, the i-th bit of bitmap k can be synchronized with subframe t. y-i×Pstep SL To subframe t y+Y-i×Pstep SL The corresponding listening window.

[0108] If an SCI is detected within one or more of the aforementioned monitoring windows, and the RSRP exceeds a threshold, the resource in the resource selection window corresponding to that SCI is excluded. Conversely, if an SCI is detected within a monitoring window, and the RSRP is less than a threshold, the resource in the resource selection window corresponding to that SCI is not excluded. This threshold could be, for example, based on priority p. TX and priority p RX According to the threshold Th set or defined for each resource within the listening window pTX p RX .

[0109] In the resource selection window with a Y subframe, terminal 20 identifies resources occupied by other UEs, and the resources that have been excluded become available resource candidates. If the set of available resource candidates is set as S... A Then in S A If the number of resources is less than 20% of the resources in the resource selection window, the threshold Th can be set according to each resource in the listening window. pTX，pRX Increase by 3dB and then perform resource identification again. That is, by increasing the threshold Th... pTX，pRX The resource identification process is repeated upon raising the threshold, thereby increasing the number of resources that were not excluded due to RSRP being less than the threshold. Additionally, S can be measured. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to set S. B In the middle. S can be repeatedly... A The minimum resource contained in RSSI is added to S B The actions in the process, up to the set S of resource candidates. B More than 20% of the resource selection window.

[0110] The lower layer of terminal 20 can report S to the higher layer. B The higher levels of terminal 20 can access S. B A random selection process is performed to determine the resources to be used. Terminal 20 can use the determined resources to perform sidelink transmissions. Additionally, once resources are secured, terminal 20 can transmit a predetermined number of times (e.g., C). resel (Time) Use resources periodically without monitoring.

[0111] In the above Figure 14 as well as Figure 15 The actions of the sending terminal 20 are described, but the receiving terminal 20 can detect data transmission from other terminals 20 and receive data from those other terminals 20 based on the results of monitoring or partial monitoring.

[0112] In the NR Release 17 sidelink, power saving based on the aforementioned random resource selection and partial listening was investigated. For example, to achieve power saving, the random resource selection and partial listening of the LTE Release 14 sidelink can be applied to the resource allocation mode 2 of the NR Release 16 sidelink. The terminal 20 where partial listening is applied only performs reception and listening within a specific time slot within the listening window.

[0113] Furthermore, in the NR version 17 sidelink, eURLLC (enhanced Ultra Reliable Low Latency Communication) was studied using inter-UE coordination as a baseline. For example, terminal 20A and terminal 20B share information about the representation resource set, and terminal 20B considers this information when selecting resources for transmission.

[0114] It can be assumed that various types of information are sent from terminal 20A to terminal 20B, and terminal 20B takes action based on this information, thereby improving communication quality. That is, it is considered effective not only to share resource sets but also to share other information among the terminals 20. However, it is not yet clear what kind of information should be shared among the terminals 20. Furthermore, it is not clear how information should be shared among the terminals 20. Additionally, it is not clear how the information shared among the terminals 20 should be used.

[0115] Therefore, terminal 20A can send information related to resource selection to terminal 20B via resources associated with the feedback channel. Figure 16 This is a timing diagram illustrating an example of inter-terminal cooperation in an embodiment of the present invention. In step S501, terminal 20A sends information related to resource selection to terminal 20B via resources associated with the feedback channel. In the following step S502, terminal 20B can select resources based on the received information related to resource selection, for example, by sending PSCCH / PSSCH to terminal 20A. PSSCH can be referred to as data.

[0116] The aforementioned "information related to resource selection" can be at least one of the following information A)-D).

[0117] A) Monitoring results. For example, RSRP (Reference Signal Received Power) and RSSI (Received Signal Strength Indicator).

[0118] B) Resources determined based on monitoring. For example, resources that should be used or resources that should not be used.

[0119] C) Instructions for re-evaluation or reselection. Resources that should be used or should not be used from the already reserved resources can be notified together. Terminal 20B can remove at least a portion of the already reserved resources (e.g., resources notified via B) to perform re-evaluation or reselection.

[0120] D) Sidelink grant. Terminal 20B may use the resources represented by the received sidelink grant.

[0121] As described above, by notifying terminal 20B of information related to resource selection, and by performing resource selection based on the information shared from terminal 20A, the probability of resource conflicts can be reduced. Furthermore, through A), terminal 20B can understand the correct interference level. Additionally, through B), terminal 20B can understand the desired resources to be used. Furthermore, through C), inter-terminal cooperation can be performed with relatively little information. Finally, through D), by having terminal 20A, which has sidelink resource scheduling capabilities, perform D), a higher level of cooperation is achieved.

[0122] The aforementioned "resources related to the feedback channel" can be either 1) or 2) as shown below.

[0123] 1) Resources available in PSFCH

[0124] For example, the time resource could be the Xth (e.g., the second) symbol from the last time slot in the parameter sl-PSFCH-Period representing the period of the PSFCH. Furthermore, the frequency resource could be a PRB determined according to the parameter sl-PSFCH-RB-Set representing the frequency domain of the PSFCH. Additionally, the code resource could be a cyclically shifted pair determined according to the parameter sl-NumMuxCS-Pair related to the cyclic shift of the PSFCH.

[0125] 2) Resources available in the PSFCH for frequency division multiplexing and / or code division multiplexing.

[0126] Figure 17 This is a diagram illustrating an example (1) of resources used in inter-terminal collaboration in an embodiment of the present invention. For example, it could be at least a portion of a PRB other than the one specified by sl-PSFCH-RB-Set within a resource pool. That is, in Figure 17 In this configuration, a PRB that is frequency-division multiplexed with a PSFCH configured with a PSSCH can be used as a resource related to the feedback channel. Additionally, a PRB specified in a resource pool via sl-PSFCH-RB-Set can be used as a resource related to the feedback channel. Figure 18 This is a diagram illustrating an example (2) of resources used in inter-terminal collaboration in an embodiment of the present invention. For example, such as... Figure 18As shown, the cyclic shift pair determined according to the specified sl-NumMuxCS-Pair can be used as a resource related to the feedback channel, all cyclic shift pairs can be used as a resource related to the feedback channel, and cyclic shift pairs determined according to a certain parameter can be used as a resource related to the feedback channel.

[0127] The methods for determining frequency resources described above can be combined with the methods for determining code resources described above to determine resources related to the feedback channel. At least a portion of the cyclic shift pairs other than those determined according to sl-NumMuxCS-Pair can be used as resources related to the feedback channel. Figure 18 In the example shown, when Y=2, that is, when 0 and 3 are used as cyclic shifts for NACK and 6 and 9 for ACK, the cyclic shifts (1, 2, 4, 5, 7, 8, 10, 11) that are not used for HARQ-ACK can be used as resources related to the feedback channel.

[0128] As shown in 1) and 2) above, by determining the resources related to the feedback channel, previously unused sidelink resources can be effectively utilized. Furthermore, through 1) above, timed PSFCHs that were not used during PSFCH timing can be used. Furthermore, through 2) above, resources in the resource pool that were not used through configuration can be used.

[0129] In the section on "resources related to the feedback channel", "information related to resource selection" can be sent using any of the methods shown below: a), b), or c).

[0130] a) During HARQ feedback, "resources related to the feedback channel" can be sent. For example, terminal 20A receives a transport block from terminal 20B, but decoding fails. In this case, the SCI associated with that transport block reserves resources for retransmission. If the reserved resources can be used for retransmission, terminal 20A only sends a NACK to terminal 20B. On the other hand, if retransmission should use resources different from the reserved resources, terminal 20A can send a NACK and / or "information related to resource selection." For example, as "information related to resource selection," resources that should be used or resources that should not be used can be sent.

[0131] When terminal 20A sends NACK and / or "information related to resource selection", it may use resources that are frequency-division multiplexed or code-division multiplexed with PSFCH resources used only for sending NACK.

[0132] Figure 19 This is a diagram illustrating an example (3) of resources used in inter-terminal collaboration in an embodiment of the present invention. Figure 19 This is an example of using at least a portion of the cyclic shifts that are code-division multiplexed, other than the cyclic shift pair determined according to sl-NumMuxCS-Pair, as resources related to the feedback channel. For example... Figure 19 As shown, indices 1 and 4 of the circular shift, which are adjacent to indices 0 and 3 of the circular shift used in the PSFCH resource that is only used for NACK, can be used to send NACK and / or information related to resource selection.

[0133] Figure 20 This is a diagram illustrating an example (4) of resources used in inter-terminal collaboration in an embodiment of the present invention. Figure 20 As shown, a PRB corresponding to a resource used in the PSFCH for sending ACK or NACK can be used as a resource for sending NACK and / or information related to resource selection, even if it is not mapped to a PSFCH and is frequency-division multiplexed.

[0134] As described above, by transmitting information related to resource selection in the resources associated with the feedback channel, the quality of retransmission can be improved and additional actions of the terminal 20 can be reduced.

[0135] b) Terminal 20A, which transmits "information related to resource selection," can decide when to transmit and / or which resource to use. The channel configured on the determined resource can be called PSXCH. PSXCH can be at least one of PSCCH, PSSCH, PSFCH, PSBCH, and a new channel. In the case where PSXCH is a new channel, for example, data and DM-RS can be frequency-division multiplexed, mapped to multiple PRBs, or encoded using polar coding.

[0136] Figure 21 This is a diagram illustrating an example (5) of resources used in inter-terminal collaboration in an embodiment of the present invention. For example, such as... Figure 21 As shown, PSXCH can be configured to be frequency-division multiplexed with PSFCH.

[0137] Furthermore, in the process of the terminal 20A, which sends "information related to resource selection" to determine when to send and / or which resource to use for transmission, information related to future resource reservations can be sent. For example, information indicating which PSFCH timing is being sent, or information indicating which frequency resource is being used, can be sent.

[0138] Furthermore, when the terminal 20A, which sends "information related to resource selection," determines when to send and / or which resource to use for sending resources, and when resources overlap with the PSFCH sending and / or receiving for HARQ feedback, for example, it can prioritize the PSFCH sending and / or receiving for HARQ feedback, or send PSFCH sending and / or receiving and information related to resource selection simultaneously. It can also determine rules for coordinating simultaneous sending, performing simultaneous sending only when the conditions for simultaneous sending are met, and dropping lower-priority transmissions when the conditions for simultaneous sending are not met.

[0139] Furthermore, terminal 20A can continuously monitor the information transmitted regarding resource selection to determine when to transmit and / or which resource to use, i.e., the resource related to the feedback channel. By continuously monitoring, terminal 20A can transmit information regarding resource selection at any time.

[0140] c) Terminal 20A, capable of sending "information related to resource selection," is requested by other terminals 20 when to send and / or which resource to use for transmission. The channel configured for the requested resource may be called PSXCH. PSXCH can be at least one of PSCCH, PSSCH, PSFCH, PSBCH, and new channels. In the case where PSXCH is a new channel, for example, data and DM-RS can be frequency-division multiplexed, mapped to multiple PRBs, and encoded via Polar coding. For example, as... Figure 21 As shown, PSXCH can be configured to be frequency-division multiplexed with PSFCH.

[0141] Furthermore, when terminal 20A, which sends "information related to resource selection," is requested by other terminals to determine when to send and / or which resource to use for transmission, information related to future resource reservations can be sent. For example, information indicating which PSFCH timing is being sent, or information indicating which frequency resource is being used, can be sent.

[0142] Furthermore, when terminal 20A, which is sending "information related to resource selection," is requested by other terminals to determine when to send and / or which resource to use for sending resources, and when this overlaps with the sending and / or receiving of PSFCH for HARQ feedback, for example, the sending and / or receiving of PSFCH for HARQ feedback can be prioritized, or the sending and / or receiving of PSFCH and the information related to resource selection can be sent simultaneously. Furthermore, rules for coordinating simultaneous sending can be determined, and simultaneous sending can only be performed if the conditions for simultaneous sending are met, while lower-priority sending is discarded if the conditions for simultaneous sending are not met.

[0143] In addition, the terminal 20 that performs partial listening can be a terminal 20 that performs a different listening method than the full listening specified in version 16, or it can be a terminal 20 that does not perform listening, or it can be a terminal 20 that receives data only for a limited time (e.g., DRX).

[0144] Additionally, full monitoring can monitor all resources within the monitoring window. The monitoring window can be defined using the time slot interval [n-T0, nT]. proc,0 According to the rules, n can be the time slot corresponding to the arrival time of the packet.

[0145] The above embodiments are not limited to V2X terminals, but can be applied to terminals that perform D2D communication.

[0146] In addition, terminal 20 can know the timing that other terminals 20 can receive and / or transmit. This timing can be determined by specification or pre-setting, thereby knowing the timing that other terminals 20 can receive and / or transmit, or it can receive notifications from other terminals 20 to know the timing that other terminals 20 can receive and / or transmit.

[0147] In addition, in the above embodiments, timing resources can be replaced with frequency resources.

[0148] The sharing of information between terminals in the above embodiments can be performed through broadcast, multicast, or unicast. Furthermore, the sharing of information between terminals in the above embodiments can be performed only between terminals that have established an RRC connection. Additionally, the actions of terminal 20 in the above embodiments can be performed only within a specific resource pool. For example, the actions of terminal 20 in the above embodiments can be performed only within a resource pool that is available to terminals 20 in versions 17 and later.

[0149] The information shared between terminals in the above embodiments may be at least one of the information shown in 1)-8) below.

[0150] 1) Listening results

[0151] 2) Resources determined based on monitoring

[0152] 3) Instructions for re-evaluation or re-selection

[0153] 4) Sidelink Authorization

[0154] 5) Information associated with the synchronization source

[0155] 6) Information related to the scheduled PSFCH transmission and reception timing

[0156] 7) Information related to transmit power reduction caused by in-device coexistence

[0157] 8) Information relating to reserved but unused planned resources

[0158] Through the above embodiments, terminal 20 can efficiently receive resource-related information from other terminals 20 via resources related to the feedback channel, and use appropriate resources when transmitting based on the information.

[0159] That is, it enables collaborative actions between terminals during direct communication, thereby improving communication efficiency.

[0160] (Device Structure)

[0161] Next, an example of the functional structure of the base station 10 and terminal 20 performing the processes and actions described above will be explained. The base station 10 and terminal 20 include the functions of the embodiments described above. However, the base station 10 and terminal 20 may each have only a portion of the functions described in the embodiments.

[0162] <Base Station 10>

[0163] Figure 22 This is a diagram illustrating an example of the functional structure of base station 10. (As shown...) Figure 22 As shown, the base station 10 includes a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. Figure 22 The functional structure shown is only one example. The functional divisions and names of the functional units can be arbitrary, as long as the actions involved in the embodiments of the present invention can be performed.

[0164] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher-level information from the received signals. In addition, the transmitting unit 110 has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0165] The setting unit 130 stores preset setting information and various setting information sent to the terminal 20 in a storage device, and reads it from the storage device as needed. The content of the setting information includes, for example, information related to D2D communication settings.

[0166] As described in the embodiment, the control unit 140 performs processing related to the settings for D2D communication with the terminal 20. Furthermore, the control unit 140 sends the scheduling of D2D and DL communication to the terminal 20 via the transmitting unit 110. Additionally, the control unit 140 receives information related to HARQ responses for D2D and DL communication from the terminal 20 via the receiving unit 120. Alternatively, the signal transmission-related functions of the control unit 140 may be included in the transmitting unit 110, and the signal reception-related functions of the control unit 140 may be included in the receiving unit 120.

[0167] Terminal 20

[0168] Figure 23 This is a diagram illustrating an example of the functional structure of terminal 20. (As shown...) Figure 23 As shown, the terminal 20 includes a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. Figure 23 The functional structure shown is only one example. The functional divisions and names of the functional units can be arbitrary, as long as the actions involved in the embodiments of the present invention can be performed.

[0169] The transmitting unit 210 generates a transmission signal based on the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and obtains higher-layer signals from the received physical layer signals. Furthermore, the receiving unit 220 has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, or reference signals transmitted from the base station 10. Additionally, 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 from other terminals 20.

[0170] The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or the terminal 20 in a 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 includes, for example, information related to D2D communication settings.

[0171] As described in the embodiment, the control unit 240 controls the establishment of D2D communication for RRC connections with other terminals 20. Furthermore, the control unit 240 performs processing related to power saving. Additionally, the control unit 240 performs HARQ processing related to D2D and DL communication. Furthermore, the control unit 240 sends information to the base station 10 regarding HARQ responses for D2D and DL communication scheduled from the base station 10 to other terminals 20. The control unit 240 can also schedule D2D communication with other terminals 20. Furthermore, the control unit 240 can autonomously select resources used in D2D communication from the resource selection window based on monitoring results, and can also perform re-evaluation or preemption. Additionally, the control unit 240 performs power saving processing related to D2D communication transmission and reception. Alternatively, the signal transmission-related functions of the control unit 240 can be included in the transmitting unit 210, and the signal reception-related functions of the control unit 240 can be included in the receiving unit 220.

[0172] (Hardware Structure)

[0173] The block diagram used in the description of the above embodiments ( Figure 22 and Figure 23 The diagram illustrates blocks organized by function. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Furthermore, there are no particular limitations on the implementation method of each functional block. That is, each functional block can be implemented using a single device that is physically or logically combined, or by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. Functional blocks can also be implemented by combining software with one or more of the aforementioned devices.

[0174] Functionally, it includes functions such as judgment, decision, determination, calculation, calculation, processing, derivation, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but is not limited to these. For example, the functional block (structural part) that enables sending to perform its function is called the transmitting unit or transmitter. In short, as mentioned above, there are no particular limitations on the implementation method.

[0175] For example, in one embodiment of this disclosure, the base station 10, terminal 20, etc., can also function as a computer for processing the wireless communication method of this disclosure. Figure 24 This is a diagram illustrating an example of the hardware structure of a base station 10 and a terminal 20 according to an embodiment of this disclosure. The base station 10 and the terminal 20 described above may also 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, etc.

[0176] Additionally, in the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware structure of base station 10 and terminal 20 can be configured to include one or more of the devices shown in the figures, or it can be configured not to include some of the devices.

[0177] The functions of the base station 10 and the terminal 20 are implemented by reading predetermined software (programs) 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 reading out and writing data in the storage device 1002 and the auxiliary storage device 1003.

[0178] The processor 1001 controls the computer as a whole, for example, by enabling the operating system to function. The processor 1001 may also be a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc. For example, the control unit 140 and control unit 240 described above can also be implemented using the processor 1001.

[0179] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage devices 1003 and communication devices 1004, and performs various processes accordingly. As a program, a program is used that causes the computer to perform at least a portion of the actions described in the above embodiments. For example, Figure 22 The control unit 140 of the base station 10 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Furthermore, for example, Figure 23The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Regarding the various processes described above, although it has been stated that they are executed by one processor 1001, they can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be implemented by more than one chip. Furthermore, the program can also be transmitted from a network via a telecommunications line.

[0180] 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. Storage device 1002 may also be referred to as a register, cache, main memory (main storage device), etc. Storage device 1002 is capable of storing programs (program code), software modules, etc., that are executable for implementing the communication method according to one embodiment of this disclosure.

[0181] The auxiliary storage device 1003 is a computer-readable recording medium, such as at least one of an optical disc like a CD-ROM (CompactDisc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (e.g., a compact disk, a digital multipurpose disk, a Blu-ray disc, a smart card), a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic stripe, etc. The aforementioned storage medium can also be, for example, a database, a server, or other suitable media that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0182] The communication device 1004 is hardware (transceiver) used for communication between computers via at least one of a wired network and a wireless network. For example, it may also be referred to as a network device, network controller, network interface card (NIC), communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, duplexer, filter, frequency synthesizer, etc., to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, transceiver antennas, amplifier sections, transceiver sections, transmission path interfaces, etc., can also be implemented through the communication device 1004. The transceiver section may also be physically or logically separated into a transmitting section and a receiving section.

[0183] Input device 1005 is an input device that accepts input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, LED, etc.). Alternatively, input device 1005 and output device 1006 can also be integrated (e.g., a touch panel).

[0184] Furthermore, the processor 1001 and storage device 1002, among other devices, are connected via a bus 1007 for communicating information. The bus 1007 can be configured using a single bus or by using different buses for each device.

[0185] Furthermore, the base station 10 and the terminal 20 can 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 a FPGA (Field Programmable Gate Array), and can also use this hardware to implement part or all of the functional blocks. For example, the processor 1001 can also be installed using at least one of these hardware components.

[0186] (Summary of Implementation Methods)

[0187] As described above, according to an embodiment of the present invention, a terminal is provided, comprising: a transmitting unit that transmits information related to resource selection to another terminal via resources associated with a HARQ (Hybrid Automatic Repeat Request) feedback channel; and a receiving unit that receives data from the other terminal via resources determined based on the information related to resource selection, wherein the information related to resource selection includes at least one of monitoring results, information indicating resources determined based on monitoring, an indication of re-evaluation or re-selection, and sidelink authorization.

[0188] With the above structure, terminal 20 can efficiently receive resource-related information from other terminals 20 via resources associated with the feedback channel, and use appropriate resources when transmitting based on this information. That is, it can perform cooperative actions between terminals in direct communication between terminals, thereby improving communication efficiency.

[0189] The resources associated with the HARQ feedback channel can be resources available for use in the feedback channel. Through this structure, terminal 20 can efficiently transmit resource-related information from other terminals 20 via the resources associated with the feedback channel.

[0190] The resources associated with the HARQ feedback channel can be resources that can be frequency-division multiplexed or code-division multiplexed with resources that can be used for the feedback channel. Through this structure, terminal 20 can efficiently transmit resource-related information from other terminals 20 via the resources associated with the feedback channel.

[0191] The transmitting unit can include information about the resources to be used for retransmission in the resource selection-related information when sending HARQ feedback for a negative response, and then send it to the other terminals. With this structure, terminal 20 can efficiently send resource-related information from other terminals 20 via resources related to the feedback channel, and use appropriate resources during retransmission.

[0192] The transmitting unit can use the resources used in transmitting HARQ feedback for negative acknowledgments (which are frequency-division multiplexed or code-division multiplexed) to transmit the resource selection-related information to the other terminals. Through this structure, terminal 20 can efficiently transmit resource-related information from other terminals 20 via resources associated with the feedback channel.

[0193] Furthermore, according to an embodiment of the present invention, a communication method is provided, wherein a terminal performs the following steps: a transmitting step, transmitting information related to resource selection to another terminal via a resource associated with a HARQ (Hybrid Automatic Repeat Request) feedback channel; and a receiving step, receiving data from the other terminal via a resource determined based on the information related to resource selection, wherein the information related to resource selection includes at least one of monitoring results, information indicating a resource determined based on monitoring, an indication of re-evaluation or re-selection, and sidelink authorization.

[0194] With the above structure, terminal 20 can efficiently receive resource-related information from other terminals 20 via resources associated with the feedback channel, and use appropriate resources when transmitting based on this information. That is, it can perform cooperative actions between terminals in direct communication between terminals, thereby improving communication efficiency.

[0195] (Supplement to the implementation method)

[0196] The embodiments of the present invention have been described above, but the disclosed invention is not limited to these embodiments. Those skilled in the art should understand various modifications, alterations, substitutions, and replacements. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these values ​​are merely examples, and any appropriate values ​​may be used. The distinctions between items in the above description are not essential to the present invention; items described in two or more items may be combined as needed, and items described in one item may be applied to items described in other items (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. Multiple functional units may be operated by a single physical component, or a single functional unit may be operated by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing may be interchanged unless there is a contradiction. For ease of explanation, base station 10 and terminal 20 have been described using functional block diagrams, but such a device may also be implemented in hardware, software, or a combination thereof. Software operating via a processor in base station 10 according to embodiments of the present invention and software operating via a processor in terminal 20 according to embodiments of the present invention may respectively be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server and other suitable storage media.

[0197] Furthermore, the notification of information is not limited to the forms / implementations described in this 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)), higher layer 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 combinations thereof. Additionally, RRC signaling may be referred to as an RRC message, for example, it may be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0198] The various forms / implementations described in this disclosure can also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), 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 802.20, UWB (Ultra-Wide Band), Bluetooth (registered trademark), systems using other suitable systems, and next-generation systems extended therefrom. Furthermore, multiple systems can be combined (e.g., a combination of at least one of LTE and LTE-A with 5G, etc.) for application.

[0199] The processing procedures, timing, and flow of the various forms / implementations described in this specification may be changed in order, provided there is no contradiction. For example, the elements of various steps are indicated using an illustrative order for the methods described in this disclosure, but are not limited to the specific order indicated.

[0200] In this specification, certain actions described as being performed by base station 10 may sometimes be performed by its upper node, depending on the circumstances. In a network consisting of one or more network nodes including base station 10, it is obvious that various actions performed to communicate with terminal 20 can be performed by at least one of base station 10 and other network nodes besides base station 10 (e.g., considering MME or S-GW, but not limited to these). The above example illustrates the case where there is only one other network node besides base station 10, but other network nodes can also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0201] The information or signals described in this disclosure can be output from a higher (or lower) layer to a lower (or higher) layer. They can also be input or output via multiple network nodes.

[0202] Input or output information can be stored in a specific location (e.g., memory) or managed using a management table. Input or output information can be overwritten, updated, or appended. Output information can also be deleted. Input information can also be sent to other devices.

[0203] The determination in this disclosure can be made by a value represented by 1 bit (0 or 1), by a Boolean value (Boolean: true or false), or by a comparison of numerical values ​​(e.g., a comparison with a predetermined value).

[0204] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted as commands, command sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0205] Furthermore, software, commands, and information can be sent and received via a transmission medium. For example, when using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) etc.) and wireless technologies (infrared, microwave, etc.) to send software from a webpage, server, or other remote source, at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0206] The information, signals, etc., described in this disclosure can also be represented using 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 can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0207] Furthermore, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms that have the same or similar meanings. For example, at least one of the channel and symbol may also be a signal (signaling). Additionally, a signal may also be a message. Furthermore, a component carrier (CC) may also be referred to as a carrier frequency, cell, frequency carrier, etc.

[0208] The terms “system” and “network” as used in this disclosure are used interchangeably.

[0209] Furthermore, the information, parameters, etc., described in this disclosure may be represented using absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0210] The names used for the above parameters are not limiting at any point. Furthermore, the formulas, etc., using these parameters sometimes differ from those explicitly stated in this disclosure. Since a wide variety of channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by appropriate names, the various names assigned to these diverse channels and information elements are not limiting in any respect.

[0211] In this disclosure, the terms "base station (BS)," "wireless base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" are used interchangeably. Sometimes, terms such as macro cell, small cell, femtocell, and picocell are also used to refer to base stations.

[0212] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, its coverage area can be divided into several smaller areas, each of which can provide communication services through a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base station and base station subsystem providing communication services within that coverage area.

[0213] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" are used interchangeably.

[0214] 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, handheld device, user agent, mobile client, client, or some other appropriate terms.

[0215] At least one of the base station and the mobile station can be referred to as a transmitting device, a receiving device, a communication device, etc. Additionally, at least one of the base station and the mobile station can be a device mounted on a mobile body, the mobile body itself, etc. The mobile body can be a vehicle (e.g., a car, an airplane, etc.), a mobile body moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Furthermore, at least one of the base station and the mobile station also includes devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station can be an IoT (Internet of Things) device such as a sensor.

[0216] Furthermore, the base station in this disclosure can be replaced by a user terminal. For example, various forms / implementations of this disclosure can be applied to a structure that replaces the communication between the base station and the user terminal with communication between multiple terminals 20 (e.g., it can also be called D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminal 20 can be configured to have the functions of the base station 10 described above. In addition, terms such as "uplink" and "downlink" can be replaced with terms corresponding to inter-terminal communication (e.g., "side"). For example, uplink channel, downlink channel, etc. can also be replaced with side channel.

[0217] Similarly, the user terminal in this disclosure can be replaced by a base station. In this case, the base station can be configured to have the functions of the user terminal described above.

[0218] The terms "determining" and "determining" as used in this disclosure sometimes encompass a variety of actions. For example, "determining" or "determining" can include actions such as judging, calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), and ascertaining, which are considered as actions of "determining" or "determining." Furthermore, "determining" or "determining" can include actions such as receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory), which are considered as actions of "determining" or "determining." Additionally, "determining" or "determining" can include actions such as resolving, selecting, choosing, establishing, and comparing, which are considered as actions of "determining" or "determining." That is, "judgment" and "decision" can include matters in which any action has been "judged" or "decided". In addition, "judgment (decision)" can be replaced by "assuming", "expecting", or "considering".

[0219] The terms “connected,” “coupled,” or any variations thereof are intended to indicate any direct or indirect connection or combination between two or more elements, including cases where there is one or more intermediate elements between the two elements that are “connected” or “coupled.” The combination or connection between elements can be physical, logical, or a combination of these. For example, “access” can be used instead of “connected.” In the context of this disclosure, for two elements, it can be considered that they are “connected” or “coupled” by using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, by using electromagnetic energy with wavelengths having wireless frequency domains, microwave regions, and light (including both visible and invisible regions).

[0220] The reference signal can be simply referred to as RS (Reference Signal), or, depending on the applicable standard, as a pilot.

[0221] As used in this disclosure, the word "based on" does not mean "based on only" unless otherwise stated. In other words, the word "based on" means "based on only" and "based on at least" both.

[0222] Any reference to elements using the designations "first," "second," etc., as 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 way to distinguish between two or more elements. Therefore, reference to a first element and a second element does not imply that only two elements can be used, or that in any form the first element must precede the second element.

[0223] The term "unit" in the above-mentioned device structures can be replaced with "section", "circuit", "equipment", etc.

[0224] When the terms “include,” “including,” and variations thereof are used in this disclosure, these terms imply inclusion in the same way as the term “comprising.” Furthermore, the term “or” as used in this disclosure implies non-exclusivity.

[0225] A radio frame can consist of one or more frames in the time domain. In the time domain, one or more frames can be called subframes. Furthermore, a subframe can consist of one or more time slots in the time domain. A subframe can be of a fixed duration (e.g., 1 ms) independent of the parameter set (numerology).

[0226] A parameter set can be communication parameters applied to at least one side of the transmission and reception of a signal or channel. For example, a parameter set can represent at least one of the following: 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, and specific windowing processing performed by the transceiver in the time domain.

[0227] In the time domain, a time slot can consist of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A time slot can be a time unit based on a set of parameters.

[0228] A time slot can contain multiple mini-time slots. Each mini-time slot can consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can consist of fewer symbols than a time slot. PDSCH (or PUSCH) transmitted in time units larger than mini-time slots can be called PDSCH (or PUSCH) mapping type (type) A. PDSCH (or PUSCH) transmitted using mini-time slots can be called PDSCH (or PUSCH) mapping type (type) B.

[0229] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can each be referred to by other corresponding names.

[0230] For example, one subframe can be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and one time slot or one mini-time slot can also be called a TTI. That is, at least one of the subframe and TTI can be a subframe in the existing LTE (1ms), a period shorter than 1ms (e.g., symbols 1-13), or a period longer than 1ms. In addition, the unit representing TTI can not be a subframe, but a time slot, mini-time slot, etc.

[0231] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules the allocation of radio resources (bandwidth, transmit power, etc., available to each terminal 20) on a TTI basis. However, the definition of TTI is not limited to this.

[0232] A Time Interval (TTI) can be a unit of time for transmitting channel-coded data packets (transmission blocks), code blocks, codewords, etc., or it can be a unit of time for scheduling, link adaptation, etc. Furthermore, when a TTI is assigned, the actual time interval (e.g., the number of symbols) for mapping transmission blocks, code blocks, codewords, etc., can be shorter than the TTI.

[0233] Furthermore, when one time slot or one mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can become the minimum time unit for scheduling. Moreover, the number of time slots (mini-time slots) constituting the minimum time unit of the schedule is controllable.

[0234] A TTI with a duration of 1ms is also known as a normal TTI (in LTE Rel.8-12), a long TTI, a normal subframe, a normal subframe, a long subframe, or a time slot. A TTI shorter than a normal TTI can be called 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, or a time slot.

[0235] Additionally, for long TTIs (e.g., normal TTIs, subframes, etc.), they can be replaced by TTIs with a duration of more than 1ms. For short TTIs (e.g., shortened TTIs, etc.), they can be replaced by TTIs with a length less than that of long TTIs and a duration of more than 1ms.

[0236] A resource block (RB) is a unit of resource allocation in both the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers contained in an RB can be the same regardless of the parameter set; for example, it can be 12. The number of subcarriers contained in an RB can also be determined based on the parameter set.

[0237] Furthermore, the temporal domain of an RB can contain one or more symbols, and can be 1 time slot, 1 mini-time slot, 1 subframe, or 1 TTI in length. 1 TTI, 1 subframe, etc., can each be composed of one or more resource blocks.

[0238] In addition, one or more RBs can be called Physical Resource Block (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB Pair, RB Pair, etc.

[0239] Furthermore, a resource block can consist of one or more resource elements (REs). For example, 1 RE can be a radio resource area consisting of 1 subcarrier and 1 symbol.

[0240] The Bandwidth Part (BWP) (also known as partial bandwidth, etc.) represents a contiguous subset of common resource blocks (RBs) used for a specific parameter set on a given carrier. Here, common resource blocks can be determined by indexing RBs based on a common reference point of that carrier. PRBs are defined and numbered within a given BWP.

[0241] A BWP can include a UL BWP and a DL BWP. One or more BWPs can be configured for terminal 20 within one carrier.

[0242] At least one of the configured BWPs can be active, and it is not assumed that the terminal 20 will transmit or receive predetermined signals / channels outside of an active BWP. Furthermore, the terms "cell," "carrier," etc., used in this disclosure can be replaced with "BWP."

[0243] The structures of radio frames, subframes, time slots, mini-time slots, and symbols described above are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained within a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc., can be varied in many ways.

[0244] In this disclosure, for example, when articles such as a, an, and the from English are added through translation, this disclosure may also include cases where the noun following these articles is in a plural form.

[0245] In this disclosure, the phrase "A and B are different" can also mean "A and B are different from each other." Furthermore, this phrase can also mean "A and B are each different from C." Terms such as "separate" and "combined" can also be interpreted in the same way as "different."

[0246] The various forms / implementations described in this disclosure can be used individually or in combination, and can be switched depending on the execution. Furthermore, the notification of predetermined information is not limited to explicit notification (e.g., a "Yes X" notification) but can also be implicit notification (e.g., not notifying the predetermined information).

[0247] Additionally, in this disclosure, PSFCH is an example of a HARQ feedback channel.

[0248] The present disclosure has been described in detail above, but it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the present disclosure is for illustrative purposes only and is not intended to be limiting.

[0249] This international patent application is based on and claims priority to Japanese Patent Application No. 2020-138279, filed on August 18, 2020, the entire contents of which are incorporated herein by reference.

[0250] Label Explanation:

[0251] 10 base stations

[0252] 110 Dispatch Department

[0253] 120 Receiving Department

[0254] 130 Setting Department

[0255] 140 Control Department

[0256] 20 terminals

[0257] 210 Sending Department

[0258] 220 Receiving Department

[0259] 230 Setting Department

[0260] 240 Control Department

[0261] 1001 processor

[0262] 1002 Storage device

[0263] 1003 Auxiliary storage device

[0264] 1004 Communication device

[0265] 1005 Input Device

[0266] 1006 Output Device

Claims

1. A terminal, wherein, The terminal has: The receiving unit receives shared channels transmitted from other terminals; The control unit determines a time resource set for a specific channel, a first frequency resource set for the specific channel, and a second frequency resource set for the specific channel. The first frequency resource is used to send a response related to retransmission control of the shared channel, and the second frequency resource is used to send information related to the selection of resources used in transmissions of the shared channel from the other terminal. as well as The transmitting unit, based on the second frequency resource which is different from the first frequency resource, transmits information related to the selection of the resource to other terminals via the specific channel during the time resource. The specific channel is the Physical Side Link Feedback Channel, i.e., PSFCH.

2. The terminal according to claim 1, wherein, The control unit determines the code resources for the specific channel used in transmitting information related to the selection of the resources.

3. The terminal according to claim 2, wherein, The code resources are determined based on parameters related to the cyclic shift of the specific channel.

4. The terminal according to claim 1 or 2, wherein, The time resources are set based on parameters representing the period of the specific channel. The first frequency resource is a resource block set based on parameters representing the frequency domain of the specific channel, and the second frequency resource is a resource block other than the first frequency resource.

5. A terminal, wherein, The terminal has: The transmitting unit sends the shared channel to other terminals; The receiving unit, in a time resource set for a specific channel, uses a second frequency resource different from the first frequency resource set for the specific channel, to receive information related to the selection of resources used in the transmission of the shared channel via the specific channel, wherein the first frequency resource is used to transmit a response related to retransmission control of the shared channel; as well as The control unit, based on information related to the selection of the resources, reselects the resources to be used in the transmission of the shared channel. The specific channel is the Physical Side Link Feedback Channel, i.e., PSFCH.

6. A system comprising the terminal of claim 1 and the terminal of claim 5.

7. A communication method for a terminal, comprising the following steps: Receive shared channels transmitted from other terminals; The system determines time resources, a first frequency resource, and a second frequency resource set for a specific channel, wherein the first frequency resource is used to transmit responses related to retransmission control of the shared channel, and the second frequency resource is used to transmit information related to the selection of resources used in transmissions of the shared channel from the other terminals; and In the time resources, using the second frequency resource, which is different from the first frequency resource, information related to the selection of the resource is transmitted to other terminals via the specific channel. The specific channel is the Physical Side Link Feedback Channel, i.e., PSFCH.

8. A communication method for a terminal, comprising the following steps: Send the shared channel to other terminals; In the time resources designated for a specific channel, using a second frequency resource different from the first frequency resource designated for the specific channel, information related to the selection of resources used for transmission on the shared channel is received via the specific channel; and the first frequency resource is used for transmission on the shared channel. Based on the information related to the selection of the resources, the resources used for transmission on the shared channel are reselected. The specific channel is the Physical Side Link Feedback Channel, i.e., PSFCH.

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