Terminal and communication method

Abstract

The terminal comprises: a control unit, which selects resources according to the timing that other terminals can receive in a resource selection window in a resource pool; and a sending unit, which sends data to the other terminals from the selected resources, and the control unit at least selects resources for retransmission related to HARQ (Hybrid automatic repeat request) feedback sent from the other terminals.

Description

Technical Field

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

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

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

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

[0005] Prior art literature

[0006] Non-patent literature

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

[0008] Non-patent document 2: 3GPP TR 22886 V15.1.0 (2017-03) Summary of the invention

[0009] Problems to be solved by the invention

[0010] As an enhancement of the NR side link, power saving is being studied. For example, as a power saving action, in resource allocation mode 2 where the terminal autonomously selects resources, there is partial sensing in which the terminal senses limited resources within the sensing window. Based on the results of partial sensing, a resource candidate that can be used is selected from the resource selection window.

[0011] Here, in the NR side link, the terminal (Power saving UE) performing power saving action performs data transmission and reception only at a specific timing. On the other hand, in order to perform retransmission based on HARQ (Hybrid automatic repeat request) feedback, the transmission and reception of initial transmission data and retransmission data and the transmission and reception of HARQ feedback are required. Therefore, depending on the timing, it is assumed that the terminal performing power saving action cannot process retransmission based on HARQ feedback.

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to execute an operation related to HARQ (Hybrid automatic repeat request) suitable for a power saving operation in inter-terminal direct communication.

[0013] Means for solving problems

[0014] According to the disclosed technology, a terminal is provided, which comprises: a control unit, which selects resources according to the timing that other terminals can receive in the resource selection window in the resource pool; and a sending unit, which sends data to the other terminals in the selected resources, and the control unit at least selects resources for retransmission related to HARQ (Hybrid automatic repeat request) feedback sent from the other terminals.

[0015] Effects of the Invention

[0016] According to the disclosed technology, it is possible to execute an operation related to HARQ (Hybrid automatic repeat request) suitable for a power saving operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram for explaining V2X.

[0018] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode.

[0019] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode.

[0020] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode.

[0021] Figure 5 This is a diagram for explaining example (4) of the V2X transmission mode.

[0022] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode.

[0023] Figure 7 This is a diagram for explaining example (1) of the V2X communication type.

[0024] Figure 8 This is a diagram for explaining example (2) of the V2X communication type.

[0025] Fig. 9 This is a diagram for explaining example (3) of the V2X communication type.

[0026] Fig.10 This is a timing diagram showing an operation example (1) of V2X.

[0027] Fig.11 This is a timing diagram showing an operation example (2) of V2X.

[0028] Fig.12 This is a timing diagram showing an operation example (3) of V2X.

[0029] Fig.13 This is a timing diagram showing an operation example (4) of V2X.

[0030] Fig.14 is a diagram showing an example of a sensing operation.

[0031] Fig.15 2 is a diagram showing an example of a partial sensing operation.

[0032] Fig.16 This is a diagram showing example (1) of the sending and receiving operation.

[0033] Fig.17 This is a diagram showing example (2) of the sending and receiving operation.

[0034] Fig.18 This is a diagram showing an example (1) of the transmission and reception operation in the embodiment of the present invention.

[0035] Fig.19 This is a diagram showing example (2) of the transmission and reception operation in the embodiment of the present invention.

[0036] Fig. 20 This is a diagram showing example (3) of the transmission and reception operation in the embodiment of the present invention.

[0037] Fig.21 This is a diagram showing example (4) of the transmission and reception operation in the embodiment of the present invention.

[0038] Fig. 22 This is a diagram showing example (5) of the sending and receiving operation in the embodiment of the present invention.

[0039] Fig.23 This is a diagram showing example (6) of the sending and receiving operation in the embodiment of the present invention.

[0040] Fig.24 It is a diagram showing an example of the functional configuration of the base station 10 in the embodiment of the present invention.

[0041] Fig.25 This is a diagram showing an example of the functional configuration of the terminal 20 in the embodiment of the present invention.

[0042] Fig.26 This is a diagram showing an example of the hardware configuration of the base station 10 or the terminal 20 in the embodiment of the present invention. DETAILED DESCRIPTION

[0043] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0044] When the wireless communication system of the embodiment of the present invention is operated, the existing technology is appropriately used. However, the existing technology is, for example, the existing LTE, but is not limited to the existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and methods after LTE-Advanced (for example, NR) or wireless LAN (Local Area Network: local area network).

[0045] Furthermore, in the embodiments of the present invention, the duplexing method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, Flexible Duplex, etc.).

[0046] In the embodiment of the present invention, “configuring” wireless parameters and the like may be pre-configuring predetermined values, or may be configuring wireless parameters notified from the base station 10 or the terminal 20 .

[0047] Figure 1This is a diagram for explaining V2X. In 3GPP, the technology to realize V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functions is being studied and standardized. Figure 1 As shown, V2X is a part of ITS (Intelligent Transport Systems), which is a general term for V2V (Vehicle to Vehicle) which represents the communication between vehicles, V2I (Vehicle to Infrastructure) which represents the communication between vehicles and roadside equipment (RSU: Road-Side Unit) installed next to the road, V2N (Vehicle to Network) which represents the communication between vehicles and ITS servers, and V2P (Vehicle to Pedestrian) which represents the communication between vehicles and mobile terminals held by pedestrians.

[0048] In addition, 3GPP is studying V2X using cellular communication and terminal-to-terminal communication using LTE or NR. V2X using cellular communication is also called cellular V2X. In NR's V2X, research is being promoted to achieve large capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0049] Regarding LTE or NR V2X, it is envisioned that research not limited to 3GPP specifications can be promoted in the future. For example, it is envisioned to study how to ensure interoperability, reduce the cost caused by high-level installation, use or switch multiple RATs (Radio Access Technology), support for regulations in various countries, and how to obtain, publish, manage and use the data of LTE or NR V2X platform.

[0050] In the embodiments of the present invention, it is mainly envisioned that the communication device is 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, the communication device can also be a device mounted on a drone or an aircraft, the communication device can also be a base station, RSU, relay station (Relay Node), a terminal with scheduling capabilities, etc.

[0051] In addition, SL (Sidelink) can also be distinguished by UL (Uplink) or DL ​​(Downlink) and any one or a combination of the following 1) to 4). In addition, SL can also be other names.

[0052] 1) Resource allocation in the time domain

[0053] 2) Resource allocation in frequency domain

[0054] 3) Reference synchronization signal (including SLSS (Sidelink Synchronization Signal))

[0055] 4) Reference signal used in path loss measurement for transmit power control

[0056] In addition, for OFDM (Orthogonal Frequency Division Multiplexing) of SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding can also be used.

[0057] In the SL of LTE, Mode 3 and Mode 4 are defined for resource allocation of the SL to the terminal 20. In Mode 3, transmission resources are dynamically allocated using DCI (Downlink Control Information) sent from the base station 10 to the terminal 20. In addition, in Mode 3, SPS (SemiPersistent Scheduling) can also be performed. In Mode 4, the terminal 20 autonomously selects transmission resources from a resource pool.

[0058] In addition, the time slot in the embodiment of the present invention may also be replaced by a symbol, a mini-time slot, a subframe, a radio frame, or a TTI (Transmission Time Interval). In addition, the cell in the embodiment of the present invention may also be replaced by a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), etc.

[0059] In addition, in the embodiment of the present invention, the terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a terminal held by a user such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0060] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode. Figure 2 In the transmission mode of the sidelink communication shown in FIG. 1 , in step 1, the base station 10 sends the scheduling information of the sidelink to the terminal 20A. Then, the terminal 20A sends the PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to the terminal 20B according to the received scheduling information (step 2). Figure 2 The transmission mode of the sidelink communication shown is called the sidelink transmission mode 3 in LTE. In the sidelink transmission mode 3 in LTE, the sidelink scheduling based on Uu is performed. Uu refers to the wireless interface between UTRAN (Universal Terrestrial Radio Access Network) and UE (User Equipment). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 1 in NR.

[0061] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode. Figure 3 In the transmission mode of the side link communication shown in FIG. 1 , the terminal 20A transmits the PSCCH and PSSCH to the terminal 20B using the resources selected autonomously. Figure 3 The transmission mode of the sidelink communication shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE performs the resource selection itself.

[0062] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode. Figure 4 In the transmission mode of the side link communication shown in FIG. 1 , in step 1, the terminal 20A uses the autonomously selected resources to transmit the PSCCH and PSSCH to the terminal 20B. Similarly, the terminal 20B uses the autonomously selected resources to transmit the PSCCH and PSSCH to the terminal 20A (step 1). Figure 4The transmission mode of the sidelink communication shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, the terminal 20 performs resource selection itself.

[0063] Figure 5 This is a diagram for explaining example (4) of the V2X transmission mode. Figure 5 In the transmission mode of the sidelink communication shown in FIG. 1 , in step 0, the base station 10 sets a grant for transmitting the sidelink to the terminal 20A via RRC (Radio Resource Control). Then, the terminal 20A transmits the PSSCH to the terminal 20B according to the received resource mode (step 1). Figure 5 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2c in NR.

[0064] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode. Figure 6 In the transmission mode of the side link communication shown in FIG. 1 , terminal 20A transmits the scheduling information of the side link to terminal 20B via PSCCH in step 1. Then, terminal 20B transmits PSSCH to terminal 20A based on the received scheduling information (step 2). Figure 6 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2d in NR.

[0065] Figure 7 This is a diagram for explaining example (1) of the V2X communication type. 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, the terminal 20A performs unicast to the terminal 20B, and performs unicast to the terminal 20C.

[0066] Figure 8 This is a diagram for explaining example (2) of the V2X communication type. Figure 8 The communication type of the side link shown is multicast. Terminal 20A sends PSCCH and PSSCH to the group to which one or more terminals 20 belong. Figure 8 In the example shown, the group includes the terminal 20B and the terminal 20C, and the terminal 20A performs multicast to the group.

[0067] Fig. 9 This is a diagram for explaining example (3) of the V2X communication type. Fig. 9 The communication type of the side link shown is broadcast. Terminal 20A sends PSCCH and PSSCH to one or more terminals 20. Fig. 9In the example shown, terminal 20A broadcasts to terminal 20B, terminal 20C, and terminal 20D. Figure 7 to Figure 9 The terminal 20A shown is referred to as a head-UE.

[0068] In addition, in NR-V2X, it is envisaged to support HARQ (Hybrid automatic repeat request) in unicast and multicast of the side link. In addition, in NR-V2X, SFCI (Sidelink Feedback Control Information) including HARQ response is defined. In addition, research is underway to send SFCI via PSFCH (Physical Sidelink Feedback Channel).

[0069] In addition, in the following description, it is assumed that PSFCH is used in the transmission of HARQ-ACK in the side link, but this is only an example. For example, PSCCH can be used to transmit HARQ-ACK in the side link, PSSCH can be used to transmit HARQ-ACK in the side link, and other channels can be used to transmit HARQ-ACK in the side link.

[0070] In the following, for convenience of explanation, all information reported by the terminal 20 in HARQ is referred to as HARQ-ACK. The HARQ-ACK may also be referred to as HARQ-ACK information. In addition, more specifically, the codebook for the HARQ-ACK information reported from the terminal 20 to the base station 10, etc. is referred to as the HARQ-ACK codebook. The HARQ-ACK codebook specifies the bit string of the HARQ-ACK information. In addition, using "HARQ-ACK", NACK is also sent in addition to ACK.

[0071] Fig.10 is a timing diagram showing an operation example (1) of V2X. Fig.10 As shown in FIG. 1 , the wireless communication system according to the embodiment of the present invention may include a terminal 20A and a terminal 20B. In addition, there are actually a plurality of user devices, but Fig.10 The terminal 20A and the terminal 20B are shown as examples.

[0072] Hereinafter, when the terminals 20A, 20B, etc. are not particularly distinguished, they are simply referred to as "terminal 20" or "user device". Fig.10In the figure, as an example, the case where both the terminal 20A and the terminal 20B are within the coverage of the cell is shown, but the actions in the embodiment of the present invention can also be applied to the case where the terminal 20B is outside the coverage.

[0073] As described above, in this embodiment, the terminal 20 is a device mounted on a vehicle such as a car, and has a cellular communication function and a side link function as a UE in LTE or NR. The terminal 20 may also be a general portable terminal (smartphone, etc.). In addition, the terminal 20 may also be an RSU. The RSU may be a UE type RSU (UE type RSU) having the function of a UE, or a gNB type RSU (gNB type RSU) having the function of a base station device.

[0074] Furthermore, the terminal 20 does not need to be a device having a single housing. For example, even when various sensors are dispersedly arranged in a vehicle, the terminal 20 may be a device including the various sensors.

[0075] In addition, the processing content of the transmission data of the side link of the terminal 20 is basically the same as the processing content of the UL transmission in LTE or NR. For example, the terminal 20 scrambles the codeword of the transmission data, modulates it to generate complex-valued symbols, maps the complex-valued symbols (transmission signal) to layer 1 or layer 2, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate a transmission signal (for example, complex-valued time-domain SC-FDMA signal: complex-valued time-domain SC-FDMA signal), and sent from each antenna port.

[0076] In addition, the base station 10 has a cellular communication function as a base station in LTE or NR, and a function for enabling the terminal 20 in this embodiment to communicate (for example, resource pool setting, resource allocation, etc.). In addition, the base station 10 can also be an RSU (gNB type RSU).

[0077] In addition, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 in the SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.

[0078] In step S101 , the terminal 20A autonomously selects resources to be used for the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0079] In step S102 and step S103, the terminal 20A uses the resources autonomously selected in step S101 to send SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and sends SL data using PSSCH. For example, the terminal 20A may send PSCCH using frequency resources adjacent to the frequency resources of PSSCH in the same time resources as at least a portion of the time resources of PSSCH.

[0080] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The received SCI may include information on PSFCH resources for terminal 20B to transmit HARQ-ACK for the received data. Terminal 20A may include information on the resources selected autonomously in SCI and transmit it.

[0081] In step S104, the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the resources of the PSFCH determined by the received SCI.

[0082] If the HARQ-ACK received in step S104 indicates a request for retransmission, that is, NACK (negative acknowledgement), the terminal 20A retransmits the PSCCH and PSSCH to the terminal 20B in step S105. The terminal 20A can retransmit the PSCCH and PSSCH using the autonomously selected resources.

[0083] In addition, when HARQ control is not performed, step S104 and step S105 may not be performed.

[0084] Fig.11 This is a timing diagram showing an example of V2X operation (2). Blind retransmission may be performed regardless of HARQ control for improving the transmission success rate or the reach distance.

[0085] In step S201 , the terminal 20A autonomously selects resources to be used for the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0086] In step S202 and step S203, terminal 20A uses the resources autonomously selected in step S201 to send SCI using PSCCH and / or PSSCH, and sends SL data using PSSCH. For example, terminal 20A may send PSCCH using frequency resources adjacent to the frequency resources of PSSCH in the same time resources as at least a portion of the time resources of PSSCH.

[0087] In step S204, the terminal 20A retransmits the SCI based on the PSCCH and / or PSSCH and the SL data based on the PSSCH to the terminal 20B using the resources autonomously selected in step S201. The retransmission in step S204 may be performed multiple times.

[0088] In addition, when blind retransmission is not performed, step S204 may not be performed.

[0089] Fig.12 is a timing diagram showing an action example (3) of V2X. The base station 10 can perform scheduling of the side link. That is, the base station 10 can determine the resources of the side link used by the terminal 20 and send information indicating the resources to the terminal 20. Furthermore, when HARQ control is applied, the base station 10 can send information indicating the resources of the PSFCH to the terminal 20.

[0090] In step S301, the base station 10 transmits DCI (Downlink Control Information) to the terminal 20A using the PDCCH, thereby performing SL scheduling. Hereinafter, for convenience of description, the DCI for SL scheduling is referred to as SL scheduling DCI (SLscheduling DCI).

[0091] In addition, the following situation is assumed: in step S301, the base station 10 also sends DCI for DL ​​scheduling (also referred to as DL allocation) to the terminal 20A using the PDCCH. Hereinafter, for the convenience of explanation, the DCI for DL ​​scheduling is referred to as DL scheduling DCI. The terminal 20A that receives the DL scheduling DCI uses the resources specified by the DL scheduling DCI to receive DL data using the PDSCH.

[0092] In step S302 and step S303, the terminal 20A uses the resources specified by the SL scheduling DCI to send SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and sends SL data using PSSCH. In addition, in the SL scheduling DCI, only the resources of PSSCH can be specified. In this case, for example, the terminal 20A can send PSCCH using frequency resources adjacent to the frequency resources of PSSCH in the same time resources as at least a part of the time resources of PSSCH.

[0093] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The SCI received using PSCCH and / or PSSCH includes information on resources of "PSFCH for terminal 20B to transmit HARQ-ACK for reception of the data".

[0094] The information of the resource is included in the DL scheduling DCI or SL scheduling DCI sent from the base station 10 in step S301, and the terminal 20A obtains the information of the resource from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, assuming that the DCI sent from the base station 10 does not include the information of the resource, the terminal 20A autonomously includes the information of the resource in the SCI and sends it.

[0095] In step S304, the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the resources of the PSFCH determined by the received SCI.

[0096] In step S305, the terminal 20A, for example, sends HARQ-ACK at a timing (e.g., timing in time slots) specified by the DL scheduling DCI (or the SL scheduling DCI) using the PUCCH (Physical uplink control channel) resources specified by the DL scheduling DCI (or the SL scheduling DCI), and the base station 10 receives the HARQ-ACK. The codebook of the HARQ-ACK may include an ARQ-ACK generated based on the HARQ-ACK received from the terminal 20B or based on the unreceived PSFCH, and a HARQ-ACK for DL ​​data. However, in the case where there is no allocation of DL data, etc., the HARQ-ACK for DL ​​data is not included. In Rel.16 of NR, the codebook of the HARQ-ACK does not include a HARQ-ACK for DL ​​data.

[0097] In addition, when HARQ control is not performed, step S304 and step S305 may not be performed.

[0098] Fig.13 It is a timing diagram showing an action example (4) of V2X. As described above, the side link of NR supports the case of sending HARQ responses through PSFCH. In addition, the format of PSFCH can use the same format as PUCCH (Physical Uplink Control Channel) format 0 (PUCCH format 0), for example. That is, regarding the format of PSFCH, it can be a timing-based format in which the PRB (Physical Resource Block) size is 1, and ACK and NACK are identified based on the difference in timing and / or cyclic shift. The format of PSFCH is not limited to this. The resources of PSFCH can be configured in the codeword at the end of the time slot or multiple codewords at the end. In addition, a period N is set or pre-defined for the PSFCH resources. The period N can be set or pre-defined in units of time slots.

[0099] exist Fig.13 In the figure, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. PSCCH can be configured in one symbol at the beginning of the time slot, or in multiple symbols starting from the beginning, or in multiple symbols starting from a symbol other than the beginning. PSFCH can be configured in one symbol at the end of the time slot, or in multiple symbols at the end of the time slot. Fig.13 In the example shown, three subchannels are set in the resource pool, and two PSFCHs are arranged three slots after the slot in which the PSSCH is arranged. The arrow from the PSSCH to the PSFCH shows an example of the PSFCH associated with the PSSCH.

[0100] In the case where the HARQ response in the NR-V2X multicast is multicast option 2 of sending ACK or NACK, it is necessary to determine the resources used for the transmission and reception of the PSFCH. Fig.13 As shown, in step S401, terminal 20A as the transmitting terminal 20 performs multicast to terminal 20B, terminal 20C and terminal 20D as the receiving terminal 20 via SL-SCH. In the next step S402, terminal 20B uses PSFCH#B to send a HARQ response to terminal 20A, terminal 20C uses PSFCH#C to send a HARQ response to terminal 20A, and terminal 20D uses PSFCH#D to send a HARQ response to terminal 20A. Here, as shown in FIG. Fig.13As shown in the example of , when the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to decide how to allocate PSFCH resources. In addition, the transmitting terminal 20 can grasp the number of receiving terminals 20 in the multicast. In addition, in multicast option 1, as a HARQ response, only NACK is sent, and ACK is not sent.

[0101] Fig.14 is a diagram showing an example of a sensing operation. When partial sensing is not set by a higher layer in the LTE side link, as shown in FIG. Fig.14 As shown, terminal 20 selects resources to send. Fig.14 As shown, the terminal 20 performs sensing in the sensing window in the resource pool. Through sensing, the terminal 20 receives the resource reservation field contained in the SCI sent from other terminals 20, and identifies the available resource candidates in the resource selection window in the resource pool according to the field. Then, the terminal 20 randomly selects resources from the available resource candidates. Sensing the resources in the entire sensing window can be called full sensing.

[0102] In addition, if Fig.14 As shown, the resource pool setting may have a period. For example, the period may be a period of 10240 milliseconds. Fig.14 is subframe t 0 SL To subframe t Tmax SL An example of being set as a resource pool. The area of ​​the resource pool within a period can be set by, for example, a bitmap.

[0103] In addition, if Fig.14 As shown, assuming that the transmission trigger in terminal 20 occurs in subframe n, the priority of the transmission is p TX The terminal 20 can detect that in subframe t n-10×Pstep SL To subframe t n-1 SL In the sensing window, for example, other terminals 20 are performing priority p RX When SCI is detected in the sensing window and RSRP is greater than the threshold, the resources in the resource selection window corresponding to the SCI are excluded. In addition, when SCI is detected in the sensing window and RSRP is less than the threshold, the resources in the resource selection window corresponding to the SCI are not excluded. The threshold may also be, for example, based on the priority p TX and priority p RX The threshold Th is set or defined according to each resource in the sensing window. pTX，pRX .

[0104] In addition, if Fig.14 The subframe t shown Z SL In this way, for example, for transmission, resources within the resource selection window that are candidates for resource reservation information corresponding to resources within the sensing window that are not monitored are excluded.

[0105] like Fig.14 As shown, in subframe n+T 1 To subframe n+T 2 In the resource selection window, the resources occupied by other UEs are identified, and the resources after the resources are excluded become the available resource candidates. When the set of available resource candidates is set to S A When S A When the resource selection window is less than 20%, the threshold value Th set for each resource in the sensing window can be set to pTX，pRX The resource identification is performed again by increasing the threshold Th by 3 dB. pTX，pRX The resource identification is performed again when the RSRP is lower than the threshold, so that the resources that are not excluded due to RSRP being lower than the threshold are increased. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to the set S B You can also repeat the process of A The resource with the smallest RSSI is appended to S B The actions in the above table are as follows: B Become more than 20% of the resource selection window.

[0106] The lower layer of terminal 20 can B The upper layer of terminal 20 can report to S B The terminal 20 may use the determined resources to perform sidelink transmission. In addition, the terminal 20 may also temporarily secure resources and not use the predetermined number of times (e.g., C resel times) to perform sensing and periodically use resources.

[0107] Fig.15 1 is a diagram showing an example of partial sensing operation. When partial sensing is set by a higher layer in the LTE side link, as shown in FIG. Fig.15 As shown, terminal 20 selects resources to send. Fig.15As shown, the terminal 20 performs partial sensing on a portion of the sensing window in the resource pool. Through partial sensing, the terminal 20 receives the resource reservation field included in the SCI sent from other terminals 20, and identifies the available resource candidates in the resource selection window in the resource pool according to the field. Then, the terminal 20 randomly selects a resource from the available resource candidates.

[0108] In addition, if Fig.15 As shown, the resource pool setting may have a period. For example, the period may be a period of 10240 milliseconds. Fig.15 is subframe t 0 SL To subframe t Tmax SL An example of being set as a resource pool. The area of ​​the resource pool within a period can be set by, for example, a bitmap.

[0109] like Fig.15 As shown, assuming that the transmission trigger in terminal 20 occurs in subframe n, the priority of the transmission is p TX .like Fig.15 As shown, subframe n+T 1 To subframe n+T 2 In subframe t Y SL To subframe t y+Y SL The Y subframe can be set as the resource selection window. Fig.15 As shown, assuming that the transmission trigger in terminal 20 occurs in subframe n, the priority of the transmission is p TX .

[0110] The terminal 20 can detect that in the subframe t which is the Y subframe length y-k×Pstep SL To subframe t y+Y-k×Pstep SL In one or more sensing windows, for example, other terminals 20 are performing priority p RX k can be, for example, a 10-bit bitmap. Fig.15 , an example is shown in which the 3rd and 6th bits of the bitmap k are set to "1" to indicate that partial sensing is performed. Fig.15 In 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 is set as the sensing window. As described above, the i-th bit of the bitmap k may correspond to the subframe t y-i×Pstep SLTo subframe t y+Y-i×Pstep SL sensing window.

[0111] When SCI is detected in one or more sensing windows and RSRP is greater than the threshold, the resources in the resource selection window corresponding to the SCI are excluded. In addition, when SCI is detected in the sensing window and RSRP is less than the threshold, the resources in the resource selection window corresponding to the SCI are not excluded. The threshold may also be, for example, based on the priority p TX and priority p RX The threshold Th is set or defined according to each resource in the sensing window. pTX，pRX .

[0112] In the resource selection window set with Y subframes, the terminal 20 identifies the resources occupied by other UEs, and the resources after the resources are excluded become the available resource candidates. A When S A When the resource selection window is less than 20%, the threshold value Th set for each resource in the sensing window can be set to pTX，pRX The resource identification is performed again by increasing the threshold Th by 3 dB. pTX，pRX The resource identification is performed again when the RSRP is lower than the threshold, so that the resources that are not excluded due to RSRP being lower than the threshold are increased. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to the set S B You can also repeat the process of A The resource with the smallest RSSI in the set S is added to SB until the set of resource candidates S B Become more than 20% of the resource selection window.

[0113] The lower layer of terminal 20 can B The upper layer of terminal 20 can report to S B The terminal 20 may use the determined resources to perform sidelink transmission. In addition, the terminal 20 may also temporarily secure resources and not use the predetermined number of times (e.g., C resel times) to perform sensing and periodically use resources.

[0114] In the above Fig.14 and Fig.15 In the description, the operation of the transmitting terminal 20 is described, but the receiving terminal 20 can also detect data transmission from other terminals 20 based on the results of sensing or partial sensing, and receive data from the other terminals 20.

[0115] Here, in the side link of NR Release 17, power saving based on the above-mentioned random resource selection and partial sensing is being studied. For example, for power saving, the random resource selection and partial sensing of the side link in LTE Release 14 can be applied to the resource allocation mode 2 of the side link of NR Release 16. The terminal 20 to which partial sensing is applied performs reception and sensing only in a specific time slot within the sensing window.

[0116] In addition, in the side link of NR version 17, inter-UE coordination is used as a baseline, and eURLLC (enhanced Ultra Reliable Low Latency Communication) is being studied. For example, terminal 20A and terminal 20B share information representing a resource set, and terminal 20B considers this information in selecting resources for transmission.

[0117] Here, the terminal 20 (power saving UE) that performs power saving action executes data transmission, data reception or sensing only at a specific timing. On the other hand, in order to perform retransmission based on HARQ (Hybrid automatic repeat request) feedback, the transmission and reception of initial transmission data and retransmission data and the transmission and reception of HARQ feedback are required. In addition, the resources used for retransmission are reserved by the control signal accompanying the initial transmission data. Therefore, depending on the timing, it is assumed that the terminal 20 that performs power saving action cannot process retransmission based on HARQ feedback. In addition, timing can refer to one or more periodic time slots, or it can refer to any interval based on other time domain units.

[0118] Fig.16 is a diagram showing an example (1) of a transmission and reception operation. When the terminal 20A transmits to the terminal 20B that is performing a power saving operation, the timing at which the terminal 20B can receive is limited. For example, Fig.16 As shown, even if the initial PSCCH / PSSCH transmission #1 and the PSFCH as HARQ feedback are included in the timing that the terminal 20B can receive, if the retransmission PSCCH / PSSCH transmission #2 is not included in the timing, the terminal 20B may not be able to receive the retransmission based on the HARQ feedback.

[0119] Fig.17 2 is a diagram showing an example (2) of a transmission and reception operation. When the terminal 20A performing a power saving operation transmits to the terminal 20B, the timing at which the terminal 20A can transmit is limited. For example, Fig.16As shown, even if the initial PSCCH / PSSCH transmission #1 and the PSFCH as HARQ feedback are included in the timing that terminal 20A can send, if the retransmission PSCCH / PSSCH transmission #2 is not included in the timing, terminal 20A may not be able to send the retransmission based on the HARQ feedback.

[0120] Therefore, when at least one of the transmitting terminal 20 and the receiving terminal 20 performs power saving operation and HARQ-based retransmission is assumed, the terminal 20 can perform operations related to at least one of resource selection, transmission and reception in consideration of HARQ-based retransmission.

[0121] In addition, the power saving operation may be, for example, at least one of the following 1) to 3).

[0122] 1) Send only at a specific time

[0123] 2) Reception only at a specific timing

[0124] 3) Sensing only at specific timing

[0125] Fig.18 1 is a diagram showing an example (1) of the transmission and reception operation in the embodiment of the present invention. When the receiving terminal 20B performs power saving operation, retransmission based on HARQ feedback can also be received without relying on timing and decoding can be attempted. Fig.18 As shown, the initial transmission of a certain transport block, ie, PSCCH / PSSCH, may necessarily be transmitted at a timing at which the receiving terminal 20B performing the power saving operation can receive it.

[0126] The transmitting terminal 20A can select and reserve resources for retransmission regardless of the timing at which the receiving terminal 20B can receive. That is, the transmitting terminal 20A can select and reserve resources for retransmission from a period including the timing at which the receiving terminal 20B can receive, or can select and reserve resources for retransmission from a period not including the timing at which the receiving terminal 20B can receive.

[0127] Furthermore, the resource selection window used by the transmission side terminal 20A may be set from the start time slot of the timing that the reception side terminal 20B can receive, or may be set from any time slot of the timing that the reception side terminal 20B can receive.

[0128] Fig.19 FIG. 2 is a diagram showing an example (2) of the transmission and reception operation in the embodiment of the present invention. Fig.19 As shown, when selecting and reserving resources for retransmission, the transmitting terminal 20A preferentially selects and reserves resources included in the timing that the receiving terminal 20B can receive. Fig.19 As shown, the transmission-side terminal 20A may also set the timing at which the reception-side terminal 20B can receive as the resource selection window.

[0129] In addition, when the transmitting terminal 20A fails to select a resource for retransmission from among the resources included in the timing that the receiving terminal 20B can receive, the transmitting terminal 20A may select and reserve a resource for retransmission regardless of the timing that the receiving terminal 20B can receive. In addition, when the transmitting terminal 20A fails to select a resource for retransmission from among the resources included in the timing that the receiving terminal 20B can receive, the transmitting terminal 20A may set a resource selection window from the start time slot of the timing that the terminal 20B can receive.

[0130] The above-mentioned "a case where the transmitting terminal 20A fails to select a resource for retransmission from among the resources included in the timing that the receiving terminal 20B can receive" may refer to, for example, a case where the ratio of available resources does not exceed the threshold value X% of the resource selection window relative to the entire resources as a result of resource exclusion. In addition, "a case where the transmitting terminal 20A fails to select a resource for retransmission from among the resources included in the timing that the receiving terminal 20B can receive" may refer to, for example, a case where there is no candidate resource for retransmission due to at least one of the processing time for HARQ feedback and the range of time that can be specified by a certain SCI.

[0131] Fig. 20 FIG. 3 is a diagram showing an example (3) of the transmission and reception operation in the embodiment of the present invention. When the receiving terminal 20B performs a power saving operation, as shown in FIG. Fig. 20 As shown, the receiving terminal 20B may receive the retransmission resource when the retransmission resource is reserved for the resource that was not originally received. Alternatively, the receiving terminal 20B may not receive the retransmission resource when the retransmission resource is reserved for the resource that was not originally received.

[0132] When receiving a resource for retransmission for a resource that was not originally received as described above, the receiving terminal 20B may or may not transmit HARQ feedback in the PSFCH corresponding to the resource for retransmission.

[0133] In the above Fig.18 , Fig.19 and Fig. 20 As shown, by performing the transmission and reception operation, when the receiving terminal 20B performs the power saving operation, the transmitting terminal 20A can perform retransmission based on HARQ feedback without being restricted by the timing at which the receiving terminal 20B can receive. That is, resource utilization efficiency can be improved.

[0134] Fig.21 FIG. 4 is a diagram showing an example (4) of the transmission and reception operation in the embodiment of the present invention. When the receiving terminal 20B performs a power saving operation, as shown in FIG. Fig.21 As shown, retransmission based on HARQ feedback can be performed at a timing that the receiving terminal 20B can receive. When the receiving terminal 20B performs a power saving operation, the transmitting terminal 20A can also select a starting resource in the time domain of resource candidates included in the timing that the receiving terminal 20B can receive in resource selection.

[0135] And, if Fig. 20 As shown in FIG. 1 , the slot indication for reserving resources for retransmission in SCI can be counted only at the timing at which the receiving terminal 20B can receive. That is, the timing at which the receiving terminal 20B can receive can be shared by the transmitting terminal 20. Fig. 20 , the following example is shown: when sending #1 in time slot n, the time slot index in the SCI is based on time slot n, and the index is only assigned to the time slot that the receiving terminal 20B can receive. n+4 is the time slot index in the SCI, and the corresponding time slot is included in the timing that the receiving terminal 20B can receive.

[0136] In addition, information indicating that "transmission is to a terminal performing power saving operation" can be notified through SCI. In addition, information indicating that "time slot notification is counted only at a timing at which the receiving terminal 20B can receive" can also be notified through SCI.

[0137] In addition, in the case where the transmitting terminal 20A cannot indicate the reservation of the timing that the receiving terminal 20B can receive, the transmitting terminal 20A may be allowed to retransmit a certain transport block without reserving resources. For example, the case where the transmitting terminal 20A cannot indicate the reservation of the timing that the receiving terminal 20B can receive may refer to "the case where the number of time slots between transmission #1 and transmission #2 is 32 or more" (or, the case where it is greater than 32).

[0138] In such Fig.21 As shown, by performing the transmission and reception operation, when the receiving terminal 20B performs the power saving operation, the transmitting terminal 20A can perform the retransmission operation without increasing the reception time of the receiving terminal 20B. That is, the power saving effect is enhanced.

[0139] Fig. 22 This is a diagram showing example (5) of the sending and receiving operation in the embodiment of the present invention. Fig.23 is a diagram showing an example (6) of the transmission and reception operation in the embodiment of the present invention. Fig. 22 and Fig.23As shown, the transmitting terminal 20A may set the resource selection window according to whether or not the resource selection is for retransmission based on HARQ feedback.

[0140] For example, the transmitting terminal 20A may select resources for retransmission based on HARQ feedback, such as Fig. 22 As shown, set the resource selection window to Y 1 Time slot. 1 It can be a value equal to a specific parameter, or a value above that parameter based on UE installation.

[0141] For example, the transmitting terminal 20A may select resources for retransmission not based on HARQ feedback, such as Fig.23 As shown, set the resource selection window to Y 2 Time slot. 2 Can be different from " 1 The value may be equal to a "certain parameter of the associated parameters" or may be a value above the parameter based on the UE installation.

[0142] For example, Y 1 Can be compared to Y 2 Big (Y 1 >Y 2 ). 1 and Y 2 For example, it may be associated with a priority level associated with the data to be sent, or it may be associated with a maximum packet delay budget associated with the data to be sent.

[0143] In addition, the resource selection window may be discontinuous in the time domain.

[0144] like Fig. 22 and Fig.23 As shown, by executing the transmission and reception operation, the transmitting terminal 20A that performs the power saving operation can expand the resource selection window only when a larger resource selection window is required. That is, it is possible to suppress excessive sensing and increase the power saving effect.

[0145] Furthermore, when the transmitting terminal 20A performs a power saving operation, the transmitting terminal 20A may set a resource selection window according to whether the resource selection for retransmission based on the HARQ feedback is successful.

[0146] For example, the transmitting terminal 20A may set the resource selection window to Y when selecting resources for retransmission based on HARQ feedback. 3 Time slot. 3 It can be a value equal to a specific parameter, or a value above that parameter based on UE installation. 3The sensing action corresponding to the time slot (eg, partial sensing) and / or the Y 3 The resources in the time slot exclude actions and determine the resource candidates.

[0147] For example, the sending terminal 20A can 3 If the resource selection for retransmission based on HARQ feedback fails in the resource selection window of the time slot, the resource selection window is increased from Y 3 Time slot changed to Y 4 Time slot. 4 Can be different from " 3 The value of a certain parameter of the associated parameter is equal to the value of the parameter installed by the UE. For example, Y 4 Can be compared to Y 3 Big (Y 4 >Y 3 ).

[0148] When selecting a resource for retransmission based on HARQ feedback, the transmitting terminal 20A 3 If resource selection fails in the resource selection window of the time slot, the RSRP threshold can be changed and the resource exclusion action can be performed again. In addition, if resource selection fails even if the RSRP threshold is changed M times, the transmitting terminal 20A can determine that the resource selection fails in the Y time slot. 3 The resource selection window in the time slot based on HARQ feedback fails to select the resource for retransmission, and the resource selection window is increased from Y 3 Time slot changed to Y 4 M can be a value equal to a specific parameter or a value greater than that parameter based on UE installation.

[0149] In addition, the resource selection window may be discontinuous in the time domain.

[0150] For example, the transmitting terminal 20A 3 If the resource selection for retransmission based on HARQ feedback fails in the resource selection window of the time slot, the position of the resource selection window can be changed and the sensing and / or resource exclusion action can be performed again. The changed position of the resource selection window can be pre-set with an offset or determined by UE installation.

[0151] When selecting a resource for retransmission based on HARQ feedback, the transmitting terminal 20A 3 If resource selection fails in the resource selection window of the time slot, you can change Y 3 For example, Y 3 Whenever resource selection fails, you can add one or more resources. And even if you change Y 3, if resource selection also fails, the sending terminal 20A can determine that 3 The resource selection window in the time slot based on HARQ feedback fails to select the resource for retransmission, and the resource selection window is increased from Y 3 Time slot changed to Y 4 time slot. N can be a value equal to a specific parameter or a value greater than that parameter based on UE installation. 3 Increase to Y MAX In the case of Y 3 The resource selection window in the time slot based on HARQ feedback fails to select the resource for retransmission, and the resource selection window is increased from Y 3 Time slot changed to Y 4 time slot. That is, Y MAX It may be a threshold value indicating "the upper limit of the size of the resource selection window when it is determined that the resource selection has failed".

[0152] As described above, by setting the resource selection window according to whether the resource selection for retransmission based on HARQ feedback is successful, a relatively small resource selection window is usually used, and the size or position of the resource selection window can be changed when necessary. That is, excessive sensing can be suppressed, and the power saving effect is increased.

[0153] In addition, the terminal 20 that performs power saving action may refer to a terminal 20 that performs partial sensing, or may refer to a terminal 20 that is set to perform partial sensing, or may refer to a terminal 20 that is pre-set to perform partial sensing, or may refer to a terminal 20 that performs a sensing method different from the full sensing specified in version 16, or may refer to a terminal 20 that does not perform sensing, or may refer to a terminal 20 that receives only for a limited time (for example, DRX).

[0154] In addition, full sensing may refer to sensing all resources within a sensing window. The sensing window may be composed of a time slot interval [nT 0 , nT proc，0 ] is used to specify that n can be the time slot corresponding to the packet arrival timing.

[0155] In the above-mentioned embodiment, the receiving terminal 20 may be a plurality of terminals 20, or may belong to the same group. In addition, both the receiving terminal 20 and the transmitting terminal 20 may be terminals 20 that perform power saving operations.

[0156] In the above-mentioned embodiment, retransmission may not be limited to retransmission based on HARQ feedback. For example, retransmission may also correspond to multiple transmissions of the same transport block.

[0157] In the above-mentioned embodiment, the terminal 20 is not limited to a V2X terminal, and may be any terminal as long as it is a device that executes D2D.

[0158] In the above-mentioned embodiment, the transmitting terminal 20A can know the timing at which the receiving terminal 20B can receive and / or the timing at which the receiving terminal 20B can send. For example, the timing can be specified by a specification, or the transmitting terminal 20A can know the timing in advance by setting or pre-setting (pre configuration). In addition, the transmitting terminal 20A can also know the timing through notification between terminals or notification from the base station 10.

[0159] According to the above-described embodiment, when the receiving terminal 20 and / or the transmitting terminal 20 performs a power saving operation, resource selection corresponding to resource limitation due to the power saving operation is performed, thereby enabling control based on HARQ feedback without hindering the power saving operation.

[0160] That is, in the inter-terminal direct communication, it is possible to perform an operation related to HARQ (Hybrid automatic repeat request) suitable for a power saving operation.

[0161] (Device Structure)

[0162] Next, the functional configuration examples of the base station 10 and the terminal 20 that perform the above-described processing and operation are described. The base station 10 and the terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions in the embodiments.

[0163] <Base station 10>

[0164] Fig.24 1 is a diagram showing an example of the functional configuration of the base station 10. Fig.24 As shown, the base station 10 includes a transmission unit 110 , a reception unit 120 , a setting unit 130 , and a control unit 140 . Fig.24 The functional configuration shown is only an example, and any functional division and name of the functional unit may be used as long as the operation involved in the embodiment of the present invention can be performed.

[0165] The transmitting unit 110 includes a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The receiving unit 120 includes a function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher layer information from the received signals. In addition, the transmitting unit 110 has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0166] The setting unit 130 stores the preset setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads the setting information from the storage device as needed. The content of the setting information is, for example, information related to the setting of the D2D communication.

[0167] As described in the embodiment, the control unit 140 performs processing related to the setting for the terminal 20 to perform D2D communication. In addition, the control unit 140 transmits scheduling information of D2D communication and DL communication to the terminal 20 via the transmission unit 110. In addition, the control unit 140 receives information related to HARQ responses of D2D communication and DL communication from the terminal 20 via the reception unit 120. The functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the reception unit 120.

[0168] <Terminal 20>

[0169] Fig.25 2 is a diagram showing an example of the functional structure of the terminal 20. Fig.25 As shown, the terminal 20 includes a transmitting unit 210 , a receiving unit 220 , a setting unit 230 , and a control unit 240 . Fig.25 The functional configuration shown is only an example, and any functional division and name of the functional unit may be used as long as the operation involved in the embodiment of the present invention can be performed.

[0170] The transmitting unit 210 generates a transmission signal according to the transmission data, and transmits the transmission signal wirelessly. The receiving unit 220 receives various signals wirelessly, and obtains a higher layer signal from the received physical layer signal. In addition, the receiving unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals, etc. transmitted from the base station 10. In addition, for example, as D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0171] The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or the terminal 20 in the storage device, and reads it from the storage device as needed. In addition, the setting unit 230 also stores pre-set setting information. The content of the setting information is, for example, information related to the setting of D2D communication.

[0172] As described in the embodiment, the control unit 240 controls the D2D communication with other terminals 20. In addition, the control unit 240 performs processing related to HARQ of D2D communication and DL communication. In addition, the control unit 240 sends information related to HARQ responses of D2D communication and DL communication to other terminals 20 scheduled from the base station 10 to the base station 10. In addition, the control unit 240 can also schedule D2D communication for other terminals 20. In addition, the control unit 240 can autonomously select resources used in D2D communication from the resource selection window based on the monitoring results. In addition, the control unit 240 performs processing related to power saving in the transmission and reception of D2D communication. The functional unit related to signal transmission in the control unit 240 can also be included in the transmitting unit 210, and the functional unit related to signal reception in the control unit 240 can also be included in the receiving unit 220.

[0173] (Hardware Structure)

[0174] The block diagram used in the description of the above embodiment ( Fig.24 and Fig.25 ) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a device that is physically or logically combined, or two or more physically or logically separated devices can be directly or indirectly connected (for example, using wires, wirelessly, etc.) and implemented using these multiple devices. The functional block can also be implemented by combining software with the above-mentioned one device or the above-mentioned multiple devices.

[0175] Functionally, it includes judging, deciding, determining, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, solving, selecting, selecting, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but is not limited to these. For example, a functional block (structural unit) that enables the sending function is called a transmitting unit or a transmitter. In short, as mentioned above, there is no particular limitation on the implementation method.

[0176] For example, the base station 10 , the terminal 20 , and the like in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig.26 1 is a diagram showing an example of the hardware structure of a base station 10 and a terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 described above may also be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0177] In the following description, the word "device" may be replaced by "circuit", "device", "unit", etc. The hardware configuration of the base station 10 and the terminal 20 may include one or more of the devices shown in the figure, or may exclude some of the devices.

[0178] Each function in the base station 10 and the terminal 20 is implemented by the following method: predetermined software (program) is read into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs calculations and controls the communication of the communication device 1004 or controls at least one of the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0179] The processor 1001 controls the entire computer by, for example, running an operating system. The processor 1001 may also be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, a computing device, a register, etc. For example, the control unit 140, the control unit 240, etc., may also be implemented by the processor 1001.

[0180] In addition, the processor 1001 reads a program (program code), a software module, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and performs various processes accordingly. As a program, a program that causes the computer to execute at least a part of the actions described in the above-mentioned embodiments is used. For example, Fig.24 The control unit 140 of the base station 10 shown may also be implemented by a control program stored in the storage device 1002 and executed in the processor 1001. In addition, for example, Fig.25 The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and running in the processor 1001. Regarding the above-mentioned various processes, although it is described that the above-mentioned various processes are performed by one processor 1001, the above-mentioned various processes can also be performed simultaneously or sequentially by more than two processors 1001. The processor 1001 can also be installed by more than one chip. In addition, the program can also be sent from the network via a telecommunication line.

[0181] The storage device 1002 is a computer-readable recording medium, and may be composed of at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, a cache, a main memory (main storage device), etc. The storage device 1002 can store programs (program codes), software modules, etc. that can be executed to implement the communication method involved in one embodiment of the present disclosure.

[0182] The auxiliary storage device 1003 is a computer-readable recording medium, and can be composed of at least one of an optical disk such as a CD-ROM (CompactDisc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (for example, a compressed disk, a digital versatile disk, a Blu-ray (registered trademark) disk, a smart card, a flash memory (for example, a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium can be, for example, a database, a server, and other appropriate media that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0183] The communication device 1004 is hardware (transceiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also called a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., to implement at least one of frequency division duplex (FDD: Frequency Division Duplex) and time division duplex (TDD: Time Division Duplex). For example, a transceiver antenna, an amplifier, a transceiver, a transmission path interface, etc. may also be implemented by the communication device 1004. The transceiver may also be physically or logically installed separately from the transmitter and the receiver.

[0184] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1006 is an output device that implements output to the outside (e.g., a display, a speaker, an LED light, etc.). In addition, the input device 1005 and the output device 1006 may also be integrally formed (e.g., a touch panel).

[0185] In addition, the processor 1001 and the storage device 1002 and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured by a single bus or may be configured by different buses between the devices.

[0186] In addition, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array), and a part or all of each functional block may be implemented by the hardware. For example, the processor 1001 may also be implemented using at least one of these hardware.

[0187] (Summary of Implementation Methods)

[0188] As described above, according to an embodiment of the present invention, there is provided a terminal comprising: a control unit, which selects resources according to a timing that other terminals can receive in a resource selection window within a resource pool; and a sending unit, which sends data to the other terminals in the selected resources, wherein the control unit at least selects resources for retransmission related to HARQ (Hybrid automatic repeat request) feedback sent from the other terminals.

[0189] According to the above structure, when the receiving terminal 20 and / or the transmitting terminal 20 performs a power saving operation, the selection of resources corresponding to the resource limitation caused by the power saving operation can be performed, so that the control based on HARQ feedback can be performed without hindering the power saving operation. That is, in the direct communication between terminals, in the direct communication between terminals, the operation related to HARQ (Hybrid automatic repeat request) suitable for the power saving operation can be performed.

[0190] The control unit may select the retransmission resource related to the HARQ feedback in either a period including the timing or a period not including the timing. According to this configuration, when the receiving terminal 20 performs power saving operation, resource selection can be performed without being restricted by resources limited by the power saving operation.

[0191] The control unit may set the timing as the resource selection window. According to this configuration, when the receiving terminal 20 performs a power saving operation, it is possible to select a resource corresponding to the resource limitation caused by the power saving operation.

[0192] The control unit may set the resource selection window according to whether the resource selection is for retransmission related to HARQ feedback. According to this configuration, when the transmitting terminal 20 performs power saving operation, it is possible to perform resource selection corresponding to resource limitation caused by the power saving operation.

[0193] The control unit may set the resource selection window according to whether the resource selection for retransmission related to the HARQ feedback is successful. According to this configuration, when the transmitting terminal 20 performs a power saving operation, it is possible to perform resource selection corresponding to the resource limitation caused by the power saving operation.

[0194] In addition, according to an embodiment of the present invention, a communication method is provided, wherein the following steps are performed by a terminal: a control step of selecting resources based on a timing that other terminals can receive in a resource selection window within a resource pool; and a sending step of sending data to the other terminals in the selected resources, the control step including at least a step of selecting resources for retransmission related to HARQ (Hybrid automatic repeat request) feedback sent from the other terminals.

[0195] According to the above structure, when the receiving terminal 20 and / or the transmitting terminal 20 performs a power saving operation, the selection of resources corresponding to the resource limitation caused by the power saving operation can be performed, so that the control based on HARQ feedback can be performed without hindering the power saving operation. That is, in the direct communication between terminals, in the direct communication between terminals, the operation related to HARQ (Hybrid automatic repeat request) suitable for the power saving operation can be performed.

[0196] (Supplementary Implementation Methods)

[0197] The above describes the embodiments of the present invention, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, substitutions, replacements, etc. In order to promote the understanding of the invention, specific numerical examples are used for description, but unless otherwise specified, these numerical values ​​are only examples, and any appropriate value may also be used. The distinction between the items in the above description is not essential to the present invention, and the matters recorded in more than two items can be combined and used as needed, and the matters recorded in a certain item can be applied to the matters recorded in another item (as long as there is no contradiction). The boundaries of the functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of the physical components. The actions of multiple functional units can be performed by one physical component, or the actions of one functional unit can be performed by multiple physical components. Regarding the processing process described in the embodiment, the order of processing can be swapped if there is no contradiction. In order to facilitate the description of the processing, the base station 10 and the terminal 20 are described using functional block diagrams, but such devices can also be implemented by hardware, software, or a combination thereof. The software that operates through the processor of the base station 10 according to the embodiment of the present invention and the software that operates through the processor of the terminal 20 according to the embodiment of the present invention may also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server and any other appropriate storage medium.

[0198] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information may be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), high-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 a combination thereof. In addition, RRC signaling may also be referred to as an RRC message, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0199] Each form / implementation described in the present disclosure may 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-WideBand), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems extended therefrom. In addition, a combination of a plurality of systems (for example, a combination of at least one of LTE and LTE-A with 5G, etc.) may be applied.

[0200] The processing procedures, timings, flows, etc. of each form / implementation described in this specification may be changed in order without contradiction. For example, for the method described in this disclosure, the elements of various steps are presented in an illustrative order, but are not limited to the specific order presented.

[0201] In this specification, a specific action that is assumed to be performed by the base station 10 may also be performed by its upper node depending on the situation. In a network composed of one or more network nodes having the base station 10, various actions performed to communicate with the terminal 20 can be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, MME or S-GW, etc., but not limited to these). In the above, the case where there is one other network node other than the base station 10 is illustrated, but the other network node may also be a combination of multiple other network nodes (for example, MME and S-GW).

[0202] The information or signal described in the present disclosure can be output from a high layer (or a low layer) to a low layer (or a high layer), and can also be input or output via a plurality of network nodes.

[0203] The input or output information can be stored in a specific location (e.g., memory) or managed using a management table. The input or output information can be rewritten, updated, or appended. The output information can also be deleted. The input information can also be sent to other devices.

[0204] The determination in the present disclosure may be performed by a value represented by 1 bit (0 or 1), by a Boolean value (Boolean: true or false), or by comparison of numerical values ​​(for example, comparison with a predetermined value).

[0205] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to commands, sets of commands, codes, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0206] In addition, software, commands, information, etc. may be sent and received via a transmission medium. For example, when software is sent from a website, server, or other remote source using at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.), at least one of these wired technology and wireless technology is included in the definition of transmission medium.

[0207] The information, signals, etc. described in the present disclosure may also be represented by any of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the above description as a whole may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0208] In addition, the terms described in the present disclosure and the terms required for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may also be a signal (signaling). In addition, a signal may also be a message. In addition, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0209] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0210] In addition, the information, parameters, etc. described in the present disclosure may be represented by absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0211] The names used for the above parameters are not limiting in any respect. Furthermore, the formulas etc. using these parameters may sometimes differ from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by all appropriate names, the various names assigned to these various channels and information elements are not limiting in any respect.

[0212] In the present disclosure, the terms "base station (BS)," "wireless base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier" and the like are used interchangeably. Sometimes, the base station is also referred to as macro cell, small cell, femto cell, pico cell and the like.

[0213] A base station can accommodate one or more (for example, 3) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services through a base station subsystem (for example, a small base station for indoor use (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a part or the entirety of the coverage area of ​​at least one of a base station and a base station subsystem that provide communication services within the coverage area.

[0214] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0215] For mobile stations, those skilled in the art sometimes also use the following terms: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client or some other appropriate terms.

[0216] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a means of transportation (e.g., a car, an airplane, etc.), a mobile body that moves in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0217] In addition, the base station in the present disclosure may also be replaced by a user terminal. For example, various forms / implementations of the present disclosure may also be applied to a structure in which the communication between a base station and a user terminal is replaced by the communication between multiple terminals 20 (for example, it may also be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, it may also be configured that the terminal 20 has the functions possessed by the above-mentioned base station 10. In addition, terms such as "uplink" and "downlink" may also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. may also be replaced by side channels.

[0218] Likewise, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station may also have the functions of the user terminal described above.

[0219] The terms "determining" and "determining" used in the present disclosure sometimes also include a variety of actions. "Judgment" and "determination" may include, for example, considering matters that have been judged, calculated, calculated, processed, derived, investigated, searched (for example, searched in a table, database or other data structure), confirmed (ascertaining) as matters that have been "judged" or "determined", etc. In addition, "judgment" and "determination" may include matters that have been received (for example, receiving information), transmitted (for example, sending information), input, output, accessed (for example, accessing data in memory) as matters that have been "judged" or "determined", etc. In addition, "judgment" and "determination" may include matters that have been resolved (resolving), selected (selecting), chosen (choosing), established (establishing), compared (comparing), etc. as matters that have been "judged" or "determined". That is, "judgment" and "decision" can include matters that are considered to be "judged" and "decided". In addition, "judgment (decision)" can also be replaced by "assuming", "expecting", "considering", etc.

[0220] The terms "connected", "coupled" or all variations of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include the situation where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used to replace "connection". In the context of the present disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the wireless frequency domain, microwave region, and light (both visible and invisible) region may be used to "connect" or "couple" to each other.

[0221] The reference signal may be referred to as RS (Reference Signal) for short, or may be referred to as a pilot signal according to the applied standard.

[0222] The phrase "according to" used in the present disclosure does not mean "only according to" unless otherwise expressly stated. In other words, the phrase "according to" means both "only according to" and "at least according to".

[0223] Any reference to an element using the designations "first", "second", etc. used in this disclosure does not necessarily limit the number or order of these elements. These designations can be used as a simple method to distinguish between two or more elements in this disclosure. Therefore, a reference to a first element and a second element does not mean that only two elements can be taken or that the first element must precede the second element in any form.

[0224] The “unit” in the structure of each of the above-mentioned devices may be replaced with a “section”, a “circuit”, a “device” or the like.

[0225] When the terms "include", "including" and their variations are used in the present disclosure, these terms are intended to be inclusive like the term "comprising". Furthermore, the term "or" used in the present disclosure does not mean an exclusive or.

[0226] A radio frame may be composed of one or more frames in the time domain. In the time domain, one or more frames may be referred to as subframes. A subframe may further be composed of one or more time slots in the time domain. A subframe may also be a fixed time length (e.g., 1 ms) that is independent of a numerology.

[0227] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a certain signal or channel. The parameter set may, for example, represent at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transceiver in the frequency domain, specific windowing processing performed by the transceiver in the time domain, and the like.

[0228] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0229] A time slot may contain multiple mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. In addition, a mini-slot may also be referred to as a sub-slot. A mini-slot may be composed of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in units of time greater than a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type B.

[0230] A radio frame, a subframe, a time slot, a mini-time slot, and a symbol all represent time units for transmitting signals. A radio frame, a subframe, a time slot, a mini-time slot, and a symbol may be referred to by other corresponding names.

[0231] For example, one subframe may also be referred to as a transmission time interval (TTI), multiple consecutive subframes may also be referred to as a TTI, and one time slot or one mini time slot may also be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. In addition, the unit representing a TTI may not be referred to as a subframe, but may be referred to as a time slot, a mini time slot, or the like.

[0232] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station schedules each terminal 20 to allocate wireless resources (frequency bandwidth, transmission power, etc. that can be used in each terminal 20) in units of TTI. In addition, the definition of TTI is not limited to this.

[0233] TTI can be a transmission time unit for data packets (transport blocks), code blocks, code words, etc. after channel coding, and can also be a processing unit for scheduling, link adaptation, etc. In addition, when TTI is given, the time interval (e.g., the number of symbols) to which the transport block, code block, code word, etc. is actually mapped can be shorter than the TTI.

[0234] In addition, when 1 time slot or 1 mini time slot is called TTI, more than one TTI (i.e., more than one time slot or more than one mini time slot) can constitute the minimum time unit of scheduling. In addition, the number of time slots (number of mini time slots) constituting the minimum time unit of scheduling can be controlled.

[0235] A TTI having a time length of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini-time slot, a sub-time slot, a time slot, etc.

[0236] In addition, for a long TTI (for example, a normal TTI, a subframe, etc.), it can be replaced with a TTI having a time length exceeding 1ms, and for a short TTI (for example, a shortened TTI, etc.), it can be replaced with a TTI length that is smaller than the long TTI (longTTI) and has a TTI length of more than 1ms.

[0237] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain. In the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers contained in an RB may be the same regardless of the parameter set, for example, it may be 12. The number of subcarriers contained in an RB may also be determined according to the parameter set.

[0238] In addition, the time domain of an RB may include one or more symbols, and may be the length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. may be composed of one or more resource blocks, respectively.

[0239] In addition, one or more RBs may be referred to as a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, and the like.

[0240] In addition, a resource block may be composed of one or more resource elements (REs). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

[0241] A bandwidth part (BWP) (which may be referred to as a partial bandwidth, etc.) may represent a subset of contiguous common RBs (common resource blocks) for a parameter set in a carrier. Here, the common RBs may be identified by the index of the RBs relative to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0242] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be set for the terminal 20 within one carrier.

[0243] At least one of the set BWPs may be active, and it is not assumed that the terminal 20 transmits and receives a predetermined signal / channel outside the activated BWP. In addition, "cell", "carrier" and the like in the present disclosure may be replaced with "BWP".

[0244] The above structures of radio frames, subframes, time slots, mini-time slots, and symbols are only examples. For example, the number of subframes included in a radio frame, the number of time slots per subframe or radio frame, the number of mini-time slots included in a time slot, the number of symbols and RBs included in a time slot or mini-time slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP: Cyclic Prefix) length, and the like can be changed in various ways.

[0245] In the present disclosure, when an article is added by translation, such as a, an, and the in English, for example, the present disclosure may also include a case where the noun following the article is in a plural form.

[0246] In the present disclosure, the term "A is different from B" may also mean "A and B are different from each other". In addition, the term may also mean "A and B are different from C, respectively". The terms "separate" and "combined" may also be interpreted in the same way as "different".

[0247] Each form / implementation described in the present disclosure may be used alone or in combination, and may be switched according to execution. In addition, notification of scheduled information is not limited to being performed explicitly (e.g., notification of "yes X"), but may also be performed implicitly (e.g., notification of the scheduled information is not performed).

[0248] In addition, in the present disclosure, PSCCH / PSSCH is an example of data.

[0249] The present disclosure is described in detail above, but it should be clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as a modification and variation without departing from the subject matter and scope of the present disclosure as determined by the claims. Therefore, the purpose of the description of the present disclosure is to illustrate and not to have any limiting meaning on the present disclosure.

[0250] Description of symbols

[0251] 10: Base station;

[0252] 110: Sending department;

[0253] 120: receiving unit;

[0254] 130: Setting department;

[0255] 140: Control Department;

[0256] 20: Terminal;

[0257] 210: Sending department;

[0258] 220: receiving unit;

[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 for performing inter-terminal communication, comprising: a transmitting unit that transmits data to other terminals operating in DRX via a shared channel for inter-terminal communication, namely, PSSCH, where the DRX is discontinuous reception and the PSSCH is a physical side link shared channel; a receiving unit configured to receive HARQ-ACK information for the data transmitted via the PSSCH from the other terminal; as well as A control unit that selects resources for retransmitting the data transmitted via the PSSCH to the other terminal from resources including resources that the other terminal originally did not receive when the HARQ-ACK information is a negative response.

2. A terminal, which operates in DRX and performs inter-terminal communication, wherein the DRX is discontinuous reception, and has: A receiving unit that receives data from other terminals via a shared channel for communication between terminals, namely, a PSSCH, where the PSSCH is a physical side link shared channel; a transmitting unit configured to transmit HARQ-ACK information for the data received via the PSSCH to the other terminal; and A control unit that performs control when the HARQ-ACK information is a negative response so that the data retransmitted from the other terminal via the PSSCH is received even in resources that were not originally received.

3. A communication method performed by a terminal, wherein the terminal performs inter-terminal communication, the communication method comprising the following steps: Sending data to other terminals operating in DRX via a shared channel for inter-terminal communication, namely PSSCH, where DRX is discontinuous reception and PSSCH is a physical sidelink shared channel; receiving, from the other terminal, HARQ-ACK information for the data sent via the PSSCH; as well as When the HARQ-ACK information is a negative response, resources for retransmitting the data transmitted via the PSSCH to the other terminal are selected from resources including resources that the other terminal originally did not receive.

4. A communication method performed by a terminal, wherein the terminal operates in DRX to perform inter-terminal communication, wherein the DRX is discontinuous reception, and the communication method comprises the following steps: Receiving data from other terminals via a shared channel for inter-terminal communication, namely PSSCH, where the PSSCH is a physical sidelink shared channel; Sending HARQ-ACK information for the data received via the PSSCH to the other terminal; as well as When the HARQ-ACK information is a negative response, control is performed so that data retransmitted from the other terminal via the PSSCH is received even on resources that were not originally received.

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