Terminals and communication methods

Abstract

In direct communication between terminals, ensure that responses related to retransmission control are sent and received appropriately. [Solution] The terminal comprises a receiving unit that receives data transmitted by groupcast from other terminals, a control unit that determines a resource to be used for sending and receiving a response related to retransmission control corresponding to the data, based on at least one of the following: the slot index of the data, the subchannel index of the data, the number of subchannels in the resource, the transmission period of the response related to retransmission control, the source ID in Layer 1, the terminal identification ID in the group, and the number of resources in the code area of ​​the response related to retransmission control, and a transmitting unit that transmits a response related to retransmission control corresponding to the data to the other terminal using the determined resource, wherein the control unit determines the cyclic shift index of the code area of ​​the resource by performing a modulo operation on the number of resources in the code area using the terminal identification ID in the group.

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 successor systems of LTE (e.g., LTE-A (LTE Advanced), NR (New Radio) (also referred to as 5G)), D2D (Device to Device) technology that enables direct communication between terminals without going through a base station has been studied (e.g., Non-Patent Document 1).

[0003] D2D reduces traffic between a terminal and a base station and enables communication between terminals even when the base station becomes inoperable during a disaster or the like. Note that in 3GPP (3rd Generation Partnership Project), D2D is referred to as "sidelink", but in this specification, the more general term D2D is used. However, in the description of the embodiments described later, sidelink is also used as necessary.

[0004] D2D communication is roughly classified into D2D discovery (also referred to as D2D discovery) for discovering other communicable terminals and D2D communication (also referred to as D2D direct communication, D2D communication, direct communication between terminals, etc.) for direct communication between terminals. Hereinafter, when not particularly distinguishing between D2D communication, D2D discovery, etc., it is simply referred to as D2D. Also, a signal transmitted and received by D2D is referred to as a D2D signal. Various use cases of services related to V2X (Vehicle to Everything) in NR have been studied (e.g., Non-Patent Document 2).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] In NR-V2X, support for HARQ (Hybrid automatic repeat request) control in groupcasts is being considered for direct terminal-to-terminal communication. However, the resource where the PSFCH (Physical Sidelink Feedback Channel), which sends and receives HARQ responses corresponding to the PSSCH (Physical Sidelink Shared Channel) used for groupcasts, is located has not been defined.

[0007] The present invention has been made in view of the above points, and aims to appropriately send and receive responses related to retransmission control in direct communication between terminals. [Means for solving the problem]

[0008] According to the disclosed technology, a terminal is provided comprising: a receiving unit that receives data transmitted in a group cast from other terminals; a control unit that determines a resource to be used for sending and receiving a response related to retransmission control corresponding to the data, based on at least one of the following: the slot index of the data, the subchannel index of the data, the number of subchannels in the resource, the transmission period of the response related to retransmission control, the source ID at Layer 1, the terminal identification ID within the group, and the number of resources in the code area of ​​the response related to retransmission control; and a transmitting unit that transmits a response related to retransmission control corresponding to the data to the other terminal using the determined resource, wherein the control unit determines the cyclic shift index of the code area of ​​the resource by performing a modulo operation on the number of resources in the code area using the terminal identification ID within the group. [Effects of the Invention]

[0009] According to the disclosed technology, responses related to retransmission control can be appropriately sent and received during direct communication between terminals. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram to explain V2X. [Figure 2] This is a diagram illustrating an example of a V2X transmission mode (1). [Figure 3] This is a diagram illustrating an example of a V2X transmission mode (2). [Figure 4] This is a diagram illustrating an example of a V2X transmission mode (3). [Figure 5] This is a diagram illustrating an example of a V2X transmission mode (4). [Figure 6] This is a diagram illustrating an example of a V2X communication type (1). [Figure 7] This is a diagram illustrating an example of a V2X communication type (2). [Figure 8] This is a diagram illustrating example (3) of V2X communication types. [Figure 9] This is a flowchart illustrating an example of a HARQ response in V2X. [Figure 10] This figure shows an example of group casting in an embodiment of the present invention. [Figure 11] This figure shows an example of channel arrangement (1) in an embodiment of the present invention. [Figure 12] This figure shows an example (2) of channel arrangement in an embodiment of the present invention. [Figure 13] This figure shows an example of the functional configuration of the base station 10 in an embodiment of the present invention. [Figure 14] This figure shows an example of the functional configuration of terminal 20 in an embodiment of the present invention. [Figure 15]This is a diagram showing an example of the hardware configuration of the base station 10 or the terminal 20 in an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

[0012] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are appropriately used. However, the existing technology is, for example, existing LTE, but is not limited to existing LTE. Also, the term "LTE" used in this specification shall have a broad meaning including LTE-Advanced, and systems after LTE-Advanced (e.g., NR), or wireless LAN (Local Area Network) unless otherwise specified.

[0013] Also, in the embodiment of the present invention, the duplex mode may be a TDD (Time Division Duplex) mode, an FDD (Frequency Division Duplex) mode, or other modes (e.g., Flexible Duplex, etc.).

[0014] Also, in the embodiment of the present invention, that a wireless parameter or the like is "configured" may mean that a predetermined value is pre-configured, or that a wireless parameter notified from the base station 10 or the terminal 20 is configured.

[0015] Figure 1 is a diagram illustrating V2X. 3GPP is considering and working on specifications to realize V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality. As shown in Figure 1, V2X is a part of ITS (Intelligent Transport Systems) and is a general term encompassing V2V (Vehicle to Vehicle), which refers to communication between vehicles; V2I (Vehicle to Infrastructure), which refers to communication between vehicles and roadside units (RSUs) installed along the roadside; V2N (Vehicle to Network), which refers to communication between vehicles and ITS servers; and V2P (Vehicle to Pedestrian), which refers to communication between vehicles and mobile terminals carried by pedestrians.

[0016] Furthermore, 3GPP is considering V2X using LTE or NR cellular communication and terminal-to-terminal communication. V2X using cellular communication is also called cellular V2X. For NR V2X, research is underway to achieve high capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0017] Regarding LTE or NR V2X, it is anticipated that future considerations will extend beyond 3GPP specifications. For example, it is expected that considerations will be given to ensuring interoperability, reducing costs through the implementation of higher layers, methods for using or switching between multiple RATs (Radio Access Technologies), compliance with regulations in various countries, and methods for data acquisition, distribution, database management, and utilization of LTE or NR V2X platforms.

[0018] While the embodiments of the present invention primarily envision a configuration in which the communication device is mounted on a vehicle, the embodiments of the present invention are not limited to this configuration. For example, the communication device may be a terminal held by a person, a device mounted on a drone or aircraft, or a base station, RSU, relay station (relay node), terminal with scheduling capabilities, etc.

[0019] Furthermore, SL (Sidelink) may be distinguished from UL (Uplink) or DL ​​(Downlink) based on any one or a combination of the following 1)-4). Also, SL may have other names. 1) Resource allocation in the time domain 2) Resource allocation in the frequency domain 3) Reference synchronization signals (including SLSS (Sidelink Synchronization Signal)) 4) Reference signal used for path loss measurement for transmit power control

[0020] Furthermore, with respect to SL or UL OFDM (Orthogonal Frequency Division Multiplexing), any of the following may be applied: CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform - Spread - OFDM), OFDM without transform precoding, or OFDM with transform precoding.

[0021] In LTE's Downlink Service Line (SL), Mode 3 and Mode 4 are defined for allocating SL resources to terminal 20. In Mode 3, transmission resources are dynamically allocated via DCI (Downlink Control Information) sent from base station 10 to terminal 20. Semi-Persistent Scheduling (SPS) is also possible in Mode 3. In Mode 4, terminal 20 autonomously selects transmission resources from the resource pool.

[0022] In the embodiments of the present invention, the term "slot" may be interpreted as a symbol, mini-slot, subframe, wireless frame, or TTI (Transmission Time Interval). Furthermore, in the embodiments of the present invention, the term "cell" may be interpreted as a cell group, carrier component, BWP, resource pool, resource, RAT (Radio Access Technology), system (including wireless LAN), etc.

[0023] Figure 2 is a diagram illustrating an example of a V2X transmission mode (1). Note that the transmission mode may be interpreted as a resource allocation mode. In the sidelink communication transmission mode shown in Figure 2, in step 1, the base station 10 transmits the sidelink scheduling to terminal 20A. Subsequently, terminal 20A transmits the PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to terminal 20B based on the received scheduling (step 2). The sidelink communication transmission mode shown in Figure 2 may also be called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu is the radio interface between UTRAN (Universal Terrestrial Radio Access Network) and UE (User Equipment). Note that the sidelink communication transmission mode shown in Figure 2 may also be called sidelink transmission mode 1 in NR.

[0024] Figure 3 is a diagram illustrating an example (2) of the V2X transmission mode. In the sidelink communication transmission mode shown in Figure 3, in step 1, terminal 20A uses autonomously selected resources to transmit PSCCH and PSSCH to terminal 20B. Similarly, terminal 20B uses autonomously selected resources to transmit PSCCH and PSSCH to terminal 20A (step 1). The sidelink communication transmission mode shown in Figure 3 may also be called sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, terminal 20 itself performs resource selection.

[0025] Figure 4 is a diagram illustrating an example of a V2X transmission mode (3). In the sidelink communication transmission mode shown in Figure 4, in step 0, the sidelink resource pattern is (pre-configured) on terminal 20A. Subsequently, terminal 20A transmits PSSCH to terminal 20B based on the received resource pattern (step 1). The sidelink communication transmission mode shown in Figure 4 may also be called the sidelink transmission mode 2c in NR.

[0026] Figure 5 is a diagram illustrating an example of a V2X transmission mode (4). In the sidelink communication transmission mode shown in Figure 5, in step 1, terminal 20C transmits the sidelink scheduling to terminal 20A via PSCCH. Subsequently, terminal 20A transmits PSSCH to terminal 20B based on the received scheduling (step 2). The sidelink communication transmission mode shown in Figure 5 may also be called the sidelink transmission mode 2d in NR.

[0027] Figure 6 is a diagram illustrating an example of a V2X communication type (1). The sidelink communication type shown in Figure 6 is unicast. Terminal 20A transmits PSCCH and PSSCH to Terminal 20. In the example shown in Figure 6, Terminal 20A unicasts to Terminal 20B and also unicasts to Terminal 20C.

[0028] Figure 7 is a diagram illustrating an example (2) of V2X communication types. The sidelink communication type shown in Figure 7 is a group cast. Terminal 20A sends PSCCH and PSSCH to a group to which one or more terminals 20 belong. In the example shown in Figure 7, the group includes terminals 20B and 20C, and terminal 20A performs a group cast to the group.

[0029] Figure 8 is a diagram illustrating an example of a V2X communication type (3). The sidelink communication type shown in Figure 8 is broadcast. Terminal 20A transmits PSCCH and PSSCH to one or more terminals 20. In the example shown in Figure 8, terminal 20A broadcasts to terminals 20B, 20C, and 20D.

[0030] Figure 9 is a flowchart illustrating an example of a HARQ response in V2X. As shown in Figure 9, in step S1, terminal 20A transmits PSCCH and PSSCH to terminal 20B. Subsequently, terminal 20B transmits a PSFCH (Physical Sidelink Feedback Channel) containing the HARQ response corresponding to the received PSSCH to terminal 20A.

[0031] NR-V2X supports HARQ in unicast or groupcast PSCCH and PSSCH. HARQ feedback and HARQ combining are supported at the physical layer in unicast and groupcast. Furthermore, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. At least one SFCI format is applied that includes the HARQ response corresponding to the PSSCH.

[0032] In NR-V2X groupcasts, the HARQ response has two options: Option 1, where the receiving terminal 20 sends only a NACK, and Option 2, where it sends either an ACK or a NACK. For example, in Option 1, all receiving terminals 20 may share one PSFCH, some receiving terminals 20 may share one PSFCH, or all or some receiving terminals 20 may share one pool of PSFCHs. For example, in Option 2, each receiving terminal 20 may use a separate PSFCH to send either an ACK or a NACK. Also, in Option 2, all or some receiving terminals 20 may share one PSFCH to send an ACK, or another PSFCH to send a NACK. Note that the PSFCH resource may be mapped to one or more of the time domain, frequency domain, and code domain. Hereinafter, "Option 1" may mean Option 1 of the HARQ response in the groupcast described above, and "Option 2" may mean Option 2 of the HARQ response in the groupcast described above.

[0033] Figure 10 shows an example of group casting in an embodiment of the present invention. As described above, in the NR sidelink, HARQ responses are supported to be transmitted in PSFCH. The PSFCH format can be the same as that of PUCCH (Physical Uplink Control Channel) format 0. That is, the PSFCH format may be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified by sequence differences. The PSFCH format is not limited to this. PSFCH resources may be placed in the last symbol or multiple last symbols of the slot. In addition, a period N is set or predetermined for the PSFCH resources. The period N may be set or predetermined on a per-slot basis.

[0034] In Figure 10, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. A PSCCH may be placed in the first symbol of a slot, in multiple symbols from the beginning, or in multiple symbols from symbols other than the beginning. A PSFCH may be placed in the last symbol of a slot, or in multiple symbols at the end of a slot. In the example shown in Figure 10, three subchannels are configured in the resource pool, and two PSFCHs are placed three slots after the slot in which the PSSCH is placed. The arrows from PSSCH to PSFCH show an example of a PSFCH associated with a PSSCH.

[0035] If the HARQ response in an NR-V2X group cast is option 2, which involves sending an ACK or NACK, it is necessary to determine which resources to use for sending and receiving PSFCH. As shown in Figure 10, in step 1, the transmitting terminal 20, UE#A, performs a group cast via SL-SCH to the receiving terminals 20, UE#B, UE#C, and UE#D. In the following step 2, UE#B uses PSFCH#B, UE#C uses PSFCH#C, and UE#D uses PSFCH#D to send HARQ responses to UE#A. Here, as shown in the example in Figure 10, if the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to determine how to allocate the PSFCH resources. The transmitting terminal 20 may also know the number of receiving terminals 20 in the group cast.

[0036] Figure 11 shows an example of channel arrangement (1) in an embodiment of the present invention. In the example shown in Figure 11, three subchannels are configured in the resource pool, with four PSFCHs placed after slots 4, 3, 2, and 1 where PSSCHs are placed. The period of placement of PSFCHs is four slots. The arrows from PSSCH to PSFCH indicate an example of a PSFCH associated with a PSSCH.

[0037] If option 2 is set or notified in the NR-V2X groupcast, where the HARQ response sends an ACK or NACK (for example, if the information element (e.g., upper layer parameter) FeedbackTypeGroupcast='type2'), the PSFCH resources identified in the time domain, frequency domain, and code domain may be determined by at least one of the parameters shown in 1)-16) below. Note that the parameters shown in 1)-16) below may also be parameters associated with the resource pool. 1) Slot index of PSCCH and / or PSSCH: A 2) PSFCH slot index: B 3) Gap between PSFCH and the preceding A: K 4) Subchannel index of PSCCH and / or PSSCH: C 5) First PRB index in the subchannel transmitting PSFCH: D 6) Number of PRBs in the subchannel transmitting PSFCH: F 7) Number of subchannels in the resource pool: G 8) Number of PRBs in the resource pool: H 9) Period of PSFCH: N 10) L1 Source ID: P 11) L1 Destination ID: Q 12) L1ID (VirtualID) for terminal identification within the group: R 13) L1ID for group identification: T 14) Number of resources in the PSFCH code region: S 15) Number of PRBs in subchannel m: E_m 16) First PRB index in subchannel m: D_m

[0038] As shown in Figure 10, when the first PSCCH and PSSCH are placed in slot n, the PSFCH resource is determined by at least one of the following parameters: A={n,n+1,n+2,n+3}, B=n+4, C=0, D=0, E=8, F=2, N=4. P is the L1 source ID, which indicates the Layer 1 ID of the transmitting terminal 20. Q is the L1 destination ID, which indicates the Layer 1 ID of the receiving terminal 20.

[0039] For example, the above parameters or the formulas used to derive the PSFCH resources from the above parameters may differ between option 2 for groupcasting and option 1 for unicasting and / or groupcasting.

[0040] Furthermore, the frequency domain of the PSFCH resource may be the same among the PSFCHs corresponding to the PSSCH of the groupcast, while the code domain of the PSFCH resource may differ. For example, the method for determining the frequency domain of the PSFCH resource may be the same for option 2 of the groupcast and option 1 of the unicast and / or groupcast. For example, the code domain of the PSFCH resource may be defined as Z=R or Z=R mod S with respect to the cyclic shift index Z. Alternatively, for example, the code domain of the PSFCH resource may be defined as Z=2×R or Z=R mod (S / 2) with respect to the cyclic shift index Z. In other words, adjacent code domain resources may not be used, and distant resources may be used. This allows for doubling the spacing of PSFCH resources in the code domain, thereby improving reception characteristics. Alternatively, for example, the code domain of the PSFCH resource may be defined as Z=Q or Z=Q mod S with respect to the cyclic shift index Z. Furthermore, for example, the code area of ​​the PSFCH resource may be defined as Z = 2 × Q or Z = Q mod (S / 2) for the cyclic shift index Z. By using Q, communication can be performed even if the VirtualID R is unknown to each receiving terminal 20 belonging to the group. Note that in the above formula for calculating Z, "2" may be replaced with other values.

[0041] Furthermore, the code domain of the PSFCH resource may be the same among the PSFCHs corresponding to the PSSCH of the groupcast, while the frequency domain of the PSFCH resource may differ. Alternatively, both the frequency domain and the code domain of the PSFCH resource may differ among the PSFCHs corresponding to the PSSCH of the groupcast.

[0042] In addition, other methods similar to cyclic shift may be used for the code area of ​​the PSFCH resource. For example, TD-OCC (Time Domain Orthogonal Cover Code) or FD-OCC (Frequency Domain Orthogonal Cover Code) may be used for the code area of ​​the PSFCH resource.

[0043] In addition, in option 2 for groupcast and option 1 for unicast and / or groupcast, different subchannels may be set or announced for PSFCH transmission and reception.

[0044] For example, when option 2 of groupcast is set or notified, the number X of receiving terminals 20 belonging to the group may be set to be less than or equal to the number Y of PSFCHs available for the HARQ response corresponding to the PSSCH used for groupcast. For example, if the number X of receiving terminals 20 exceeds the number Y of PSFCHs, an error may be considered to have occurred. That is, terminal 20 does not need to assume X greater than Y. As another example, if the number X of receiving terminals 20 exceeds the number Y of PSFCHs, some receiving terminals 20 may not send a HARQ response, may postpone sending a HARQ response, or may resend a HARQ response. The above some receiving terminals 20 may be determined based on terminal ID. As yet another example, the above some receiving terminals 20 may be determined based on the distance between the transmitting terminal 20 and the receiving terminals 20, the number X of receiving terminals 20 belonging to the group, and the number Y of PSFCHs available for the HARQ response corresponding to the PSSCH used for groupcast. In other words, the threshold for the distance between the transmitting terminal 20 and the receiving terminal 20 for determining whether the HARQ response is valid or invalid may be changed based on X and Y. As another example, some of the receiving terminals 20 may be determined based on notifications from the transmitting terminal 20 or the base station 10. Note that the distance between terminals may mean an element determined based on at least one piece of information such as the (sub)zone in which each terminal is located, the path loss of transmitted power between terminals, and the signal arrival time between terminals or between terminals and the base station.

[0045] For example, when option 2 of groupcast is set or notified, the number X of receiving terminals 20 belonging to the group may be set to be less than or equal to a certain number Z. For example, the number Z may be set or predefined. For example, if the number X of receiving terminals 20 exceeds the number Z, an error may be considered to have occurred. That is, terminal 20 does not need to assume an X greater than Z. As another example, if the number X of receiving terminals 20 exceeds the number Z, some receiving terminals 20 may not send a HARQ response, may postpone sending a HARQ response, or may retransmit a HARQ response. The above some receiving terminals 20 may be determined based on terminal ID. As yet another example, the above some receiving terminals 20 may be determined based on the distance between the transmitting terminal 20 and the receiving terminals 20, the number X of receiving terminals 20 belonging to the group, and the number Z of PSFCHs available for the HARQ response corresponding to the PSSCH used for groupcast. As yet another example, the above some receiving terminals 20 may be determined based on notification from the transmitting terminal 20 or base station 10. Furthermore, the distance between terminals may refer to an element determined based on at least one piece of information, such as the subzone in which each terminal is located, the path loss of transmitted power between terminals, or the signal arrival time between terminals or between a terminal and a base station.

[0046] Figure 12 shows an example of channel configuration (2) in an embodiment of the present invention. When option 2 of the groupcast is set or notified, resources associated with other PSSCHs may be used to transmit the PSCCH and / or PSFCH corresponding to the PSSCH of the groupcast.

[0047] The receiving terminal 20 may detect PSFCH resources that are not being used for other HARQ responses through sensing. As shown in Figure 12, if the receiving terminal 20, UE#D, detects through sensing that PSCCH and / or PSSCH are not being transmitted in a slot on subchannel #1, it may transmit PSFCH#D using the resources corresponding to that PSSCH. If the receiving terminal 20, UE#D, detects through sensing that PSCCH and / or PSSCH are not being transmitted and transmits PSFCH#D using the resources corresponding to that PSSCH, the PSFCH resources on subchannel #0 that were initially available (i.e., PSFCH#B and PSFCH#C in the example of Figure 12) do not need to be changed. Here, sensing refers to, for example, decoding SCI, measuring signal power such as DMRS, etc.

[0048] Furthermore, if the number X of receiving terminals 20 belonging to the group exceeds the number Y of PSFCHs available for HARQ responses corresponding to PSSCHs used for group casting, the receiving terminals 20 may detect PSFCH resources not used for other HARQ responses through sensing and use them as additional PSFCH resources.

[0049] For example, when option 2 of a groupcast is set or notified, if the number X of receiving terminals 20 exceeds the number Y of PSFCHs, it may be changed to option 1. In this case, the change in option may be explicitly or implicitly notified from the transmitting terminal 20 to the receiving terminals 20, or from the receiving terminals 20 to the transmitting terminal 20. The transmitting terminal 20 may, additionally or alternatively, apply the change in option to each groupcast transmission and / or reception.

[0050] In the above embodiment, the transmitting terminal 20 and the receiving terminal 20 can configure the PSFCH resource that receives or transmits the HARQ response corresponding to the PSSCH based on the parameters of the resource pool. Furthermore, in option 2, where an ACK or NACK is sent, the transmitting terminal 20 can detect when the HARQ response of the groupcast is DTX, thereby improving the reliability of the communication.

[0051] In other words, responses related to retransmission control can be appropriately sent and received during direct communication between terminals.

[0052] (Device configuration) Next, we will describe an example of the functional configuration of the base station 10 and terminal 20 that perform the processes and operations described above. The base station 10 and terminal 20 include functions to implement the embodiments described above. However, the base station 10 and terminal 20 may each have only some of the functions in the embodiments.

[0053] <Base station 10> Figure 13 shows an example of the functional configuration of a base station 10. As shown in Figure 13, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 13 is merely an example. The names of the functional categories and functional units can be anything as long as they can perform the operations according to the embodiment of the present invention.

[0054] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 and obtaining information from the received signals, for example, information from a higher layer. The transmitting unit 110 also has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0055] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads it from the storage device as needed. The contents of the setting information include, for example, information related to D2D communication settings.

[0056] As described in the embodiment, the control unit 140 performs processing related to the settings for the terminal 20 to perform D2D communication. The control unit 140 also transmits the D2D communication scheduling to the terminal 20 via the transmission unit 110. The signal transmission functions of the control unit 140 may be included in the transmission unit 110, and the signal reception functions of the control unit 140 may be included in the reception unit 120.

[0057] <Terminal 20> Figure 14 shows an example of the functional configuration of terminal 20. As shown in Figure 14, terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Figure 14 is merely an example. The names of the functional categories and functional units can be anything as long as they can perform the operations according to the embodiment of the present invention.

[0058] The transmitting unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and acquires signals from higher layers from the received physical layer signals. The receiving unit 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals transmitted from the base station 10. For example, 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 as D2D communication, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0059] The setting unit 230 stores various setting information received from the base station 10 or terminal 20 by the receiving unit 220 in its storage device and reads it from the storage device as needed. The setting unit 230 also stores pre-configured setting information. The content of the setting information is, for example, information related to D2D communication settings.

[0060] The control unit 240 controls D2D communication with other terminals 20, as described in the embodiment. The control unit 240 also performs processing related to HARQ for D2D communication. The control unit 240 may also schedule D2D communication with other terminals 20. The signal transmission function unit of the control unit 240 may be included in the transmission unit 210, and the signal reception function unit of the control unit 240 may be included in the reception unit 220.

[0061] (Hardware configuration) The block diagrams (Figures 13 and 14) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the one or more devices with software.

[0062] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. As mentioned above, the method of implementation is not particularly limited.

[0063] For example, the base station 10, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 15 is a diagram showing an example of the hardware configuration of the base station 10 and terminal 20 according to one embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 may 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, etc.

[0064] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0065] Each function in the base station 10 and terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of the reading and writing of data in the storage device 1002 and auxiliary storage device 1003.

[0066] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0067] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes a computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station 10 shown in Figure 13 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in Figure 14 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-described processes have been explained as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunications line.

[0068] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: 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, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of this disclosure.

[0069] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0070] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include high-frequency switches, duplexers, filters, frequency synthesizers, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the transmitting and receiving antennas, amplifier section, transmitting and receiving section, transmission path interface, etc., may be implemented by the communication device 1004. The transmitting and receiving section may be implemented in a physically or logically separated manner, with a transmitting section and a receiving section.

[0071] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0072] Furthermore, each device, such as the processor 1001 and the storage device 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0073] Furthermore, the base station 10 and 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), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0074] (Summary of the embodiments) As described above, according to an embodiment of the present invention, a transmission unit is provided that transmits data to a plurality of other terminals via a physical shared channel located in a resource pool; a control unit identifies a resource where a channel used for sending and receiving responses related to retransmission control corresponding to the data is located; and a receiving unit in the identified resource receives responses related to retransmission control corresponding to the data from the other terminals, wherein the control unit is provided with a terminal that determines some of the plurality of other terminals to which the responses related to retransmission control are transmitted if the responses related to retransmission control include an affirmative response or a negative response and the number of the plurality of other terminals is greater than the number of resources located therein.

[0075] With the above configuration, the transmitting terminal 20 and the receiving terminal 20 can configure the PSFCH resource that receives or transmits the HARQ response corresponding to the PSSCH based on the parameters of the resource pool. Furthermore, in option 2, where an ACK or NACK is sent, the transmitting terminal 20 can detect when the HARQ response of the groupcast is DTX, thereby improving the reliability of the communication. In other words, responses related to retransmission control can be appropriately sent and received in direct communication between terminals.

[0076] The control unit may determine, based on the identifier of each of the plurality of other terminals, some of the plurality of other terminals to which the response related to the retransmission control will be transmitted. With this configuration, the response related to the retransmission control can be appropriately sent and received in direct communication between terminals.

[0077] The control unit may determine some of the multiple other terminals to which it will transmit the response related to the retransmission control, based on the distance between its own terminal and each of the multiple other terminals. With this configuration, responses related to retransmission control can be appropriately sent and received in direct communication between terminals.

[0078] The control unit may change a threshold value relating to the distance between its own terminal and each of the multiple other terminals, which determines some of the multiple other terminals to which the response related to retransmission control is transmitted, based on the number of the multiple other terminals and the number of resources to which the multiple other terminals are located. With this configuration, responses related to retransmission control can be appropriately sent and received in direct terminal-to-terminal communication.

[0079] The control unit may identify a resource associated with a non-transmitting physical shared channel detected by sensing as a resource where a channel used for sending and receiving responses related to retransmission control corresponding to the data is located. This configuration enables appropriate sending and receiving of responses related to retransmission control in direct communication between terminals.

[0080] Furthermore, according to an embodiment of the present invention, a terminal is provided which includes a receiving unit that receives data from other terminals via a physical shared channel located in a resource pool, a control unit that identifies a resource where a channel used for sending and receiving responses related to retransmission control corresponding to the data is located, and a transmitting unit that transmits a response related to retransmission control corresponding to the data to the other terminal in the identified resource, wherein the control unit is provided with a terminal that determines some of the plurality of other terminals to which the response related to retransmission control is transmitted if the response related to retransmission control includes an affirmative response or a negative response, and the number of terminals to which the other terminals are destinations is greater than the number of resources located.

[0081] With the above configuration, the transmitting terminal 20 and the receiving terminal 20 can configure the PSFCH resource that receives or transmits the HARQ response corresponding to the PSSCH based on the parameters of the resource pool. Furthermore, in option 2, where an ACK or NACK is sent, the transmitting terminal 20 can detect when the HARQ response of the groupcast is DTX, thereby improving the reliability of the communication. In other words, responses related to retransmission control can be appropriately sent and received in direct communication between terminals.

[0082] (Supplement to the embodiment) While embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. Regarding the processing procedures described in the embodiments, the order of processing may be changed as long as it does not contradict each other. For the convenience of explaining the processing, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to an embodiment of the present invention and the software operated by the processor of the terminal 20 according to an embodiment of the present invention may 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, or any other suitable storage medium.

[0083] Furthermore, the notification of information is not limited to the embodiments / models described herein and may be carried out by other methods. For example, the notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0084] Each aspect / embodiment described in this disclosure may be applied to at least one of the following systems: 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), and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0085] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0086] In this specification, specific operations performed by the base station 10 may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station 10, it is clear that various operations performed for communication with the terminal 20 can be performed by the base station 10 and at least one of the other network nodes (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station 10, the other network node may be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0087] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0088] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0089] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0090] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0091] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0092] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0093] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0094] The terms “system” and “network” as used in this disclosure are interchangeable.

[0095] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0096] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0097] In this disclosure, terms such as "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", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0098] A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into several smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0099] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0100] A mobile station may also be referred to by those skilled in the art as a 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 several other appropriate terms.

[0101] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. 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 vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operation. 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.

[0102] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminals 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0103] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

[0104] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in a table, database, or other data structure), and ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0105] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0106] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

[0107] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0108] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

[0109] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0110] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0111] A wireless frame may consist of one or more frames in the time domain. Each of these frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0112] Numerical logic may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerical logic may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0113] A slot may consist of one or more symbols in the time domain (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A slot may also be a time unit based on neurology.

[0114] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0115] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0116] For example, one subframe may be called a Transmission Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one mini-slot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, mini-slot, etc., instead of a subframe.

[0117] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each terminal 20 to allocate wireless resources (such as the frequency bandwidth and transmission power available to each terminal 20) in TTI units. However, the definition of TTI is not limited to this.

[0118] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0119] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled.

[0120] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0121] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0122] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0123] Furthermore, the time domain of RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0124] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0125] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0126] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a particular neurology system in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. A Bandwidth Part (PRB) may be defined and numbered within a given BWP.

[0127] A BWP may include a BWP for UL (Ultraviolet Link) and a BWP for DL ​​(Download Link). One or more BWPs may be set for a terminal 20 within a single carrier.

[0128] At least one of the configured BWPs may be active, and terminal 20 does not need to be expected to send or receive a predetermined signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0129] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within a TTI can be varied in various ways.

[0130] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0131] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0132] Each aspect / embodiment described herein may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0133] In this disclosure, the HARQ response is an example of a response related to retransmission control. PSSCH is an example of a physical shared channel. PSFCH is an example of a channel used for sending and receiving responses related to retransmission control. PSCCH is an example of a physical control channel.

[0134] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way.

[0135] <Note> The embodiments described above can also be further described as follows (see addendum).

[0136] (Note 1) A transmission unit that transmits data to multiple other terminals via a physical shared channel located in a resource pool, A control unit that identifies a resource where a channel used for sending and receiving responses related to retransmission control corresponding to the aforementioned data is located, The identified resource includes a receiving unit that receives a response related to retransmission control corresponding to the data from the other terminal, The control unit determines which of the multiple other terminals to which the response relating to the retransmission control is transmitted, if the response relating to the retransmission control includes an affirmative response or a negative response, and the number of the multiple other terminals is greater than the number of resources to be deployed.

[0137] (Note 2) The control unit determines, based on the identifier of each of the plurality of other terminals, some of the plurality of other terminals to which the response relating to the retransmission control is transmitted, as described in Appendix 1.

[0138] (Note 3) The control unit determines, based on the distance between itself and each of the other terminals, some of the other terminals to which the response relating to the retransmission control is transmitted, as described in Appendix 1.

[0139] (Note 4) The control unit modifies a threshold value relating to the distance between its own terminal and each of the multiple other terminals, based on the number of the multiple other terminals and the number of resources to be deployed, to determine some of the multiple other terminals to which the response relating to the retransmission control is transmitted.

[0140] (Note 5) The terminal according to Appendix 1, wherein the control unit identifies a resource associated with a non-transmitting physical shared channel detected by sensing as a resource where a channel used for sending and receiving responses related to retransmission control corresponding to the data is located.

[0141] (Note 6) A receiving unit that receives data from other terminals via a physical shared channel located in a resource pool, A control unit that identifies a resource where a channel used for sending and receiving responses related to retransmission control corresponding to the aforementioned data is located, The identified resource includes a transmitting unit that transmits a response related to retransmission control corresponding to the data to the other terminal, The control unit determines a portion of the terminals to which the data is to be sent to transmit the response related to the retransmission control, if the response related to the retransmission control includes an affirmative response or a negative response, and the number of terminals to which the data is to be sent is greater than the number of resources to which the data is to be deployed. [Explanation of Symbols]

[0142] 10 base station 110 Transmitter 120 Receiver 130 Setting section 140 Control Unit 20 devices 210 Transmitter 220 Receiver 230 Setting section 240 Control Unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

1. A receiving unit that receives data transmitted via Groupcast from other terminals, The resources used for sending and receiving responses related to retransmission control corresponding to the aforementioned data are The slot index of the aforementioned data, Subchannel index of the aforementioned data, The number of subchannels in the aforementioned resource, The transmission period of the response related to the retransmission control, Source ID in Layer 1, Device identification ID within the group, A control unit that determines based on at least one of the following: and the number of resources in the code area of ​​the response related to the retransmission control, A transmission unit that transmits a response related to retransmission control corresponding to the data to the other terminal in the resource determined above, Equipped with, The control unit determines the circular shift index of the code area of ​​a resource by performing a modulo operation on the number of resources in the code area using the terminal identification ID within the group.

2. The terminal according to claim 1, which allows at least one of the frequency domain and code domain of the resource to be different among the multiple terminals in the groupcast.

3. The terminal according to claim 1 or 2, which enables the transmission of a positive or negative response as a response related to the retransmission control when the number of terminals in the group cast is less than or equal to the number of resources for the response related to the retransmission control.

4. The procedure for receiving data sent via Groupcast from another device, The resources used for sending and receiving responses related to retransmission control corresponding to the aforementioned data are The slot index of the aforementioned data, Subchannel index of the aforementioned data, The number of subchannels in the aforementioned resource, The transmission period of the response related to the retransmission control, Source ID in Layer 1, Device identification ID within the group, A procedure for determining based on at least one of the following: and the number of resources in the code area of ​​the response relating to the retransmission control, A procedure for sending a response related to retransmission control corresponding to the data to the other terminal in the resource determined above, A communication method for determining the circular shift index of the code area of ​​a resource by performing a modulo operation on the number of resources in the code area using the terminal identification ID within the group in the procedure for making the determination.

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