Terminals and communication methods

Abstract

The terminal includes: a receiving unit that receives data based on direct inter-terminal communication from other terminals; a sending unit that sends a response related to retransmission control corresponding to the data to the other terminals; and a control unit that, when the receiving unit receives multiple data based on direct inter-terminal communication, determines which retransmission control-related response to send to the other terminals based on the multiple retransmission control-related responses.

Description

Technical Field

[0001] This invention relates to terminals and communication methods in wireless communication systems. Background Technology

[0002] In LTE (Long Term Evolution) and its successor systems (e.g., LTE-A (LTE Advanced), NR (New Radio) (also known as 5G)), D2D (Device to Device) technology, which enables direct communication between terminals without going through a base station, is being researched (e.g., Non-Patent Literature 1).

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

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

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent document 1: 3GPP TS 36.211V15.6.0 (2019-06)

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

[0009] The problem that the invention aims to solve

[0010] In NR-V2X, support for HARQ (Hybrid Automatic Repeat Request) control is being investigated for direct inter-terminal communication. However, the method for notifying the base station of information related to the HARQ response for the direct inter-terminal communication and the downlink HARQ response from the terminal that initiated the direct inter-terminal communication is still unclear.

[0011] The present invention was made in view of the above, and its object is to properly perform retransmission control in direct communication between terminals.

[0012] Methods for solving problems

[0013] According to the disclosed technology, a terminal is provided, comprising: a receiving unit that receives data based on direct inter-terminal communication from other terminals; a sending unit that sends a response related to retransmission control corresponding to the data to the other terminals; and a control unit that, when the receiving unit receives multiple data based on direct inter-terminal communication, determines the retransmission control-related response to be sent to the other terminals based on multiple retransmission control-related responses.

[0014] Invention Effects

[0015] According to publicly available technology, retransmission control can be appropriately implemented in direct communication between terminals. Attached Figure Description

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

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

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

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

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

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

[0022] Figure 7 This is a diagram illustrating example (1) of the communication types in V2X.

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

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

[0025] Figure 10 This is a diagram illustrating the structure and operation (1) of a wireless communication system according to an embodiment of the present invention.

[0026] Figure 11 This is a diagram illustrating an example of transmitting a HARQ-ACK codebook.

[0027] Figure 12 This is a diagram illustrating an example of the HARQ-ACK sequence.

[0028] Figure 13 This is a diagram used to illustrate DAI.

[0029] Figure 14 This is a diagram illustrating the structure and operation (2) of the wireless communication system in an embodiment of the present invention.

[0030] Figure 15 This is a diagram illustrating an example of the functional structure of base station 10 in an embodiment of the present invention.

[0031] Figure 16 This is a diagram illustrating an example of the functional structure of terminal 20 in an embodiment of the present invention.

[0032] Figure 17 This is a diagram illustrating an example of the hardware structure of a base station 10 or a terminal 20 in an embodiment of the present invention. Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are merely examples, and the application of the present invention is not limited to the embodiments described below.

[0034] When the wireless communication system according to the embodiments of the present invention is in operation, existing technologies are appropriately used. However, the existing technology is, for example, existing LTE, but is not limited to existing LTE. In addition, unless otherwise stated, the term "LTE" as used in this specification has a broad meaning that includes LTE-Advanced and LTE-Advanced and beyond (e.g., NR) or wireless LAN (Local Area Network).

[0035] Furthermore, in embodiments of the present invention, the duplex mode can be TDD (Time Division Duplex), FDD (Frequency Division Duplex), or other modes (e.g., Flexible Duplex).

[0036] Furthermore, in embodiments of the present invention, the "configure" wireless parameters can be pre-configured predetermined values, or wireless parameters notified from the base station 10 or the terminal 20.

[0037] Figure 1 This diagram illustrates V2X. Within 3GPP, technologies for implementing V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality are being researched and standardized. Figure 1 As shown, V2X is a part of ITS (Intelligent Transport Systems). It is a collective term for V2V (Vehicle to Vehicle), V2I (Vehicle to Infrastructure), V2N (Vehicle to Network), and V2P (Vehicle to Pedestrian), which are communication forms between vehicles, roadside units (RSUs) located beside the road, ITS servers.

[0038] Furthermore, 3GPP is researching V2X using LTE or NR cellular communication and terminal-to-terminal communication. V2X using cellular communication is also referred to as cellular V2X. In NR V2X, research is underway to achieve high capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0039] Regarding V2X for LTE or NR, it is envisioned that future research could be advanced beyond 3GPP specifications. For example, research is envisioned on ensuring interoperability, reducing costs incurred due to higher-level installations, methods for the concurrent use or switching of multiple RATs (Radio Access Technologies), regulatory support in various countries, and methods for data acquisition, distribution, database management, and usage on LTE or NR V2X platforms.

[0040] In the embodiments of the present invention, the communication device is primarily envisioned to be mounted on a vehicle; however, the embodiments of the present invention are not limited to this method. 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.

[0041] Additionally, SL (Sidelink) can also be distinguished by UL (Uplink) or DL ​​(Downlink) and any one or a combination of 1)-4) below. Furthermore, SL can also be other names.

[0042] 1) Resource allocation in the time domain

[0043] 2) Frequency domain resource allocation

[0044] 3) Reference synchronization signals (including SLSS (Sidelink Synchronization Signal))

[0045] 4) Reference signal used in path loss measurement for transmission power control

[0046] In addition, for SL or UL OFDM (Orthogonal Frequency Division Multiplexing), any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transformation precoding, or OFDM with transformation precoding can be used.

[0047] In LTE's SL (Send-On) architecture, two modes, Mode 3 and Mode 4, are specified for resource allocation to terminal 20. In Mode 3, transmission resources are dynamically allocated using the DCI (Downlink Control Information) sent from base station 10 to terminal 20. Furthermore, Mode 3 also enables SPS (Semi-Persistent Scheduling). In Mode 4, terminal 20 autonomously selects transmission resources from the resource pool.

[0048] In addition, the slot in the embodiments of the present invention can also be replaced by symbol, mini slot, subframe, radio frame, or TTI (Transmission Time Interval). Furthermore, the cell in the embodiments of the present invention can also be replaced by cell group, carrier component, BWP, resource pool, resource, RAT (Radio Access Technology), system (including wireless LAN), etc.

[0049] Figure 2 This is a diagram used to illustrate example (1) of the V2X transmission mode. In Figure 2 In the sidelink communication transmission mode shown, in step 1, base station 10 sends sidelink scheduling information to terminal 20A. Then, terminal 20A, based on the received scheduling information, sends PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to terminal 20B (step 2). Alternatively... Figure 2 The sidelink communication transmission mode shown is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 of LTE, sidelink scheduling is performed based on Uu. Uu refers to the radio interface between the UTRAN (Universal Terrestrial Radio Access Network) and the UE (User Equipment). Alternatively, it can also be... Figure 2 The sidelink communication transmission mode shown is called sidelink transmission mode 1 in NR.

[0050] Figure 3 This is a diagram illustrating example (2) of the V2X transmission mode. In Figure 3In the side-link communication transmission mode shown, in step 1, terminal 20A uses autonomously selected resources to send PSCCH and PSSCH to terminal 20B. Alternatively... Figure 3 The sidelink communication transmission mode shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0051] Figure 4 This is a diagram used to illustrate example (3) of the V2X transmission mode. In Figure 4 In the side-link communication transmission mode shown, in step 1, terminal 20A sends PSCCH and PSSCH to terminal 20B using autonomously selected resources. Similarly, terminal 20B sends PSCCH and PSSCH to terminal 20A using autonomously selected resources (step 1). Alternatively... Figure 4 The sidelink communication transmission mode shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2a in NR, terminal 20 performs resource selection itself.

[0052] Figure 5 This is a diagram used to illustrate example (4) of the V2X transmission mode. In Figure 5 In the sidelink communication transmission mode shown, in step 0, base station 10 sends a sidelink grant to terminal 20A via RRC (Radio Resource Control). Then, terminal 20A sends a PSSCH to terminal 20B according to the received resource mode (step 1). Alternatively... Figure 5 The sidelink communication transmission mode shown is called sidelink transmission mode 2c in NR.

[0053] Figure 6 This is a diagram used to illustrate the transmission mode of V2X (5). Figure 6 This is a diagram used to illustrate example (5) of the V2X transmission mode. In Figure 6 In the sidelink communication transmission mode shown, in step 1, terminal 20A sends the sidelink schedule to terminal 20B via PSCCH. Then, terminal 20B sends PSSCH to terminal 20A according to the received schedule information (step 2). Alternatively... Figure 6 The sidelink communication transmission mode shown is called sidelink transmission mode 2d in NR.

[0054] Figure 7 This is a diagram illustrating example (1) of the communication types in V2X. Figure 7 The communication type of the side link shown is unicast. Terminal 20A sends PSCCH and PSSCH to terminal 20. Figure 7In the example shown, terminal 20A unicasts to terminal 20B and unicasts to terminal 20C.

[0055] Figure 8 This is a diagram used to illustrate example (2) of the V2X communication type. Figure 8 The sidelink communication type 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 terminal 20B and terminal 20C, and terminal 20A multicasts to the group.

[0056] Figure 9 This is a diagram used to illustrate the communication type of V2X (3). Figure 9 The communication type of the side link shown is broadcast. Terminal 20A sends PSCCH and PSSCH to one or more terminals 20. Figure 9 In the example shown, terminal 20A broadcasts to terminals 20B, 20C, and 20D. Alternatively, it can also... Figures 7-9 The terminal 20A shown is called the header UE.

[0057] Furthermore, NR-V2X envisions supporting HARQ in unicast and multicast on sidelinks. Additionally, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Moreover, the transmission of SFCI via PSFCH (Physical Sidelink Feedback Channel) is under investigation.

[0058] Furthermore, in the following explanation, it is assumed that PSFCH is used for HARQ-ACK transmission in the side link, but this is only one example. For example, PSCCH, PSSCH, or other channels can be used for HARQ-ACK transmission in the side link.

[0059] As described above, supporting HARQ actions in NR-V2X is envisioned. However, the envisioned architecture for NR-V2X does not propose a specific scheme regarding how to multiplex and transmit multiple HARQ-ACKs corresponding to SL and DL data. Nor does it propose a specific scheme regarding the structure of the HARQ codebook corresponding to SL and DL data. Furthermore, no specific scheme is proposed regarding the payload size for transmitting the HARQ-ACKs corresponding to SL and DL data. Therefore, in the prior art, there is a problem of not being able to properly implement multiple HARQ-ACK reports.

[0060] For ease of explanation, all information reported by terminal 20 in HARQ will be referred to as HARQ-ACK. This HARQ-ACK can also be called HARQ-ACK information. More specifically, the codebook used for the HARQ-ACK information reported from terminal 20 to base station 10, etc., is called the HARQ-ACK codebook. The HARQ-ACK codebook specifies the bit string of the HARQ-ACK information. In addition to ACK, NACK is also sent using "HARQ-ACK".

[0061] (Example 1)

[0062] In Example 1, Figure 2 In the side-link transmission mode 1 shown, terminal 20B, which receives SL data using PSSCH, sends a HARQ-ACK to terminal 20A, which sent the data, using PSFCH. Furthermore, terminal 20A sends a HARQ-ACK containing this HARQ-ACK to base station 10.

[0063] <Structural Example of Embodiment 1>

[0064] Figure 10 This is a diagram illustrating the structure (and operation) of the wireless communication system in Embodiment 1. The same structure can be implemented in Embodiment 2.

[0065] like Figure 10 As shown, the wireless communication system of this embodiment 1 includes a base station 10, a terminal 20A, and a terminal 20B. In addition, there are actually multiple user devices, but... Figure 10 Terminals 20A and 20B are shown as examples.

[0066] Hereinafter, without specifically distinguishing between terminals 20A, 20B, etc., they will simply be referred to as "Terminal 20" or "User Equipment". Figure 10 As an example, the example shows a situation where both terminal 20A and terminal 20B are within the coverage area of ​​the cell, but the actions in Example 1 can also be applied to a situation where terminal 20B is outside the coverage area.

[0067] As described above, in this embodiment, terminal 20 is, for example, a device mounted in a vehicle such as an automobile, and has cellular communication functions as a UE in LTE or NR, as well as sidelink functions. Terminal 20 can also be a general portable terminal (such as a smartphone). Furthermore, terminal 20 can also be an RSU. This RSU can be a UE-type RSU with UE functions, or a gNB-type RSU with base station functions.

[0068] In addition, terminal 20 does not need to be a device with a housing. For example, even if various sensors are distributed throughout the vehicle, the device including these various sensors is also terminal 20.

[0069] Furthermore, the processing of data transmitted via the sidelink of terminal 20 is essentially the same as that of UL transmission in LTE or NR. For example, user equipment 20 scrambles and modulates the codewords of the transmitted data to generate complex-valued symbols, maps these complex-valued symbols (transmitted signals) to layer 1 or layer 2, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate a transmitted signal (e.g., complex-valued time-domain SC-FDMA signal) and transmitted from each antenna port.

[0070] Furthermore, base station 10 has cellular communication functions as a base station in LTE or NR, and functions for enabling terminal 20 in this embodiment to communicate (e.g., resource pool setting, resource allocation, etc.). Additionally, base station 10 can also be an RSU (gNB type RSU).

[0071] Furthermore, in the wireless communication system of Embodiment 1, the signal waveform used by terminal 20 in SL or UL can be OFDMA, SC-FDMA, or other signal waveforms.

[0072] <Example of Action in Example 1>

[0073] Reference Figure 10 An example of the operation of the wireless communication system in Embodiment 1 is explained.

[0074] In S101, base station 10 uses PDCCH to send DCI (Downlink Control Information) to terminal 20A, thereby performing SL scheduling. For ease of explanation, the DCI used for SL scheduling will be referred to as SL scheduling DCI.

[0075] Furthermore, in this embodiment 1, the following scenario is envisioned: In S101, base station 10 also sends a DCI for DL ​​scheduling (also known as DL allocation) to terminal 20A using PDCCH. Hereinafter, for ease of explanation, the DCI for DL ​​scheduling will be referred to as DL scheduling DCI. Terminal 20A, upon receiving the DL scheduling DCI, uses the resources specified by the DL scheduling DCI to receive DL data using PDSCH.

[0076] In S102 and S103, terminal 20A uses the resources specified by the SL scheduling DCI to send SCI (Sidelink Control Information) via PSCCH and SL data via PSSCH. Alternatively, the SL scheduling DCI can specify only the PSSCH resources. In this case, for example, terminal 20A can send SCI (PSCCH) using the same time resources as the PSSCH and the frequency resources adjacent to the PSSCH frequency resources.

[0077] Terminal 20B receives SCI (PSCCH) and SL data (PSSCH) sent from terminal 20A. The SCI received using PSCCH contains information about the resources of PSFCH for terminal 20B to send HARQ-ACK for the received data.

[0078] The information about this resource is included in the DL scheduling DCI or SL scheduling DCI sent from base station 10 in S101. Terminal 20A can also obtain the information about this resource from the DL scheduling DCI or SL scheduling DCI and include it in the SCI. Alternatively, assuming that the DCI sent from base station 10 does not contain the information about this resource, terminal 20A can autonomously include the information about this resource in the SCI and send it.

[0079] In S104, terminal 20B uses the resources of PSFCH specified by the received SCI to send a HARQ-ACK for the received data to terminal 20A.

[0080] In S105, terminal 20A, for example, at a timing specified by the DL scheduling DCI (or SL scheduling DCI) (e.g., timing in time slots), uses the PUCCH resources specified by the DL scheduling DCI (or the SL scheduling DCI) to send a HARQ-ACK, which is received by base station 10. The codebook of this HARQ-ACK may include the HARQ-ACK received from terminal 20B and the HARQ-ACK for DL ​​data. However, in cases where no DL data is allocated, etc., the HARQ-ACK for DL ​​data is not included.

[0081] <Example 1: Processing related to the HARQ-ACK codebook>

[0082] The following provides a more detailed example of the structure of the HARQ-ACK codebook sent by terminal 20A to base station 10.

[0083] <Construction>

[0084] The DL scheduling DCI and SL scheduling DCI received by terminal 20A each contain the value of the PDSCH / PDCCH-to-HARQ_feedback timing indicator field. If this value represents the same time slot in both the DL scheduling DCI and SL scheduling DCI, terminal 20A uses the same PUCCH resources to send HARQ-ACK for DL ​​data and HARQ-ACK for SL data (the HARQ-ACK received by terminal 20A from terminal 20B in S104). That is, in this case, terminal 20A includes the HARQ-ACK for DL ​​data and the HARQ-ACK for SL data (the HARQ-ACK received by terminal 20A in S104) in a single HARQ-ACK codebook and sends this HARQ-ACK codebook.

[0085] The “PDSCH / PDCCH-to-HARQ_feedback timing indicator field” mentioned above refers to either the “PDSCH-to-HARQ_feedback timing indicator field” or the “PDCCH-to-HARQ_feedback timing indicator field”.

[0086] The “PDSCH-to-HARQ_feedback timing indicator field” is a field included in the DL scheduling DCI. This value represents the HARQ feedback timing (e.g., the number of time slots) from the reception of PDSCH (DL data).

[0087] The "PDCCH-to-HARQ_feedback timing indicator field" is a field included in the SL scheduling DCI, and its value represents the HARQ feedback timing (e.g., the number of time slots) from the reception of the PDCCH (this SL scheduling DCI).

[0088] The above are only examples. The DL scheduling DCI may also include the "PDCCH-to-HARQ_feedback timing indicator field", and the SL scheduling DCI may also include the "PDSCH-to-HARQ_feedback timing indicator field".

[0089] The above processing content can be replaced, for example, with "The value of the PDSCH-to-HARQ_feedback timing indicator field is included in the DL scheduling DCI received by the terminal 20A, and the value of the PDCCH-to-HARQ_feedback timing indicator field is included in the SL scheduling DCI. When these values indicate the same time slot as the HARQ feedback timing, the terminal 20A uses the same PUCCH resource to send the HARQ-ACK for the DL data and the HARQ-ACK for the SL data (the HARQ-ACK received by the terminal 20A in S104)".

[0090] [[ID=u11]] Figure 11 An example of DCI reception and HARQ-ACK transmission in the terminal 20A is shown. In Figure 11 DCI 1 represents the DL scheduling DCI, and DCI 2 represents the SL scheduling DCI. In Figure 11 For example, in time slot 1, the terminal 20A receives DCI 1 and DCI 2. When they both indicate time slot 5 as the HARQ feedback timing, the terminal 20A uses the PUCCH resource 1 to send a HARQ-ACK codebook including the HARQ-ACK for the DL data and the HARQ-ACK for the SL data to the base station 10.

[0091] <Order of HARQ-ACK>

[0092] Regarding the order of HARQ-ACK when the terminal 20 generates a HARQ-ACK codebook including the HARQ-ACK for the DL data and the HARQ-ACK for the SL data, there are the following options A, B, and C.

[0093] Option A) In Option A, for example, as Figure 12As shown in (a), the HARQ-ACK for DL ​​data is first stored (in Figure 12 In the middle, it is denoted as Uu HARQ-ACK), and then the HARQ-ACK for SL data is stored (denoted as SL HARQ-ACK).

[0094] Option B) In option B, for example, such as Figure 12 As shown in (b), the HARQ-ACK for SL data is stored first, followed by the HARQ-ACK for DL ​​data.

[0095] In addition, Figure 12 The example shows the case where the HARQ-ACK codebook consists of 4 bits of HARQ-ACK information bits, and as an example, it shows the case where all bits are 1. Furthermore, it envisions... Figure 12 The left end of the HARQ-ACK codebook shown indicates the starting point in the order in which the bits of the HARQ-ACK codebook are arranged, with the bits arranged from left to right. Also, this is just one example.

[0096] In addition, Figure 12 In the example, terminal 20A is envisioned sending SL data (PSSCH) to multiple user devices and receiving HARQ-ACK for the SL data from the multiple user devices.

[0097] When terminal 20A receives HARQ-ACKs for SL data from multiple user equipments and stores the HARQ-ACKs from each user equipment in the bits of the HARQ-ACK codebook, the order in which the HARQ-ACKs from the multiple user equipments are arranged in the HARQ-ACK codebook can be determined, for example, based on the UE-IDs of the multiple user equipments (e.g., in descending order of IDs or in ascending order of IDs). Alternatively, when terminal 20A receives SL scheduling DCIs for multiple user equipments from base station 10 for sending SL data to multiple user equipments, the order in which the HARQ-ACKs from the multiple user equipments are arranged in the HARQ-ACK codebook can be determined according to the time order in which the SL scheduling DCIs are received, or according to the time order in which each SCI sent to the multiple user equipments is sent.

[0098] Option C) In option C, instead of the predetermined order determination method as described above, the order is specified in the DL schedule DCI or SL schedule DCI received by terminal 20A, and the order is determined according to the specification.

[0099] <dai>

[0100] The DCI for DL scheduling (or the DCI for SL scheduling) includes DAI (Downlink assignment index). Figure 13 It is a diagram for explaining an example of DAI. In Figure 13 the example, an example of the following situation is shown: A setting for terminal 20A is made such that HARQ-ACK for DL data received in slot 6 (DL) and DL data received in slot 7 (DL) is transmitted in slot 9 (UL). In this case, as an example, DCI for allocating DL data received in slot 6 includes 1 as DAI, and DCI for allocating DL data received in slot 7 includes 2 as DAI. Thus, terminal 20A can determine whether it has received DL data corresponding to the HARQ-ACK to be transmitted in slot 9. Regarding DAI, there are the following options D and option E.

[0101] Option D) In option D, the SL scheduling DCI sent from base station 10 to terminal 20A does not include DAI, and the DAI included in the DL scheduling DCI has no association with the HARQ-ACK for SL data.

[0102] In this case, regarding terminal 20B that receives SL data in the PSSCH, for example, it may be that terminal 20A includes the DAI for SL data in the SCI sent through the PSCCH, and terminal 20B obtains the DAI from the SCI and uses it.

[0103] Option E) In option E, the SL scheduling DCI sent from base station 10 to terminal 20A includes DAI. This DAI is included in the SCI and sent from terminal 20A to terminal 20B using the PSCCH, and terminal 20B uses this DAI to perform SL HARQ-ACK transmission. Regarding the transmission of HARQ-ACK for DL data, terminal 20A uses the DAI included in the DL scheduling DCI.

[0104] <PUCCH resource>

[0105] Regarding the PUCCH resource, there are the following options F to H.

[0106] In option F, in terminal 20A, the PUCCH resource for sending a HARQ-ACK codebook containing both HARQ-ACK for DL ​​data and HARQ-ACK for SL data (or, containing either HARQ-ACK for DL ​​data or HARQ-ACK for SL data) is determined by the last received DCI among multiple DL-scheduled DCIs having a PDSCH-to-HARQ_feedbacktiming indicator field specifying the same time slot.

[0107] That is, for example, terminal 20A receives DCI-A, DCI-B, and DCI-C sequentially as DL scheduling DCIs. When DCI-A, DCI-B, and DCI-C each contain values ​​specifying the same time slot as PDSCH-to-HARQ_feedback timing, terminal 20A uses the PUCCH resources contained in DCI-C to send the HARQ-ACK codebook in that time slot.

[0108] In option G, in terminal 20A, the PUCCH resource for sending a HARQ-ACK codebook containing both HARQ-ACK for DL ​​data and HARQ-ACK for SL data (or, containing either HARQ-ACK for DL ​​data or HARQ-ACK for SL data) is determined by the last received DCI among multiple SL scheduled DCIs having a PDSCH / PDCCH-to-HARQ_feedback timing indicator field specifying the same time slot.

[0109] That is, for example, if terminal 20A receives DCI-A, DCI-B, and DCI-C sequentially as SL scheduling DCIs, and DCI-A, DCI-B, and DCI-C each contain a value specifying the same time slot as the PDSCH / PDCCH-to-HARQ_feedback timing indicator field, terminal 20A uses the PUCCH resources contained in DCI-C to send the HARQ-ACK codebook in that time slot.

[0110] In option H, in terminal 20A, the PUCCH resource for sending a HARQ-ACK codebook containing HARQ-ACK for DL ​​data and HARQ-ACK for SL data (or, containing HARQ-ACK for DL ​​data or HARQ-ACK for SL data) is determined by one or more SL-scheduled DCIs having a PDSCH / PDCCH-to-HARQ_feedback timing indicator field specifying the same time slot, and the last received DCI among one or more DL-scheduled DCIs.

[0111] That is, for example, terminal 20A receives DCI-A and DCI-B sequentially as SL-scheduled DCI, and then receives DCI-C as DL-scheduled DCI. When DCI-A, DCI-B, and DCI-C each contain a value specifying the same time slot as the PDSCH / PDCCH-to-HARQ_feedback timing indicator field, terminal 20A uses the PUCCH resources contained in DCI-C to send the HARQ-ACK codebook in that time slot.

[0112] In addition, in cases where PUCCH resources conflict with PUSCH resources (at least when they are allocated to resources at the same time), terminal 20A may send the HARQ-ACK codebook through PUSCH resources instead of using PUCCH resources.

[0113] <Other examples>

[0114] In the example above, the DCI sent from base station 10 to terminal 20A contains information about the PSFCH resources used by terminal 20B to send HARQ-ACK, and the SCI sent from terminal 20A contains information about the PSFCH resources.

[0115] Alternatively, neither the DL scheduling DCI nor the SL scheduling DCI sent from base station 10 to terminal 20A contains information about the PSFCH resources, nor does the SCI sent from terminal 20A contain information about the PSFCH resources.

[0116] In this case, for example, terminal 20B, which receives the SCI corresponding to the SL data, autonomously selects the resources of the PSFCH and uses the selected resources to send a HARQ-ACK for the SL data to terminal 20A.

[0117] In addition, terminal 20A may include a PSFCH resource indicator (PRI) in the SCI sent to terminal 20B, the value of which indicates whether a specified PSFCH resource exists.

[0118] As an example, if PRI = 000, terminal 20B determines that no PSFCH resource is specified and selects a resource independently. Furthermore, for example, if PRI is a value greater than 000 (e.g., 010), terminal 20B selects the PSFCH resource corresponding to that value and uses it for sending HARQ-ACK for SL data.

[0119] (Example 2)

[0120] In Example 2, Figure 2 In the sidelink transmission mode 1 shown, terminal 20B, which receives SL data using PSSCH, sends HARQ-ACK to terminal 20A, which sent the data, using PSFCH. Next, terminal 20A sends a HARQ-ACK containing the HARQ-ACK and a HARQ-ACK related to PDSCH reception to base station 10.

[0121] <Structural Example of Embodiment 2>

[0122] Figure 14 This is a diagram illustrating the structure (and operation) of the wireless communication system in Embodiment 2.

[0123] In S201, base station 10 sends a DCI to terminal 20A using PDCCH, thereby performing SL scheduling. In S202, base station 10 sends a DCI for DL ​​scheduling to terminal 20A using PDCCH. Terminal 20A, upon receiving the DL scheduling DCI, uses the resources specified by the DL scheduling DCI to receive DL data using PDSCH. The execution order of S201 and S202 can be reversed, or S202 can be executed after S203 or S204.

[0124] In S203, terminal 20A uses the resources specified by the SL scheduling DCI to transmit SCI via PSCCH and transmits SL data via PSSCH. Alternatively, in the SL scheduling DCI, only the PSSCH resources can be specified. In this case, for example, terminal 20A can transmit SCI (PSCCH) using the same time resources as the PSSCH and the frequency resources adjacent to the PSSCH frequency resources.

[0125] Terminal 20B receives SCI (PSCCH) and SL data (PSSCH) sent from terminal 20A. The SCI received using PSCCH may contain information about the resources of PSFCH used by terminal 20B to send HARQ-ACK for the received data.

[0126] The information about this resource can be included in the DL scheduling DCI or SL scheduling DCI sent from base station 10 in S201 and S202. Terminal 20A obtains the information about this resource from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, the DCI sent from base station 10 may not include the information about this resource, and terminal 20A may independently include the information about this resource in the SCI and send it.

[0127] In S204, terminal 20B uses the resources of PSFCH specified by the received SCI to send a HARQ-ACK for the received data to terminal 20A.

[0128] In S205, terminal 20A, for example, at a timing specified by the DL scheduling DCI (or SL scheduling DCI) (e.g., timing in time slots), uses the PUCCH resources specified by the DL scheduling DCI (or SL scheduling DCI) to send a HARQ-ACK, which is received by base station 10. The codebook of this HARQ-ACK may include HARQ-ACKs for SL data and HARQ-ACKs for DL ​​data received from terminal 20B. However, in the absence of DL data allocation, HARQ-ACKs for DL ​​data may not be included.

[0129] Here, terminal 20A can use a PUCCH resource to send multiple HARQ-ACK bits, including a HARQ-ACK for SL data. For example, the HARQ-ACK corresponding to DL data can be multiplexed with the HARQ-ACK corresponding to SL data on a single HARQ-ACK codebook.

[0130] For example, the HARQ-ACK corresponding to DL data and the HARQ-ACK corresponding to SL data can be reused using the HARQ-ACK codebook corresponding to DL data.

[0131] For example, a Type 1 HARQ-ACK codebook, which is a semi-static HARQ-ACK codebook, can be applied to both the HARQ-ACK codebook corresponding to DL data and the HARQ-ACK codebook corresponding to SL data. For instance, the HARQ-ACK payload size in this Type 1 HARQ-ACK codebook can be obtained by adding the "payload size of the HARQ-ACK corresponding to DL data" to the "number of PSCCH and PSSCH transmission opportunities fed back at the same timing". Furthermore, if no PDSCH or PSSCH is received during a PDSCH transmission opportunity or a PSSCH transmission opportunity, a NACK can be generated and transmitted.

[0132] Furthermore, for example, a Type 2 HARQ-ACK codebook, which is a dynamic HARQ-ACK codebook, can also be applied to both the HARQ-ACK codebook corresponding to DL data and the HARQ-ACK codebook corresponding to SL data. For example, the HARQ-ACK payload size in this Type 2 HARQ-ACK codebook can be notified to the terminal 20A by the DAI.

[0133] The information notified by DAI can be the PDSCH, plus the counters of the PSCCH and PSSCH sent from the sending UE to the receiving UE, or it can be the sum of the PDSCH and the PSCCH and PSSCH sent from the sending UE to the receiving UE.

[0134] NACK can be generated and sent if the DAI detects an error in the PDCCH.

[0135] By using the HARQ-ACK codebook of type 1 or type 2 mentioned above, terminal 20A can report HARQ-ACK corresponding to DL data and HARQ-ACK corresponding to SL data at any time interval, and can process SL as a CC (Component Carrier) of DL.

[0136] As another example, when multiplexing HARQ-ACK corresponding to DL data and HARQ-ACK corresponding to SL data, the HARQ-ACK codebook related to DL data and the HARQ-ACK codebook related to SL data can be used respectively.

[0137] For example, the HARQ-ACK codebook related to DL data and the HARQ-ACK codebook related to SL data can be set through high-level parameters or defined in advance using specifications.

[0138] For example, regarding the HARQ-ACK codebook related to DL data or the HARQ-ACK codebook related to SL data, the same HARQ-ACK codebook can be applied to one side as to the other. That is, the HARQ-ACK codebook related to DL data can be set in the same way as the HARQ-ACK codebook related to SL data, and vice versa.

[0139] When using HARQ-ACK codebooks related to DL data and SL data respectively, and applying a Type 1 HARQ-ACK codebook (as a semi-static codebook) to the HARQ-ACK codebook related to SL data, the HARQ-ACK payload size of this Type 1 HARQ-ACK codebook can correspond to the number of PSCCH and PSSCH transmission opportunities with the same timing feedback. Furthermore, NACK can also be generated and transmitted even if neither PSCCH nor PSSCH is received during any of the PSCCH and PSSCH transmission opportunities.

[0140] For example, the order of the HARQ-ACK bits in the HARQ-ACK codebook of type 1 can be either the order of HARK-ACK corresponding to DL data and HARQ-ACK corresponding to SL data, or the order of HARK-ACK corresponding to SL data and HARQ-ACK corresponding to DL data.

[0141] When a Type 1 HARQ-ACK codebook is applied to the HARQ-ACK codebook related to SL data, and the PUCCH and PUSCH overlap, and the HARQ-ACK bits are multiplexed on the PUSCH, the DAI included in the UL license can be represented by a 2-bit field indicating the presence of both HARK-ACK corresponding to DL data and HARQ-ACK corresponding to SL data. Alternatively, when the PUCCH and PUSCH overlap, and the HARQ-ACK bits are multiplexed on the PUSCH, the DAI included in the UL license can indicate the presence of either HARK-ACK corresponding to DL data or HARQ-ACK corresponding to SL data. Alternatively, when the PUCCH and PUSCH overlap, and the HARQ-ACK bits are multiplexed on the PUSCH, the DAI included in the UL license can indicate the presence of at least either HARK-ACK corresponding to DL data or HARQ-ACK corresponding to SL data.

[0142] When using separate HARQ-ACK codebooks for DL ​​data and SL data, and applying a Type 2 HARQ-ACK codebook (a dynamic HARQ-ACK codebook) to the SL data-related HARQ-ACK codebook, the HARQ-ACK payload size of this Type 2 HARQ-ACK codebook can be notified by the DAI. The DAI can also perform counting or management separately in the HARQ-ACK codebooks related to DL data and SL data.

[0143] The information notified by DAI can be the PDSCH plus the counters obtained from the PSCCH and PSSCH sent from the sending UE to the receiving UE, or it can be the sum of the PDSCH and the PSCCH and PSSCH sent from the sending UE to the receiving UE.

[0144] NACK can be generated and sent if the DAI detects an error in the PDCCH.

[0145] When a Type 2 HARQ-ACK codebook is applied to the HARQ-ACK codebook related to SL data, and the PUCCH and PUSCH overlap, and the HARQ-ACK bits are multiplexed on the PUSCH, the DAI included in the UL license can be represented by a 2-bit field indicating the presence of both HARK-ACK corresponding to DL data and HARQ-ACK corresponding to SL data. Alternatively, when the PUCCH and PUSCH overlap, and the HARQ-ACK bits are multiplexed on the PUSCH, the DAI included in the UL license can indicate the presence of either HARK-ACK corresponding to DL data or HARQ-ACK corresponding to SL data. Alternatively, when the PUCCH and PUSCH overlap, and the HARQ-ACK bits are multiplexed on the PUSCH, the DAI included in the UL license can indicate the presence of at least either HARK-ACK corresponding to DL data or HARQ-ACK corresponding to SL data.

[0146] As another example, terminal 20B can use a PSFCH resource to send multiple HARQ-ACK bits, including HARQ-ACK for SL data, to terminal 20A.

[0147] When a Type 1 HARQ-ACK codebook, serving as a semi-static HARQ-ACK codebook, is applied to a HARQ-ACK codebook related to SL data, the HARQ-ACK payload size of this Type 1 HARQ-ACK codebook can correspond to the number of PSCCH and PSSCH transmission opportunities in a PSFCH cycle. Furthermore, when CA is applied, the HARQ-ACK payload size of this Type 1 HARQ-ACK codebook can correspond to the value obtained by multiplying the number of PSCCH and PSSCH transmission opportunities in a PSFCH cycle by the CC number. Additionally, NACK can also be generated and transmitted even if no PSCCH or PSSCH is received during any of the PSCCH and PSSCH transmission opportunities. When the aforementioned Type 1 HARQ-ACK codebook, serving as a semi-static HARQ-ACK codebook, is applied to a HARQ-ACK codebook related to SL data, erroneous payload size identification can be prevented.

[0148] Furthermore, when a Type 2 HARQ-ACK codebook, which is a dynamic HARQ-ACK codebook, is applied to a HARQ-ACK codebook related to SL data, the HARQ-ACK payload size of this Type 2 HARQ-ACK codebook can be indicated by the Sidelink Assignment Indicator (hereinafter referred to as "SAI") included in the SCI. The SAI can have the same functionality as the DAI.

[0149] The information notified by SAI can be either a counter added to the PSCCH and PSSCH sent from the sending UE to the receiving UE, or the sum of the PSCCH and PSSCH sent from the sending UE to the receiving UE.

[0150] NACK can be generated and sent if the error detection of PSCCH is detected by SAI.

[0151] When the aforementioned HARQ-ACK codebook of type 2, which is a semi-static HARQ-ACK codebook, is applied to the HARQ-ACK codebook related to SL data, it is possible to prevent the generation of redundant bits.

[0152] The type of HARQ-ACK codebook applied to HARQ-ACK codebooks related to SL data can be defined in advance by the specification, preset, set by RRC signaling, or notified by MAC-CE (Medium Access Control-Control Element), DCI, or SCI.

[0153] In the PSFCH resource, when HARQ-ACKs corresponding to multiple SL data are multiplexed, the PSFCH resource can be associated with the last received SCI, or it can be notified by the last received SCI. Furthermore, when HARQ-ACKs corresponding to multiple SL data are multiplexed in the PSFCH resource, the PSFCH resource can be associated with the first received SCI, or it can be notified by the first received SCI. Additionally, when HARQ-ACKs corresponding to multiple SL data are multiplexed in the PSFCH resource, the PSFCH resource can be associated with the SCI corresponding to the largest sub-channel index among the received SCIs, or it can be notified by the SCI corresponding to the largest sub-channel index among the received SCIs. Furthermore, when HARQ-ACKs corresponding to multiple SL data are multiplexed in the PSFCH resource, the PSFCH resource can be associated with the SCI corresponding to the smallest sub-channel index among the received SCIs, or it can be notified by the SCI corresponding to the smallest sub-channel index among the received SCIs. Furthermore, when HARQ-ACKs corresponding to multiple SL data are multiplexed in a PSFCH resource, this PSFCH resource can be associated with the SCI corresponding to the largest CC index among the received SCIs, or it can be notified by the SCI corresponding to the largest CC index among the received SCIs. By establishing associations as described above, the multiplexed PSFCH for HARQ-ACKs can be shared between the sending and receiving sides.

[0154] Furthermore, the methods for reporting HARQ-ACK from terminal 20A to base station 10 and from terminal 20B to terminal 20A can be combined. That is, the method for reporting HARQ-ACK from terminal 20B to terminal 20A can be further applied to the method for reporting HARQ-ACK from terminal 20A to base station 10, and vice versa.

[0155] According to the above embodiments, terminal 20 can use the HARQ-ACK codebook to multiplex the HARQ-ACK corresponding to SL data and the HARQ-ACK corresponding to DL data to report to base station 10. Furthermore, terminal 20 can use the HARQ-ACK codebook to multiplex the HARQ-ACK corresponding to multiple SL data sets to report to transmitting terminal 20.

[0156] That is, in direct communication between terminals, retransmission control can be appropriately implemented.

[0157] (Device Structure)

[0158] Next, an example of the functional structure of the base station 10 and terminal 20 performing the processes and actions described above will be explained. The base station 10 and terminal 20 include the functions implemented in the above embodiments. However, the base station 10 and terminal 20 may each have only a portion of the functions described in the embodiments.

[0159] <Base Station 10>

[0160] Figure 15 This is a diagram illustrating an example of the functional structure of base station 10. (As shown...) Figure 15 As shown, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130 and a control unit 140. Figure 15 The functional structure shown is only one example. As long as the actions involved in the embodiments of the present invention can be performed, the functional distinctions and names of the functional parts can be arbitrary.

[0161] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher-level information from the received signals. In addition, the transmitting unit 110 has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0162] The setting unit 130 stores preset setting information and various setting information sent to the terminal 20 into a storage device, and reads it from the storage device as needed. The content of the setting information includes, for example, information related to D2D communication settings.

[0163] As described in the embodiment, the control unit 140 performs processing related to the settings for D2D communication by the terminal 20. Furthermore, the control unit 140 sends the scheduling of D2D and DL communication to the terminal 20 via the transmitting unit 110. Additionally, the control unit 140 receives information related to HARQ responses for D2D and DL communication from the terminal 20 via the receiving unit 120. Alternatively, the signal transmission-related functions of the control unit 140 may be included in the transmitting unit 110, and the signal reception-related functions of the control unit 140 may be included in the receiving unit 120.

[0164] Terminal 20

[0165] Figure 16 This is a diagram illustrating an example of the functional structure of terminal 20. (As shown...) Figure 16 As shown, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. Figure 16 The functional structure shown is only one example. As long as the actions involved in the embodiments of the present invention can be performed, the functional distinctions and names of the functional parts can be arbitrary.

[0166] The transmitting unit 210 generates a transmission signal based on the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and obtains higher-layer signals from the received physical layer signals. Furthermore, the receiving unit 220 has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals transmitted from the base station 10. Additionally, for example, as D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc., to other terminals 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH, or PSBCH from other terminals 20.

[0167] The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or the terminal 20 into a storage device, and reads it from the storage device as needed. In addition, the setting unit 230 also stores preset setting information. The content of the setting information includes, for example, information related to D2D communication settings.

[0168] As described in the embodiment, the control unit 240 controls D2D communication with other terminals 20. Furthermore, the control unit 240 performs HARQ processing related to D2D and DL communication. Additionally, the control unit 240 sends information scheduled from the base station 10 related to HARQ responses for D2D and DL communication to other terminals 20. Furthermore, the control unit 240 can also schedule D2D communication with other terminals 20. Alternatively, the signal transmission-related functions of the control unit 240 can be included in the transmitting unit 210, and the signal reception-related functions of the control unit 240 can be included in the receiving unit 220.

[0169] (Hardware Structure)

[0170] The block diagram used in the description of the above embodiments ( Figure 15 and Figure 16 The diagram illustrates blocks organized by function. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Furthermore, there are no particular limitations on the implementation method of each functional block. That is, each functional block can be implemented using a single device that is physically or logically combined, or by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. Functional blocks can also be implemented by combining software with one or more of the aforementioned devices.

[0171] Functionally, it includes functions such as judgment, decision, determination, calculation, calculation, processing, derivation, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but is not limited to these. For example, the functional block (structural part) that enables sending to perform its function is called the transmitting unit or transmitter. In short, as mentioned above, there are no particular limitations on the implementation method.

[0172] For example, in one embodiment of this disclosure, the base station 10, terminal 20, etc., can also function as a computer for processing the wireless communication method of this disclosure. Figure 17 This is a diagram illustrating an example of the hardware structure of a base station 10 and a terminal 20 according to an embodiment of 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, etc.

[0173] Additionally, in the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware structure of base station 10 and terminal 20 can be configured to include one or more of the devices shown in the figures, or it can be configured to not include any of them.

[0174] The functions of the base station 10 and the terminal 20 are implemented by reading predetermined software (programs) into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs calculations and controls the communication of the communication device 1004 or controls at least one of reading out and writing data in the storage device 1002 and the auxiliary storage device 1003.

[0175] The processor 1001 controls the computer as a whole, for example, by enabling the operating system to function. The processor 1001 may also be a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc. For example, the aforementioned control unit 140, control unit 240, etc., can also be implemented using the processor 1001.

[0176] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage devices 1003 and communication devices 1004, and performs various processes accordingly. As a program, a program is used that causes the computer to perform at least a portion of the actions described in the above embodiments. For example, Figure 15 The control unit 140 of the base station 10 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Furthermore, for example, Figure 16 The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Regarding the various processes described above, although it has been stated that the various processes are executed by one processor 1001, the various processes can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be installed using more than one chip. Furthermore, the program can also be transmitted from a network via a telecommunications line.

[0177] Storage device 1002 is a computer-readable recording medium, and may be composed of at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. Storage device 1002 may also be referred to as a register, cache, main memory (main storage device), etc. Storage device 1002 can store programs (program code), software modules, etc., that are executable for implementing the communication method according to one embodiment of this disclosure.

[0178] The auxiliary storage device 1003 is a computer-readable recording medium, such as at least one of the following: CD-ROM (CompactDisc ROM) or other optical discs, hard disks, floppy disks, magneto-optical discs (e.g., compact discs, digital multipurpose discs, Blu-ray discs, smart cards, flash memory (e.g., cards, sticks, key drives), floppy disks, magnetic stripes, etc. The aforementioned storage medium may, for example, be a database, server, or other suitable media that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0179] The communication device 1004 is hardware (transceiver) used for communication between computers via at least one of a wired network and a wireless network. It may also be referred to as a network device, network controller, network interface card (NIC), communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, duplexer, filter, frequency synthesizer, etc., to implement at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, transceiver antennas, amplifiers, transceiver units, transmission path interfaces, etc., can also be implemented using the communication device 1004. The transceiver unit may also consist of a transmitting unit and a receiving unit that are physically or logically separate.

[0180] Input device 1005 is an input device that accepts input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, LED, etc.). Alternatively, input device 1005 and output device 1006 can also be integrated (e.g., a touch panel).

[0181] Furthermore, the processor 1001 and storage device 1002, among other devices, are connected via a bus 1007 for communicating information. The bus 1007 can be configured using a single bus or different buses for each device.

[0182] Furthermore, the base station 10 and the terminal 20 can be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or a FPGA (Field Programmable Gate Array), and can also use this hardware to implement part or all of the functional blocks. For example, the processor 1001 can also be installed using at least one of these hardware components.

[0183] (Summary of Implementation Methods)

[0184] As explained above, according to an embodiment of the present invention, a terminal is provided, comprising: a receiving unit that receives data based on direct inter-terminal communication from another terminal; a transmitting unit that transmits a response related to retransmission control corresponding to the data to the other terminal; and a control unit that, when the receiving unit receives multiple data based on direct inter-terminal communication, determines which response related to retransmission control to transmit to the other terminal based on the multiple responses related to retransmission control.

[0185] Based on the above structure, terminal 20 can use the HARQ-ACK codebook to multiplex the HARQ-ACK corresponding to multiple SL data and report it to the sending terminal 20. That is, in direct communication between terminals, retransmission control can be appropriately performed.

[0186] When the codebook specifying "the retransmission response to the retransmission control response applied to the decision" is semi-static, the payload size of the codebook specifying "the retransmission response to the retransmission control response applied to the decision" can be determined based on "the amount of data contained in one cycle of the resources used to send the retransmission control response to the other terminal". According to this structure, terminal 20 can use the HARQ-ACK codebook to multiplex HARQ-ACKs corresponding to multiple SL data and report them to the sending terminal 20.

[0187] When carrier aggregation is applied to direct communication between terminals, the payload size of the codebook for "the retransmission response applied to the retransmission control response of the decision" can be determined based on "the number of data contained in one cycle of the resources used to send the retransmission control response to the other terminal, multiplied by the number of carriers aggregated". According to this structure, terminal 20 can use the HARQ-ACK codebook to multiplex HARQ-ACKs corresponding to multiple SL data and report them to the transmitting terminal 20.

[0188] When the codebook for the retransmission response applied to the third response is specified to be dynamic, the payload size of the codebook for the retransmission response applied to the third response can be determined based on the fields included in the information of the data based on direct inter-terminal communication. According to this structure, terminal 20 can use the HARQ-ACK codebook to multiplex HARQ-ACKs corresponding to multiple SL data and report them to the sending terminal 20.

[0189] Resources used to send the multiple responses related to retransmission control to the other terminals, and information for scheduling the data based on direct inter-terminal communication, can be associated with this structure. According to this structure, terminal 20 can use a HARQ-ACK codebook to multiplex HARQ-ACKs corresponding to multiple SL data and report them to the sending terminal 20.

[0190] Furthermore, according to an embodiment of the present invention, a communication method executed by a terminal is provided, comprising the following steps: a receiving step, receiving data based on direct inter-terminal communication from another terminal; a sending step, sending a response related to retransmission control corresponding to the data to the other terminal; and a control step, in the case that the receiving unit receives a plurality of the data based on direct inter-terminal communication, determining, based on the plurality of responses related to retransmission control, a response related to retransmission control to be sent to the other terminal.

[0191] Based on the above structure, terminal 20 can use the HARQ-ACK codebook to multiplex the HARQ-ACK corresponding to multiple SL data and report it to the sending terminal 20. That is, in direct communication between terminals, retransmission control can be appropriately performed.

[0192] (Supplement to the implementation method)

[0193] The embodiments of the present invention have been described above, but the disclosed invention is not limited to these embodiments. Those skilled in the art should understand various modifications, alterations, substitutions, and replacements. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these values ​​are merely examples, and any appropriate values ​​may be used. The distinctions between items in the above description are not essential to the present invention; items described in two or more items may be combined as needed, and items described in one item may be applied to items described in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. Multiple functional units may be operated by a single physical component, or a single functional unit may be operated by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing may be interchanged unless there is a contradiction. For ease of explanation, the base station 10 and terminal 20 have been described using functional block diagrams, but this device may also be implemented in hardware, software, or a combination thereof. The software operating via the processor of the base station 10 according to an embodiment of the present invention and the software operating via the processor of the terminal 20 according to an embodiment of the present invention can also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server and other suitable storage media, respectively.

[0194] Furthermore, the notification of information is not limited to the forms / implementations described in this disclosure, and other methods may also be used. For example, the notification of information may be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. Additionally, RRC signaling may be referred to as an RRC message, for example, it may be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0195] The various forms / implementations described in this disclosure can also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-Wide Band), Bluetooth (registered trademark), systems using other suitable systems, and next-generation systems extended therefrom. Furthermore, multiple systems can be combined (e.g., a combination of at least one of LTE and LTE-A with 5G, etc.) for application.

[0196] The processing procedures, timing, and flow of the various forms / implementations described in this specification may be changed in order, provided there is no contradiction. For example, the elements of various steps are indicated using an illustrative order for the methods described in this disclosure, but are not limited to the specific order indicated.

[0197] In this specification, certain actions performed by base station 10 may sometimes also be performed by its upper node, depending on the circumstances. In a network consisting of one or more network nodes having base station 10, it is obvious that various actions performed to communicate with terminal 20 can be performed by at least one of base station 10 and other network nodes besides base station 10 (e.g., considering MME or S-GW, but not limited to these). The above example illustrates the case where there is one other network node besides base station 10, but other network nodes can also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0198] The information or signals described in this disclosure can be output from a higher (or lower) layer to a lower (or higher) layer. They can also be input or output via multiple network nodes.

[0199] Input or output information can be stored in a specific location (e.g., memory) or managed using a management table. Input or output information can be overwritten, updated, or appended. Output information can also be deleted. Input information can also be sent to other devices.

[0200] The determination in this disclosure can be made by a value represented by 1 bit (0 or 1), by a Boolean value (Boolean: true or false), or by a comparison of numerical values ​​(e.g., a comparison with a predetermined value).

[0201] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted as commands, command sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0202] Furthermore, software, commands, and information can be sent and received via a transmission medium. For example, when using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) etc.) and wireless technologies (infrared, microwave, etc.) to send software from a webpage, server, or other remote source, at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0203] The information, signals, etc., described in this disclosure can also be represented using any of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc., that may be involved in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0204] Furthermore, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms that have the same or similar meanings. For example, at least one of the channel and symbol may also be a signal (signaling). Additionally, a signal may also be a message. Furthermore, a component carrier (CC) may also be referred to as carrier frequency, cell, frequency carrier, etc.

[0205] The terms "system" and "network" as used in this disclosure are used interchangeably.

[0206] Furthermore, the information, parameters, etc., described in this disclosure may be represented using absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0207] The names used for the above parameters are not limiting in any way. Furthermore, the formulas, etc., using these parameters sometimes differ from those explicitly disclosed in this disclosure. A wide variety of channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by all appropriate names, and therefore the various names assigned to these wide variety of channels and information elements are not limiting in any way.

[0208] In this 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," and "component carrier" are used interchangeably. Sometimes, terms such as macro cell, small cell, femtocell, and picocell are also used to refer to base stations.

[0209] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, its coverage area can be divided into several smaller areas, each of which can provide communication services through a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base station and base station subsystem providing communication services within that coverage area.

[0210] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" are used interchangeably.

[0211] For mobile stations, those skilled in the art sometimes also use the following terms: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handheld device, user agent, mobile client, client, or some other appropriate terms.

[0212] At least one of the base station and mobile station can also be referred to as a transmitting device, receiving device, communication device, etc. Furthermore, at least one of the base station and mobile station can be a device mounted on a mobile body, the mobile body itself, etc. This mobile body can be a vehicle (e.g., a car, an airplane, etc.), a mobile body moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Additionally, at least one of the base station and mobile station also includes devices that do not necessarily move during communication operations. For example, at least one of the base station and mobile station can be an IoT (Internet of Things) device such as a sensor.

[0213] Furthermore, the base station in this disclosure can also be replaced by a user terminal. For example, various forms / implementations of this disclosure can be applied to a structure that replaces the communication between the base station and the user terminal with communication between multiple terminals 20 (e.g., also referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminal 20 can also be configured to have the functions of the base station 10 described above. In addition, terms such as "uplink" and "downlink" can be replaced with terms corresponding to communication between terminals (e.g., "side"). For example, uplink channel, downlink channel, etc., can also be replaced with side channel.

[0214] Similarly, the user terminal in this disclosure can be replaced by a base station. In this case, the base station can also be configured to have the functions of the user terminal described above.

[0215] As used in this disclosure, terms such as "determining" and "determining" sometimes encompass a variety of actions. For example, "determining" and "determining" can include actions that involve judging, calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), or ascertaining, which are considered to have been "judged" or "determined." Furthermore, "determining" and "determining" can also include actions that involve receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory), which are considered to have been "judged" or "determined." Furthermore, "judgment" and "decision" can encompass matters that have undergone resolving, selecting, choosing, establishing, or comparing, and are thus considered as matters that have undergone "judgment" or "decision." That is, "judgment" and "decision" can include matters that have "judged" or "decided" on any action. Additionally, "judgment (decision)" can also be replaced by "assuming," "expecting," or "considering," etc.

[0216] The terms "connected," "coupled," or any variations thereof are intended to indicate any direct or indirect connection or combination between two or more elements, including cases where there is one or more intermediate elements between the two elements that are "connected" or "coupled." The combination or connection between elements can be physical, logical, or a combination of these. For example, "access" can be used instead of "connected." In the context of this disclosure, for two elements, it can be considered that they are "connected" or "coupled" by using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, by using electromagnetic energy with wavelengths having wireless frequency domains, microwave regions, and light (including both visible and invisible regions).

[0217] The reference signal can be simply referred to as RS (Reference Signal), or, depending on the standard applied, as a pilot.

[0218] As used in this disclosure, the word "based on" does not mean "based on only" unless otherwise expressly stated. In other words, the word "based on" means both "based on only" and "based on at least" both.

[0219] Any reference to elements using the terms "first," "second," etc., as used in this disclosure does not necessarily limit the number or order of these elements. These terms may be used in this disclosure as a convenient way to distinguish between two or more elements. Therefore, reference to a first element and a second element does not imply that only two elements can be used or that in any form the first element must precede the second element.

[0220] Alternatively, the "unit" in the structure of the above devices can be replaced with "section", "circuit", "equipment", etc.

[0221] When the terms "include," "including," and variations thereof are used in this disclosure, these terms, like the term "comprising," imply inclusion. Furthermore, the term "or" as used in this disclosure means not XOR.

[0222] A radio frame can consist of one or more frames in the time domain. In the time domain, one or more frames can be called subframes. A subframe can consist of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) independent of the parameter set (numerology).

[0223] A parameter set can also be communication parameters applied to at least one side of the transmission and reception of a signal or channel. For example, a parameter set can represent at least one of the following: Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0224] In the time domain, a time slot can be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A time slot can be a time unit based on a set of parameters.

[0225] A time slot can contain multiple mini-time slots. Each mini-time slot can consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can consist of fewer symbols than a time slot. PDSCH (or PUSCH) transmitted in time units larger than mini-time slots can be called PDSCH (or PUSCH) mapping type (type) A. PDSCH (or PUSCH) transmitted using mini-time slots can be called PDSCH (or PUSCH) mapping type (type) B.

[0226] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can each be referred to by other corresponding names.

[0227] For example, one subframe can be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and one time slot or one mini-time slot can also be called a TTI. That is, at least one of the subframe and TTI can be a subframe in the existing LTE (1ms), a period shorter than 1ms (e.g., symbols 1-13), or a period longer than 1ms. In addition, the unit representing TTI may not be called a subframe, but a time slot, mini-time slot, etc.

[0228] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules the allocation of radio resources (bandwidth, transmit power, etc., available to each terminal 20) on a TTI basis. However, the definition of TTI is not limited to this.

[0229] The Time Interval (TTI) can be a unit of time for transmitting channel-coded data packets (transmission blocks), code blocks, codewords, etc., or it can be a processing unit such as scheduling or link adaptation. Furthermore, when a TTI is assigned, the actual time interval (e.g., the number of symbols) that is mapped to the transmission block, code block, codeword, etc., can be shorter than the TTI.

[0230] Furthermore, when one time slot or one mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can constitute the minimum time unit of scheduling. Moreover, the number of time slots (mini-time slots) constituting the minimum time unit of scheduling can be controlled.

[0231] A TTI with a duration of 1ms is also known as a normal TTI (in LTE Rel.8-12), a long TTI, a normal subframe, a normal subframe, a long subframe, or a time slot. A TTI shorter than a normal TTI can be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini time slot, a sub-time slot, or a time slot.

[0232] Additionally, for long TTIs (e.g., regular TTIs, subframes, etc.), they can be replaced with TTIs with a duration of more than 1ms. For short TTIs (e.g., shortened TTIs, etc.), they can be replaced with TTIs with a duration of less than long TTIs and a duration of more than 1ms.

[0233] A resource block (RB) is a unit of resource allocation in both the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers in an RB is independent of the parameter set and can be the same, for example, 12. The number of subcarriers in an RB can also be determined based on the parameter set.

[0234] Furthermore, the temporal domain of an RB can contain one or more symbols, and can be 1 time slot, 1 mini-time slot, 1 subframe, or 1 TTI in length. 1 TTI, 1 subframe, etc., can each be composed of one or more resource blocks.

[0235] In addition, one or more RBs can be called Physical Resource Block (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB Pair, RB Pair, etc.

[0236] Furthermore, a resource block can consist of one or more resource elements (REs). For example, 1 RE can be a radio resource area consisting of 1 subcarrier and 1 symbol.

[0237] The Bandwidth Part (BWP) (also known as partial bandwidth, etc.) can also represent a subset of contiguous common resource blocks (RBs) used for a certain parameter set in a certain carrier. Here, common resource blocks can be determined by the index of RBs based on a common reference point of that carrier. PRBs can be defined and numbered within a BWP.

[0238] A BWP can include a UL BWP and a DL BWP. One or more BWPs can be configured for terminal 20 within one carrier.

[0239] At least one of the configured BWPs can be active, and it is not assumed that the terminal 20 will transmit or receive predetermined signals / channels outside of an active BWP. In addition, "cell", "carrier", etc. in this disclosure can be replaced by "BWP".

[0240] The structures of radio frames, subframes, time slots, mini-time slots, and symbols described above are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained in a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, and the number of symbols in a TTI, symbol length, cyclic prefix (CP) length, etc., can be varied in many ways.

[0241] In this disclosure, for example, in cases where articles are added through translation, such as in English (a, an, and the), this disclosure also includes cases where the noun following these articles is in a plural form.

[0242] In this disclosure, the phrase "A and B are different" can also mean "A and B are different from each other." Furthermore, this phrase can also mean "A and B are each different from C." Terms such as "separate" and "combined" can also be interpreted in the same way as "different."

[0243] The various forms / implementations described in this disclosure can be used individually or in combination, and can be switched depending on the execution. Furthermore, the notification of predetermined information is not limited to explicit notification (e.g., a "Yes X" notification), but can also be implicit notification (e.g., not notifying the predetermined information).

[0244] Furthermore, in this disclosure, a HARQ response is an example of a response related to retransmission control. ACK is an example of a positive response. NACK is an example of a negative response. The HARQ-ACK codebook is an example of a codebook that specifies retransmission responses.

[0245] The present disclosure has been described in detail above, but it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the present disclosure is for illustrative purposes only and is not intended to be limiting.

[0246] Label Explanation

[0247] This international patent application asserts priority based on Japanese Patent Application No. 2019-155869, filed on August 28, 2019, and the entire contents of Japanese Patent Application No. 2019-155869 are incorporated herein by reference.

[0248] 10: Base station;

[0249] 110: Dispatch Department;

[0250] 120: Receiving Unit;

[0251] 130: Setting Department;

[0252] 140: Control Department;

[0253] 20: Terminal;

[0254] 210: Sending Department;

[0255] 220: Receiving unit;

[0256] 230: Setting Department;

[0257] 240: Control Unit;

[0258] 1001: Processor;

[0259] 1002: Storage device;

[0260] 1003: Auxiliary storage device;

[0261] 1004: Communication devices;

[0262] 1005: Input device;

[0263] 1006: Output device.< / dai>

Claims

1. A terminal having: The receiving unit receives data from other terminals based on direct inter-terminal communication. The transmitting unit sends a response to the other terminals related to retransmission control corresponding to the data; as well as When the receiving unit receives multiple data packets based on direct inter-terminal communication, the control unit multiplexes multiple retransmission control-related responses in the PSFCH resource and determines which retransmission control-related responses to send to the other terminals. Carrier aggregation is used for direct communication between the terminals. The PSFCH resource is associated with the SCI corresponding to the smallest component carrier index among the multiple side link control information (SCI) corresponding to the multiple data.

2. The terminal according to claim 1, wherein, When the codebook for "retransmission response to retransmission control related to the decision" is semi-static, the payload size of the codebook for "retransmission response to retransmission control related to the decision" is determined based on "the amount of data contained in one cycle of the resources used to send retransmission control related responses to the other terminals".

3. The terminal according to claim 2, wherein, The payload size of the codebook for "the retransmission response to the retransmission control response applied to the decision" is determined by "the number of data contained in one cycle of the resources used to send the retransmission control response to the other terminal multiplied by the number of carriers aggregated by the carriers".

4. The terminal according to claim 1, wherein, When the codebook specifying "retransmission response to retransmission control related to the decision" is dynamic, the payload size of the codebook specifying "retransmission response to retransmission control related to the decision" is determined based on the fields contained in the information of the data scheduled based on direct inter-terminal communication.

5. A communication method executed by a terminal, comprising the following steps: The receiving step involves receiving data from other terminals based on direct inter-terminal communication. The sending step involves sending a response related to the retransmission control corresponding to the data to the other terminals. as well as In the control step, if multiple data related to direct inter-terminal communication are received in the receiving step, multiple responses related to retransmission control are multiplexed in the PSFCH resource to determine which retransmission control responses to send to the other terminals. Carrier aggregation is used for direct communication between the terminals. The PSFCH resource is associated with the SCI corresponding to the smallest component carrier index among the multiple side link control information (SCI) corresponding to the multiple data.

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