Terminal and communication method

Abstract

The terminal includes: a receiving unit that receives information related to direct communication between terminals for determining available resources from other terminals; a control unit that identifies resource candidates based on the information and selects the resources to be used; and a sending unit that uses the selected resources to perform transmission in direct communication between terminals.

Description

Technical Field

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

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

[0003] D2D reduces the traffic between terminals and base stations, enabling inter-terminal communication even when base stations are unable to communicate, such as during disasters. While 3GPP (3rd Generation Partnership Project) refers to D2D as "sidelink," this specification uses the more general term D2D. However, in the following descriptions of the embodiments, sidelink may also be used as needed.

[0004] D2D communication is broadly divided into D2D discovery (also called D2D discovery) for discovering other terminals that can communicate, and D2D communication (also called D2D direct communication, D2D communication, direct communication between terminals, etc.) for direct communication between terminals. Hereinafter, when no special distinction is made between D2D communication, D2D discovery, etc., they are referred to as D2D. In addition, signals sent and received via D2D are referred to as D2D signals. Various use cases for services related to V2X (Vehicle to Everything) in NR are being studied (e.g., Non-Patent Document 2).

[0005] Prior art literature

[0006] Non-patent literature

[0007] Non-Patent Document 1: 3GPP TS 38.211 V16.0.0 (December 2019)

[0008] Non-Patent Document 2: 3GPP TR 22.886 V15.1.0 (March 2017) Summary of the Invention

[0009] Problems to be solved by the invention

[0010] It is assumed that in direct inter-terminal communication, one terminal receives information about resources to be used from another terminal and uses this information to select resources, thereby improving communication quality. However, the details of the information to be shared between terminals and the method of using this information to improve communication quality are still unclear.

[0011] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to improve communication quality based on information notified from other terminals in inter-terminal direct communication.

[0012] Means for solving problems

[0013] According to the disclosed technology, a terminal is provided, comprising: a receiving unit that receives information related to direct communication between terminals for determining available resources from other terminals; a control unit that identifies resource candidates based on the information and selects the resources to be used; and a sending unit that uses the selected resources to perform sending in direct communication between terminals.

[0014] Effects of the Invention

[0015] According to the disclosed technology, in inter-terminal direct communication, communication quality can be improved based on information notified from other terminals. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode.

[0018] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode.

[0019] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode.

[0020] Figure 5 This is a diagram for explaining example (4) of the V2X transmission mode.

[0021] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode.

[0022] Figure 7 This is a diagram for explaining example (1) of the V2X communication type.

[0023] Figure 8 This is a diagram for explaining example (2) of the V2X communication type.

[0024] Figure 9 This is a diagram for explaining example (3) of the V2X communication type.

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

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

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

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

[0029] Figure 14 This is a diagram showing an example (1) of information related to a synchronization source in an embodiment of the present invention.

[0030] Figure 15 This is a diagram showing example (2) of information related to the synchronization source in the embodiment of the present invention.

[0031] Figure 16 This is a diagram showing an example (1) of information related to the HARQ response in the embodiment of the present invention.

[0032] Figure 17 This is a diagram showing example (2) of information related to the HARQ response in the embodiment of the present invention.

[0033] Figure 18 This is a diagram showing an example (1) of information related to transmission power reduction in the embodiment of the present invention.

[0034] Figure 19 This is a diagram showing an example (1) of information related to transmission power reduction in the embodiment of the present invention.

[0035] Figure 20 This is a diagram showing an example of information on unused resources in the embodiment of the present invention.

[0036] Figure 21 This is a diagram showing an example of the functional configuration of the base station 10 in the embodiment of the present invention.

[0037] Figure 22 This is a diagram showing an example of the functional configuration of the terminal 20 in the embodiment of the present invention.

[0038] Figure 23 This is a diagram showing an example of the hardware configuration of the base station 10 or the terminal 20 in the embodiment of the present invention. DETAILED DESCRIPTION

[0039] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0040] When operating the wireless communication system according to the embodiments of the present invention, existing technologies are appropriately used. However, this existing technology is, for example, existing LTE, but is not limited to existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning that includes LTE-Advanced and subsequent technologies (such as NR) or wireless LANs (Local Area Networks).

[0041] Furthermore, in the embodiment of the present invention, the duplexing method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, flexible duplex, etc.).

[0042] In addition, in the embodiment of the present invention, "configuring" wireless parameters and the like may be pre-configuring predetermined values, or setting wireless parameters notified from the base station 10 or the terminal 20, or pre-specifying them according to specifications.

[0043] Figure 1 This is a diagram for explaining V2X. 3GPP is researching technologies to implement V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality and is promoting standardization. Figure 1As shown, V2X is a part of ITS (Intelligent Transport Systems), and is a general term for V2V (Vehicle to Vehicle) which represents the communication between vehicles, V2I (Vehicle to Infrastructure) which represents the communication between vehicles and roadside equipment (RSU: Road-Side Unit) installed next to the road, V2N (Vehicle to Network) which represents the communication between vehicles and ITS servers, and V2P (Vehicle to Pedestrian) which represents the communication between vehicles and mobile terminals held by pedestrians.

[0044] Furthermore, 3GPP is researching V2X, which utilizes cellular communications and inter-device communications using LTE or NR. V2X using cellular communications is also referred to as cellular V2X. Research is progressing on achieving high capacity, low latency, high reliability, and QoS (Quality of Service) control in NR-based V2X.

[0045] Regarding LTE and NR V2X, research is envisioned to continue beyond 3GPP specifications. For example, research is envisioned to ensure interoperability, reduce costs associated with high-level installation, integrate and switch between multiple RATs (Radio Access Technologies), support regulations in various countries, and acquire, publish, manage, and utilize data from LTE and NR V2X platforms.

[0046] While the embodiments of the present invention primarily envision the communication device being 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 node, or terminal with scheduling capabilities.

[0047] In addition, SL (Sidelink) can also be distinguished by UL (Uplink) or DL (Downlink) and any one or a combination of the following 1) to 4). In addition, SL can also be other names.

[0048] 1) Time Domain Resource Allocation

[0049] 2) Frequency Domain Resource Allocation

[0050] 3) Reference synchronization signal (including SLSS (Sidelink Synchronization Signal))

[0051] 4) Reference signal used for path loss measurement for transmit power control

[0052] In addition, for OFDM (Orthogonal Frequency Division Multiplexing) of SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding can also be used.

[0053] LTE's SL specifies Mode 3 and Mode 4 for SL resource allocation to terminal 20. In Mode 3, transmission resources are dynamically allocated using DCI (Downlink Control Information) sent from base station 10 to terminal 20. Mode 3 also supports Semi-Persistent Scheduling (SPS). In Mode 4, terminal 20 autonomously selects transmission resources from a resource pool.

[0054] In addition, the time slot in the embodiments of the present invention may be replaced by a symbol, a mini-slot, a subframe, a radio frame, or a TTI (Transmission Time Interval). Furthermore, the cell in the embodiments of the present invention may be replaced by a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), or the like.

[0055] Furthermore, in the embodiments of the present invention, the terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a user-held terminal such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0056] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode. Figure 2 In the transmission mode of the sidelink communication shown in FIG, in step 1, the base station 10 sends the sidelink scheduling information to the terminal 20A. Then, the terminal 20A sends the PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to the terminal 20B based on the received scheduling information (step 2). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, sidelink scheduling based on Uu is performed. Uu refers to the radio interface between UTRAN (Universal Terrestrial Radio Access Network) and UE (User Equipment). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 1 in NR.

[0057] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode. Figure 3 In the transmission mode of the side link communication shown in FIG, in step 1, the terminal 20A transmits the PSCCH and PSSCH to the terminal 20B using the resources selected autonomously. Figure 3 The transmission mode of the sidelink communication shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0058] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode. Figure 4 In the transmission mode of the sidelink communication shown in FIG, in step 1, the terminal 20A uses the resources selected autonomously to transmit the PSCCH and PSSCH to the terminal 20B. Similarly, the terminal 20B uses the resources selected autonomously to transmit the PSCCH and PSSCH to the terminal 20A (step 1). Figure 4 The transmission mode for sidelink communication shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, terminal 20 performs resource selection itself. The mode in which terminal 20 selects resources for sidelink transmission in NR can also be called resource allocation mode 2.

[0059] Figure 5This is a diagram for explaining example (4) of the V2X transmission mode. Figure 5 In the transmission mode of the sidelink communication shown in FIG, in step 0, the base station 10 sets a grant for transmitting the sidelink to the terminal 20A via RRC (Radio Resource Control). Then, the terminal 20A transmits the PSSCH to the terminal 20B according to the received resource mode (step 1). Figure 5 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2c in NR.

[0060] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode. Figure 6 In the transmission mode of the sidelink communication shown in FIG, in step 1, terminal 20A transmits information related to the scheduling of the sidelink to terminal 20B via PSCCH. Then, terminal 20B transmits PSSCH to terminal 20A based on the received scheduling information (step 2). Figure 6 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2d in NR. In NR, the mode in which the base station 10 allocates resources to the terminal 20 and performs sidelink transmission can also be called resource allocation mode 1.

[0061] Figure 7 This is a diagram for explaining example (1) of the V2X communication type. Figure 7 The communication type of the side link shown is unicast. Terminal 20A sends PSCCH and PSSCH to terminal 20. Figure 7 In the example shown, the terminal 20A performs unicast to the terminal 20B, and also performs unicast to the terminal 20C.

[0062] Figure 8 This is a diagram for explaining example (2) of the V2X communication type. Figure 8 The communication type of the side link shown is multicast. Terminal 20A transmits PSCCH and PSSCH to the group to which one or more terminals 20 belong. Figure 8 In the example shown, the group includes the terminal 20B and the terminal 20C, and the terminal 20A performs multicast for the group.

[0063] Figure 9 This is a diagram for explaining example (3) of the V2X communication type. Figure 9 The communication type of the side link shown is broadcast. Terminal 20A transmits PSCCH and PSSCH to one or more terminals 20. Figure 9 In the example shown, terminal 20A broadcasts to terminal 20B, terminal 20C, and terminal 20D. Figures 7 to 9 The terminal 20A shown is referred to as a head UE (header-UE).

[0064] Furthermore, NR-V2X envisions supporting HARQ (Hybrid Automatic Repeat Request) in both unicast and multicast on the sidelink. Furthermore, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Furthermore, research is underway to transmit SFCI via the Physical Sidelink Feedback Channel (PSFCH).

[0065] In the following description, it is assumed that the PSFCH is used for transmission of HARQ-ACK on the sidelink. However, this is only an example. For example, HARQ-ACK on the sidelink may be transmitted using the PSCCH, the PSSCH, or other channels.

[0066] For convenience, all information reported by terminal 20 in HARQ will be referred to below as HARQ-ACK. This HARQ-ACK may also be referred to as HARQ-ACK information. Furthermore, more specifically, the codebook used for HARQ-ACK information reported from terminal 20 to base station 10, etc., is referred to as the HARQ-ACK codebook. The HARQ-ACK codebook defines the bit string of the HARQ-ACK information. Furthermore, HARQ-ACK allows NACKs to be transmitted in addition to ACKs.

[0067] Figure 10 This is a timing diagram showing an example of V2X operation (1). Figure 10 As shown, the wireless communication system according to the embodiment of the present invention may include a terminal 20A and a terminal 20B. In addition, there are actually multiple user devices, but Figure 10 The terminal 20A and the terminal 20B are shown as examples.

[0068] Hereinafter, when the terminals 20A and 20B are not particularly distinguished, they are simply referred to as "terminal 20" or "user device". Figure 10 In the embodiment, the case where both the terminal 20A and the terminal 20B are within the coverage of the cell is shown as an example, but the operation in the embodiment of the present invention can also be applied to the case where the terminal 20B is outside the coverage.

[0069] As described above, in this embodiment, the terminal 20 is a device mounted on a vehicle, such as an automobile, and has cellular communication functions and sidelink functions as a UE in LTE or NR. The terminal 20 may also be a general portable terminal (such as a smartphone). Furthermore, the terminal 20 may also be an RSU. This RSU may be a UE-type RSU (UE type RSU) that has UE functions, or a gNB-type RSU (gNB type RSU) that has base station functions.

[0070] Furthermore, the terminal 20 does not need to be a device having a single housing. For example, even when various sensors are dispersedly arranged in a vehicle, the terminal 20 may be a device including these various sensors.

[0071] Furthermore, the processing of sidelink transmit data by terminal 20 is essentially the same as that of UL transmission in LTE or NR. For example, terminal 20 scrambles the codewords of transmit data, modulates them, and generates complex-valued symbols. These complex-valued symbols (transmit signals) are mapped to layer 1 or layer 2 and precoded. The precoded complex-valued symbols are then mapped to resource elements to generate a transmit signal (e.g., a complex-valued time-domain SC-FDMA signal), which is then transmitted from each antenna port.

[0072] The base station 10 also has cellular communication functions as a base station in LTE or NR, as well as functions for enabling communication with the terminal 20 in this embodiment (e.g., resource pool configuration, resource allocation, etc.). Furthermore, the base station 10 may also be an RSU (gNB-type RSU).

[0073] In addition, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 in the SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.

[0074] In step S101 , the terminal 20A autonomously selects resources to be used for the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0075] In steps S102 and S103, terminal 20A uses the resources autonomously selected in step S101 to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. For example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, within the same time resources as at least a portion of the time resources of the PSSCH.

[0076] Terminal 20B receives the SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The received SCI may include information about the PSFCH resources used by terminal 20B to transmit HARQ-ACK for the received data. Terminal 20A may include information about the autonomously selected resources in the SCI and transmit it.

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

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

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

[0080] Figure 11 This is a timing diagram showing an example of V2X operation (2). Blind retransmissions may be performed independently of HARQ control for improving the transmission success rate or the reach distance.

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

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

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

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

[0085] Figure 12 This is a sequence diagram illustrating an example of V2X operation (3). The base station 10 can perform sidelink scheduling. Specifically, the base station 10 can determine the sidelink resources used by the terminal 20 and transmit information indicating the resources to the terminal 20. Furthermore, when HARQ control is applied, the base station 10 can transmit information indicating PSFCH resources to the terminal 20.

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

[0087] Furthermore, the following scenario is envisioned: in step S301, the base station 10 also transmits DCI for DL scheduling (also referred to as DL allocation) to the terminal 20A using the PDCCH. Hereinafter, for convenience, the DCI for DL scheduling is referred to as DL scheduling DCI. Upon receiving the DL scheduling DCI, the terminal 20A receives DL data using the PDSCH, using the resources specified by the DL scheduling DCI.

[0088] In steps S302 and S303, terminal 20A uses the resources specified by the SL scheduling DCI to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. Alternatively, the SL scheduling DCI may specify only PSSCH resources. In this case, for example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, within the same time resources as at least a portion of the time resources of the PSSCH.

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

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

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

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

[0093] In addition, when HARQ control is not performed, step S304 and step S305 may not be performed.

[0094] Figure 13 This is a timing diagram showing an example of V2X operation (4). As described above, the side link of NR supports the case of sending HARQ responses through PSFCH. In addition, the format of PSFCH can use the same format as PUCCH (Physical Uplink Control Channel) format 0 (PUCCH format 0), for example. That is, regarding the format of PSFCH, it can be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified based on the difference in the sequence. The format of PSFCH is not limited to this. The resources of PSFCH can be configured as a codeword at the end of the time slot or multiple codewords at the end. In addition, a period N is set or predefined for the PSFCH resources. The period N can be set or predefined in units of time slots.

[0095] exist Figure 13 In the figure, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. PSCCH can be configured in one symbol at the beginning of the time slot, or in multiple symbols starting from the beginning, or in multiple symbols starting from symbols other than the beginning. PSFCH can be configured in one symbol at the end of the time slot, or in multiple symbols at the end of the time slot. Figure 13 In the example shown, three subchannels are configured in the resource pool, and two PSFCHs are allocated three slots after the slot in which the PSSCH is allocated. The arrow from the PSSCH to the PSFCH shows an example of the PSFCH associated with the PSSCH.

[0096] When the HARQ response in NR-V2X multicast is option 2 of sending ACK or NACK, it is necessary to determine the resources used for PSFCH transmission and reception. Figure 13 As shown, in step S401, terminal 20A as the transmitting terminal 20 performs multicast via SL-SCH to terminal 20B, terminal 20C and terminal 20D as the receiving terminal 20. In the next step S402, terminal 20B uses PSFCH#B to send a HARQ response to terminal 20A, terminal 20C uses PSFCH#C to send a HARQ response to terminal 20A, and terminal 20D uses PSFCH#D to send a HARQ response to terminal 20A. Figure 13As shown in the example, when the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to decide how to allocate PSFCH resources. In addition, the transmitting terminal 20 can grasp the number of receiving terminals 20 in the multicast.

[0097] In future releases (e.g., NR Release 17), sidelink enhancements (SL enhancements) are being studied. For example, regarding power reduction, based on the random resource selection and partial monitoring in LTE Release 14, enhancements are being studied. Furthermore, for example, as enhanced URLLC (enhanced Ultra-Reliable and Low Latency Communications), based on the inter-UE coordination in the NR sidelink research phase, enhancements are being studied. As an example of inter-UE coordination, terminal 20A and terminal 20B share a resource set, and terminal 20B can consider this resource set in resource selection.

[0098] It is believed that by transmitting various information from terminal 20A to terminal 20B, and terminal 20B operating based on this information, communication quality can be improved. In other words, it is believed that sharing not only resource sets but also other information among terminals 20 is effective. However, it is not clear what information should be shared among terminals 20. Furthermore, it is not clear how the information shared among terminals 20 should be used.

[0099] Therefore, the terminal 20A may transmit at least one of the following information A) to D) to the terminal 20B.

[0100] A) Information about the synchronization source

[0101] B) Information related to scheduled PSFCH opportunities for transmission and reception

[0102] C) Information on transmit power reduction due to in-device coexistence

[0103] D) Information about reserved but unused resources

[0104] Here, terminal 20B may be a single terminal 20 or multiple terminals 20. That is, terminal 20A may multicast the above information, or terminal 20A may broadcast the above information. The "intra-device coexistence" in C) above may correspond to a situation where multiple channels overlap at least in the time domain at terminal 20A.

[0105] In addition, the terminal 20A may perform resource selection for the terminal 20B according to at least one of the above A)-D).

[0106] By performing resource selection using the additional information shown in A) to D) above, higher reliability or communication quality can be ensured.

[0107] Figure 14 This figure shows an example (1) of information related to a synchronization source in an embodiment of the present invention. The information related to the synchronization source described in A) above may be information based on an S-SSB (Sidelink-SS / PBCH block) received by Terminal 20. An S-SSB is a signal containing a synchronization signal and broadcast information in a sidelink transmitted by Terminal 20. Furthermore, S-SSB_TX indicates that an S-SSB signal has been transmitted.

[0108] like Figure 14 As shown, terminal 20A receives S-SSB_TX(i) from terminal 20C. On the other hand, terminal 20A sets the S-SSB_TX received from terminal 20B as a synchronization source. Here, terminal 20A can send information related to S-SSB_TX(i) received from terminal 20C, which is a synchronization source other than the synchronization source in use, to terminal 20B. For example, the information related to S-SSB_TX(i) can be an RSRP (Reference Signal Received Power) value. In addition, for example, the information related to S-SSB_TX(i) can also be the time difference (for example, Xms) between the S-SSB_TX from terminal 20B, which is the synchronization source in use, and the S-SSB_TX(i) from terminal 20C, which is a synchronization source that is not standardized.

[0109] Furthermore, the terminal 20A may transmit the RSRP value of S-SSB_TX received from the terminal 20B set as the synchronization source to the terminal 20B.

[0110] in addition, Figure 14Examples of synchronization source priorities are shown. The base station 10, which is the gNB / eNB with the highest priority, corresponds to priority P0. Terminal 20D, which is the UE directly synchronizing with the gNB / eNB with the second highest priority, corresponds to priority P1. Terminal 20B, which is the UE indirectly synchronizing with the gNB / eNB with the next highest priority, corresponds to priority P2. The GNSS 30, which is the UE directly synchronizing with the GNSS with the next highest priority, corresponds to priority P3. Terminal 20E, which is the UE directly synchronizing with the GNSS with the next highest priority, corresponds to priority P4. Terminal 20F, which is the UE indirectly synchronizing with the GNSS with the next highest priority, corresponds to priority P5. Terminals 20A, 20C, and 20G, which are the other UEs with the lowest priority, correspond to priority P6.

[0111] Figure 15 This is a diagram showing example (2) of information related to the synchronization source in the embodiment of the present invention. Figure 14 The terminal 20B shown may also perform resource allocation operations based on the information related to S-SSB sent from the terminal 20C and received from the terminal 20A.

[0112] For example, the terminal 20B may also decode the SCI in the PSCCH / PSSCH based on the information on the S-SSB transmitted from the terminal 20C and received from the terminal 20A, and perform monitoring.

[0113] In addition, for example, Figure 15 As shown, the time difference of the synchronization source can be calculated based on the information related to S-SSB transmitted from terminal 20C and received from terminal 20A. This time difference can correspond to the time difference between the resource pool based on the information related to the synchronization source received from other UEs and the resource pool based on the synchronization source in use. Terminal 20B can detect power based on the time difference of the synchronization source. For example, if a power change exceeding a predetermined value is detected through monitoring assuming the time difference of the synchronization source, terminal 20B can determine that some transmission is present, regardless of whether SCI decoding is successful or not.

[0114] Terminal 20B can identify resources based on the aforementioned time difference of the synchronization source, determine unusable resources, and exclude them from the set of candidate resources that are assumed to be usable. For example, terminal 20B can exclude resources determined based on the time resource assignment field and / or resource reservation period field of the decoded SCI from the set of candidate resources that are assumed to be usable. In addition, for example, if it is determined that a transmission has occurred through monitoring based on the aforementioned time difference of the synchronization source, resources determined based on the time resource assignment field and / or resource reservation period field that can be indicated by the transmission can be excluded from the set of candidate resources that are assumed to be usable.

[0115] Furthermore, for example, the terminal 20B may determine whether to suspend transmission based on the time difference and / or power detection of the synchronization source. For example, upon detecting transmission based on a different synchronization source, the terminal 20B may suspend sidelink transmission in the associated resource.

[0116] As described above, by performing resource selection or resource allocation based on information on the synchronization source acquired from other terminals 20 , resources can be selected so as not to conflict with transmissions from terminals 20 operating based on other synchronization sources.

[0117] Figure 16 This figure shows an example (1) of information related to HARQ responses in an embodiment of the present invention. The information related to the scheduled PSFCH opportunity (B) mentioned above may be information related to the transmission and reception of the PSFCH associated with communications with any terminal. The information related to the PSFCH opportunity may be, for example, information indicating the time domain and / or frequency domain and / or code domain in which the PSFCH opportunity is set. For example, the information related to the PSFCH opportunity shown in 1) to 4) below may also be.

[0118] 1) PSFCH opportunity corresponding to PSCCH / PSSCH received by terminal 20

[0119] 2) PSFCH opportunity corresponding to the resource indicated by the time resource allocation field contained in the SCI in the PSCCH / PSSCH received by the terminal 20

[0120] 3) PSFCH opportunity corresponding to the resource indicated by the resource reservation period field included in the SCI in the PSCCH / PSSCH received by the terminal 20

[0121] 4) PSFCH opportunities corresponding to resources selected for transmission in terminal 20 (i.e., unreserved resources)

[0122] exist Figure 16 In FIG. 2 , an example corresponding to the above 2) is shown in which the terminal 20B notifies the terminal 20C of information related to the PSFCH opportunity corresponding to the PSCCH / PSSCH received from the terminal 20A. Figure 16 The period of the starting number of PSCCH / PSSCH symbols shown in FIG. 1 is an example of the time required for switching the side link transmission and reception. Figure 16 As shown, terminal 20A transmits PSCCH / PSSCH to terminal 20B. Terminal 20B may notify terminal 20C of information on PSFCH opportunities corresponding to two resources indicated by the time resource allocation field notified to terminal 20B by the PSCCH / PSSCH.

[0123] In addition, the priority can be notified together with the information related to the PSFCH opportunity or independently. The priority can be the priority in the SCI or the priority in the upper layer (for example, the priority of the logical channel associated with the corresponding PSCCH / PSSCH). In addition, for the PSFCH opportunities shown in 1)-4) above, "receive" can also be replaced by "send". For example, information related to the PSFCH opportunity corresponding to the PSCCH / PSSCH sent by the terminal 20 can be notified to other terminals 20. In addition, the terminal 20 shown in 1)-4) above can also be replaced by any terminal 20. For example, Figure 16 Terminal 20A is shown as being able to send information regarding scheduled transmission PSFCH opportunities to terminal 20C.

[0124] As described above, by notifying other terminals 20 of information related to the PSFCH received or transmitted by the terminal 20, it is possible to predict collisions between the transmission and reception of the PSFCH and the PSFCH transmitted and received by the terminal itself, and avoid collisions as needed.

[0125] Figure 17 This is a diagram showing an example (2) of information related to HARQ response in an embodiment of the present invention. The terminal 20 can perform resource allocation based on information related to PSFCH opportunities received from other terminals. Figure 17 In, such as Figure 16 As shown, it is assumed that the terminal 20C receives, from the terminal 20B, information on the PSFCH opportunity corresponding to the PSCCH / PSSCH transmitted from the terminal 20A to the terminal 20B.

[0126] like Figure 17 As shown, the terminal 20C performs at least one of the operations shown in 1) to 3) below based on the information on the PSFCH opportunity received from the terminal 20B.

[0127] 1) Terminal 20C can determine the PSCCH / PSSCH resource corresponding to the PSFCH opportunity used by terminal 20B and exclude it from the set of candidate resources that can be used (i.e., the resource selection window). This exclusion can be applied only when terminal 20C intends to perform retransmission based on HARQ response. In addition, it can also be applied only when the priority of the PSFCH sent or received by terminal 20B is higher than a specific value in the PSFCH opportunity used by terminal 20B. The specific value can, for example, refer to the priority corresponding to the predetermined PSCCH / PSSCH sent by terminal 20C to terminal 20B. In addition, this exclusion can be applied only when terminal 20C transmits to one or more terminals 20 including terminal 20B. In addition, the PSFCH opportunity used by the above-mentioned terminal 20B can be a PSFCH opportunity in which terminal 20B can perform PSFCH transmission, or it can be a PSFCH opportunity in which terminal 20B can perform PSFCH reception.

[0128] 2) Only in the case of a PSFCH opportunity in which terminal 20B is capable of performing PSFCH transmission, or when the number of PSFCH transmissions in the PSFCH opportunity is greater than the predetermined number or is above the predetermined number, terminal 20C can determine the PSCCH / PSSCH resources corresponding to the PSFCH opportunity used by terminal 20B and exclude them from the group of available candidate resources (i.e., the resource selection window).

[0129] 3) Only in the case of a PSFCH opportunity in which terminal 20B is capable of PSFCH reception, or when the number of PSFCH receptions in the PSFCH opportunity is greater than a predetermined number or is above a predetermined number, terminal 20C can determine the PSCCH / PSSCH resources corresponding to the PSFCH opportunity used by terminal 20B and exclude them from the group of available candidate resources (i.e., the resource selection window).

[0130] As described above, by notifying other terminals 20 of information related to the PSFCH received or transmitted by the terminal 20, resources other than those where PSFCH transmission from the receiving terminal cannot be expected can be selected, thereby ensuring HARQ feedback.

[0131] Figure 18: is a diagram showing an example (1) of information related to transmit power reduction in an embodiment of the present invention. The above-mentioned C) information related to transmit power reduction due to in-device coexistence may be information related to transmit power reduction caused by the overlap of SL transmission and UL transmission in at least the time domain in any terminal 20. Alternatively, SL transmission and UL transmission may be replaced by the first SL transmission and the second SL transmission, the first SL transmission may be the SL transmission in NR, and the second SL transmission may be the SL transmission in LTE. SL transmission and UL transmission are described below as an example. For example, the information related to transmit power reduction may be the fact that transmit power is reduced when UL transmission takes priority over SL transmission and the transmit power of SL transmission is reduced. For example, the information related to transmit power reduction may be the amount of transmit power reduction when UL transmission takes priority over SL transmission and the transmit power of SL transmission is reduced. Regarding the transmit power reduction amount, a specific granularity may also be applied.

[0132] like Figure 18 As shown, when the transmission power of the SL transmission is reduced due to the UL transmission, i.e., PUSCH, which overlaps with the SL transmission reserved through the time resource allocation field in the time domain, the terminal 20 of the transmission source of the SL transmission can notify the terminal 20 of the transmission destination of the SL transmission or other terminals 20 of the information related to the transmission power reduction.

[0133] Figure 19 FIG. 1 is a diagram showing an example (1) of information related to transmission power reduction in an embodiment of the present invention. Figure 19 As shown, when the transmission power of the SL transmission is reduced due to the UL transmission, i.e., PUSCH, which overlaps with the transmitted SL transmission resources in the time domain, the terminal 20 of the transmission source of the SL transmission can notify the terminal 20 of the transmission destination of the SL transmission or other terminals 20 of the information related to the transmission power reduction.

[0134] At least one of the UL transmission and the SL transmission may be a transmission scheduled by a dynamic grant. Furthermore, at least one of the UL transmission and the SL transmission may be a transmission configured or indicated as semi-persistent. That is, at least one of the UL transmission and the SL transmission may be a transmission scheduled by configured grant type 1 or configured grant type 2.

[0135] As described above, the terminal 20 notifies other terminals 20 of information related to transmission power reduction, whereby the other terminals 20 can grasp the resource utilization status more accurately.

[0136] The terminal 20 can perform resource allocation operations based on information received from other terminals 20 regarding transmission power reduction due to in-device coexistence.

[0137] As actions based on information on reduction in transmission power in resources reserved from other terminals 20 , the terminal 20 may perform actions shown in 1) to 3) below.

[0138] 1) In resource identification, with respect to resources indicated by the SCI received from other terminals 20, if the terminal 20 receives information regarding transmit power reduction due to in-device coexistence from the other terminal 20, the terminal 20 determines that the resource with reduced transmit power can be used. If the terminal 20 does not receive information regarding transmit power reduction due to in-device coexistence from the other terminal 20, the terminal 20 may determine that the resource is unusable and exclude it from the set of candidate resources that can use the resource. In other words, the terminal 20 can determine whether to use the resource based on information regarding transmit power reduction received from the other terminal 20.

[0139] 2) Terminal 20 determines that resources with reduced transmit power can be used only when the power value (e.g., RSRP) of the PSCCH / PSSCH received from another terminal 20 is lower than or equal to a predetermined value. If the power value (e.g., RSRP) of the PSCCH / PSSCH received from another terminal 20 is higher than or equal to a predetermined value, terminal 20 excludes the corresponding resource from the set of available resource candidates. In other words, terminal 20 can determine whether a resource can be used based on the power value received from the other terminal 20.

[0140] 3) In the resource identification action, taking the resources indicated by the SCI received from other terminals 20 as the object, the terminal 20 subtracts the transmission power reduction amount caused by the coexistence within the device from the power value (e.g., RSRP) of the PSCCH / PSSCH received by the other terminal 20 (e.g., when a 3dB reduction is notified, 3dB is subtracted from the power value), and uses the subtracted transmission power value to determine whether the resource can be used.

[0141] As operations based on information on reduction in transmission power in resources transmitted from other terminals 20 , the terminal 20 may perform operations shown in 1) to 3) below.

[0142] 1) During resource identification, with respect to resources indicated by the SCI received from other terminals 20, if the terminal 20 receives information regarding transmit power reduction due to in-device coexistence, the terminal 20 may determine that the resource with reduced transmit power is usable. If the terminal 20 does not receive information regarding transmit power reduction due to in-device coexistence, the terminal 20 may determine that the resource is unusable and exclude it from the set of candidate resources that can use the resource. In other words, the terminal 20 can determine whether to use the resource based on information regarding transmit power reduction received from the other terminal 20.

[0143] 2) Terminal 20 may determine that the resource corresponding to the resource with reduced transmit power can be used only when the power value (e.g., RSRP) of the PSCCH / PSSCH received from another terminal 20 is lower than or equal to a predetermined value. If the power value (e.g., RSRP) of the PSCCH / PSSCH received from another terminal 20 is higher than or equal to a predetermined value, terminal 20 may exclude the corresponding resource from the set of available resource candidates. In other words, terminal 20 may determine whether to use a resource based on the power value received from another terminal 20.

[0144] 3) In the resource identification action, taking the resource indicated by the SCI received from the other terminal 20 as the object, the terminal 20 adds the power value of the PSCCH / PSSCH received from the other terminal 20 (for example, RSRP) and the transmission power reduction amount caused by the above-mentioned coexistence within the device (for example, when a 3dB reduction is notified, the power value is added by 3dB), and uses the added transmission power value to determine whether the resource can be used.

[0145] Furthermore, resource identification may be an action of determining unusable resources and excluding them from the set of available candidate resources. Furthermore, the terminal 20 described above may not be limited to being the SL transmission destination of other terminals 20 but may also be the target of multicast or broadcast from other terminals 20.

[0146] As described above, the terminal 20 can perform resource selection based on the actual received power prediction value after the transmission power reduction, thereby improving the performance of collision avoidance.

[0147] The information D) about the reserved but unused scheduled resources may be information about a resource that is available but not used, or information about a resource that cannot be used. For example, the processing of the information may also be applied to the situations 1) to 5) below.

[0148] 1) Although resource reservation is performed, the transport block is successfully sent (i.e., ACK is received) and no retransmission is required

[0149] 2) Although resources are reserved, the retransmission of the first transport block is suspended or postponed due to the occurrence of further important SL data.

[0150] 3) Although resources are reserved, they are preempted by other terminals 20 (pre-emption)

[0151] 4) Although resources are reserved, transmission is suspended or postponed due to overlap with UL transmission at least in the time domain

[0152] 5) Although resources are reserved, the decision formula (Σ i≧ k CR(i)≦CR Limit (k)) If delivery is suspended or delayed due to

[0153] In addition, CR (channel occupancy ratio) is an indicator related to the resources used by the device itself, and CBR (channel busy ratio) is an indicator related to the resources used by other devices. CR(i) is the CR evaluation value in time slot nN used for PSSCH transmission with priority field i in SCI. Limit (k) corresponds to the higher-layer parameter sl-CR-Limit and is associated with a CBR range that includes priority k and the CBR measured in time slot nN. N is the processing time for congestion control. Furthermore, pre-emption can mean that terminal 20 receives a signal from another terminal 20 notifying it of resources reserved for that terminal 20.

[0154] In addition, the information related to the reserved but unused scheduled resources can be information indicating the unused resources or information indicating the reason for non-use. In addition, the resource reservation can be made based on an indication based on the time resource allocation field in the SCI or based on an indication based on the resource reservation period field.

[0155] As described above, by notifying the other terminal 20 of information on the reserved but unused planned resources, it is possible to grasp the resource utilization status more accurately.

[0156] Figure 20 FIG2 is a diagram showing an example of information on unused resources in an embodiment of the present invention. The terminal 20 can perform resource allocation based on information on reserved but unused resources received from other terminals 20.

[0157] For example, Figure 20 As shown, when terminal 20C targets a resource indicated by the SCI received from terminal 20A by terminal 20B based on a notification from terminal 20A or terminal 20B, and further receives a notification from terminal 20A or terminal 20B that the resource will not be used, terminal 20C can determine that the resource can be used and not exclude it from the set of available candidate resources. If terminal 20A or terminal 20B does not receive a notification that the resource will not be used, terminal 20C can determine that the resource cannot be used and perform resource exclusion.

[0158] Furthermore, the terminal 20C can determine whether the resource can be used without being excluded from the set of available candidate resources based on the priority in the SCI received from the terminal 20A and / or the priority in the predetermined SCI transmitted by the terminal 20C.

[0159] As described above, by notifying the other terminal 20 of information on the reserved but unused resources, the terminal 20 can use the unused resources, thereby improving the efficiency of resource use.

[0160] According to the above-described embodiment, the terminal 20 can perform resource selection based on information notified from other terminals 20 , thereby reducing the probability of resource conflict and improving resource usage efficiency.

[0161] That is, in inter-terminal direct communication, communication quality can be improved based on information notified from other terminals.

[0162] (Device Structure)

[0163] Next, the functional configuration examples of the base station 10 and terminal 20 that perform the above-described processing and operations are described. The base station 10 and terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and terminal 20 may each include only a portion of the functions described in the embodiments.

[0164] <Base Station 10>

[0165] Figure 21 1 is a diagram showing an example of the functional configuration of the base station 10. Figure 21 As shown, the base station 10 includes a transmitting unit 110 , a receiving unit 120 , a setting unit 130 , and a control unit 140 . Figure 21 The functional configuration shown is merely an example, and any functional divisions and names of functional units may be used as long as the operations according to the embodiments of the present invention can be executed.

[0166] The transmitter 110 includes a function of generating a signal to be transmitted to the terminal 20 and wirelessly transmitting the signal. The receiver 120 includes a function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher-layer information from the received signals. Furthermore, the transmitter 110 includes a function of transmitting the NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, and the like to the terminal 20.

[0167] The setting unit 130 stores pre-set setting information and various setting information to be sent to the terminal 20 in a storage device, and reads the setting information from the storage device as needed. The content of the setting information is, for example, information related to the setting of D2D communication.

[0168] As described in the embodiments, the control unit 140 performs processing related to the configuration for the terminal 20 to perform D2D communication. Furthermore, the control unit 140 transmits the schedule for D2D communication and DL communication to the terminal 20 via the transmission unit 110. Furthermore, the control unit 140 receives information related to HARQ responses for D2D communication and DL communication from the terminal 20 via the reception unit 120. Functional units related to signal transmission within the control unit 140 may be included in the transmission unit 110, while functional units related to signal reception within the control unit 140 may be included in the reception unit 120.

[0169] <Terminal 20>

[0170] Figure 22 2 is a diagram showing an example of the functional structure of the terminal 20. Figure 22 As shown, the terminal 20 includes a transmitting unit 210 , a receiving unit 220 , a setting unit 230 , and a control unit 240 . Figure 22 The functional configuration shown is merely an example, and any functional divisions and names of functional units may be used as long as the operations according to the embodiments of the present invention can be executed.

[0171] The transmitting unit 210 generates a transmission signal based on the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 receives various signals wirelessly and obtains higher-layer signals from the received physical layer signals. In addition, 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. In addition, for example, as D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0172] The configuration unit 230 stores various configuration information received by the receiving unit 220 from the base station 10 or the terminal 20 in a storage device and reads it from the storage device as needed. Furthermore, the configuration unit 230 also stores pre-set configuration information. This configuration information may include, for example, information related to D2D communication configuration.

[0173] As described in the embodiment, the control unit 240 controls D2D communication with other terminals 20. Furthermore, the control unit 240 performs processing related to HARQ for D2D communication and DL communication. Furthermore, the control unit 240 transmits to the base station 10 information related to HARQ responses for D2D communication and DL communication to other terminals 20, which are scheduled from the base station 10. Furthermore, the control unit 240 may also schedule D2D communication for other terminals 20. Furthermore, the control unit 240 may autonomously select resources used for D2D communication from a resource selection window based on monitoring results. Furthermore, the control unit 240 performs processing related to PSBCH transmission and reception for D2D communication. Functional units related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and functional units related to signal reception in the control unit 240 may be included in the receiving unit 220.

[0174] (Hardware Structure)

[0175] The block diagram used in the description of the above embodiment ( Figure 21 and Figure 22) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a device that is physically or logically combined, or it can be implemented by connecting two or more physically or logically separated devices directly or indirectly (for example, using wired or wireless connections) and using these multiple devices. The functional block can also be implemented by combining software with the above-mentioned one device or the above-mentioned multiple devices.

[0176] Functionally, these include, but are not limited to, judging, deciding, determining, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, resolving, selecting, choosing, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning. For example, a functional block (structural unit) that enables the transmission function is called a transmitting unit or a transmitter. In short, as described above, there is no particular limitation on the implementation method.

[0177] For example, the base station 10 , the terminal 20 , and the like in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 23 This figure shows an example of the hardware configuration of a base station 10 and a terminal 20 according to one embodiment of the present disclosure. The base station 10 and the terminal 20 described above can also be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0178] In the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and the terminal 20 may include one or more of the devices shown in the figures, or may exclude some of the devices.

[0179] The various functions in 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 the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0180] Processor 1001 controls the entire computer by, for example, running an operating system. Processor 1001 may also be comprised of a central processing unit (CPU) that includes interfaces with peripheral devices, a control device, a computing device, registers, and the like. For example, control unit 140 and control unit 240 described above may also be implemented by processor 1001.

[0181] In addition, the processor 1001 reads a program (program code), a software module, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and performs various processes based on the program. As a program, a program that causes the computer to execute at least a part of the actions described in the above embodiment is used. For example, Figure 21 The control unit 140 of the base station 10 shown may also be implemented by a control program stored in the storage device 1002 and executed in the processor 1001. Figure 22 The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and executed by the processor 1001. Regarding the various processes described above, although they are described as being executed by a single processor 1001, they can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be implemented on one or more chips. Furthermore, the program can be transmitted from a network via a telecommunications line.

[0182] The storage device 1002 is a computer-readable recording medium and may be composed of, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and RAM (Random Access Memory). The storage device 1002 may also be referred to as a register, cache, or main memory (main storage device). The storage device 1002 can store executable programs (program code), software modules, and the like for implementing the communication method according to one embodiment of the present disclosure.

[0183] The auxiliary storage device 1003 is a computer-readable recording medium, and can be composed of at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (for example, a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic stripe, etc. The above-mentioned storage medium can be, for example, a database, a server, or other appropriate medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0184] Communication device 1004 is hardware (a transceiver) used to communicate between computers via at least one of a wired network and a wireless network. It is also referred to as a network device, network controller, network card, or communication module. Communication device 1004 may include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, communication device 1004 may also implement a transceiver antenna, an amplifier, a transceiver, a transmission path interface, and the like. The transceiver may also be physically or logically separated from the transmitter and receiver.

[0185] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to the outside (e.g., a display, speaker, LED light, etc.). Alternatively, the input device 1005 and the output device 1006 may be integrally formed (e.g., a touch panel).

[0186] Furthermore, the processor 1001, the storage device 1002, and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using separate buses for each device.

[0187] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array), and may implement some or all of the functional blocks using this hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0188] (Summary of Implementation Methods)

[0189] As described above, according to an embodiment of the present invention, a terminal is provided, comprising: a receiving unit that receives information related to direct communication between terminals for determining usable resources from other terminals; a control unit that identifies resource candidates based on the information and selects the resources to be used; and a sending unit that uses the selected resources to perform sending in direct communication between terminals.

[0190] With the above configuration, the terminal 20 can perform resource selection based on information notified from other terminals 20, thereby reducing the probability of resource conflicts and improving resource utilization efficiency. In other words, in inter-terminal direct communication, communication quality can be improved based on information notified from other terminals.

[0191] The information may be information related to transmission power reduction due to in-device coexistence. According to this configuration, the terminal 20 can perform resource selection based on information notified from other terminals 20, thereby improving resource usage efficiency.

[0192] The control unit can determine that resources to which the transmit power reduction is applied can be used based on the information related to the transmit power reduction due to intra-device coexistence. With this configuration, terminal 20 can perform resource selection based on information notified from other terminals 20, thereby improving resource usage efficiency.

[0193] The information may be information about unused resources among the reserved resources. According to this configuration, the terminal 20 can perform resource selection based on information notified from other terminals 20, thereby improving resource utilization efficiency.

[0194] The control unit can determine that the unused resources are available based on the information about the unused resources among the reserved resources. According to this configuration, the terminal 20 can perform resource selection based on information notified from other terminals 20, thereby improving resource utilization efficiency.

[0195] In addition, according to an embodiment of the present invention, a communication method performed by a terminal is provided, wherein the terminal performs the following steps: a receiving step of receiving information related to direct communication between terminals for determining available resources from other terminals; a control step of identifying resource candidates based on the information and selecting the resources to be used; and a sending step of using the selected resources to perform sending in direct communication between terminals.

[0196] With the above configuration, the terminal 20 can perform resource selection based on information notified from other terminals 20, thereby reducing the probability of resource conflicts and improving resource utilization efficiency. In other words, in inter-terminal direct communication, communication quality can be improved based on information notified from other terminals.

[0197] (Supplementary Implementation Methods)

[0198] The above describes the embodiments of the present invention, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, substitutions, and replacements. Specific numerical examples are used to facilitate understanding of the invention, but unless otherwise specified, these numerical values are merely examples, and any appropriate value may be used. The distinction between the items in the above description is not essential to the present invention. Matters recorded in two or more items may be combined and used as needed, and matters recorded in one item may be applied to matters recorded 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. The actions of multiple functional units may be performed by a single physical component, or the actions of one functional unit may be performed by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing may be reversed if there is no contradiction. For the convenience of explaining the processing, the base station 10 and the terminal 20 are described using functional block diagrams, but such devices may also be implemented using hardware, software, or a combination thereof. The software that operates by the processor of the base station 10 according to the embodiment of the present invention and the software that operates by the processor of the terminal 20 according to the embodiment of the present invention can also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server and any other appropriate storage medium.

[0199] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information can be implemented through physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), high-layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, RLC (Radio Link Control) signaling, PDCP (Packet Data Convergence Protocol) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals or a combination thereof. In addition, RRC signaling may also be referred to as an RRC message, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc. In addition, the notification of information may be carried out using certain channels, for example, PSCCH, PSSCH, PSFCH, PSBCH.

[0200] Each form / embodiment described in this disclosure may also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems derived therefrom. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G) may also be applied.

[0201] The processing procedures, timings, and flows of each form / implementation described in this specification may be performed in a different order unless there is a conflict. For example, the methods described in this disclosure use an illustrative order to present the elements of various steps, but are not limited to the specific order presented.

[0202] In this specification, specific operations performed by base station 10 may also be performed by its upper node depending on the situation. In a network consisting of one or more network nodes including base station 10, various operations performed to communicate with terminal 20 can be performed by at least one of base station 10 and other network nodes other than base station 10 (e.g., MME or S-GW, but not limited to these). While the above example illustrates a single other network node other than base station 10, the other network node may also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0203] The information or signals described in this disclosure can be output from a higher layer (or lower layer) to a lower layer (or higher layer), and can also be input or output via multiple network nodes.

[0204] 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.

[0205] The determination in the present disclosure may be performed using a value represented by one bit (0 or 1), a Boolean value (Boolean: true or false), or a comparison of numerical values (for example, comparison with a predetermined value).

[0206] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to instructions, sets of instructions, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0207] Furthermore, software, commands, information, and the like 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 a wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and a wireless technology (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0208] The information, signals, etc. described in this disclosure may also be represented using any of a variety of different technologies. For example, data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be referred to in the entire description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0209] In addition, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0210] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0211] In addition, the information, parameters, etc. described in this disclosure may be represented by absolute values, relative values relative to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0212] The names used for the above parameters are not limiting in any way. Furthermore, the formulas and the like using these parameters may sometimes differ from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting in any way.

[0213] 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" are used interchangeably. Base stations are sometimes also referred to as macrocells, small cells, femtocells, and picocells.

[0214] A base station can accommodate one or more (for example, three) cells. When a base station accommodates multiple cells, the base station's overall coverage area can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (for example, a small base station for indoor use (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a portion or the entire coverage area of at least one of the base station and base station subsystem that provide communication services within the coverage area.

[0215] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0216] For mobile stations, those skilled in the art sometimes also use the following terms to refer to them: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client or some other appropriate terms.

[0217] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), a mobile body that moves unmanned (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0218] In addition, the base station in the present disclosure can also be replaced by a user terminal. For example, regarding a structure in which the communication between the base station and the user terminal is replaced by the communication between multiple terminals 20 (for example, it can also be called D2D (Device-to-Device), V2X (Vehicle-to-Everything: vehicle to everything system), etc.), the various forms / implementations of the present disclosure can also be applied. In this case, it can also be set as a structure in which the terminal 20 has the functions of the above-mentioned base station 10. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can also be replaced by side channels.

[0219] Likewise, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station may also have the functions of the user terminal described above.

[0220] As used in this disclosure, terms such as “determining” and “determining” sometimes also include a variety of actions. “Determining” and “judging” may, for example, include considering matters such as judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (for example, searching in a table, database or other data structure), and ascertaining as matters that have been “determined” or “determined”. In addition, “determining” and “receiving” (for example, receiving information), transmitting (for example, sending information), inputting, outputting, accessing (for example, accessing data in a memory) as matters that have been “determined” or “determined”. In addition, “determining” and “resolving” may include matters such as selecting, choosing, establishing, and comparing as matters that have been “determined” or “determined”. That is, "judgment" and "decision" can include matters that are considered to have "judged" or "decided" any action. In addition, "judgment (decision)" can also be replaced by "assuming (assuming)", "expecting (expecting)", "considering (considering)", etc.

[0221] The terms "connected", "coupled" or any variation of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include situations where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used instead of "connection". As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the wireless frequency domain, microwave region and optical (visible and invisible) region may be used to "connect" or "couple" to each other.

[0222] The reference signal may be referred to as RS (Reference Signal) for short, or may be called a pilot signal depending on the applied standard.

[0223] The phrase "according to" used in this disclosure does not mean "only according to" unless otherwise expressly stated. In other words, the phrase "according to" means both "only according to" and "at least according to."

[0224] Any reference to an element using the terms "first," "second," etc., as used in this disclosure, does not necessarily limit the number or order of these elements. These terms can be used as a convenient way to distinguish between two or more elements in this disclosure. Therefore, a reference to a first element and a second element does not imply that only two elements can be used or that the first element must precede the second element in any manner.

[0225] The “unit” in the configuration of each of the above-mentioned devices may be replaced with a “section,” “circuit,” “device,” or the like.

[0226] When the terms "include," "including," and variations thereof are used in this disclosure, these terms, like the term "comprising," are intended to be inclusive. Furthermore, the term "or" used in this disclosure does not mean an exclusive or.

[0227] A radio frame can be composed of one or more frames in the time domain. In the time domain, one or more frames can be called a subframe. A subframe can be further composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) that is independent of the numerology.

[0228] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a signal or channel. For example, the parameter set may 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 performed by the transceiver in the frequency domain, specific windowing performed by the transceiver in the time domain, and the like.

[0229] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0230] A time slot may contain multiple mini-slots. Each mini-slot may consist of one or more symbols in the time domain. Furthermore, a mini-slot may also be referred to as a sub-slot. A mini-slot may consist of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in time units larger than a mini-slot may be referred to as PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as PDSCH (or PUSCH) mapping type B.

[0231] Radio frame, subframe, time slot, mini-time slot, and symbol all represent time units for signal transmission. Radio frame, subframe, time slot, mini-time slot, and symbol may be referred to by other corresponding names.

[0232] For example, a subframe can also be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and a slot or a mini-slot can also be called a TTI. That is, at least one of a subframe and a TTI can be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. Furthermore, the unit representing a TTI can be a slot, a mini-slot, or the like, rather than a subframe.

[0233] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communications. For example, in the LTE system, a base station schedules each terminal 20 by allocating wireless resources (such as the frequency bandwidth and transmit power available to each terminal 20) in units of TTI. The definition of TTI is not limited to this.

[0234] The TTI can be the time unit for transmitting data packets (transport blocks), code blocks, code words, etc. after channel coding, and can also be the processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the time interval (for example, the number of symbols) to which the transport blocks, code blocks, code words, etc. are actually mapped can be shorter than the TTI.

[0235] In addition, when one time slot or one mini-time slot is referred to as a TTI, one or more TTIs (i.e., one or more time slots or one or more mini-time slots) can constitute the minimum time unit for scheduling. In addition, the number of time slots (the number of mini-time slots) constituting the minimum time unit for scheduling can be controlled.

[0236] A TTI with a time length of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a time slot, etc.

[0237] In addition, for long TTI (for example, normal TTI, subframe, etc.), it can be replaced with a TTI with a time length of more than 1ms, and for short TTI (for example, shortened TTI, etc.), it can be replaced with a TTI length that is smaller than long TTI (longTTI) and has a TTI length of more than 1ms.

[0238] A resource block (RB) is a unit of resource allocation in the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers contained in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers contained in an RB can also be determined by the parameter set.

[0239] In addition, the time domain of an RB may include one or more symbols and may be the length of one slot, one mini-slot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0240] In addition, one or more RBs may be referred to as a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, and the like.

[0241] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0242] A bandwidth part (BWP) (also known as a fractional bandwidth) can represent a subset of contiguous common resource blocks (RBs) used for a parameter set within a carrier. Common RBs can be identified by their index relative to the common reference point of the carrier. PRBs can be defined within a BWP and numbered within that BWP.

[0243] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be configured for the terminal 20 within one carrier.

[0244] At least one of the set BWPs may be active, and it is not assumed that the terminal 20 transmits or receives predetermined signals / channels outside the active BWP. In addition, "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

[0245] The above-described structures of radio frames, subframes, slots, mini-slots, and symbols are merely examples. For example, various modifications may be made to the structures including the number of subframes in a radio frame, the number of slots per subframe or radio frame, the number of mini-slots in a slot, the number of symbols and RBs in a slot or mini-slot, the number of subcarriers in an RB, the number of symbols in a TTI, the symbol length, and the cyclic prefix (CP) length.

[0246] In the present disclosure, when an article is added by translation, such as a, an, and the in English, the present disclosure may also include cases where the noun following the article is in a plural form.

[0247] In this disclosure, the phrase "A is different from B" may also mean "A and B are different from each other." Furthermore, the phrase may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

[0248] Each form / implementation described in this disclosure may be used individually or in combination, and may be switched between them depending on the execution. Furthermore, notification of scheduled information is not limited to being performed explicitly (e.g., a notification of "yes X") but may also be performed implicitly (e.g., not notifying the scheduled information).

[0249] While the present disclosure has been described in detail above, it should 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 various modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes only and does not have any limiting meaning on the present disclosure.

[0250] Label Description

[0251] 10: base station;

[0252] 110: Sending department;

[0253] 120: receiving unit;

[0254] 130: Setting department;

[0255] 140: Control Department;

[0256] 20: terminal;

[0257] 210: Sending department;

[0258] 220: receiving unit;

[0259] 230: Setting department;

[0260] 240: Control Department;

[0261] 30: GNSS;

[0262] 1001: processor;

[0263] 1002: storage device;

[0264] 1003: auxiliary storage device;

[0265] 1004: Communication device;

[0266] 1005: input device;

[0267] 1006: Output device.

Claims

1. A terminal comprising: a receiving unit configured to receive control information from the first terminal via the control channel; and a transmitting unit that transmits information for avoiding a conflict between a first resource and a second resource to a second terminal, the first resource being indicated by the control information, the first terminal using the first resource when transmitting a PSSCH as a shared channel, and the second terminal using the second resource when transmitting the PSSCH as a shared channel; The transmitting unit transmits information for avoiding the collision to the second terminal in a transmission opportunity for a feedback channel corresponding to a reception time slot of the control information via the control channel.

2. The terminal according to claim 1, wherein: The transmitting unit transmits information for avoiding the collision to the second terminal in a transmission opportunity for a feedback channel corresponding to the first resource indicated by the control information.

3. A communication method performed by a terminal, wherein: The following steps are involved: a receiving step of receiving control information from the first terminal via a control channel; as well as a sending step of sending information for avoiding a conflict between a first resource and a second resource to a second terminal, wherein the first resource is indicated by the control information, the first terminal uses the first resource when transmitting a PSSCH as a shared channel, and the second terminal uses the second resource when transmitting the PSSCH as a shared channel; The transmitting step transmits information for avoiding the collision to the second terminal in a transmission opportunity for a feedback channel corresponding to a reception time slot of the control information via the control channel.

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