Terminals and communication methods

Abstract

This terminal comprises: a reception unit that receives, from another terminal, a signal for reserving a resource in a resource pool; a control unit that detects collision in the reserved resource; and a transmission unit that, when the control unit detects the collision in the reserved resource, transmits a signal related to the resource collision to the other terminal. The reception unit receives, from the other terminal 20, a signal using a resource that is different from the reserved resource.

Description

Technical Field

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

Background Art

[0002] In LTE (Long Term Evolution) and successor systems of LTE (for example, LTE-A (LTE Advanced), NR (New Radio) (also referred to as 5G)), D2D (Device to Device) technology in which terminals communicate directly without going through a base station has been studied (for example, Non-Patent Document 1).

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

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

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] As an enhancement to NR sidelinks, eURLLC (enhanced Ultra Reliable Low Latency Communication) is being considered. For example, in Resource allocation mode 2, where terminals autonomously select resources, terminal 20A shares information indicating the resource set with terminal 20B, and terminal 20B considers this information when selecting resources for transmission, thereby improving communication reliability and reducing latency.

[0007] On the other hand, in resource allocation mode 2, when the transmitting terminal performs sensing, for example, if other terminals exist outside the line of sight of the transmitting terminal, the quality of the resource at the receiving terminal may differ significantly from the quality based on the results of the transmitting terminal's sensing of that resource.

[0008] This invention has been made in view of the above points, and aims to improve the reliability of communication during autonomous resource selection in direct communication between terminals. [Means for solving the problem]

[0009] According to the disclosed technology, a first terminal includes a receiving unit that receives reservation information from the second terminal for reserving a first resource used for transmitting a shared channel for inter-terminal communication by the second terminal, and from the first resource reserved by the reservation information First periodA terminal is provided, comprising: a control unit that determines a time resource to transmit information regarding a collision between the first resource and the second resource based on retrospective time resources; and a transmission unit that transmits the collision information to the second terminal via a feedback channel for inter-terminal communication at the determined time resource. [Effects of the Invention]

[0010] According to the disclosed technology, the reliability of communication during autonomous resource selection in direct terminal-to-terminal communication can be improved. [Brief explanation of the drawing]

[0011] [Figure 1] This is a diagram to explain V2X. [Figure 2] This is a diagram illustrating an example of a V2X transmission mode (1). [Figure 3] This is a diagram illustrating an example of a V2X transmission mode (2). [Figure 4] This is a diagram illustrating an example of a V2X transmission mode (3). [Figure 5] This is a diagram illustrating an example of a V2X transmission mode (4). [Figure 6] This is a diagram illustrating an example of a V2X transmission mode (5). [Figure 7] This is a diagram illustrating an example of a V2X communication type (1). [Figure 8] This is a diagram illustrating an example of a V2X communication type (2). [Figure 9] This is a diagram illustrating example (3) of V2X communication types. [Figure 10] This is a sequence diagram showing an example of V2X operation (1). [Figure 11] This is a sequence diagram showing an example of V2X operation (2). [Figure 12] This is a sequence diagram showing an example of V2X operation (3). [Figure 13] This is a sequence diagram showing an example of V2X operation (4). [Figure 14] This figure shows an example of sensing operation. [Figure 15] This is a flowchart illustrating an example of preemption behavior. [Figure 16] This figure shows an example of preemption behavior. [Figure 17] This figure shows an example of partial sensing operation. [Figure 18] This is a diagram illustrating an example of communication conditions (1). [Figure 19] This is a diagram illustrating example (2) of the communication status. [Figure 20] This is a diagram illustrating example (3) of the communication status. [Figure 21] This is a diagram illustrating example (4) of the communication status. [Figure 22] This is a diagram illustrating example (5) of the communication status. [Figure 23] This figure illustrates an example (1) of inter-UE cooperation in an embodiment of the present invention. [Figure 24] This figure illustrates an example (2) of inter-UE cooperation in an embodiment of the present invention. [Figure 25] This figure illustrates an example (3) of inter-UE cooperation in an embodiment of the present invention. [Figure 26] This figure illustrates an example (4) of inter-UE cooperation in an embodiment of the present invention. [Figure 27] This figure shows an example of the functional configuration of the base station 10 in an embodiment of the present invention. [Figure 28] This figure shows an example of the functional configuration of terminal 20 in an embodiment of the present invention. [Figure 29] This figure shows an example of the hardware configuration of a base station 10 or terminal 20 in an embodiment of the present invention. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiments described below are examples, and the embodiments to which the present invention is applied are not limited to those described below.

[0013] In the operation of the wireless communication system according to the embodiments of the present invention, existing technologies may be used as appropriate. However, such existing technologies include, for example, existing LTE, but are not limited to existing LTE. Furthermore, the term "LTE" as used herein has a broad meaning that includes LTE-Advanced and LTE-Advanced and later methods (e.g., NR), or wireless LAN (Local Area Network), unless otherwise specified.

[0014] Furthermore, in the embodiments of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or any other method (for example, a Flexible Duplex).

[0015] Furthermore, in the embodiments of the present invention, "configuring" wireless parameters may mean that predetermined values ​​are pre-configured, or that wireless parameters notified from the base station 10 or terminal 20 are configured.

[0016] Figure 1 is a diagram illustrating V2X. 3GPP is considering and working on specifications to realize V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality. As shown in Figure 1, V2X is a part of ITS (Intelligent Transport Systems) and is a general term encompassing V2V (Vehicle to Vehicle), which refers to communication between vehicles; V2I (Vehicle to Infrastructure), which refers to communication between vehicles and roadside units (RSUs) installed along the roadside; V2N (Vehicle to Network), which refers to communication between vehicles and ITS servers; and V2P (Vehicle to Pedestrian), which refers to communication between vehicles and mobile terminals carried by pedestrians.

[0017] Furthermore, 3GPP is considering V2X using LTE or NR cellular communication and terminal-to-terminal communication. V2X using cellular communication is also called cellular V2X. For NR V2X, research is underway to achieve high capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0018] Regarding LTE or NR V2X, it is anticipated that future considerations will extend beyond 3GPP specifications. For example, it is expected that considerations will be given to ensuring interoperability, reducing costs through the implementation of higher layers, methods for using or switching between multiple RATs (Radio Access Technologies), compliance with regulations in various countries, and methods for data acquisition, distribution, database management, and utilization of LTE or NR V2X platforms.

[0019] While the embodiments of the present invention primarily envision a configuration in which the communication device is mounted on a vehicle, the embodiments of the present invention are not limited to this configuration. For example, the communication device may be a terminal held by a person, a device mounted on a drone or aircraft, or a base station, RSU, relay station (relay node), terminal with scheduling capabilities, etc.

[0020] Furthermore, SL (Sidelink) may be distinguished from UL (Uplink) or DL ​​(Downlink) based on any one or a combination of the following 1)-4). Also, SL may have other names. 1) Resource allocation in the time domain 2) Resource allocation in the frequency domain 3) Reference synchronization signals (including SLSS (Sidelink Synchronization Signal)) 4) Reference signal used for path loss measurement for transmit power control

[0021] Furthermore, with respect to SL or UL OFDM (Orthogonal Frequency Division Multiplexing), any of the following may be applied: CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform - Spread - OFDM), OFDM without transform precoding, or OFDM with transform precoding.

[0022] In LTE's Downlink Service Line (SL), Mode 3 and Mode 4 are defined for allocating SL resources to terminal 20. In Mode 3, transmission resources are dynamically allocated via DCI (Downlink Control Information) sent from base station 10 to terminal 20. Semi-Persistent Scheduling (SPS) is also possible in Mode 3. In Mode 4, terminal 20 autonomously selects transmission resources from the resource pool.

[0023] In the embodiments of the present invention, the term "slot" may be interpreted as a symbol, mini-slot, subframe, wireless frame, or TTI (Transmission Time Interval). Furthermore, in the embodiments of the present invention, the term "cell" may be interpreted as a cell group, carrier component, BWP, resource pool, resource, RAT (Radio Access Technology), system (including wireless LAN), etc.

[0024] In the embodiments of the present invention, terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, terminal 20 may be a user-owned terminal such as a smartphone, or it may be an IoT (Internet of Things) device such as a smart meter.

[0025] Figure 2 is a diagram illustrating an example of a V2X transmission mode (1). In the sidelink communication transmission mode shown in Figure 2, in step 1, the base station 10 transmits the sidelink scheduling to terminal 20A. Subsequently, terminal 20A transmits the PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to terminal 20B based on the received scheduling (step 2). The sidelink communication transmission mode shown in Figure 2 may also be called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu is the radio interface between UTRAN (Universal Terrestrial Radio Access Network) and UE (User Equipment). The sidelink communication transmission mode shown in Figure 2 may also be called sidelink transmission mode 1 in NR.

[0026] Figure 3 is a diagram illustrating an example (2) of the V2X transmission mode. In the sidelink communication transmission mode shown in Figure 3, in step 1, terminal 20A uses autonomously selected resources to transmit PSCCH and PSSCH to terminal 20B. The sidelink communication transmission mode shown in Figure 3 may also be called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0027] Figure 4 is a diagram illustrating an example of a V2X transmission mode (3). In the sidelink communication transmission mode shown in Figure 4, in step 1, terminal 20A uses autonomously selected resources to transmit PSCCH and PSSCH to terminal 20B. Similarly, terminal 20B uses autonomously selected resources to transmit PSCCH and PSSCH to terminal 20A (step 1). The sidelink communication transmission mode shown in Figure 4 may also be called sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, terminal 20 itself performs resource selection.

[0028] Figure 5 is a diagram illustrating an example of a V2X transmission mode (4). In the sidelink communication transmission mode shown in Figure 5, in step 0, the sidelink resource pattern is transmitted from the base station 10 to terminal 20A via RRC (Radio Resource Control) settings, or is pre-configured. Subsequently, terminal 20A transmits PSSCH to terminal 20B based on the resource pattern (step 1). The sidelink communication transmission mode shown in Figure 5 may also be called the sidelink transmission mode 2c in NR.

[0029] Figure 6 is a diagram illustrating an example of a V2X transmission mode (5). In the sidelink communication transmission mode shown in Figure 6, in step 1, terminal 20A transmits the sidelink scheduling to terminal 20B via PSCCH. Subsequently, terminal 20B transmits PSSCH to terminal 20A based on the received scheduling (step 2). The sidelink communication transmission mode shown in Figure 6 may also be called the sidelink transmission mode 2d in NR.

[0030] Figure 7 is a diagram illustrating an example of a V2X communication type (1). The sidelink communication type shown in Figure 7 is unicast. Terminal 20A transmits PSCCH and PSSCH to Terminal 20. In the example shown in Figure 7, Terminal 20A unicasts to Terminal 20B and also unicasts to Terminal 20C.

[0031] Figure 8 is a diagram illustrating an example (2) of V2X communication types. The sidelink communication type shown in Figure 8 is a group cast. Terminal 20A sends PSCCH and PSSCH to a group to which one or more terminals 20 belong. In the example shown in Figure 8, the group includes terminals 20B and 20C, and terminal 20A performs a group cast to the group.

[0032] Figure 9 is a diagram illustrating an example of a V2X communication type (3). The sidelink communication type shown in Figure 9 is broadcast. Terminal 20A sends PSCCH and PSSCH to one or more terminals 20. In the example shown in Figure 9, terminal 20A broadcasts to terminals 20B, 20C, and 20D. Note that terminal 20A shown in Figures 7 to 9 may also be referred to as the header UE.

[0033] Furthermore, it is anticipated that NR-V2X will support HARQ (Hybrid automatic repeat request) for sidelink unicast and groupcast. In addition, NR-V2X will define SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Moreover, it is being considered that SFCI will be transmitted via PSFCH (Physical Sidelink Feedback Channel).

[0034] Note that the following explanation assumes the use of PSFCH for transmitting HARQ-ACK over a sidelink, but this is just one example. For example, you may use PSCCH to transmit HARQ-ACK over a sidelink, or PSSCH, or any other channel to transmit HARQ-ACK over a sidelink.

[0035] In the following, for convenience, all information reported by terminal 20 in HARQ will be referred to as HARQ-ACK. This HARQ-ACK may also be called HARQ-ACK information. More specifically, the codebook applied to the HARQ-ACK information reported from terminal 20 to base station 10, etc., will be called the HARQ-ACK codebook. The HARQ-ACK codebook defines the bit sequence of the HARQ-ACK information. In addition to ACK, NACK is also transmitted with "HARQ-ACK".

[0036] Figure 10 is a sequence diagram showing an example of V2X operation (1). As shown in Figure 10, the wireless communication system according to the embodiment of the present invention may have terminals 20A and 20B. In reality, there are many user devices, but Figure 10 shows terminals 20A and 20B as examples.

[0037] Hereafter, unless otherwise specified, terminals 20A, 20B, etc., will simply be referred to as "terminal 20" or "user device." Figure 10 shows an example where both terminal 20A and terminal 20B are within the cell coverage, but the operation in the embodiment of the present invention can also be applied when terminal 20B is outside the coverage.

[0038] As described above, in this embodiment, terminal 20 is, for example, a device mounted on a vehicle such as an automobile, and has cellular communication functionality as a UE in LTE or NR, as well as side-link functionality. Terminal 20 may be a general mobile terminal (such as a smartphone). Alternatively, terminal 20 may be an RSU. The RSU may be a UE-type RSU with UE functionality, or a gNB-type RSU with base station functionality.

[0039] Furthermore, the terminal 20 does not need to be a single-casing device; for example, even if various sensors are distributed throughout the vehicle, the device including these various sensors may be considered the terminal 20.

[0040] Furthermore, the processing of the sidelink transmission data of terminal 20 is basically the same as the processing of UL transmission in LTE or NR. For example, terminal 20 scrambles the codeword of the transmission data, modulates it to generate complex-valued symbols, maps these complex-valued symbols (transmission signal) to one or two layers, and performs precoding. Then, it maps the precoded complex-valued symbols to resource elements to generate a transmission signal (e.g., a complex-valued time-domain SC-FDMA signal) and transmits it from each antenna port.

[0041] The base station 10 has the functionality of a cellular communication base station in LTE or NR, and functions to enable communication for the terminal 20 in this embodiment (e.g., resource pool setting, resource allocation, etc.). The base station 10 may also be an RSU (gNB type RSU).

[0042] Furthermore, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 for SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.

[0043] In step S101, terminal 20A autonomously selects resources to be used for PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window may be set from base station 10 to terminal 20. Here, the predetermined period of the resource selection window may be defined by terminal implementation conditions such as processing time or maximum allowable packet delay time, or it may be defined in advance by specifications, or the predetermined period may be called an interval in the time domain.

[0044] In steps S102 and S103, terminal 20A transmits SCI (Sidelink Control Information) via PSCCH and / or PSSCH using the resources autonomously selected in step S101, and also transmits SL data via PSSCH. For example, terminal 20A may transmit PSCCH using the same time resources as at least a portion of the time resources of PSSCH, and using frequency resources adjacent to the frequency resources of PSSCH.

[0045] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The received SCI may include information about the PSFCH resource that terminal 20B uses to send a HARQ-ACK for receiving the data. Terminal 20A may also include information about an autonomously selected resource in the SCI and transmit it.

[0046] In step S104, terminal 20B uses the PSFCH resources determined from the received SCI to send a HARQ-ACK for the received data to terminal 20A.

[0047] In step S105, if the HARQ-ACK received in step S104 indicates a request for retransmission, i.e., it is a NACK (negative response), terminal 20A retransmits PSCCH and PSSCH to terminal 20B. Terminal 20A may also retransmit PSCCH and PSSCH using a resource that it has autonomously selected.

[0048] If HARQ control with HARQ feedback is not performed, steps S104 and S105 do not need to be performed.

[0049] Figure 11 is a sequence diagram showing an example of V2X operation (2). Blind retransmission without HARQ control may be performed to improve the transmission success rate or range.

[0050] In step S201, terminal 20A autonomously selects resources to be used for PSCCH and PSSCH from a resource selection window having a predetermined period of time. The resource selection window may be set from base station 10 to terminal 20.

[0051] In steps S202 and S203, terminal 20A transmits SCI via PSCCH and / or PSSCH, and transmits SL data via PSSCH, using the resources autonomously selected in step S201. For example, terminal 20A may transmit PSCCH using the same time resources as at least a portion of the time resources of PSSCH, and using frequency resources adjacent to the frequency resources of PSSCH.

[0052] In step S204, terminal 20A uses the resources autonomously selected in step S201 to retransmit SCI via PSCCH and / or PSSCH and SL data via PSSCH to terminal 20B. The retransmission in step S204 may be performed multiple times.

[0053] If blind retransmission is not performed, step S204 does not need to be executed.

[0054] Figure 12 is a sequence diagram showing an example of V2X operation (3). The base station 10 may perform sidelink scheduling. That is, the base station 10 may determine the sidelink resources to be used by the terminal 20 and transmit information indicating those resources to the terminal 20. Furthermore, if HARQ control with HARQ feedback is applied, the base station 10 may transmit information indicating PSFCH resources to the terminal 20.

[0055] In step S301, base station 10 performs SL scheduling by sending DCI (Downlink Control Information) to terminal 20A via PDCCH. Hereafter, for convenience, the DCI used for SL scheduling will be referred to as SL scheduling DCI.

[0056] Furthermore, in step S301, it is assumed that the base station 10 also transmits a DCI for DL ​​scheduling (which may also be called DL allocation) to the terminal 20A via PDCCH. Hereafter, for convenience, the DCI for DL ​​scheduling will be referred to as DL scheduling DCI. Upon receiving the DL scheduling DCI, the terminal 20A receives DL data via PDSCH using the resources specified in the DL scheduling DCI.

[0057] In steps S302 and S303, terminal 20A transmits SCI (Sidelink Control Information) via PSCCH and / or PSSCH using the resources specified in the SL scheduling DCI, and also transmits SL data via PSSCH. Note that only the resources for PSSCH may be specified in the SL scheduling DCI. In this case, for example, terminal 20A may transmit PSCCH using the same time resources as at least a portion of the time resources for PSSCH, and using frequency resources adjacent to the frequency resources for PSSCH.

[0058] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The SCI received via PSCCH and / or PSSCH contains information about the PSFCH resource that terminal 20B uses to send a HARQ-ACK for the reception of the data.

[0059] The resource information is included in the DL scheduling DCI or SL scheduling DCI transmitted from the base station 10 in step S301, and the terminal 20A retrieves the resource information from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, the DCI transmitted from the base station 10 may not include the resource information, and the terminal 20A may autonomously include the resource information in the SCI and transmit it.

[0060] In step S304, terminal 20B uses the PSFCH resources determined from the received SCI to send a HARQ-ACK for the received data to terminal 20A.

[0061] In step S305, terminal 20A transmits a HARQ-ACK using the PUCCH (Physical uplink control channel) resource specified by the DL scheduling DCI (or SL scheduling DCI) at a timing (e.g., a slot-based timing) specified by the DL scheduling DCI (or SL scheduling DCI), and base station 10 receives the HARQ-ACK. The codebook of the HARQ-ACK may include a HARQ-ACK generated based on the HARQ-ACK received from terminal 20B or a PSFCH that was not received, and a HARQ-ACK for DL ​​data. However, if there is no allocation of DL data, the HARQ-ACK for DL ​​data will not be included. In NR Rel.16, the codebook of the HARQ-ACK does not include a HARQ-ACK for DL ​​data.

[0062] If HARQ control with HARQ feedback is not performed, steps S304 and / or S305 may not be performed.

[0063] Figure 13 is a sequence diagram showing an example of V2X operation (4). As mentioned above, in the NR sidelink, it is supported that the HARQ response is transmitted in PSFCH format. The PSFCH format can be the same as, for example, the PUCCH (Physical Uplink Control Channel) format 0. That is, the PSFCH format may be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified by the difference in sequence and / or cyclic shift. The PSFCH format is not limited to this. The PSFCH resource may be placed in the symbol at the end of the slot or in multiple symbols at the end. In addition, a period N is set or predetermined for the PSFCH resource. The period N may be set or predetermined on a per-slot basis.

[0064] In Figure 13, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. A PSCCH may be placed in the first symbol of a slot, in multiple symbols from the beginning, or in multiple symbols from symbols other than the first. A PSFCH may be placed in the last symbol of a slot, or in multiple symbols at the end of a slot. Note that the above-mentioned "beginning of the slot" and "end of the slot" may omit consideration of symbols for AGC (Automatic Gain Control) and symbols for transmit / receive switching. That is, for example, if one slot consists of 14 symbols, "beginning of the slot" and "end of the slot" may mean the first and last symbols, respectively, among the 12 symbols excluding the first and last symbols. In the example shown in Figure 13, three subchannels are set in the resource pool, and two PSFCHs are placed three slots after the slot in which the PSSCH is placed. The arrow from PSSCH to PSFCH shows an example of a PSFCH associated with a PSSCH.

[0065] If the NR-V2X group cast uses group cast option 2, where the HARQ response is either an ACK or a NACK, it is necessary to determine the resources to be used for sending and receiving PSFCH. As shown in Figure 13, in step S401, the transmitting terminal 20, terminal 20A, performs a group cast via SL-SCH to the receiving terminals 20, terminals 20B, 20C, and 20D. In the following step S402, terminal 20B uses PSFCH#B, terminal 20C uses PSFCH#C, and terminal 20D uses PSFCH#D to send the HARQ response to terminal 20A. Here, as shown in the example in Figure 13, if the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to determine how to allocate the PSFCH resources. The transmitting terminal 20 may also know the number of receiving terminals 20 in the group cast. In group cast option 1, only a NACK is sent as the HARQ response; an ACK is not sent.

[0066] Figure 14 shows an example of sensing operation in NR. In Resource allocation mode 2, terminal 20 selects and transmits a resource. As shown in Figure 14, terminal 20 performs sensing in the sensing window within the resource pool. Through sensing, terminal 20 receives resource reservation or resource assignment fields included in the SCI transmitted from other terminals 20, and identifies available resource candidates in the resource selection window within the resource pool based on these fields. Subsequently, terminal 20 randomly selects a resource from the available resource candidates.

[0067] Furthermore, as shown in Figure 14, the resource pool settings may have a period. For example, the period may be a duration of 10240 milliseconds. Figure 14 shows slot t0 SL From slot t Tmax-1 SL This is an example of how the resource pool is configured. The resource pool within each period may be defined by, for example, a bitmap.

[0068] Furthermore, as shown in Figure 14, the transmission trigger in terminal 20 occurs in slot n, and the priority of this transmission is p TX Let's assume that terminal 20 is connected from slot n-T0 to slot nT proc,0 In the sensing window up to the slot immediately preceding it, for example, if another terminal 20 has priority p RXIt is possible to detect that the transmission of [[ID=]] is being performed. When an SCI is detected within the sensing window and the RSRP (Reference Signal Received Power) exceeds the threshold, the resources within the resource selection window corresponding to the SCI are excluded. Also, when an SCI is detected within the sensing window and the RSRP is less than the threshold, the resources within the resource selection window corresponding to the SCI are not excluded. The threshold may be, for example, the threshold Th [[ID=]] TX and priority p [[ID=]] RX [[ID=]4]which is set or defined for each resource within the sensing window based on [[ID=]] pTX,pRX and may be. [[ID=]]

[0069] Also, as in slot t [[ID=]] m SL shown in FIG. 14, for example, for transmission, the resources within the resource selection window that are candidates for resource reservation information corresponding to the resources within the sensing window that were not monitored are excluded. [[ID=]]

[0070] The resource selection window from slot n + T1 to slot n + T2, as shown in FIG. 14, identifies the resources occupied by other UEs, and the resources from which such resources are excluded become candidate available resources. Let the set of candidate available resources be S [[ID=]] A Then, if S [[ID=]] A is less than 20% of the resource selection window, the threshold Th [[ID=]] pTX,pRX set for each resource of the sensing window may be increased by 3 dB and the resource identification may be performed again. That is, by increasing the threshold Th [[ID=]] pTX,pRX and performing the resource identification again, the resources not excluded due to the RSRP being less than the threshold are increased so that the set S [[ID=]] A of resource candidates becomes 20% or more of the resource selection window. If S [[ID=]] A is less than 20% of the resource selection window, the operation of increasing the threshold Th [[ID=]] pTX,pRX set for each resource of the sensing window by 3 dB and performing the resource identification again may be repeated.

[0071] The lower layer of terminal 20 is S A This may be reported to the upper layer. The upper layer of terminal 20 is S A A random selection may be performed to determine which resource to use. Terminal 20 may then use the determined resource to perform a sidelink transmission.

[0072] Although Figure 14 above illustrates the operation of the transmitting terminal 20, the receiving terminal 20 may detect data transmission from another terminal 20 based on the results of sensing or partial sensing and receive data from that other terminal 20.

[0073] Figure 15 is a flowchart showing an example of preemption in NR. Figure 16 is a diagram showing an example of preemption in NR. In step S501, terminal 20 performs sensing in the sensing window. If terminal 20 is performing power-saving operation, sensing may be performed for a predetermined limited period. Subsequently, terminal 20 identifies each resource in the resource selection window based on the sensing results and selects a set of resource candidates S A The terminal 20 then determines the set of resource candidates S and selects the resource to be used for transmission (S502). A Select a resource set (r_0, r_1, ...) from which to determine preemption (S503). This resource set may be notified to the PHY layer from the upper layer as a resource to determine whether or not preemption has occurred.

[0074] In step S504, terminal 20, at timings T(r_0)-T3 shown in Figure 16, re-identifies each resource in the resource selection window based on the sensing results and selects a set of resource candidates S. A The system determines this and then determines preemption for the resource set (r_0, r_1, ...) based on priority. For example, in Figure 16, r_1 is detected by resensing as an SCI transmitted from another terminal 20, and S AIt is not included in S. If preemption is enabled, terminal 20 determines that resource r_1 has been preempted if the value prio_RX, which indicates the priority of an SCI sent from another terminal 20, is lower than the value prio_TX, which indicates the priority of a transport block sent from its own terminal. Note that a lower value indicates a higher priority. In other words, if the value prio_RX, which indicates the priority of an SCI sent from another terminal 20, is higher than the value prio_TX, which indicates the priority of a transport block sent from its own terminal, terminal 20 determines that resource r_1 has been preempted. A It is not excluded. Alternatively, if preemption is only effective for a specific priority (for example, if sl-PreemptionEnable is one of pl1, pl2, ..., pl8), this priority is set to prio_pre. In this case, if the value prio_RX, which indicates the priority of the SCI sent from another terminal 20, is lower than prio_pre, and prio_RX is lower than the value prio_TX, which indicates the priority of the transport block sent from the terminal itself, terminal 20 determines that resource r_1 has been preempted.

[0075] In step S505, if preemption is determined in step S504, terminal 20 notifies the upper layer of the preemption, the upper layer re-selects the resource, and the preemption check is terminated.

[0076] If re-evaluation is performed instead of preemption checking, in step S504 above, the set of resource candidates S A After deciding, S A If the resource set (r_0, r_1, ...) does not contain any resources, those resources will not be used, and a re-selection of resources will be performed in the higher layer.

[0077] Figure 17 shows an example of partial sensing operation in LTE. When partial sensing is configured from the upper layer in an LTE sidelink, terminal 20 selects and transmits resources as shown in Figure 17. As shown in Figure 17, terminal 20 performs partial sensing on a portion of the sensing window in the resource pool, i.e., the sensing target. Through partial sensing, terminal 20 receives the resource reservation field included in the SCI transmitted from another terminal 20 and identifies available resource candidates in the resource selection window in the resource pool based on this field. Subsequently, terminal 20 randomly selects a resource from the available resource candidates.

[0078] Figure 17 shows subframe t0 SL From subframe t Tmax-1 SL This is an example of setting the resource pool up to this point. The resource pool may also have its target area defined by, for example, a bitmap. As shown in Figure 17, the transmission trigger at terminal 20 is assumed to occur in subframe n. As shown in Figure 17, of the subframes from subframe n+T1 to subframe n+T2, subframe t y1 SL From subframe t yY SL The Y subframe up to this point may be set as the resource selection window.

[0079] Terminal 20 has a subframe t whose Y subframe length. y1-k×Pstep SL From subframe t yY-k×Pstep SL Up to one or more sensing targets, it is possible to detect, for example, that another terminal 20 is transmitting. k may be determined by, for example, a 10-bit bitmap. Figure 17 shows an example where the 3rd and 6th bits of the bitmap are set to "1" to indicate that partial sensing is being performed. That is, in Figure 17, subframe t y1-6×Pstep SL From subframe t yY-6×PstepSL up to and subframe t y1-3×Pstep SL From subframe t yY-3×Pstep SL Up to and are set as sensing targets. As described above, the k-th bit of the bitmap is subframe t y1-k×Pstep SL From subframe t yY-k×Pstep SL It may also support a sensing window up to y. i This corresponds to the index (1...Y) within the Y subframe.

[0080] Note that k is set as a 10-bit bitmap or is predetermined, P step It may be 100ms. However, when performing SL communication with DL and UL carriers, P step This can also be expressed as (U / (D+S+U))*100ms, where U is the number of UL subframes, D is the number of DL subframes, and S is the number of special subframes.

[0081] If an SCI is detected in the sensing target and the RSRP exceeds the threshold, the resources in the resource selection window corresponding to the resource reservation field of that SCI are excluded. Conversely, if an SCI is detected in the sensing target and the RSRP is below the threshold, the resources in the resource selection window corresponding to the resource reservation field of that SCI are not excluded. This threshold is, for example, the sender priority p. TX and receiver priority p RX Based on this, thresholds Th are set or defined for each resource within the sensing target. pTX,pRX That's fine.

[0082] As shown in Figure 17, in the resource selection window set in the Y subframe of the interval [n+T1, n+T2], terminal 20 identifies resources occupied by other UEs, and the resources remaining after excluding those resources become the available resource candidates. Note that the Y subframes do not have to be consecutive. The set of available resource candidates is S ATherefore, S A If the number is less than 20% of the resources in the resource selection window, the threshold Th is set for each resource of the sensing target. pTX,pRX You can increase the level by 3dB and perform resource identification again.

[0083] That is, the threshold Th pTX,pRX You may increase the number of resources that are not excluded because their RSRP is below the threshold by raising the value and performing resource identification again. A Measure the RSSI of each resource and set the resource with the smallest RSSI to group S. B It may also be added to the set of resource candidates S. B Until it fills more than 20% of the resource selection window, S A The RSSI included is the smallest resource S B You may repeat the action of adding to it.

[0084] The lower layer of terminal 20 is S B This may be reported to the upper layer. The upper layer of terminal 20 is S B Terminal 20 may perform a random selection to determine which resource to use. Terminal 20 may use the determined resource to perform a sidelink transmission. After securing a resource once, terminal 20 may perform a predetermined number of operations (for example, C resel (This time) Resources may be used periodically without performing sensing.

[0085] Here, in NR Release 17 sidelinks, power saving based on random resource selection and partial sensing is being considered. For example, for power saving purposes, random resource selection and partial sensing in sidelinks in LTE Release 14 may be applied to resource allocation mode 2 of NR Release 16 sidelinks. Terminal 20 to which partial sensing is applied performs reception and sensing only in specific slots within the sensing window.

[0086] Furthermore, in NR Release 17 Sidelink, eURLLC (enhanced Ultra Reliable Low Latency Communication) is being considered with inter-UE coordination as the baseline. For example, terminal 20A may share information indicating the resource set with terminal 20B, and terminal 20B may take this information into consideration when selecting resources for transmission.

[0087] For example, as a method of resource allocation in a side link, terminal 20 may perform full sensing as shown in Figure 14. Alternatively, terminal 20 may perform partial sensing, which identifies resources by sensing only a limited set of resources compared to full sensing, and selects resources from the identified resource set. Furthermore, terminal 20 may perform random selection, which identifies the resources in the resource selection window as an identified resource set without excluding any resources from the resources in the resource selection window, and selects resources from that identified resource set.

[0088] Furthermore, at the time of resource selection, a method that performs random selection and uses sensing information during re-evaluation or preemption checks may be treated as partial sensing or as random selection.

[0089] Furthermore, the following 1) and 2) may be applied as operations in sensing.

[0090] 1)Periodic-based partial sensing In a system that performs sensing on only a portion of the slots, this operation determines which slots to sense based on the reservation periodicity. The reservation period is a value related to the resource reservation period field.

[0091] 2) Contiguous partial sensing In a system where sensing is performed on only a portion of the slots, the sensing slots are determined based on aperiodic reservations. Note that aperiodic reservations are values ​​related to the time resource assignment field.

[0092] Release 17 may define the operation assuming three types of terminals 20. One is type A, and a type A terminal 20 has no ability to receive any sidelink signals and channels, except for receiving PSFCH and S-SSB.

[0093] The other is type B, and terminal 20 of type B does not have the ability to receive any sidelink signals and channels except PSFCH and S-SSB reception.

[0094] The other is Type D, and a Type D terminal 20 has the ability to receive signals and channels of all sidelinks as defined in Release 16, except that it does not exclude receiving signals and channels of some sidelinks.

[0095] Furthermore, UE types other than the above-mentioned types A, B, and D may be assumed, and UE types and UE capabilities may or may not be associated.

[0096] Furthermore, in Release 17, multiple resource allocation methods can be configured for a given resource pool. Additionally, SL-DRX (Discontinuous reception) is supported as a power-saving feature; that is, reception operations are performed only during predetermined time intervals.

[0097] In resource allocation mode 2, where terminal 20 autonomously selects resources, terminal 20 receives resource reservation information from other terminals 20 via sensing and selects the resources to use for transmission based on that resource reservation information. However, even when each transmitting terminal 20 selects resources based on sensing, resource collisions can still occur. To improve communication reliability and reduce latency, there are communication situations that should be considered, as shown below.

[0098] Figure 18 shows an example of a communication situation (1). As an example of the hidden terminal problem, as shown in Figure 18, when terminal 20B attempts to transmit to terminal 20A, terminal 20C, which cannot be detected by terminal 20B, may be located in a position that interferes with the receiving terminal 20A. For example, if terminal 20C transmits within the time / frequency resources reserved by terminal 20B, resource overlap will occur when terminal 20A receives.

[0099] Half-duplex communication should also be considered. If the sidelink is half-duplex, for example, if both terminals 20 transmit reserved signals simultaneously, a conflict of reserved resources may occur.

[0100] Figure 19 shows an example of a communication situation (2). As an example of the near-far problem, as shown in Figure 19, when terminal 20C attempts to transmit to terminal 20A, terminal 20B, which is detected with low power by the transmitting terminal 20C, may be located in a position that causes significant interference to the receiving terminal 20A.

[0101] Figure 20 shows an example of a communication situation (3). As an example of a transmission resource collision in the time domain, as shown in Figure 20, a PSFCH transmission resource reserved from terminal 20B or associated with PSSCH and a PSFCH transmission resource reserved from terminal 20C or associated with PSSCH may overlap at terminal 20A. When multiple transmissions overlap, drops or power reductions occur. For example, it is expected that overlaps between PSFCH and PSFCH, or between PSFCH and UL channels, may occur as shown in Figure 20.

[0102] Figure 21 is a diagram illustrating example (4) of the communication situation. As an example of a collision between receiving and transmitting resources in the time domain, as shown in Figure 21, there is a case where PSSCH reception on a resource reserved by terminal 20B and PSSCH transmission on a resource reserved by terminal 20A overlap at terminal 20A.

[0103] Figure 22 is a diagram illustrating an example of a communication situation (5). As an example of a collision between transmitting and receiving resources in the time domain, as shown in Figure 22, a PSFCH transmission associated with a PSSCH resource reserved by terminal 20B and a PSFCH reception associated with a PSSCH resource reserved by terminal 20A may overlap at terminal 20A.

[0104] Inter-terminal coordination is being considered as a method to improve reliability and latency performance. For example, types A, B, and C shown below are being considered. Note that the names and classifications are not limited to these.

[0105] Type A) Terminal 20A may notify terminal 20B of the preferred resource set for transmission. For example, this notification may be based on the sensing results at terminal 20A.

[0106] Type B) Terminal 20A may notify Terminal 20B of a set of resources that are not preferred for transmission. For example, this notification may be based on sensing results at Terminal 20A, or on expected or potential resource collisions.

[0107] Type C) Terminal 20A may notify Terminal 20B of the resource set in which a resource conflict has been detected. For example, this notification may be based on resource conflicts detected in the past.

[0108] For example, regarding inter-terminal coordination, the methods described in 1)-6) below may be decided.

[0109] 1) When and how does terminal 20A determine the contents of the resource set, taking UL scheduling into consideration? 2) When does terminal 20A notify terminal 20B of the resource set, and which terminal 20 notifies the resource set? 3) How to determine which terminal 20 notifies which other terminal 20 of the resource set. 4) How does terminal 20A notify about resource sets? What method of notification should be used, explicitly or implicitly? 5) When and how does terminal 20B receive or not receive the resource set? Also, how does terminal 20B reflect this in its resource selection for transmission? 6) How to define the support and signaling for inter-terminal coordination and its association with cast types?

[0110] Here, it is necessary to determine the methods A)-D) below regarding the anticipated or possible resource conflicts in Type B described above.

[0111] A) Criteria for determining anticipated or potential resource conflicts. B) Method for notifying resource conflicts. C) Actions when the notification timing is missed. For example, if a resource corresponding to a reserved signal is used to notify terminal 20B of collision-related information, it may not be possible to notify terminal 20B of future collisions that are detected after the notification resource is used. D) How to apply to groupcasts and / or broadcasts.

[0112] Therefore, if terminal 20A detects an expected or possible resource collision regarding a future transmission by terminal 20B, terminal 20A may send a predetermined notification to terminal 20B in a predetermined manner, and terminal 20B may perform a predetermined action based on that notification.

[0113] For example, terminal 20A may determine that it has detected an expected or potential resource collision if certain conditions are met. For example, terminal 20A may send a predetermined notification in a predetermined manner. For example, terminal 20A may send a predetermined notification to terminal 20B in another manner if certain conditions are met. For example, terminal 20A may perform a predetermined action if terminal 20B's future transmission is a groupcast or broadcast.

[0114] As described above, the operation of terminals 20A and 20B makes it possible to avoid resource collisions related to the resources transmitted by terminal 20B.

[0115] Figure 23 is a diagram illustrating an example (1) of inter-UE cooperation in an embodiment of the present invention. As shown in Figure 23, there is transmission data to be sent from terminal 20B to terminal 20A, and terminal 20B makes a resource reservation for transmission. Terminal 20A receives the resource reservation, and if any collision is expected to occur in the reserved resource, terminal 20A sends a signal related to the collision prediction to terminal 20B. Figure 23 shows an example in which the PSSCH transmission resource reserved by terminal 20C and the resource reservation by terminal 20B collide. After receiving the signal from terminal 20A, terminal 20B stops using the reserved resource and performs resource reselection. Terminal 20B then transmits the transmission data to terminal 20A using the reselected resource.

[0116] Terminal 20A may determine that it has detected an expected or potential resource collision if certain conditions are met.

[0117] For example, a resource reservation made by terminal 20B, which detects resource collisions, may be a reservation for the same transport block or a reservation for a different transport block.

[0118] For example, resource collision detection may target PSSCH and PSCCH. Terminal 20A may determine that a resource collision has been detected if at least a portion of the PSSCH (and / or PSCCH) resources reserved by terminal 20B are the same time and frequency as the reserved resources of another terminal 20C. Also, terminal 20A may determine that a resource collision has been detected if at least a portion of the PSSCH (and / or PSCCH) resources reserved by terminal 20B are the same time as the transmission resources selected or reserved by terminal 20A (i.e., its own device).

[0119] For example, resource collision detection may target PSFCH and PSFCH. Terminal 20A may determine that a resource collision has been detected if the PSFCH resource associated with a PSSCH (and / or PSCCH) resource reserved by terminal 20B is at the same time as a PSFCH associated with a reserved resource of another terminal 20C. Also, terminal 20A may determine that a resource collision has been detected if the PSFCH resource associated with a PSSCH (and / or PSCCH) resource reserved by terminal 20B is at the same time as a PFSCH receiving scheduled resource of terminal 20A (the associated PSCCH / PSSCH is selected or reserved).

[0120] For example, resource collision detection may apply to both SL and UL. Terminal 20A may determine that a resource collision has been detected if at least a portion of the PSSCH (and / or PSCCH) resources reserved by terminal 20B coincide with the time of terminal 20A's UL resources. Terminal 20A may also determine that a resource collision has been detected if the PSFCH resources associated with the PSSCH (and / or PSCCH) resources reserved by terminal 20B coincide with the time of terminal 20A's UL resources.

[0121] For example, terminal 20A may determine that a resource collision has been detected only if the resource reservation of terminal 20B occurs at the same time as or after the resource confirmation timing of the conflicting resource (e.g., PSSCH, PSFCH, UL) (e.g., resource selection or reservation by terminal 20A or terminal 20C, UL scheduling by base station 10).

[0122] For example, terminal 20A may determine that a resource collision has been detected only when it receives predetermined information from terminal 20B. This may be limited to cases where a PC5-RRC connection has been established in advance between terminal 20A and terminal 20B. That is, the predetermined information may be information related to the RRC connection. Furthermore, this may be limited to cases where a PC5-RRC connection has been established in advance between terminal 20A and terminal 20B, and the operation according to this embodiment is applicable, i.e., the corresponding UE capability indicates support. Furthermore, this may be limited to cases where the operation according to this embodiment is notified by a signal related to the resource reservation (e.g., 1st stage SCI in PSCCH, 2nd stage SCI in PSSCH). Furthermore, this may be limited to cases where a predetermined cast type is implicitly or explicitly notified by a signal related to the resource reservation (e.g., 2nd stage SCI in PSSCH).

[0123] As described above, terminal 20A determines that a resource collision has been detected only when it receives specific information from terminal 20B, thereby enabling terminal 20B to use the information it sends from terminal 20A to terminal 20B without wasting it.

[0124] Terminal 20A may determine that a resource collision has been detected only if the first HARQ feedback for the resource reservation signal of terminal 20B and the second HARQ feedback for the resource reservation signal relating to the collision partner satisfy predetermined conditions. For example, terminal 20A may determine that a resource collision has been detected only if both the first and second HARQ feedbacks are NACK. The limitation that both the first and second HARQ feedbacks are NACK may be limited to those corresponding to reservations related to transmission of the same transport block. Furthermore, the first and second HARQ feedbacks may be limited to those corresponding to reservations related to unicast transmission. The collision partner may mean a signal that, with respect to a given signal, collides with that signal.

[0125] For example, if the priority of resource reservation for terminal 20B satisfies the conditions 1)-3) shown below, terminal 20A may determine that a resource conflict has been detected.

[0126] 1) When the priority associated with the collision partner is the same as or lower than the priority related to resource reservation of terminal 20B. That is, when the value indicating priority is the same or higher. For example, if the priority associated with the collision partner is higher than the priority related to resource reservation of terminal 20B, it may be determined that no resource collision was detected. 2) When the priority for resource reservation of terminal 20B is higher or lower than the threshold corresponding to the priority associated with the collision partner. The threshold may be, for example, sl-PriorityThreshold, sl-PriorityThreshold-UL-URLLC, ul-PrioritizationThres, etc. 3) When the priority for resource reservation of terminal 20B exceeds or falls below the corresponding value or threshold. The threshold may be, for example, sl-PrioritizationThres.

[0127] Note that the above priority may be replaced with PDB (Packet Delay Budget). As described above, by determining resource collision detection based on priority, information that should be prioritized can be sent preferentially by sending data with high priority and re-selecting resources with low priority.

[0128] For example, if the received power related to the resource reservation of terminal 20B satisfies the conditions 1)-3) shown below, terminal 20A may determine that a resource collision has been detected.

[0129] 1) When the received power related to the resource reservation of terminal 20B is higher or lower than the received power related to the collision partner. For example, if the received power associated with the collision partner is lower or higher than the received power related to the resource reservation of terminal 20B, it may be determined that no resource collision was detected. 2) When the received power related to resource reservation of terminal 20B exceeds or falls below the threshold associated with the collision partner. 3) When the received power related to resource reservation of terminal 20B exceeds or falls below the corresponding threshold.

[0130] The above thresholds may be set for each priority. As described above, by setting the threshold to be lower than the standard when the received power related to the resource reservation of terminal 20B is below the standard, transmission can be permitted when sufficient received power is expected to be available to receive the signal from terminal 20B. Also, by setting the threshold to be higher than the standard when the received power related to the resource reservation of terminal 20B is above the standard, transmission can be stopped when the signal from the other party in the collision may cause interference during reception.

[0131] Furthermore, if the conditions 1)-7) shown below are met, the above-mentioned notification may be sent from terminal 20A to terminal 20B.

[0132] 1) When the resource reservation of terminal 20B satisfies certain time constraints. For example, when the time from receiving the reservation information to the reserved resource is greater than or equal to a predetermined value. Also, for example, when the time from receiving the reservation information to sending a predetermined notification is greater than or equal to a predetermined value. Also, for example, when the time from sending a predetermined notification to the reserved resource is greater than or equal to a predetermined value. Note that the predetermined value may be given by a higher-layer parameter, may be defined as the number of symbols or the number of slots, or may be set to a different value by SCS (Sub-carrier spacing) or numerology.

[0133] 2) When the destinations related to the resource reservation information of terminal 20B meet the specified conditions. For example, when at least one destination includes terminal 20A. Also, for example, when all destinations include terminal 20A.

[0134] 3) When the location information related to the resource reservation information of terminal 20B satisfies predetermined conditions. For example, when the distance between multiple terminals 20 that transmitted the reservation information is greater than or less than a predetermined value. Also, for example, when the distance between terminal 20 that transmitted the reservation information and terminal 20A that received the reservation information is greater than or less than a predetermined value.

[0135] 4) When the resource from which terminal 20B transmits resource reservation information satisfies predetermined conditions. For example, when at least one reservation information transmission is transmitted using a resource selected autonomously (e.g., mode 2). Also, for example, when all reservation information transmissions are transmitted using resources selected autonomously (e.g., mode 2). Furthermore, terminal 20A may be notified in connection with the transmission of reservation information whether the resource is set or instructed by the network (e.g., mode 1) or whether it is a resource selected autonomously (e.g., mode 2). For example, terminal 20A may be notified by SCI (1st stage SCI, 2nd stage SCI, PSCCH or PSSCH) or DCI.

[0136] 5) When the number of reserved resources associated with the resource reservation information of terminal 20B satisfies the specified conditions. For example, when at least one reservation information reserves two or more resources. Also, for example, when all reservation information reserves two or more resources.

[0137] 6) When the Packet delay budget (PDB) associated with the resource reservation information of terminal 20B satisfies a predetermined condition. For example, when the PDB associated with at least one reservation information or the remaining time until that PDB is greater than or equal to a predetermined size. Also, for example, when the PDB associated with all reservation information or the remaining time until that PDB is greater than or equal to a predetermined size.

[0138] 7) When terminal 20A is requested by another terminal 20 to send the above-mentioned notification.

[0139] For example, terminal 20A may send a predetermined notification in a predetermined manner. For example, the predetermined notification may be sent using a resource with the same symbol as the resource of release 16PSFCH, and the channel on which the predetermined notification is sent may be called PSFCH.

[0140] As described above, the specified notification may be sent using the resources or transmission methods related to the feedback channel. The resources or transmission methods related to the feedback channel may be those shown in a)-l) below.

[0141] a) Resources available for PSFCH. For example, the time resource may be the Xth (e.g., the second) symbol from the end in each slot for the parameter sl-PSFCH-Period which indicates the period of the PSFCH. Also, for example, the frequency resource may be a PRB determined based on the parameter sl-PSFCH-RB-Set which indicates the frequency domain of the PSFCH. Furthermore, the sign resource may be a pair of cyclic shifts determined based on the parameter sl-NumMuxCS-Pair which relates to the cyclic shift of the PSFCH. Note that the PSFCH resource determination formula in Release 16 is {(P ID +M ID ) mod R PSFCH PRB,CS PSFCH resources may be determined in a different way than}. ID is the source ID of the PHY layer, MID is the ID of the UE, and R PSFCH PRB,CS This is the number of PSFCH resources that transmit (multiplex) HARQ-ACKs during a single PSFCH transmission opportunity.

[0142] b) Resources available to PSFCH and resources that will be frequency-division multiplexed and / or code-division multiplexed. For example, it may be at least some of the PRBs other than those specified by the upper layer parameter sl-PSFCH-RB-Set in a given resource pool. That is, the PRB in which the PSFCH associated with the PSSCH is located and the frequency-division multiplexed PRB may be used as resources related to the feedback channel. Alternatively, the PRB specified by sl-PSFCH-RB-Set in a given resource pool may be used as resources related to the feedback channel. For example, a cyclic shift pair determined based on the upper layer parameter sl-NumMuxCS-Pair may be used as a resource related to the feedback channel, all cyclic shift pairs may be used as resources related to the feedback channel, or a cyclic shift pair determined based on a certain parameter may be used as a resource related to the feedback channel.

[0143] Alternatively, resources that are associated one-to-one with PSFCH resources determined by the PSFCH resource determination formula in Release 16 (for example, resources used for NACK transmission) may be used as resources related to the feedback channel.

[0144] A PRB specified in sl-PSFCH-RB-Set may use at least a portion of cyclic shift pairs other than those determined based on sl-NumMuxCS-Pair as resources for the feedback channel. For example, if Y=2, i.e., 0 and 3 for NACK and 6 and 9 for ACK as cyclic shifts, then the cyclic shifts {1,2,4,5,7,8,10,11} not used for HARQ-ACK may be used as resources for the feedback channel.

[0145] Alternatively, an index adjacent to the CS index used for NACK transmission may be used as a resource related to the feedback channel. For example, if the CS index used for NACK transmission is {0,3}, then the CS index {1,4} may be used as the resource related to the feedback channel.

[0146] c) Resources not based on source ID.

[0147] d) Resources determined based on the source ID or part of the source ID included in the 1st stage SCI.

[0148] e) May be sent as an alternative to the HARQ feedback in Release 16. For example, a NACK or specific information may be sent for the resource determined by a) or b) above. Alternatively, nothing may be sent for the resource determined by the PSFCH resource determination formula in Release 16 above.

[0149] f) May be sent together with the HARQ feedback of Release 16. For example, NACK or specific information may be sent for the resource determined by a) or b) above. It may also be sent for the resource determined by the PSFCH resource determination formula in Release 16 above.

[0150] The transmissions in g)a)-l) may be treated as PSFCH transmissions. For example, the operation of terminal 20 related to simultaneous PSFCH transmissions may include the transmissions in a)-l) in the processing.

[0151] The transmissions in h)a)-l) do not necessarily have to be treated as PSFCH transmissions. For example, they may be defined as channels separate from PSFCH. Terminal 20 may also report its ability to simultaneously transmit on PSFCH and the channel in question to other terminals 20 or the network.

[0152] i)a)-l) The transmission priority may be determined by a predetermined method. For example, the priority may be determined based on the corresponding PSCCH / PSSCH reception or PSFCH transmission. Alternatively, the priority may be treated as a specific priority and set, or predetermined.

[0153] j) Terminal 20A may decide when to transmit and / or which resource to use for transmission. The channel assigned to the determined resource may be called PSXCH. PSXCH may be at least one of PSCCH, PSSCH, PSFCH, PSBCH, and a new channel. If PSXCH is a new channel, for example, the data and DM-RS may be frequency-division multiplexed, mapped to multiple PRBs, or encoded by polar coding.

[0154] Furthermore, information relating to future resource reservations may be transmitted for the determined resource. For example, information indicating which PSFCH opportunity it is may be transmitted, or information indicating which frequency resource will be used may be transmitted. Also, if the determined resource overlaps with PSFCH transmission and / or reception for HARQ feedback, for example, PSFCH transmission and / or reception for HARQ feedback may be given priority, or PSFCH transmission and / or reception and information relating to resource selection may be transmitted simultaneously, or rules may be established to mediate simultaneous transmissions, and simultaneous transmissions may be performed only when the conditions for simultaneous transmission are met, and if the conditions for simultaneous transmission are not met, the lower-priority transmission may be dropped.

[0155] k) Furthermore, terminal 20A may continuously monitor the determined resource, i.e., the resource related to the feedback channel. By continuously monitoring, terminal 20A can send a "predetermined notification" at any time.

[0156] l) Terminal 20A may be requested by other terminals 20 to determine when and / or on which resource to transmit. The channel to which the determined resource is to be placed may be called PSXCH. PSXCH may be at least one of PSCCH, PSSCH, PSFCH, PSBCH, and a new channel. If PSXCH is a new channel, for example, the data and DM-RS may be frequency-division multiplexed, mapped to multiple PRBs, or encoded by polar coding.

[0157] Furthermore, information relating to future resource reservations may be transmitted for the requested resource. For example, information indicating which PSFCH opportunity it is may be transmitted, or information indicating which frequency resource to use may be transmitted. Also, if the requested resource overlaps with PSFCH transmission and / or reception for HARQ feedback, for example, PSFCH transmission and / or reception for HARQ feedback may be prioritized, or PSFCH transmission and / or reception and information relating to resource selection may be transmitted simultaneously, or rules may be established to mediate simultaneous transmission, and simultaneous transmission may only occur if the conditions for simultaneous transmission are met, and if the conditions for simultaneous transmission are not met, the lower-priority transmission may be dropped. In addition, terminal 20A may constantly monitor the requested resource, i.e., the resource relating to the feedback channel. By constantly monitoring, terminal 20A can transmit a "prescribed notification" at any time.

[0158] Hereafter, the channel through which the prescribed notification is sent will be referred to as PSCICH (Physical Sidelink Collision Indication Channel), but will not be limited to this, and may also be called PFSCH.

[0159] For example, the time resource of PSCICH for a certain reserved signal may be determined based on the reserved signal of terminal 20B. For example, the time resource of PSCICH may be the same as the method for determining the release 16PSFCH resource. That is, terminal 20A may transmit in the first slot among the slots containing PSFCH resources that are a number of slots later than the last slot that received PSSCH, specified by the upper-layer parameter sl-MinTimGapPSFCH set in the resource pool.

[0160] Furthermore, the PSCICH time resource may be determined by parameters different from those of the release 16PSFCH resource. Figure 24 is a diagram illustrating an example (2) of inter-UE coordination in an embodiment of the present invention. As shown in Figure 24, terminal 20A may transmit in the first slot among the slots containing PSCICH resources that are a number of slots later than the last slot that received the PSSCH, specified by the upper-layer parameter sl-MinTimGapPSCICH set in the resource pool. Note that the procedure for determining the PSCICH frequency resource may be the same as the procedure for determining the PSFCH.

[0161] Furthermore, for example, the PSCICH time resource for a reserved signal may be determined based on the reserved resource of terminal 20B. The PSCICH time resource may be a time resource that is a predetermined time prior to the reserved resource, and the time prior to the reserved resource may be determined based on a parameter. For example, the parameter may be sl-MinTimGapPSCICH. Figure 25 is a diagram illustrating an example (3) of inter-UE coordination in an embodiment of the present invention. As shown in Figure 25, terminal 20A may transmit in the first slot of a set of slots containing a PSCICH resource that is a number of slots prior to the PSSCH resource reserved by terminal 20B that has detected a resource collision, by the number of slots specified by the upper-layer parameter sl-MinTimGapPSCICH set in the resource pool. Note that the procedure for determining the frequency resource of PSCICH may be the same as the procedure for PSFCH.

[0162] For example, terminal 20A may send a predetermined notification to terminal 20B by other means if predetermined conditions are met. Figure 26 is a diagram illustrating an example (4) of inter-UE cooperation in an embodiment of the present invention. The predetermined conditions are as shown in Figure 26, where T_conflict is the timing of the resource for transmitting a signal related to a resource collision, corresponding to the resource reservation signal received from terminal 20B, and if a collision is detected between a future resource reserved by terminal 20B and some transmission or reception (e.g., a reservation signal or UL scheduling from terminal 20C) after the predetermined timing related to T_conflict, terminal 20A may send a predetermined notification to terminal 20B by other means.

[0163] Alternatively, if terminal 20A detects a conflict between a future resource reserved by terminal 20B and some transmission or reception (e.g., a reservation signal or UL scheduling by terminal 20C) at a time corresponding to the processing time prior to a predetermined timing related to T_conflict, terminal 20A may send a predetermined notification to terminal 20B by other means.

[0164] Furthermore, the above-mentioned predetermined conditions may also include the condition that the terminal 20B is notified of a signal related to a resource collision and that the corresponding action is performed. The condition that causes the corresponding action to be performed may be the same as the condition that the terminal 20A determines to have detected a resource collision.

[0165] The prescribed notification, i.e., the signal relating to a resource collision, may be transmitted by any of the following methods 1)-7).

[0166] 1) It may be transmitted by SCI. It may be a 1st stage SCI or a 2nd stage SCI. It may or may not be accompanied by PSSCH transmission.

[0167] 2) It may be transmitted via PSFCH. It may be a resource with the same symbol as the resource of release 16PSFCH, and the name is not limited to PSFCH, for example it may be PSCICH or another name. The time domain of the resource may be determined based on the reserved signal or reserved resource of terminal 20B by applying the above-mentioned upper layer parameter sl-MinTimeGapPSCICH. 3) It may be sent via a dedicated channel or resource. A separate channel or resource may be defined or configured for sending this notice.

[0168] 4) May be transmitted by MAC-CE.

[0169] 5) It may be transmitted by RRC signaling. It may also be transmitted by PC5-RRC signaling.

[0170] 6) The notification may also indicate which reservation signal the information pertains to a resource collision. For example, the time gap between this notification and the resource reservation signal may be notified.

[0171] 7) The information regarding the resource conflict for which reserved resource is being communicated may be provided. The time gap between this notification and the reserved resource may also be provided.

[0172] For example, terminal 20A may perform a predetermined action if terminal 20B's future transmission is a groupcast or broadcast.

[0173] For example, if terminal 20B's future transmission is a groupcast or broadcast, terminal 20A does not need to send a corresponding notification even if it detects a resource collision.

[0174] For example, if terminal 20B's future transmission is groupcast option 2, terminal 20A will send a predetermined notification when it detects a resource collision, but if terminal 20B's future transmission is groupcast option 1 or broadcast, it does not need to send a predetermined notification when it detects a resource collision.

[0175] For example, if terminal 20B's future transmission is a groupcast, terminal 20A will send a predetermined notification if it detects a resource collision, but if terminal 20B's future transmission is a broadcast, terminal 20A does not need to send a predetermined notification if it detects a resource collision.

[0176] For example, terminal 20A may transmit a predetermined notification only if the received power and / or priority of the reservation signal from terminal 20B meets predetermined conditions.

[0177] For example, among the terminals 20 that have received resource reservation information from terminal 20B, a specific terminal 20 may receive a predetermined notification. This specific terminal 20 may be determined based on its UE-ID or by its geographical location.

[0178] The above-described embodiment may be applied to an operation in which one terminal 20 sets or allocates transmission resources for another terminal 20.

[0179] The above-described embodiment is not limited to V2X terminals, but may also be applied to terminals that perform D2D communication.

[0180] The operation described in the above embodiment may be performed only in a specific resource pool. For example, it may be performed only in resource pools where terminal 20 of release 17 or later is available.

[0181] In the embodiment described above, when terminal 20 receives resource reservation information from another terminal 20, it can detect a conflict in reserved resources based on that resource reservation information and notify the other terminal 20 of the information regarding the resource conflict. The other terminal 20 can then appropriately control its transmission operation based on the notified information regarding the resource conflict.

[0182] In other words, it is possible to improve the reliability of communication during autonomous resource selection in direct communication between terminals.

[0183] (Device configuration) Next, we will describe an example of the functional configuration of the base station 10 and terminal 20 that perform the processes and operations described above. The base station 10 and terminal 20 include functions to implement the embodiments described above. However, the base station 10 and terminal 20 may each have only some of the functions in the embodiments.

[0184] <Base station 10> Figure 27 shows an example of the functional configuration of the base station 10. As shown in Figure 27, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 27 is merely an example. The names of the functional categories and functional units can be anything as long as they can perform the operations according to the embodiment of the present invention.

[0185] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 and obtaining information from the received signals, for example, information from a higher layer. The transmitting unit 110 also has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0186] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads it from the storage device as needed. The contents of the setting information include, for example, information related to D2D communication settings.

[0187] As described in the embodiment, the control unit 140 performs processing related to the settings for the terminal 20 to perform D2D communication. The control unit 140 also transmits the scheduling of D2D communication and DL communication to the terminal 20 via the transmission unit 110. The control unit 140 also receives information related to the HARQ response of D2D communication and DL communication from the terminal 20 via the reception unit 120. The signal transmission function unit of the control unit 140 may be included in the transmission unit 110, and the signal reception function unit of the control unit 140 may be included in the reception unit 120.

[0188] <Terminal 20> Figure 28 is a diagram showing an example of the functional configuration of terminal 20. As shown in Figure 28, terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Figure 28 is merely an example. The names of the functional categories and functional units can be anything as long as they can perform the operations according to the embodiment of the present invention.

[0189] The transmitting unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and acquires signals from higher layers from the received physical layer signals. The receiving unit 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals transmitted from the base station 10. For example, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20 as D2D communication, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0190] The setting unit 230 stores various setting information received from the base station 10 or terminal 20 by the receiving unit 220 in its storage device and reads it from the storage device as needed. The setting unit 230 also stores pre-configured setting information. The content of the setting information is, for example, information related to D2D communication settings.

[0191] As described in the embodiment, the control unit 240 controls D2D communication to establish an RRC connection with other terminals 20. The control unit 240 also performs power-saving operations. The control unit 240 also performs HARQ processing for D2D and DL communication. The control unit 240 transmits information related to the HARQ response for D2D and DL communication scheduled from the base station 10 to the base station 10. The control unit 240 may also schedule D2D communication with other terminals 20. The control unit 240 may also autonomously select resources to be used for D2D communication from a resource selection window based on sensing results, or it may perform re-evaluation or preemption. The control unit 240 also performs power-saving processing for D2D communication transmission and reception. The control unit 240 also performs processing related to inter-terminal coordination in D2D communication. The signal transmission function unit of the control unit 240 may be included in the transmission unit 210, and the signal reception function unit of the control unit 240 may be included in the reception unit 220.

[0192] (Hardware configuration) The block diagrams (Figures 27 and 28) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the above one device or the above multiple devices with software.

[0193] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. As mentioned above, the method of implementation is not particularly limited.

[0194] For example, the base station 10, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 29 is a diagram showing an example of the hardware configuration of the base station 10 and terminal 20 according to one embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0195] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0196] Each function in the base station 10 and terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of the reading and writing of data in the storage device 1002 and auxiliary storage device 1003.

[0197] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0198] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes a computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station 10 shown in Figure 27 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in Figure 28 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunications line.

[0199] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of this disclosure.

[0200] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0201] The communication device 1004 is hardware (transceiver / receiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may include high-frequency switches, duplexers, filters, frequency synthesizers, etc., to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the transmit / receive antenna, amplifier section, transmit / receive section, transmission path interface, etc., may be implemented by the communication device 1004. The transmit / receive section may be implemented with physically or logically separated transmitting and receiving sections.

[0202] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0203] Furthermore, each device, such as the processor 1001 and the storage device 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0204] Furthermore, the base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0205] (Summary of the embodiments) As described above, according to the embodiment of the present invention, the system includes a receiving unit that receives a signal from another terminal to reserve a resource in a resource pool, a control unit that detects a collision in the reserved resource, and a transmitting unit that, when the control unit detects a collision in the reserved resource, transmits a signal relating to the resource collision to the other terminal, wherein the receiving unit is provided as a terminal that receives a signal from the other terminal 20 for a resource different from the reserved resource.

[0206] With the above configuration, when terminal 20 receives resource reservation information from another terminal 20, it can detect a conflict in reserved resources based on that resource reservation information and notify the other terminal 20 of the resource conflict. The other terminal 20 can then appropriately control its transmission operation based on the notified information regarding the resource conflict. In other words, the reliability of communication during autonomous resource selection in direct terminal-to-terminal communication can be improved.

[0207] The control unit may determine that a collision has occurred in the reserved resource if the priority of the reserved resource is lower than the priority of the resource at the collision target, and may determine that no collision has occurred in the reserved resource if the priority of the reserved resource is higher than the priority of the resource at the collision target. With this configuration, when terminal 20 receives resource reservation information from another terminal 20, it can detect that a reserved resource based on that resource reservation information is in conflict according to its priority, and notify the other terminal 20 of the resource collision information. The other terminal 20 can then appropriately control its transmission operation based on the notified resource collision information.

[0208] The control unit may determine that a collision has occurred in the reserved resource if the received power for the reserved resource is lower than the received power for the resource at the collision target, and may determine that no collision has occurred in the reserved resource if the received power for the reserved resource is higher than the received power for the resource at the collision target. With this configuration, when terminal 20 receives resource reservation information from another terminal 20, it can detect that a reserved resource based on the resource reservation information is in conflict according to the received power, and notify the other terminal 20 of the resource collision information. The other terminal 20 can then appropriately control its transmission operation based on the notified resource collision information.

[0209] The transmitting unit may transmit the signal relating to the resource collision to the other terminal in the resource of the signal reserving the resource or in the resource determined based on the reserved resource. With this configuration, when terminal 20 receives resource reservation information from another terminal 20, it can detect that a reserved resource based on that resource reservation information is in conflict and notify the other terminal 20 of the information relating to the resource collision. The other terminal 20 can then appropriately control its transmission operation based on the notified information relating to the resource collision.

[0210] If the control unit detects that a collision has occurred in the reserved resource at a time prior to the timing of the signal relating to the resource collision, the transmission unit may transmit the signal relating to the resource collision to the other terminal. With this configuration, when terminal 20 receives resource reservation information from another terminal 20, it can detect that a reserved resource based on that resource reservation information is in conflict and notify the other terminal 20 of the information relating to the resource collision. The other terminal 20 can then appropriately control its transmission operation based on the notified information relating to the resource collision.

[0211] Furthermore, according to an embodiment of the present invention, a communication method is provided in which a terminal performs the following steps: a receiving step of receiving a signal from another terminal to reserve a resource in a resource pool; a control step of detecting a collision in the reserved resource; a transmission step of transmitting a signal relating to the resource collision to the other terminal if a collision is detected in the reserved resource; and a step of receiving a signal from the other terminal 20 for a resource different from the reserved resource.

[0212] With the above configuration, when terminal 20 receives resource reservation information from another terminal 20, it can detect a conflict in reserved resources based on that resource reservation information and notify the other terminal 20 of the resource conflict. The other terminal 20 can then appropriately control its transmission operation based on the notified information regarding the resource conflict. In other words, the reliability of communication during autonomous resource selection in direct terminal-to-terminal communication can be improved.

[0213] (Supplement to the embodiment) While embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. Regarding the processing procedures described in the embodiments, the order of processing may be changed as long as it does not contradict each other. For the convenience of explaining the processing, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to an embodiment of the present invention and the software operated by the processor of the terminal 20 according to an embodiment of the present invention may be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

[0214] Furthermore, the notification of information is not limited to the embodiments / models described herein and may be carried out by other methods. For example, the notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0215] Each aspect / embodiment described in this disclosure may be applied to at least one of the following systems: LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0216] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0217] In this specification, specific operations performed by the base station 10 may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station 10, it is clear that various operations performed for communication with the terminal 20 can be performed by the base station 10 and at least one of the other network nodes (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station 10, the other network node may be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0218] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0219] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0220] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0221] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0222] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0223] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0224] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0225] The terms “system” and “network” as used in this disclosure are interchangeable.

[0226] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or corresponding other information. For example, wireless resources may be indicated by an index.

[0227] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0228] In this disclosure, terms such as "base station (BS)", "wireless base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0229] A base station can house one or more (e.g., three) cells. If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into several smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0230] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0231] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or several other appropriate terms.

[0232] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0233] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminals 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0234] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

[0235] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in a table, database, or other data structure), and ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0236] The terms "connected" or "coupled", or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed". As used in this disclosure, two elements can be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as, by way of some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region.

[0237] The reference signal can also be abbreviated as RS (Reference Signal) and may be called a Pilot according to the applicable standard.

[0238] As used in this disclosure, the description "based on" does not mean "based only on" unless otherwise specified. In other words, the description "based on" means both "based only on" and "based at least on".

[0239] Any reference to an element using designations such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in any way.

[0240] In the configuration of each of the above devices, "means" may be replaced with "section", "circuit", "device", etc.

[0241] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0242] A wireless frame may consist of one or more frames in the time domain. Each of these frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0243] Numerical logic may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerical logic may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0244] A slot may consist of one or more symbols in the time domain (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A slot may also be a time unit based on neurology.

[0245] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0246] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0247] For example, one subframe may be called a Transmission Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one mini-slot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, mini-slot, etc., instead of a subframe.

[0248] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each terminal 20 to allocate wireless resources (such as the frequency bandwidth and transmission power available to each terminal 20) in TTI units. However, the definition of TTI is not limited to this.

[0249] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0250] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled.

[0251] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0252] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0253] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0254] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. Each TTI, subframe, etc., may consist of one or more resource blocks.

[0255] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0256] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0257] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a particular neurology system in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. A Bandwidth Part (PRB) may be defined and numbered within a given BWP.

[0258] A BWP may include a BWP for UL (Ultraviolet Link) and a BWP for DL ​​(Download Link). One or more BWPs may be set for a terminal 20 within a single carrier.

[0259] At least one of the configured BWPs may be active, and terminal 20 does not need to be expected to send or receive a predetermined signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0260] The structures such as the above-mentioned radio frames, sub-frames, slots, mini-slots, and symbols are merely illustrative. For example, the number of sub-frames included in a radio frame, the number of slots per sub-frame or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of sub-carriers included in an RB, and the number of symbols within a TTI, symbol length, cyclic prefix (CP) length, etc. can be variously changed.

[0261] In the present disclosure, for example, when an article is added by translation, such as a, an, and the in English, the present disclosure may include that the noun following these articles is in the plural form.

[0262] In the present disclosure, the term "A and B are different" may mean that "A and B are different from each other". Note that the term may also mean that "A and B are each different from C". Terms such as "separate", "coupled", etc. may also be interpreted in the same way as "different".

[0263] Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched and used during execution. Also, the notification of predetermined information (for example, the notification of "being X") is not limited to being explicitly performed, and may be performed implicitly (for example, by not performing the notification of the predetermined information).

[0264] As described above, the present disclosure has been described in detail. However, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure defined by the claims. Therefore, the description of the present disclosure is for the purpose of illustrative explanation and has no restrictive meaning for the present disclosure.

Description of Reference Numerals

[0265] 10 base station 110 Transmitter 120 Receiver 130 Setting section 140 Control Unit 20 devices 210 Transmitter 220 Receiver 230 Setting section 240 Control Unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

1. The first terminal, A receiving unit that receives reservation information from the second terminal for reserving a first resource used for transmitting a shared channel for inter-terminal communication by the second terminal, A control unit that determines a time resource to transmit information regarding a collision between the first resource and the second resource, based on a time resource that is a first time step back from the first resource reserved by the reservation information, Within the time resources determined above, a transmitting unit transmits information regarding the collision to the second terminal via a feedback channel for inter-terminal communication. A terminal.

2. The first time is the number of slots specified by the upper layer parameters. The terminal according to claim 1.

3. The receiving unit receives other reservation information for reserving the second resource from the third terminal, and the second resource is used by the third terminal for transmission on the shared channel. The terminal according to claim 1 or claim 2.

4. The transmitting unit transmits reservation information for reserving the second resource to other terminals, and the second resource is used by the first terminal for transmission on the shared channel. The terminal according to claim 1 or claim 2.

5. The second terminal, A transmission unit that transmits reservation information to the first terminal for reserving a first resource used for transmitting a shared channel for inter-terminal communication by the second terminal, A receiving unit receives information regarding a collision between the first resource and the second resource in a time resource determined based on a time resource that is a first time step back from the first resource reserved by the reservation information, via a feedback channel for inter-terminal communication from the first terminal. A terminal.

6. A communication method performed by the first terminal, A procedure for receiving reservation information from the second terminal for reserving a first resource used for transmitting a shared channel for inter-terminal communication by the second terminal, A procedure for determining a time resource to transmit information regarding a collision between the first resource and the second resource, based on a time resource that is a first time step back from the first resource reserved by the reservation information, In the time resources determined above, the procedure involves transmitting information regarding the collision to the second terminal via a feedback channel for inter-terminal communication, A communication method for performing [this action].

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