Terminal and communication method

Abstract

The terminal has: a receiving unit that receives, from one or more other terminals, one or more reservation messages related to the same resource; a control unit that determines whether a specific condition is satisfied; and a transmitting unit that, when the control unit determines that the specific condition is satisfied, transmits information related to the same resource to any of the other terminals.

Description

Technical Field

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

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

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

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

[0005] Prior Art Documents

[0006] Non-Patent Documents

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

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

[0009] Problems to be Solved by the Invention

[0010] As an enhancement of the NR sidelink, power saving is being studied. For example, in Resource Allocation Mode 2 where the terminal autonomously selects resources, the terminal performs partial sensing for monitoring limited resources within the monitoring window, and based on the result, selects resource candidates that can be used from the resource selection window.

[0011] Here, in Resource Allocation Mode 2, when the transmitting terminal performs monitoring, for example, when there are other terminals outside the field of view of the transmitting terminal, the quality of the resources in the receiving terminal may be very different from the quality based on the result obtained by the transmitting terminal monitoring the resources.

[0012] The present invention has been completed in view of the above, and its object is to improve the reliability of communication during autonomous resource selection in direct communication between terminals.

[0013] Means for Solving the Problem

[0014] According to the disclosed technology, a terminal is provided, which has: a receiving unit that respectively receives one or more reservation messages related to the same resource from one or more other terminals; a control unit that determines whether a specific condition is satisfied; and a transmitting unit that, when the control unit determines that the specific condition is satisfied, the transmitting unit transmits information related to the same resource to any one of the other terminals.

[0015] Effect of the Invention

[0016] According to the disclosed technology, in direct communication between terminals, the reliability of communication during autonomous resource selection can be improved. Description of the Drawings

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

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

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

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

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

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

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

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

[0025] Figure 9 It is a diagram for explaining Example (3) of the communication type of V2X.

[0026] Figure 10 It is a timing diagram showing Example (1) of the operation of V2X.

[0027] Figure 11 It is a timing diagram showing Example (2) of the operation of V2X.

[0028] Figure 12 It is a timing diagram showing Example (3) of the operation of V2X.

[0029] Figure 13 It is a timing diagram showing Example (4) of the operation of V2X.

[0030] Figure 14 It is a diagram showing an example of a monitoring operation.

[0031] Figure 15 It is a flowchart for explaining an example of a preemption operation.

[0032] Figure 16 It is a diagram showing an example of a preemption operation.

[0033] Figure 17 It is a diagram showing Example (1) of the communication status.

[0034] Figure 18 It is a diagram showing Example (2) of the communication status.

[0035] Figure 19 It is a diagram showing Example (3) of the communication status.

[0036] Figure 20 It is a flowchart for explaining the communication method in the embodiment of the present invention.

[0037] Figure 21 It is a diagram showing Example (1) of the reservation information in the embodiment of the present invention.

[0038] Figure 22 It is a diagram showing Example (2) of the reservation information in the embodiment of the present invention.

[0039] Figure 23 It is a diagram showing Example (3) of the reservation information in the embodiment of the present invention.

[0040] Figure 24 This is a diagram showing Example (4) of the reserved information in the embodiments of the present invention.

[0041] Figure 25 This is a diagram showing Example (5) of the reserved information in the embodiments of the present invention.

[0042] Figure 26 This is a diagram showing Example (6) of the reserved information in the embodiments of the present invention.

[0043] Figure 27 This is a diagram showing Example (1) of the resources for communication in the embodiments of the present invention.

[0044] Figure 28 This is a diagram showing Example (2) of the resources for communication in the embodiments of the present invention.

[0045] Figure 29 This is a diagram showing Example (3) of the resources for communication in the embodiments of the present invention.

[0046] Figure 30 This is a diagram showing Example (4) of the resources for communication in the embodiments of the present invention.

[0047] Figure 31 This is a diagram showing an example of the functional structure of Base Station 10 in the embodiments of the present invention.

[0048] Figure 32 This is a diagram showing an example of the functional structure of Terminal 20 in the embodiments of the present invention.

[0049] Figure 33 This is a diagram showing an example of the hardware structure of Base Station 10 or Terminal 20 in the embodiments of the present invention. Detailed Embodiments

[0050] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the embodiments described below are merely examples, and the embodiments applying the present invention are not limited to the following embodiments.

[0051] When the wireless communication system according to the embodiments of the present invention operates, existing technologies are appropriately used. However, such existing technologies are, for example, existing LTE, but are not limited to existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and subsequent modes (e.g., NR) or wireless LAN (Local Area Network).

[0052] In addition, in an embodiment of the present invention, the duplex mode may be a TDD (Time Division Duplex) mode, an FDD (Frequency Division Duplex) mode, or a mode other than these (e.g., Flexible Duplex, etc.).

[0053] In addition, in an embodiment of the present invention, "configuring" wireless parameters, etc. may be pre-configuring a predetermined value, or may be configuring wireless parameters notified from the base station 10 or the terminal 20.

[0054] Figure 1 This is a diagram for explaining V2X. In 3GPP, technologies for implementing V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functions are being studied, and standardization is being promoted. As Figure 1 shown, V2X is a part of ITS (Intelligent Transport Systems), and is a general term for V2V (Vehicle to Vehicle), which represents a communication form between vehicles, V2I (Vehicle to Infrastructure), which represents a communication form between a vehicle and a roadside unit (RSU) installed beside the road, V2N (Vehicle to Network), which represents a communication form between a vehicle and an ITS server, and V2P (Vehicle to Pedestrian), which represents a communication form between a vehicle and a mobile terminal held by a pedestrian.

[0055] In addition, in 3GPP, V2X using cellular communication and inter-terminal communication is being studied. V2X using cellular communication is also called cellular V2X. In the V2X of NR, research on achieving large capacity, low latency, high reliability, and QoS (Quality of Service) control is being promoted.

[0056] Regarding V2X for LTE or NR, it is envisioned that research beyond the 3GPP specifications can also be promoted in the future. For example, research on ensuring interoperability, reducing costs due to the installation of higher layers, methods for using or switching between multiple RATs (Radio Access Technologies), regulatory support in various countries, and data acquisition, distribution, database management, and usage methods for V2X platforms of LTE or NR are envisioned.

[0057] In the embodiments of the present invention, a mode in which a communication device is mounted on a vehicle is mainly envisioned, but the embodiments of the present invention are not limited to this mode. For example, the communication device can be a terminal held by a person, the communication device can also be a device mounted on a drone or an aircraft, and the communication device can also be a base station, an RSU, a relay node (Relay Node), a terminal with scheduling capabilities, etc.

[0058] In addition, SL (Sidelink) can also be distinguished according to UL (Uplink) or DL (Downlink) and any one or combination of the following 1)-4). In addition, SL can also have other names.

[0059] 1) Resource configuration in the time domain

[0060] 2) Resource configuration in the frequency domain

[0061] 3) Reference synchronization signals (including SLSS (Sidelink Synchronization Signal))

[0062] 4) Reference signals used in path loss measurements for transmit power control

[0063] In addition, regarding OFDM (Orthogonal Frequency Division Multiplexing) for SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding can also be adopted.

[0064] In the SL of LTE, regarding the resource allocation of the SL to the terminal 20, Mode 3 and Mode 4 are defined. In Mode 3, the transmission resources are dynamically allocated by using the DCI (Downlink Control Information) sent from the base station 10 to the terminal 20. In addition, in Mode 3, SPS (Semi-Persistent Scheduling) can also be performed. In Mode 4, the terminal 20 autonomously selects the transmission resources from the resource pool.

[0065] In addition, the slot in the embodiment of the present invention may also be replaced with a symbol, a mini-slot, a subframe, a radio frame, a TTI (Transmission Time Interval). In addition, the cell in the embodiment of the present invention may also be replaced with a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), etc.

[0066] In addition, in the embodiment of the present invention, the terminal 20 is not limited to a V2X terminal, and may also be all types of terminals performing D2D communication. For example, the terminal 20 may be a terminal held by a user such as a smart phone, or an IoT (Internet of Things) device such as a smart meter.

[0067] Figure 2 It is a diagram for explaining Example (1) of the transmission mode of V2X. In Figure 2 In the shown sidelink communication transmission mode, in step 1, the base station 10 sends sidelink scheduling information to the terminal 20A. Then, the terminal 20A sends a PSCCH (Physical Sidelink Control Channel) and a PSSCH (Physical Sidelink Shared Channel) to the terminal 20B according to the received scheduling information (step 2). It is also possible to Figure 2 The shown sidelink communication transmission mode is called the sidelink transmission mode 3 in LTE. In the sidelink transmission mode 3 in LTE, sidelink scheduling based on Uu is performed. Uu refers to the radio interface between the UTRAN (Universal Terrestrial Radio Access Network) and the UE (User Equipment). In addition, it is also possible to Figure 2The transmission mode of sidelink communication shown is referred to as sidelink transmission mode 1 in NR.

[0068] Figure 3 This is a diagram for explaining Example (2) of the transmission mode of V2X. In Figure 3 the sidelink communication transmission mode shown, in step 1, terminal 20A uses the autonomously selected resources to send PSCCH and PSSCH to terminal 20B. It is also possible to Figure 3 refer to the sidelink communication transmission mode shown as sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0069] Figure 4 This is a diagram for explaining Example (3) of the transmission mode of V2X. In Figure 4 the sidelink communication transmission mode shown, in step 1, terminal 20A uses the autonomously selected resources to send PSCCH and PSSCH to terminal 20B. Similarly, terminal 20B uses the autonomously selected resources to send PSCCH and PSSCH to terminal 20A (step 1). It is also possible to Figure 4 refer to the sidelink communication transmission mode shown as sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, terminal 20 itself performs resource selection.

[0070] Figure 5 This is a diagram for explaining Example (4) of the transmission mode of V2X. In Figure 5 the sidelink communication transmission mode shown, in step 0, the resource mode for sending to terminal 20A is set from base station 10 via RRC (Radio Resource Control) or pre-set for the sidelink. Then, terminal 20A sends PSSCH to terminal 20B according to this resource mode (step 1). It is also possible to Figure 5 refer to the sidelink communication transmission mode shown as sidelink transmission mode 2c in NR.

[0071] Figure 6 This is a diagram for explaining Example (5) of the transmission mode of V2X. In Figure 6 the sidelink communication transmission mode shown, in step 1, terminal 20A sends sidelink scheduling information to terminal 20B via PSCCH. Then, terminal 20B sends PSSCH to terminal 20A according to the received scheduling information (step 2). It is also possible to Figure 6 refer to the sidelink communication transmission mode shown as sidelink transmission mode 2d in NR.

[0072] Figure 7 This is a diagram for explaining Example (1) of the communication type of V2X.Figure 7 The communication type of the sidelink shown is unicast. The terminal 20A transmits PSCCH and PSSCH to the terminal 20. In Figure 7 the example shown, the terminal 20A performs unicast to the terminal 20B and performs unicast to the terminal 20C.

[0073] Figure 8 It is a diagram for explaining Example (2) of the communication type of V2X. Figure 8 The communication type of the sidelink shown is multicast. The terminal 20A transmits PSCCH and PSSCH to the group to which one or more terminals 20 belong. In Figure 8 the example shown, the group includes the terminal 20B and the terminal 20C, and the terminal 20A performs multicast to the group.

[0074] Figure 9 It is a diagram for explaining Example (3) of the communication type of V2X. Figure 9 The communication type of the sidelink shown is broadcast. The terminal 20A transmits PSCCH and PSSCH to one or more terminals 20. In Figure 9 the example shown, the terminal 20A performs broadcast to the terminal 20B, the terminal 20C, and the terminal 20D. In addition, the Figures 7 - 9 terminal 20A shown can also be referred to as the header UE (header-UE).

[0075] In addition, in NR-V2X, it is envisioned to support HARQ (Hybrid automatic repeat request) in unicast and multicast of the sidelink. And in NR-V2X, SFCI (Sidelink Feedback Control Information) including HARQ responses is defined. And research is underway to transmit SFCI via the PSFCH (Physical Sidelink Feedback Channel).

[0076] In addition, in the following description, it is assumed that the PSFCH is used for transmitting HARQ-ACK in the sidelink, but this is only an example. For example, the PSCCH can be used to transmit HARQ-ACK in the sidelink, the PSSCH can be used to transmit HARQ-ACK in the sidelink, and other channels can also be used to transmit HARQ-ACK in the sidelink.

[0077] Hereinafter, for convenience of explanation, all the information reported by the terminal 20 in HARQ is referred to as HARQ-ACK. This HARQ-ACK may also be referred to as HARQ-ACK information. Furthermore, more specifically, the codebook applied to the information of HARQ-ACK reported from the terminal 20 to the base station 10 etc. is referred to as the HARQ-ACK codebook. The HARQ-ACK codebook defines the bit string of the HARQ-ACK information. In addition, using "HARQ-ACK", in addition to ACK, NACK is also transmitted.

[0078] Figure 10 is a timing chart showing an operation example (1) of V2X. As Figure 10 shown, the wireless communication system according to the embodiment of the present invention may include a terminal 20A and a terminal 20B. In addition, although there are actually multiple user devices, Figure 10 the terminal 20A and the terminal 20B are shown as examples.

[0079] Hereinafter, without particularly distinguishing between the terminal 20A, 20B, etc., it is simply denoted as "terminal 20" or "user device". In Figure 10 this, as an example, the case where both the terminal 20A and the terminal 20B are within the coverage area of the cell is shown, but the operation in the embodiment of the present invention can also be applied to the case where the terminal 20B is outside the coverage area.

[0080] As described above, in the present embodiment, the terminal 20 is, for example, a device mounted on a vehicle such as an automobile, and has a cellular communication function as a UE in LTE or NR and a sidelink function. The terminal 20 may also be a general portable terminal (such as a smartphone). In addition, the terminal 20 may also be an RSU. This RSU may be a UE type RSU having the function of a UE, or a gNB type RSU having the function of a base station device.

[0081] In addition, the terminal 20 does not need to be a device in one housing. For example, even when various sensors are dispersedly arranged in a vehicle, the device including these various sensors may be the terminal 20.

[0082] In addition, the processing of the transmitted data on the sidelink of the terminal 20 is basically the same as the processing of UL transmission in LTE or NR. For example, the terminal 20 scrambles the codewords of the transmitted data, modulates them to generate complex-valued symbols, maps the complex-valued symbols (transmitted signals) to layer 1 or layer 2, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate transmitted signals (e.g., complex-valued time-domain SC-FDMA signal), and are transmitted from each antenna port.

[0083] In addition, for the base station 10, it has the function of cellular communication as a base station in LTE or NR, and the function for enabling the terminal 20 in the present embodiment to communicate (e.g., resource pool setting, resource allocation, etc.). In addition, the base station 10 may also be an RSU (gNB type RSU).

[0084] In addition, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 in SL or UL may be OFDMA, may be SC-FDMA, or may be other signal waveforms.

[0085] In step S101, the terminal 20A autonomously selects the resources used in the PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window may also be set for the terminal 20 by the base station 10. Here, for the predetermined period of the resource selection window, for example, the period may be specified according to the installation conditions of the terminal such as the processing time or the packet maximum allowable delay time, or the period may be specified in advance according to the specification. The predetermined period may also be referred to as an interval in the time domain.

[0086] In steps S102 and S103, the terminal 20A uses the resources autonomously selected in step S101 to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. For example, the terminal 20A may use the frequency resources adjacent to the frequency resources of the PSSCH to transmit the PSCCH in the time resources at least partially the same as the time resources of the PSSCH.

[0087] The terminal 20B receives the SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from the terminal 20A. In the received SCI, the information on the resources of the PSFCH for the terminal 20B to send the HARQ-ACK for the reception of this data may be included. The terminal 20A may include the information on the autonomously selected resources in the SCI and send it.

[0088] In step S104, the terminal 20B uses the resources of the PSFCH determined by the received SCI to send the HARQ-ACK for the received data to the terminal 20A.

[0089] When the HARQ-ACK received in step S104 indicates a request for retransmission, that is, NACK (negative acknowledgment), in step S105, the terminal 20A retransmits the PSCCH and PSSCH to the terminal 20B. The terminal 20A may use the autonomously selected resources to retransmit the PSCCH and PSSCH.

[0090] In addition, when HARQ control accompanied by HARQ feedback is not performed, steps S104 and S105 may not be performed either.

[0091] Figure 11 It is a timing diagram showing the operation example (2) of V2X. Blind retransmission independent of HARQ control for improving the transmission success rate or the reach distance may also be performed.

[0092] In step S201, the terminal 20A autonomously selects the resources used in the PSCCH and PSSCH from a resource selection window with a predetermined period. The resource selection window may also be set for the terminal 20 by the base station 10.

[0093] In steps S202 and S203, the terminal 20A uses the resources autonomously selected in step S201 to send the SCI using the PSCCH and / or PSSCH, and send the SL data using the PSSCH. For example, the terminal 20A may use the frequency resources adjacent to the frequency resources of the PSSCH to send the PSCCH in the time resources that are at least partially the same as the time resources of the PSSCH.

[0094] In step S204, the terminal 20A uses the resources autonomously selected in step S201 to retransmit the SCI based on the PSCCH and / or PSSCH and the SL data based on the PSSCH to the terminal 20B. The retransmission in step S204 may also be performed multiple times.

[0095] In addition, when blind retransmission is not performed, step S204 may not be performed either.

[0096] Figure 12 It is a timing chart showing an operation example (3) of V2X. The base station 10 can perform sidelink scheduling. That is, the base station 10 can determine the resources of the sidelink used by the terminal 20 and send information indicating the resources to the terminal 20. Also, in the case of applying HARQ control accompanied by HARQ feedback, the base station 10 can send information indicating the resources of the PSFCH to the terminal 20.

[0097] In step S301, the base station 10 performs SL scheduling by sending DCI (Downlink Control Information) to the terminal 20A using the PDCCH. Hereinafter, for convenience of explanation, the DCI for SL scheduling is referred to as SL scheduling DCI.

[0098] In addition, the following situation is envisaged: in step S301, the base station 10 also sends DCI for DL scheduling (which may also be referred to as DL allocation) to the terminal 20A using the PDCCH. Hereinafter, for convenience of explanation, the DCI for DL scheduling is referred to as DL scheduling DCI. The terminal 20A that receives the DL scheduling DCI uses the resources specified by the DL scheduling DCI and receives DL data using the PDSCH.

[0099] In steps S302 and S303, the terminal 20A uses the resources specified by the SL scheduling DCI and sends SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and sends SL data using the PSSCH. Also, in the SL scheduling DCI, only the resources of the PSSCH may be specified. In this case, for example, the terminal 20A can use a frequency resource adjacent to the frequency resource of the PSSCH in a time resource that is at least partially the same as the time resource of the PSSCH to send the PSCCH.

[0100] The terminal 20B receives the SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from the terminal 20A. The SCI received using the PSCCH and / or PSSCH contains information on the resources of the "PSFCH for the terminal 20B to send HARQ-ACK for receiving this data".

[0101] The information of the resource is included in the DL scheduling DCI or the SL scheduling DCI sent from the base station 10 in step S301. The terminal 20A obtains the information of the resource from the DL scheduling DCI or the SL scheduling DCI and includes it in the SCI. Alternatively, assuming that the DCI sent from the base station 10 does not include the information of the resource, the terminal 20A autonomously includes the information of the resource in the SCI and sends it.

[0102] In step S304, the terminal 20B uses the resource of the PSFCH determined by the received SCI to send a HARQ-ACK for the received data to the terminal 20A.

[0103] In step S305, the terminal 20A, for example, at the timing specified by the DL scheduling DCI (or the SL scheduling DCI) (e.g., timing in units of time slots), uses the PUCCH (Physical Uplink Control Channel) resource specified by the DL scheduling DCI (or the SL scheduling DCI) to send a HARQ-ACK. The 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 the terminal 20B or based on the non-received PSFCH, and a HARQ-ACK for DL data. However, in the case where there is no allocation of DL data, etc., the HARQ-ACK for DL data is not included. In NR Rel.16, the codebook of the HARQ-ACK does not include the HARQ-ACK for DL data.

[0104] In addition, in the case where HARQ control accompanied by HARQ feedback is not performed, steps S304 and / or S305 may not be performed either.

[0105] Figure 13It is a timing diagram showing an operation example (4) of V2X. As described above, the following situation is supported: in the side link of NR, HARQ feedback is sent through PSFCH. In addition, for example, the format of PSFCH can use the same format as PUCCH (Physical Uplink Control Channel) format 0 (PUCCH format 0). That is, regarding the format of PSFCH, it can be a sequence-based format with a PRB (Physical Resource Block) size of 1, where ACK and NACK are identified based on differences in timing and / or cyclic shift. The format of PSFCH is not limited to this. The resources of PSFCH can be configured in the last symbol or multiple last symbols of a time slot. In addition, a period N is set or predefined for the PSFCH resources. The period N can be set or predefined in units of time slots.

[0106] In Figure 13 , the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. PSCCH can be configured in 1 symbol at the start of a time slot, can also be configured in multiple symbols starting from the start, or can be configured in multiple symbols starting from symbols other than the start. PSFCH can be configured in 1 symbol at the end of a time slot, or can be configured in multiple symbols at the end of a time slot. In addition, for the above-mentioned "start of a time slot" and "end of a time slot", the symbols for AGC (Automatic Gain Control) and the symbols for transmit / receive switching can be omitted from consideration. That is, for example, when a time slot consists of 14 symbols, the "start of a time slot" and "end of a time slot" can mean the start and end symbols respectively among the 12 symbols excluding the start and end symbols. In Figure 13 In the example shown, 3 sub-channels are set in the resource pool, and 2 PSFCHs are configured 3 time slots after the time slot in which PSSCH is configured. The arrows from PSSCH to PSFCH show examples of PSFCHs associated with PSSCH.

[0107] In the case of HARQ feedback in the multicast of NR-V2X where the multicast option 2 for sending ACK or NACK is used, it is necessary to determine the resources used in the transmission and reception of PSFCH. As Figure 13 shown, in step S401, the terminal 20A as the transmitting side terminal 20 performs multicast to the terminals 20B, 20C, and 20D as the receiving side terminals 20 via SL-SCH. In the next step S402, the terminal 20B sends a HARQ feedback to the terminal 20A using PSFCH#B, the terminal 20C sends a HARQ feedback to the terminal 20A using PSFCH#C, and the terminal 20D sends a HARQ feedback to the terminal 20A using PSFCH#D. Here, asFigure 13 As shown in the example of [], when the number of available PSFCH resources is less than the number of receiving-side terminals 20 belonging to the group, it is necessary to decide how to allocate the PSFCH resources. In addition, the transmitting-side terminal 20 can know the number of receiving-side terminals 20 in the multicast. In addition, in multicast option 1, as a HARQ response, only NACK is transmitted and ACK is not transmitted.

[0108] Figure 14 is a diagram showing an example of a monitoring operation in NR. In resource allocation mode 2 (Resourceallocation mode 2), the terminal 20 selects resources for transmission. As Figure 14 shown, the terminal 20 performs monitoring in the monitoring window within the resource pool. Through the monitoring, the terminal 20 receives the resource reservation field or the resource assignment field included in the SCI transmitted from other terminals 20, and based on this field, identifies the available resource candidates within the resource selection window in the resource pool. Then, the terminal 20 randomly selects a resource from the available resource candidates.

[0109] In addition, as Figure 14 shown, the setting of the resource pool can have a period. For example, this period can be a period of 10240 milliseconds. Figure 14 is time slot t0 SL to time slot t Tmax SL is an example of being set as a resource pool. The area of the resource pool within each period can be set by a bitmap, for example.

[0110] In addition, as Figure 14 shown, it is assumed that a transmission trigger in the terminal 20 occurs in time slot n, and the priority of this transmission is p TX . The terminal 20 can detect that, for example, other terminals 20 are performing transmission with priority p proc,0 in the monitoring window from time slot n - T0 to the time slot immediately before time slot n - T RX . When an SCI is detected in the monitoring window and the RSRP (ReferenceSignal Received Power) is greater than the threshold, the resources within the resource selection window corresponding to the SCI are excluded. In addition, when an SCI is detected in the monitoring window and the RSRP is less than the threshold, the resources within the resource selection window corresponding to the SCI are not excluded. This threshold can also be, for example, based on priority p TX and priority p RXThe threshold Th set or defined according to each resource within the monitoring window pTX,pRX .

[0111] In addition, as Figure 14 shown by the time slot t m SL For example, resources within the resource selection window that are candidates for resource reservation information corresponding to resources within the unmonitored monitoring window for transmission are excluded.

[0112] As Figure 14 shown, in the resource selection window from time slot n + T1 to time slot n + T2, resources occupied by other UEs are identified, and the resources after excluding these resources become candidate resources that can be used. When the set of candidate resources that can be used is set as S A If S A is less than 20% of the resource selection window, the threshold Th set according to each resource of the monitoring window pTX,pRX can be increased by 3 dB and the resource identification can be performed again. That is, by increasing the threshold Th pTX,pRX and performing the resource identification again, the resources not excluded due to RSRP being less than the threshold can be increased, so that the set S A of candidate resources becomes 20% or more of the resource selection window. If S A is less than 20% of the resource selection window, the action of increasing the threshold Th pTX,pRX set according to each resource of the monitoring window by 3 dB and performing the resource identification again can be repeated.

[0113] The lower layer of the terminal 20 can report S A to the upper layer. The upper layer of the terminal 20 can perform random selection on S A to determine the resources to be used. The terminal 20 can use the determined resources to perform sidelink transmission.

[0114] In the above Figure 14 , the actions of the transmitting terminal 20 are described, but the receiving terminal 20 can also detect data transmission from other terminals 20 based on the monitoring or partial monitoring results and receive data from these other terminals 20.

[0115] 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, the terminal 20 performs monitoring in the monitoring window. When the terminal 20 performs power saving actions, the monitoring can be performed within a predefined limited period. Then, the terminal 20 identifies each resource within the resource selection window based on the monitoring results and determines the set S A(S502). Next, the terminal 20 selects a resource set (r_0, r_1, ……) from the set S of resource candidates (S503). A In step S504, the terminal 20 re-identifies each resource within the resource selection window according to the monitoring result at the timing of T(r_0) - T3 shown in

[0116] and determines the set S of resource candidates Figure 16 A , and then determines preemption according to the priority. For example, r_1 shown in Figure 16 detects an SCI sent from another terminal 20 through re-monitoring and is not included in S A . When preemption is valid, when the value prio_RX representing the priority of the SCI sent from another terminal 20 is lower than the value prio_TX representing the priority of the transport block sent from this terminal, the terminal 20 determines that the resource r_1 is preempted. In addition, if the value representing the priority is a lower value, the priority becomes higher. That is, when the value prio_RX representing the priority of the SCI sent from another terminal 20 is higher than the value prio_TX representing the priority of the transport block sent from this terminal, the terminal 20 does not exclude the resource r_1 from S A . Or, when preemption is only valid for specific priorities (for example, sl-PreemptionEnable is any one of pl1, pl2, ……, pl8), set this priority to prio_pre. At this time, when the value prio_RX representing 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 representing the priority of the transport block sent from this terminal, the terminal 20 determines that the resource r_1 is preempted.

[0117] In step S505, when the terminal 20 determines preemption in step S504, it notifies the upper layer of the preemption, and the upper layer re-selects resources, ending the processing related to preemption.

[0118] In the side link of NR version 17, power saving based on the above-mentioned random resource selection and partial monitoring is being studied. For example, for power saving, the random resource selection and partial monitoring of the side link in LTE version 14 can be applied to the resource allocation mode 2 of the side link in NR version 16. The terminal 20 to which partial monitoring is applied only performs reception and monitoring in specific time slots within the monitoring window.

[0119] In addition, in the sidelink of NR Release 17, with inter-UE coordination as the baseline, enhanced Ultra Reliable Low Latency Communication (eURLLC) is being studied. For example, terminal 20A shares information representing a resource set with terminal 20B, and terminal 20B can consider this information in the resource selection for transmission.

[0120] In resource allocation mode 2 where terminal 20 autonomously selects resources, it receives resource reservation information of other terminals 20 through monitoring, and terminal 20 selects resources for transmission based on this resource reservation information. However, even when each transmitting terminal 20 makes a resource selection based on monitoring, resource conflicts may occur.

[0121] Figure 17 It is a diagram showing example (1) of the communication situation. As an example of the hidden terminal problem, as Figure 17 shown, when transmitting from terminal 20A to terminal 20B, terminal 20C that cannot be detected from terminal 20A sometimes exists at a position that interferes with the receiving terminal 20B. For example, when terminal 20C transmits during the time resource reserved by terminal 20A, resource overlap occurs when terminal 20B receives.

[0122] In addition, since the sidelink is half-duplex communication, resource conflicts may occur when both terminals 20 transmit.

[0123] Figure 18 It is a diagram showing example (2) of the communication situation. As an example of the near-far problem, there is a situation where: as Figure 18 shown, when transmitting from terminal 20C to terminal 20B, terminal 20A detected with a smaller power in the transmitting terminal 20C exists at a position that causes greater interference to the receiving terminal 20B.

[0124] Each terminal 20 can reserve future transmission resources. Figure 19 It is a diagram showing example (3) of the communication situation. As Figure 19 shown, resource conflicts may occur between the resources indicated as reserved by terminal 20A and terminal 20C. That is, terminal 20B that receives multiple reservation messages can know in advance that resource conflicts will occur in the future. On the other hand, in the prior art, even if it is detected that resource conflicts will occur in the future, it is difficult to avoid such conflicts.

[0125] Therefore, when a specific condition is satisfied, the terminal 20 that has received one or more reservation information related to the same resource can send specific information to a specific terminal 20 using a specific method.

[0126] Figure 20 This is a flowchart for illustrating a communication method in an embodiment of the present invention. In step S601, terminal 20 receives one or more reservation information related to the same resource. In the next step S602, terminal 20 determines whether a specific condition is met. If the specific condition is met ("Yes" in S602), the process proceeds to step S603. If the specific condition is not met ("No" in S602), the process ends. In step S603, terminal 20 sends specific information to a specific terminal 20 through a specific method.

[0127] By executing the above flowchart, resource conflicts can be avoided, and reliability and delay can be improved. Each step is described in detail below. Hereinafter, the terminal 20 that receives the reservation information is set as the terminal 20B, and the terminal 20 that sends the reservation information is set as the terminal 20A or the terminal 20C, etc.

[0128] Figure 20 The "one or more reservation information related to the same resource" in step S601 may refer to any one of the following 1)-6).

[0129] 1) Information on reserving PSCCH / PSSCH resources with the same time resources for multiple reservation signals. For example, the reservation information is sent by terminal 20A and terminal 20C and received by terminal 20B. Figure 21 The reservation information shown.

[0130] 2) Information on reserving multiple PSCCH / PSSCH resources with the same time resources and at least a portion of the same frequency resources for multiple reservation signals. For example, the reservation information is sent by the terminal 20A and the terminal 20C and received by the terminal 20B. Figure 22 The reservation information shown.

[0131] 3) Information on PSCCH / PSSCH resources corresponding to the PSFCH opportunity with the same time resource as reserved multiple reservation signals. For example, the reservation information is sent by terminal 20A and terminal 20C and received by terminal 20B. Figure 23 The reservation information shown.

[0132] 4) Information about PSCCH / PSSCH resources that reserve one or more reservation signals and whose time resources are the same as the resources that the terminal 20B is scheduled to send (selected or reserved). For example, the reservation information is from the terminal 20A and received by the terminal 20B. Figure 24The reserved information shown.

[0133] 5) Information on PSCCH / PSSCH resources that reserve more than one reserved signal, have the same time resources as the resources scheduled for transmission (selected or reserved) by terminal 20B, and at least a part of the frequency resources are the same. For example, this reserved information is from terminal 20A and received by terminal 20B. Figure 25 The reserved information shown.

[0134] 6) Information on PSCCH / PSSCH resources corresponding to PSFCH opportunities that reserve more than one reserved signal and are the same as the time resources and the PSFCH resources scheduled for transmission or reception by terminal 20B. For example, this reserved information is sent by terminal 20A and received by terminal 20B. Figure 26 The reserved information shown.

[0135] In addition, Figure 20 The "one or more reserved information related to the same resource" in step S601 shown can be periodic reservation (for example, reservation based on a resource reservation period field), or non-periodic reservation (for example, reservation based on a time resource assignment field). According to the above 1)-6), for communication failures caused by at least one of the hidden terminal problem, half-duplex communication, and near-far problem, it is expected to avoid communication failures by the method described later.

[0136] Figure 20 The "specific condition" in step S602 shown can refer to at least one of the conditions shown in the following 1)-12).

[0137] 1) The received power of the received reserved information satisfies a predetermined condition, for example, when it satisfies the following a) or b). It is possible to judge the necessity of applying the method described later according to the interference situation.

[0138] a) The received power P of at least one of the received reserved information satisfies being greater than X (it can also be X or more) or less than X (it can also be X or less). X can be given by a high-layer parameter, and X can also be associated with the priority.

[0139] b) The difference P_dif between any two received reserved information satisfies being greater than Y (it can also be Y or more) or less than Y (it can also be Y or less). Y can be given by a high-layer parameter, and Y can also be associated with the priority.

[0140] 2) The case where the priority of the received reservation information and / or the priority related to the transmission or reception of the terminal 20B satisfies a predetermined condition (e.g., a predetermined relationship). For example, in the case of receiving two reservation information, the case where the priority of any one is higher than the other. In addition, for example, in the case of receiving two reservation information, the case where the received RSRP of the reservation information with a higher priority is smaller than the other received RSRP or smaller than Z dB or more. Z can be given by a higher layer parameter or can be associated with the priority. In addition, the priority can be the priority in the PHY layer or the priority in the MAC layer. It is possible to judge the necessity of applying the method described below based on the priority.

[0141] 3) The case where the HARQ feedback corresponding to the transmission including the reservation information satisfies a predetermined condition. For example, the case where at least two PSFCH transmissions are NACK transmissions. Furthermore, the case where all transmissions including the reservation information are unicast transmissions can also be added to the conditions. It is possible to judge the necessity of applying the method described below based on whether to use the reserved resources.

[0142] 4) The case where a specific time limit is satisfied. For example, the case where the time from receiving the reservation information to the reserved destination resource is a predetermined value or more. In addition, for example, the case where the time from receiving the reservation information to the specific information in step S603 shown in the figure is a predetermined value or more. In addition, for example, the case where the time from transmitting the specific information in step S603 shown in the figure to the reserved destination resource is a predetermined value or more. In addition, this predetermined value can be given by a higher layer parameter, can be defined as the number of symbols or the number of time slots, and can also be set to different values according to the SCS (Sub-carrier spacing) or the numerology. It is possible to judge the necessity of applying the method described below based on whether there is a time when the method described below can be applied. Figure 20 shown to the specific information in step S603 is a predetermined value or more. In addition, for example, from the transmission Figure 20 shown to the reserved destination resource is a predetermined value or more. In addition, this predetermined value can be given by a higher layer parameter, can be defined as the number of symbols or the number of time slots, and can also be set to different values according to the SCS (Sub-carrier spacing) or the numerology. It is possible to judge the necessity of applying the method described below based on whether there is a time when the method described below can be applied.

[0143] 5) The case where the transmission destination related to the reservation information satisfies a predetermined condition. For example, the case where at least one transmission destination includes the terminal 20B. In addition, for example, the case where all transmission destinations include the terminal 20B. It is possible to judge the necessity of applying the method described below based on whether oneself should apply the method described below.

[0144] 6) The case where the location information related to the reservation information satisfies a predetermined condition. For example, the case where the distance between multiple terminals 20 that have transmitted the reservation information is a predetermined value or more or less. In addition, for example, the case where the distance between the terminal 20 that has transmitted the reservation information and the terminal 20B that has received the reservation information is a predetermined value or more or less. It is possible to judge the necessity of applying the method described below based on the interference situation.

[0145] 7) The case where the terminal 20 that has sent the reservation information is a terminal 20 with specific functions. For example, the case where the terminal 20B receives a specific indication through a bit field (such as the field included in the SCI) that can only be understood by terminals 20 of version 17 or higher. For example, the case where the terminal 20B receives a notification supported in specific UE capability signaling. It is possible to judge the necessity of applying the method described below based on whether it is a communication object to which the method described below can be applied.

[0146] 8) The case where the transmission resources of the reservation information satisfy a predetermined condition. For example, the case where at least one reservation information is transmitted through a resource based on autonomous resource selection (such as mode 2). In addition, for example, the case where all reservation information is transmitted through a resource based on autonomous resource selection (such as mode 2). In addition, regarding whether the resource is set or indicated by the network (such as mode 1) or a resource based on autonomous resource selection (such as mode 2), it can be notified to the terminal 20B in association with the transmission of the reservation information. For example, it can be notified to the terminal 20B by the SCI (first-level SCI, second-level SCI, PSCCH, or PSSCH) or DCI. It is possible to judge the necessity of applying the method described below based on whether autonomous resource change is possible.

[0147] 9) The case where the propagation type related to the reservation information satisfies a predetermined condition. For example, the case where at least one propagation type is a specific propagation type. In addition, for example, the case where all propagation types are specific propagation types. It is possible to judge the necessity of applying the method described below based on the propagation type, for example, based on whether it is a propagation type to which the method described below can be applied.

[0148] 10) The case where the number of reservation resources related to the reservation information satisfies a predetermined condition. For example, the case where at least one reservation information reserves two or more resources. In addition, for example, the case where all reservation information reserves two or more resources. It is possible to judge the necessity of applying the method described below based on whether resources that do not cause problems are reserved together.

[0149] 11) The case where the packet maximum delay (PDB: Packet delay budget) related to the reservation information satisfies a predetermined condition. For example, the case where the PDB related to at least one reservation information or the remaining time to the PDB is equal to or greater than a predetermined size. In addition, for example, the case where the PDB related to all reservation information or the remaining time to the PDB is equal to or greater than a predetermined size. It is possible to judge the necessity of applying the method described below based on whether the delay of transmission is allowed.

[0150] 12) Transmission is requested by another terminal 20 Figure 20The case of the specific information in step S603 shown above.

[0151] Figure 20 The "specific terminal 20" in step S603 shown above can refer to at least one of the terminals 20 shown in 1)-12) below.

[0152] 1) The terminal 20 of the reservation information whose received power satisfies a predetermined condition, for example, satisfies a) or b) below. A terminal that can determine which method to apply according to the interference situation.

[0153] a) The received power P of at least one of the received reservation information satisfies being greater than X (can also be X or more) or less than X (can also be X or less). X can be given by a higher layer parameter, and X can also be associated with the priority.

[0154] b) The difference P_dif between any two received reservation information satisfies being greater than Y (can also be Y or more) or less than Y (can also be Y or less). Y can be given by a higher layer parameter, and Y can also be associated with the priority.

[0155] 2) The terminal 20 whose priority related to the reservation information satisfies a predetermined condition. For example, the terminal 20 whose priority related to the reservation information is lower than a predetermined value. In addition, the priority can be the priority in the PHY layer or the priority in the MAC layer. A terminal that can determine which method to apply according to the priority.

[0156] 3) The terminal 20 whose HARQ feedback corresponding to the transmission including the reservation information satisfies a predetermined condition. For example, the terminal 20 that sends a NACK for the corresponding HARQ feedback. A terminal that can determine the terminal using the reserved resources as a terminal that should apply the method described below.

[0157] 4) The terminal 20 that satisfies a specific time limit. For example, the terminal 20 that sends the reservation information of "the time from receiving the reservation information to the reserved destination resource is a predetermined value or more". In addition, for example, the terminal 20 that sends the reservation information of "the time from receiving the reservation information to sending Figure 20 The terminal 20 of the specific information in step S603 shown above is a predetermined value or more". In addition, for example, the terminal 20 that sends the reservation information of "the time from sending Figure 20 The terminal 20 of the specific information in step S603 shown above to the reserved destination resource is a predetermined value or more". In addition, the predetermined value can be given by a higher layer parameter, can also be defined as the number of symbols or the number of time slots, and can also set different values according to SCS or the parameter set. In addition, for example, the terminal 20 that receives the reservation information at the earliest or latest in the time domain. In addition, for example, the terminal 20 that sends "send Figure 20The terminal 20 of the reserved information where "the moment of the specific information in step S603 shown is the foremost or the last in the time domain". In addition, for example, the terminal 20 that has sent the reserved information of "the moment of reserving the destination resource is the foremost or the last in the time domain". It is possible to determine the terminal suitable for applying the method described later based on the processing time and the delay performance.

[0158] 5) The terminal 20 where the transmission destination related to the reserved information satisfies a predetermined condition. For example, the terminal 20 that has sent the reserved information of "at least one transmission destination of the reserved information is unicast, multicast, or broadcast including terminal 20B". In addition, for example, the terminal 20 that has sent the reserved information whose transmission destination is only unicast to terminal 20B. In addition, for example, the terminal 20 that has sent the reserved information whose transmission destination does not include terminal 20B and whose priority is lower than other reserved information. It is possible to determine the terminal suitable for applying the method described later based on the communication object.

[0159] 6) The terminal 20 where the location information related to the reserved information satisfies a predetermined condition. For example, the terminal 20 that has sent the reserved information of "the distance from terminal 20B is the maximum or the minimum". In addition, for example, the terminal 20 that has sent the reserved information of "the distance from terminal 20B is above or below a predetermined value". It is possible to determine the terminal that should apply the method described later based on the interference situation.

[0160] 7) The case where the terminal 20 that has sent the reserved information is a terminal 20 with a specific function. For example, a terminal 20 capable of performing coordinated actions between terminals. It is possible to judge the terminal to which the method described later can be applied as the terminal that should apply the method described later.

[0161] 8) The terminal 20 where the transmission resource of the reserved information satisfies a predetermined condition. For example, the transmitting terminal 20 that has sent the reserved information through a resource based on autonomous resource selection (e.g., mode 2). In addition, regarding whether the resource is set or indicated by the network (e.g., mode 1) or a resource based on autonomous resource selection (e.g., mode 2), it can be notified to terminal 20B in association with the transmission of the reserved information. For example, it can be notified to terminal 20B by SCI (first-level SCI, second-level SCI, PSCCH, or PSSCH) or DCI. It is possible to judge the terminal capable of autonomous resource change as the terminal that should apply the method described later.

[0162] 9) The terminal 20 where the propagation type related to the reserved information satisfies a predetermined condition. For example, the terminal 20 that has sent the reserved information with a specific propagation type. For example, it is possible to judge the terminal performing communication based on the propagation type to which the method described later can be applied as the terminal that should apply the method described later.

[0163] 10) A terminal 20 in which the number of reserved resources related to the reserved information satisfies a predetermined condition. For example, a terminal 20 that has sent reserved information for reserving more than two resources. A terminal that has reserved resources without problems together can be determined as a terminal to which the method described below should be applied.

[0164] 11) A terminal 20 in which the packet maximum delay (PDB: Packet delay budget) related to the reserved information satisfies a predetermined condition. For example, a terminal 20 in which the PDB related to the reserved information or the remaining time to the PDB is equal to or greater than a predetermined size. A terminal that is allowed to have a delay in transmission can be determined as a terminal to which the method described below should be applied.

[0165] 12) A terminal 20 that has requested the transmission of Figure 20 the specific information in step S603 shown.

[0166] Figure 20 The "specific information" in step S603 shown can refer to at least one of the information shown in 1)-6) below. A terminal 20 that has received the "specific information" can know that it should perform actions to avoid conflicts.

[0167] 1) Information indicating "the case of detecting the fact of a conflict".

[0168] 2) Information indicating "the case of recommending or requesting a change in resources". In addition, a recommendation means that a terminal 20 that has received this information follows it within the possible range, and may not follow it depending on the situation, and a request means that a terminal 20 that has received this information must follow it.

[0169] 3) Information indicating "the case of recommending or requesting not to use resources".

[0170] 4) Recommend or request a change in transmission power. It is possible to notify the difference between the transmission power and the transmission power of the signal related to this reservation, or it is also possible to notify the absolute value of the transmission power.

[0171] 5) Information indicating the resources as the object. For example, it is possible to notify the time slot index and / or offset, and in the case where this reservation is periodic, it is also possible to notify which resource it is.

[0172] 6) Information indicating the value or range of the priority that should be transmitted through this resource. For example, it is possible to notify "only the case where transmission with a priority value of X or less can be performed". This information can be transmitted by broadcast.

[0173] Figure 20 The "specific method" in step S603 shown can refer to at least one of the methods shown in 1)-3) below. It is possible to clarify the transmission method of the specific information.

[0174] 1) The specific information in step S603 shown can be sent through resources or a sending method related to the feedback channel. The resources or sending method related to the feedback channel can refer to the resources or sending methods shown in a)-l) below. Figure 20 The resources or sending method related to the feedback channel can refer to the resources or sending methods shown in a)-l) below.

[0175] a) Resources that can be used for PSFCH.

[0176] For example, the time resource can also be the penultimate (e.g., the second) symbol in the time slot of each parameter sl-PSFCH-Period representing the period of PSFCH. In addition, for example, the frequency resource can be the PRB determined based on the parameter sl-PSFCH-RB-Set representing the frequency domain of PSFCH. In addition, the code resource can be the pair of cyclic shifts determined based on the parameter sl-NumMuxCS-Pair related to the cyclic shift of PSFCH. Additionally, the PSFCH resources can also be determined by a method different from the PSFCH resource determination formula in Release 16 {(P ID +M ID ) mod R PSFCH PRB.CS}. Additionally, P ID is the source ID of the PHY layer, MID is the ID of the UE, and R PSFCH PRB,CS is the number of PSFCH resources for HARQ-ACK in one PSFCH transmission opportunity for transmission (multiplexing).

[0177] b) Resources that are frequency-division multiplexed and / or code-division multiplexed with the resources that can be used for PSFCH.

[0178] Figure 27 is a diagram showing an example (1) of the resources for communication in an embodiment of the present invention. For example, it can be at least a part of the PRBs in a certain resource pool other than the PRBs specified by sl-PSFCH-RB-Set. That is, in Figure 27 , the PRBs that are frequency-division multiplexed with the PRBs configured with PSFCH associated with PSSCH can be used as the resources related to the feedback channel. In addition, the PRBs specified by sl-PSFCH-RB-Set in a certain resource pool can also be used as the resources related to the feedback channel. Figure 28 is a diagram showing an example (2) of the resources for communication in an embodiment of the present invention. For example, it can be used based on, as Figure 28The cyclic shift pair determined by the sl-NumMuxCS-Pair specified as such can be used as a resource related to the feedback channel. Also, all cyclic shift pairs can be used as resources related to the feedback channel, and cyclic shift pairs determined based on a certain parameter can be used as resources related to the feedback channel.

[0179] Figure 29 FIG. (3) is a diagram showing an example of resources for communication in an embodiment of the present invention. As Figure 29 shown, resources associated in a one-to-one manner with the PSFCH resources determined by the PSFCH resource determination formula in Release 16 (e.g., resources for NACK transmission) can be used as resources related to the feedback channel.

[0180] At least a part of the cyclic shift pairs of the PRBs specified by sl-PSFCH-RB-Set, other than the cyclic shift pair determined based on sl-NumMuxCS-Pair, can also be used as resources related to the feedback channel. In the Figure 28 example shown, when Y = 2, that is, when 0 and 3 are used as cyclic shifts for NACK and 6 and 9 are used as cyclic shifts for ACK, the cyclic shifts {1, 2, 4, 5, 7, 8, 10, 11} not used for HARQ-ACK can also be used as resources related to the feedback channel.

[0181] Figure 30 FIG. (4) is a diagram showing an example of resources for communication in an embodiment of the present invention. As Figure 30 shown, adjacent indices of the CS index for NACK transmission can be used as resources related to the feedback channel. Figure 20 This is an example where the CS index for NACK transmission is {0, 3} and the CS indices {1, 4} are used as resources related to the feedback channel.

[0182] c) Resources not based on the source ID.

[0183] d) Resources determined based on the source ID or a part of the source ID included in the first-level SCI.

[0184] e) It can be transmitted as an alternative to the HARQ feedback in Release 16. For example, NACK or specific information can be transmitted in the resources determined by a) or b) above. In addition, no information can be transmitted in the resources determined by the PSFCH resource determination formula in Release 16 described above.

[0185] f) It can be sent together with the HARQ feedback of version 16. For example, NACK or specific information can also be sent in the resources determined by a) or b) above. In addition, it can also be sent in the resources determined by the PSFCH resource determination formula in version 16 above.

[0186] g) The transmission in 1) above can be understood as being sent as PSFCH. For example, the actions related to the simultaneous transmission of PSFCH by terminal 20 can also include the transmission in 1) above for processing.

[0187] h) The transmission in 1) above can also not be understood as being sent as PSFCH. For example, it can be defined as a channel different from PSFCH. In addition, terminal 20 can report the capabilities related to the simultaneous transmission of PSFCH and this channel to other terminals 20 or the network.

[0188] i) The priority of the transmission in 1) above can be determined by a predetermined method. For example, it can be determined according to the corresponding PSCCH / PSSCH reception or PSFCH transmission. In addition, this priority can be understood and set as a specific priority, or it can be predefined.

[0189] j) It can be determined when terminal 20B transmits and / or through which resources to transmit. The channel configured in the determined resources can be called PSXCH. PSXCH can be at least one of PSCCH, PSSCH, PSFCH, PSBCH, and a new channel. In the case where PSXCH is a new channel, for example, data and DM-RS can be frequency-division multiplexed, can also be mapped to multiple PRBs, and can also be encoded by Polar coding.

[0190] In addition, information related to future resource reservation can be sent through the determined resources. For example, information indicating "which PSFCH opportunity" can be sent, or information indicating "which frequency resources are used" can be sent. In addition, in the case where the determined resources overlap with the PSFCH transmission and / or reception for HARQ feedback, for example, the PSFCH transmission and / or reception for HARQ feedback can be prioritized, or the PSFCH transmission and / or reception and the information related to resource selection can be sent simultaneously, and the rules for mediating simultaneous transmission can also be determined. Only when the conditions for simultaneous transmission are met, simultaneous transmission is performed. When the conditions for simultaneous transmission are not met, the transmission with a lower priority is discarded.

[0191] k) In addition, terminal 20B can always monitor the determined resources, that is, the resources related to the feedback channel. By always monitoring, terminal 20B can send "specific information" at any time.

[0192] l) The terminal 20B can request from other terminals 20 when to send and / or through which resource to send. The channel configured for the determined resource can be referred to as PSXCH. PSXCH can be at least one of PSCCH, PSSCH, PSFCH, PSBCH, and a new channel. In the case where PSXCH is a new channel, for example, data and DM-RS can be frequency-division multiplexed, can also be mapped to multiple PRBs, and can also be encoded by Polar coding.

[0193] In addition, information related to future resource reservation can be sent through the requested resource. For example, information indicating "which PSFCH opportunity" can be sent, or information indicating "which frequency resource to use" can be sent. In addition, in the case where the requested resource overlaps with the PSFCH transmission and / or reception for HARQ feedback, for example, the PSFCH transmission and / or reception for HARQ feedback can be prioritized, or the PSFCH transmission and / or reception and information related to resource selection can be sent simultaneously, or rules for mediating simultaneous transmission can be determined, and simultaneous transmission can be performed only when the conditions for simultaneous transmission are met, and in the case where the conditions for simultaneous transmission are not met, the transmission with lower priority can be discarded. In addition, the terminal 20B can always monitor the requested resource, that is, the resource related to the feedback channel. By always monitoring, the terminal 20B can send "specific information" at any time.

[0194] 2) The specific information in step S603 shown can be sent through a resource related to control information. For example, a dedicated SCI format can be defined as this resource, or it can be a first-level SCI, or it can be a second-level SCI. In addition, for example, a dedicated field of an existing SCI format (for example, SCI format 1-A / 2-A / 2-B) can be used as this resource. In addition, for example, a combination of existing fields of an existing SCI format (for example, SCI format 1-A / 2-A / 2-B) can also be used as this resource. For example, this combination can be such that the cast type indicator field is not 10 (unicast) and the CSI request field is 1. Figure 20

[0195] 3) The specific information can be sent via a new channel having the same length as PSCCH + PSSCH. For example, the length can be changed according to the presence or absence of a PSFCH opportunity.

[0196] Figure 20 Received Figure 20The terminal 20 with the "specific information" in step S603 shown can perform actions for avoiding conflicts, such as the actions shown in 1)-6) below. It can avoid transmission conflicts and improve reliability and latency performance.

[0197] 1) Resource reselection can be performed according to specific information.

[0198] 2) Resources can be discarded according to specific information.

[0199] 3) Transmission power can be changed according to specific information.

[0200] 4) Actions based on the terminal installation can be performed according to specific information.

[0201] 5) Actions related to re-evaluation or preemption can be performed according to specific information.

[0202] 6) Whether to apply the above 1)-5) can be determined according to at least one of the information shown in a)-j) below.

[0203] a) Priority

[0204] b) RSRP

[0205] c) PDB

[0206] d) Monitoring result of the terminal 20 that receives the specific information

[0207] e) Transmission source of the specific information

[0208] f) Location information

[0209] g) Resource allocation method (e.g., mode 1 or mode 2)

[0210] h) Propagation type

[0211] i) Number of reserved resources

[0212] j) Number of selected resources

[0213] The embodiments of the present invention can also be applied to the action of setting or allocating the transmission resources of other terminals 20 by a certain terminal 20. That is, the transmission resources of other terminals 20 can be set or allocated so as to meet the conditions of resource selection or resource allocation in the embodiments of the present invention.

[0214] The above embodiments are not limited to V2X terminals and can also be applied to terminals performing D2D communication.

[0215] The operations involved in the above embodiments can be performed only in a specific resource pool. For example, the operations involved in the above embodiments can also be performed only in a resource pool that can be used by terminals 20 of version 17 or higher.

[0216] According to the above embodiments, the terminal 20 can reduce the probability of signal conflicts sent from other terminals 20 in a certain resource by sending specific information to other terminals 20 based on monitored reservation information.

[0217] That is, in direct communication between terminals, the reliability of communication during autonomous resource selection can be improved.

[0218] (Device Structure)

[0219] Next, an example of the functional structures of the base station 10 and the terminal 20 that perform the above-described processes and operations will be described. The base station 10 and the terminal 20 include the functions of implementing the above embodiments. However, the base station 10 and the terminal 20 may each have only a part of the functions in the embodiments.

[0220] <Base Station 10>

[0221] Figure 31 is a diagram showing an example of the functional structure of the base station 10. As Figure 31 shown, the base station 10 has a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. Figure 31 The functional structure shown is only an example. As long as the operations involved in the embodiments of the present invention can be performed, the functional division and the names of the functional units can be arbitrary.

[0222] The transmission unit 110 includes the function of generating a signal to be sent to the terminal 20 side and wirelessly sending the signal. The reception unit 120 includes the function of receiving various signals sent from the terminal 20 and obtaining, for example, higher-layer information from the received signals. In addition, the transmission unit 110 has the function of sending NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0223] The setting unit 130 stores preset setting information and various setting information to be sent to the terminal 20 in a storage device, and reads it out from the storage device as needed. The content of the setting information is, for example, information related to the setting of D2D communication, etc.

[0224] As described in the embodiments, the control unit 140 performs processing related to settings for the terminal 20 to perform D2D communication. In addition, the control unit 140 transmits scheduling information for D2D communication and DL communication to the terminal 20 via the transmission unit 110. In addition, the control unit 140 receives information related to HARQ responses for D2D communication and DL communication from the terminal 20 via the reception unit 120. The functional units related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional units related to signal reception in the control unit 140 may be included in the reception unit 120.

[0225] <Terminal 20>

[0226] Figure 32 is a diagram showing an example of the functional structure of the terminal 20. As Figure 32 shown, the terminal 20 includes a transmission unit 210, a reception unit 220, a setting unit 230, and a control unit 240. Figure 32 The functional structure shown is only an example. As long as the operations related to the embodiments of the present invention can be performed, the functional division and the names of the functional units can be arbitrary.

[0227] The transmission unit 210 generates a transmission signal based on transmission data and transmits the transmission signal wirelessly. The reception unit 220 receives various signals wirelessly and obtains a higher-layer signal from the received physical layer signal. In addition, the reception unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, or reference signals, etc., transmitted from the base station 10. In addition, for example, as D2D communication, the transmission unit 210 transmits a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), etc., to other terminals 20, and the reception unit 220 receives a PSCCH, a PSSCH, a PSDCH, or a PSBCH, etc., from other terminals 20.

[0228] The setting unit 230 stores various setting information received by the reception unit 220 from the base station 10 or the terminal 20 in a storage device and reads it out from the storage device as needed. In addition, the setting unit 230 also stores preset setting information. The content of the setting information is, for example, information related to the setting of D2D communication.

[0229] As described in the embodiments, the control unit 240 controls D2D communication for establishing an RRC connection with another terminal 20. In addition, the control unit 240 performs processing related to power saving operations. In addition, the control unit 240 performs processing related to HARQ for D2D communication and DL communication. In addition, the control unit 240 transmits to the base station 10 information related to HARQ responses for D2D communication and DL communication scheduled by the base station 10 to another terminal 20. In addition, the control unit 240 may also schedule D2D communication for another terminal 20. In addition, the control unit 240 may autonomously select resources used in D2D communication from a resource selection window based on the listening result, and may also perform re-evaluation or preemption. In addition, the control unit 240 performs processing related to power saving during the transmission and reception of D2D communication. In addition, the control unit 240 performs processing related to inter-terminal coordination in D2D communication. The functional unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and the functional unit related to signal reception in the control unit 240 may be included in the reception unit 220.

[0230] (Hardware Structure)

[0231] The block diagrams ( Figure 31 and Figure 32 ) used in the description of the above embodiments show blocks in terms of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block may be implemented using a single device physically or logically combined, or two or more physically or logically separated devices may be directly or indirectly (e.g., using wired, wireless, etc.) connected and these multiple devices may be used for implementation. The functional block may also be implemented by combining software with the above single device or the above multiple devices.

[0232] Functionally, it has judgment, decision, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, regarded as, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), assigning, etc., but not limited to these. For example, the functional block (structural part) that enables transmission to function is called a transmitting unit or a transmitter. In short, as described above, there is no particular limitation on the implementation method.

[0233] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure can also function as a computer that processes the wireless communication method of the present disclosure. Figure 33 FIG. is an example of the hardware structure of the base station 10 and the terminal 20 showing an embodiment of the present disclosure. Physically, the above base station 10 and terminal 20 can also be configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0234] In addition, in the following description, the term "device" can be replaced with "circuit", "device", "unit", etc. The hardware structure of the base station 10 and the terminal 20 can be configured to include one or more of the illustrated devices, or can also be configured not to include some of the devices.

[0235] Each function in the base station 10 and the terminal 20 is realized by the following method: a predetermined software (program) is read into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs operations and controls at least one of the communication of the communication device 1004 or the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0236] The processor 1001 controls the entire computer by, for example, operating an operating system. The processor 1001 can also be constituted by a central processing unit (CPU: Central Processing Unit) including an interface with peripheral devices, a control device, an arithmetic device, registers, etc. For example, the above control unit 140, control unit 240, etc. can also be implemented by the processor 1001.

[0237] In addition, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and performs various processes based on this. As the program, a program that causes the computer to execute at least a part of the operations described in the above embodiment is used. For example, Figure 31 The control unit 140 of the illustrated base station 10 can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. In addition, for example, Figure 32The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Regarding the various processes described above, although it has been described that the various processes are executed by one processor 1001, the various processes can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be installed by one or more chips. In addition, the program can also be sent from a network via a telecommunication line.

[0238] The storage device 1002 is a computer-readable recording medium and can be constituted by at least one of, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), and the like. The storage device 1002 can also be referred to as a register, a cache, a main memory (main storage device), and the like. The storage device 1002 can store a program (program code), a software module, etc. that can be executed in order to implement the communication method according to one embodiment of the present disclosure.

[0239] The auxiliary storage device 1003 is a computer-readable recording medium and can be constituted by at least one of, for example, an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disc (for example, a compact disc, a digital versatile disc, a Blu-ray (registered trademark) disc, a smart card, a flash memory (for example, a card, a stick, a key drive (Key drive)), a Floppy (registered trademark) disk, a magnetic stripe, and the like. The above storage medium can be, for example, a database, a server, and other appropriate media including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0240] The communication device 1004 is hardware (a transceiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 can also be configured to include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., to implement at least one of frequency-division duplex (FDD: Frequency Division Duplex) and time-division duplex (TDD: Time Division Duplex). For example, a transceiver antenna, an amplifier unit, a transceiver unit, a transmission path interface, etc. can also be implemented by the communication device 1004. The transceiver unit can also be physically or logically separately installed by a transmission unit and a reception unit.

[0241] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts an input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs an output to the outside. In addition, the input device 1005 and the output device 1006 can also be integrally configured (e.g., a touch panel).

[0242] In addition, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 can be configured by a single bus or by different buses between devices.

[0243] In addition, the base station 10 and the terminal 20 can be configured to include hardware such as a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit: application-specific integrated circuit), a PLD (Programmable Logic Device: programmable logic device), an FPGA (Field Programmable Gate Array: field programmable gate array), etc., and a part or all of each functional block can also be implemented by this hardware. For example, the processor 1001 can also be implemented using at least one of these hardwares.

[0244] (Summary of the Embodiment)

[0245] As described above, according to an embodiment of the present invention, there is provided a terminal comprising: a receiving unit, which receives one or more reservation information related to the same resource from one or more other terminals, respectively; a control unit, which determines whether a specific condition is satisfied; and a sending unit, wherein when the control unit determines that the specific condition is satisfied, the sending unit sends information related to the same resource to any terminal among the other terminals.

[0246] According to the above configuration, the terminal 20 transmits specific information to other terminals 20 based on the reservation information monitored, thereby reducing the probability of collision of signals transmitted from other terminals 20 in a certain resource. That is, in inter-terminal direct communication, the reliability of communication during autonomous resource selection can be improved.

[0247] The same resource may overlap at least partially with the scheduled resource. According to this structure, the terminal 20 sends specific information to other terminals 20 based on the scheduled resource and the monitored reservation information, thereby reducing the collision probability of signals sent from other terminals 20 in a certain resource.

[0248] The specific condition may be that there is a first reservation information in the reservation information whose received power is greater than a threshold, and the sending unit sends information related to the same resource to the terminal that sent the first reservation information. According to this structure, the terminal 20 sends specific information to other terminals 20 with greater interference based on the reservation information based on monitoring, thereby reducing the probability of collision of signals sent from other terminals 20 in a certain resource.

[0249] The specific condition may be that: there is a second reservation information having a lower priority than other reservation information in the reservation information, and the sending unit sends the information related to the same resource to the terminal that sent the second reservation information. According to this structure, the terminal 20 can reduce the probability of collision of signals sent from other terminals 20 in a certain resource by sending specific information to other terminals 20 that perform transmission with lower priority based on the reservation information based on monitoring.

[0250] The information related to the same resource may also be information indicating that a resource conflict has occurred. According to this structure, the terminal 20 sends information indicating that a resource conflict has occurred to other terminals 20 based on the reservation information based on monitoring, thereby reducing the probability of collision of signals sent from other terminals 20 in a certain resource.

[0251] In addition, according to an embodiment of the present invention, there is provided a communication method, in which a terminal performs the following steps: a receiving step of receiving, from one or more other terminals, one or more reservation messages related to the same resource; a control step of determining whether a specific condition is satisfied; and a sending step of sending, when it is determined that the specific condition is satisfied, information related to the same resource to any one of the other terminals.

[0252] According to the above structure, the terminal 20 sends specific information to other terminals 20 based on the monitored reservation information, whereby the collision probability of signals transmitted from other terminals 20 in a certain resource can be reduced. That is, in direct communication between terminals, the reliability of communication during autonomous resource selection can be improved.

[0253] (Supplement of the embodiment)

[0254] The embodiments of the present invention have been described above, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, alternatives, substitutions, etc. Specific numerical examples have been used for the purpose of facilitating the understanding of the invention, but these numerical values are only examples and any appropriate arbitrary values can be used as long as not specifically indicated. The distinction of items in the above description is not essential for the present invention, and the matters described in two or more items can be combined as needed, or the matters described in one item can be applied to the matters described in another item (as long as there is no contradiction). The boundary of the functional units or processing units in the functional block diagram does not necessarily correspond to the boundary of the physical components. Physically, multiple functional units can be operated by one component, or one functional unit can be operated by multiple components. Regarding the processing procedures described in the embodiments, the order of processing can be switched without contradiction. For the convenience of explaining the processing, the base station 10 and the terminal 20 are described using functional block diagrams, but such devices can also be implemented by hardware, software, or a combination thereof. The software operating through the processor of the base station 10 according to the embodiments of the present invention and the software operating through the processor of the terminal 20 according to the embodiments of the present invention can also be stored in a random access memory (RAM), a flash memory, a read only memory (ROM), an EPROM, an EEPROM, a register, a hard disk drive (HDD), a removable disk, a CD-ROM, a database, a server, and other appropriate arbitrary storage media, respectively.

[0255] In addition, the notification of information is not limited to the forms / embodiments described in the present disclosure, and other methods can also be used. For example, the notification of information can be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. In addition, RRC signaling can also be referred to as an RRC message. For example, it can also be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0256] Each of the forms / embodiments described in the present disclosure can also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, UMB (UltraMobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems extended therefrom. In addition, multiple systems can also be combined (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) for application.

[0257] For the processing procedures, timings, flows, etc. of the various forms / embodiments described in this specification, the order can be changed without contradiction. For example, for the methods described in this disclosure, the order of illustration indicates the elements of various steps, but is not limited to the specific order indicated.

[0258] In this specification, specific actions assumed to be performed by the base station 10 may sometimes be performed by its upper node depending on the situation. In a network composed of one or more network nodes having the base station 10, it is obvious that various actions performed for communicating with the terminal 20 can be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, MME or S-GW etc. are considered, but not limited to these). In the above, the case where there is one other network node other than the base station 10 is illustrated, but the other network nodes can also be a combination of multiple other network nodes (for example, MME and S-GW).

[0259] It is possible to output the information, signals, etc. described in this disclosure from a higher layer (or a lower layer) to a lower layer (or a higher layer). It can also be input or output via multiple network nodes.

[0260] The information, etc. input or output can be stored in a specific location (for example, memory), or can also be managed using a management table. The information, etc. input or output can be rewritten, updated or appended. The information, etc. output can also be deleted. The information, etc. input can also be sent to other devices.

[0261] The determination in this disclosure can be made by a value represented by 1 bit (0 or 1), can also be made by a Boolean value (true or false), and can also be made by a numerical comparison (for example, comparison with a predetermined value).

[0262] Regarding software, whether it is called software, firmware, middleware, microcode, hardware description language, or by other names, it should be interpreted broadly as referring to commands, command sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc.

[0263] In addition, software, commands, information, etc. can be transmitted and received via a transmission medium. For example, in the case of transmitting software from a website, server, or other remote source using at least one of wired technologies (such as coaxial cables, fiber optic cables, twisted pairs, digital subscriber line (DSL), etc.) and wireless technologies (such as infrared rays, microwaves, etc.), at least one of these wired technologies and wireless technologies is included in the definition of the transmission medium.

[0264] The information, signals, etc. described in this disclosure can also be represented using any one of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the overall description above can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination of these.

[0265] In addition, the terms described in this disclosure and the terms required to understand this disclosure can be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol can also be a signal (signaling). In addition, a signal can also be a message. In addition, a component carrier (CC) can also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0266] The terms "system" and "network" used in this disclosure can be used interchangeably.

[0267] In addition, the information, parameters, etc. described in this disclosure can be represented using absolute values, relative values with respect to a predetermined value, or other corresponding information. For example, wireless resources can also be indicated by an index.

[0268] The names used for the above parameters are non-restrictive in any aspect. Furthermore, the mathematical expressions using these parameters are sometimes different from the content explicitly disclosed in this disclosure. Since various channels (such as PUCCH, PDCCH, etc.) and information elements can be identified by all appropriate names, the various names assigned to these various channels and information elements are non-restrictive in any aspect.

[0269] In the present disclosure, terms such as "Base Station (BS)", "radio base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier" can be used interchangeably. Sometimes, terms such as macro cell, small cell, femto cell, pico cell are also used to refer to the base station.

[0270] A base station can accommodate one or more (e.g., 3) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services through a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services within the coverage range.

[0271] In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal" can be used interchangeably.

[0272] For a mobile station, those skilled in the art sometimes also use the following terms to refer to it: subscriber station, mobile unit, subscriber unit, radio unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client or some other appropriate terms.

[0273] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may also be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves in an unmanned manner (e.g., a drone, a self-driving car, etc.), or a robot (humanoid or non-humanoid). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during a 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.

[0274] In addition, the base station in the present disclosure may also be replaced by a user terminal. For example, with respect to a structure in which communication between a base station and a user terminal is replaced by communication between a plurality of terminals 20 (e.g., it may also be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.), various forms / embodiments of the present disclosure may also be applied. In this case, it may also be configured such that the terminal 20 has the functions of the above-described base station 10. In addition, terms such as "uplink" and "downlink" may also be replaced by terms corresponding to inter-terminal communication (e.g., "side"). For example, an uplink channel, a downlink channel, etc. may also be replaced by a side channel.

[0275] Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, it may also be configured such that the base station has the functions of the above-described user terminal.

[0276] As used in this disclosure, terms such as "determining" and "deciding" sometimes also encompass a variety of actions. For example, "determining" and "deciding" can include considering a matter that has been judged, calculated, computed, processed, derived, investigated, looked up (e.g., searched in a table, database, or other data structure), or ascertained as having been "determined" or "decided". Additionally, "determining" and "deciding" can include considering a matter that has been received (e.g., receiving information), transmitted (e.g., transmitting information), input, output, or accessed (e.g., accessing data in memory) as having been "determined" or "decided". Further, "determining" and "deciding" can include considering a matter that has been resolved, selected, chosen, established, or compared as having been "determined" or "decided". That is, "determining" and "deciding" can include a matter that is considered to have "determined" or "decided" any action. Additionally, "determining (deciding)" can also be replaced by "assuming", "expecting", "considering", etc.

[0277] Terms such as "connected" and "coupled" or any variations of these terms are intended to represent all direct or indirect connections or couplings between two or more elements, and can include cases where there is one or more intermediate elements between the two elements that are "connected" or "coupled" to each other. The coupling or connection between elements can be a physical coupling or connection, a logical coupling or connection, or a combination of these. For example, "access" can also be used to replace "connected". In the context of this disclosure, it can be considered that two elements "connect" or "couple" to each other using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave region, and optical (both visible and invisible) region is used to "connect" or "couple" to each other.

[0278] The reference signal can be abbreviated as RS (Reference Signal), or can be called Pilot according to the applied standard.

[0279] The description such as "according to" used in this disclosure does not mean "only according to" unless otherwise clearly stated. In other words, the description such as "according to" means both "only according to" and "at least according to".

[0280] Any reference to elements using terms such as "first", "second", etc. used in this disclosure does not entirely limit the quantity or order of these elements. These terms can be used in this disclosure as a simple way to distinguish between two or more elements. Therefore, the reference to the first element and the second element does not mean that only two elements can be adopted or that the first element must precede the second element in any form.

[0281] The "unit" in the structure of each of the above devices can also be replaced with "section", "circuit", "equipment", etc.

[0282] When "include", "including" and their variants are used in this disclosure, these terms mean inclusive in the same way as the term "comprising". And the term "or" used in this disclosure does not mean exclusive or.

[0283] A radio frame can be composed of one or more frames in the time domain. In the time domain, each of the one or more frames can be called a subframe. A subframe can be further composed of one or more time slots in the time domain. A subframe can also have a fixed time length (e.g., 1 ms) independent of the numerology.

[0284] The numerology can be communication parameters applied to at least one of the transmission and reception of a certain signal or channel. The numerology can represent, for example, at least one of subcarrier spacing (SCS: SubCarrier Spacing), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI: Transmission Time Interval), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transceiver in the frequency domain, specific windowing processing performed by the transceiver in the time domain, etc.

[0285] A time slot can be composed of one or more symbols (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A time slot can be a time unit based on a parameter set.

[0286] A time slot can contain multiple mini-slots. Each mini-slot can be composed of one or more symbols in the time domain. In addition, a mini-slot can also be referred to as a sub-slot. A mini-slot can be composed of a smaller number of symbols than a time slot. The PDSCH (or PUSCH) transmitted in units of time larger than a mini-slot can be referred to as PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using a mini-slot can be referred to as PDSCH (or PUSCH) mapping type B.

[0287] A radio frame, a sub-frame, a time slot, a mini-slot, and a symbol all represent time units when transmitting a signal. A radio frame, a sub-frame, a time slot, a mini-slot, and a symbol can be respectively referred to by corresponding other names.

[0288] For example, a sub-frame can also be referred to as a Transmission Time Interval (TTI), multiple consecutive sub-frames can also be referred to as a TTI, and a time slot or a mini-slot can also be referred to as a TTI. That is, at least one of a sub-frame and a TTI can be a sub-frame (1 ms) in the existing LTE, or a period shorter than 1 ms (for example, 1 - 13 symbols), or a period longer than 1 ms. In addition, the unit representing a TTI can be referred to not as a sub-frame but as a time slot, a mini-slot, etc.

[0289] Here, a TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as the bandwidth and transmission power that can be used in each terminal 20) to each terminal 20 in units of a TTI. In addition, the definition of a TTI is not limited to this.

[0290] A TTI can be the transmission time unit for data packets (transport blocks), code blocks, codewords, etc. after channel coding, or the processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the actual time interval (such as the number of symbols) to which a transport block, a code block, a codeword, etc. are mapped can be shorter than the TTI.

[0291] In addition, when one time slot or one mini time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini time slot) can constitute the minimum time unit for scheduling. Furthermore, the number of time slots (number of mini time slots) that constitute the minimum time unit for scheduling can be controlled.

[0292] A TTI having a time length of 1 ms can also be referred to as a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than the normal TTI can also be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini time slot, a sub time slot, a time slot, etc.

[0293] In addition, for a long TTI (e.g., a normal TTI, a subframe, etc.), it can be replaced with a TTI having a time length exceeding 1 ms, and for a short TTI (e.g., a shortened TTI, etc.), it can be replaced with a TTI having a TTI length less than that of the long TTI and having a TTI length of 1 ms or more.

[0294] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain. In the frequency domain, it can include one or more consecutive subcarriers. The number of subcarriers included in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers included in an RB can also be determined according to the parameter set.

[0295] Furthermore, the time domain of an RB can include one or more symbols, and can also be the length of 1 time slot, 1 mini time slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. can be constituted by one or more resource blocks respectively.

[0296] In addition, one or more RBs can be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0297] Furthermore, a resource block can be constituted by one or more resource elements (RE). For example, 1 RE can be a radio resource area of 1 subcarrier and 1 symbol.

[0298] A bandwidth part (BWP) (which may be referred to as a bandwidth part or the like) may represent a subset of consecutive common resource blocks (RB) used for a certain parameter set in a certain carrier. Herein, the common RB may be determined by the index of the RB based on the common reference point of the carrier. The PRB may be defined in a certain BWP and numbered within that BWP.

[0299] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be set for the terminal 20 within one carrier.

[0300] At least one of the set BWPs may be active, and it may not be assumed that the terminal 20 transmits and receives a predetermined signal / channel outside the active BWP. In addition, in the present disclosure, “cell”, “carrier”, etc. may be replaced by “BWP”.

[0301] The structures of the above-mentioned radio frames, sub-frames, time slots, mini time slots, and symbols are merely illustrative. For example, the number of sub-frames included in a radio frame, the number of time slots per sub-frame or radio frame, the number of mini time slots included in a time slot, the symbols included in a time slot or mini time slot, the number of RBs, the number of sub-carriers included in an RB, and the number of symbols, symbol length, cyclic prefix (CP) length, etc. within a TTI can be changed in various ways.

[0302] In the present disclosure, for example, when articles are added through translation as in the case of a, an, and the in English, the present disclosure may also include cases where the nouns following these articles are in the plural form.

[0303] In the present disclosure, the term “A is different from B” may also mean “A and B are different from each other”. In addition, this term may also mean “A and B are respectively different from C”. Terms such as “separate” and “combine” may be interpreted in the same way as “different”.

[0304] Each form / embodiment described in the present disclosure may be used alone, in combination, or switched according to the execution. In addition, the notification of predetermined information is not limited to being explicit (for example, the notification of “is X”), and may also be implicit (for example, without the notification of the predetermined information).

[0305] As described above, the present disclosure has been described in detail. However, for those skilled in the art, it should be clear that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in the form of modifications and changes without departing from the gist and scope of the present disclosure determined by the claims. Therefore, the purpose of the description of the present disclosure is to illustrate, and it has no restrictive meaning for the present disclosure.

[0306] Reference Numeral Explanation

[0307] 10: Base Station;

[0308] 110: Transmitting Unit;

[0309] 120: Receiving Unit;

[0310] 130: Setting Unit;

[0311] 140: Control Unit;

[0312] 20: Terminal;

[0313] 210: Transmitting Unit;

[0314] 220: Receiving Unit;

[0315] 230: Setting Unit;

[0316] 240: Control Unit;

[0317] 1001: Processor;

[0318] 1002: Storage Device;

[0319] 1003: Auxiliary Storage Device;

[0320] 1004: Communication Device;

[0321] 1005: Input Device;

[0322] 1006: Output Device.

Claims

1. A terminal, which is the first terminal, has: A receiving unit that receives first reservation information for reserving a first resource from a second terminal and second reservation information for reserving a second resource from a third terminal; A control unit that determines whether a specific condition based on a first time and a second time is satisfied. The first time is the time from the reception of the first reservation information or the second reservation information to the resource for transmitting information related to the conflict between the first resource and the second resource, and the second time is the time from the resource for transmitting information related to the conflict to the resource where the conflict may occur; and A transmitting unit that, when the control unit determines that the specific condition is satisfied, transmits information related to the conflict.

2. The terminal according to claim 1, wherein, The specific conditions are as follows: the first time is greater than or equal to the value given by a higher-layer parameter, and the second time is greater than or equal to the value corresponding to the subcarrier spacing.

3. The terminal according to claim 1, wherein, The control unit determines the destination terminal for the information related to the conflict based on whether the first time is greater than or equal to the value given by a higher-layer parameter.

4. The terminal according to claim 1, wherein, The control unit determines the destination terminal for the information related to the conflict based on whether inter-terminal coordination operations can be performed.

5. The terminal according to claim 1, wherein, The control unit determines the destination terminal for the information related to the conflict based on the priority related to the first reservation information and the priority related to the second reservation information.

6. The terminal according to claim 1, wherein, The control unit transmits the information related to the conflict via a feedback channel for terminal communication.

7. A terminal, which is the second terminal, has: A transmitting unit that transmits first reservation information for reserving a first resource; A receiving unit that, when a specific condition based on a first time and a second time is satisfied in the first terminal, receives information related to the conflict between the first resource and a second resource reserved by second reservation information transmitted from a third terminal from the first terminal. The first time is the time from the reception of the first reservation information or the second reservation information to the resource for transmitting information related to the conflict, and the second time is the time from the resource for transmitting information related to the conflict to the resource where the conflict may occur; and A control unit that controls the re-selection of resources used in inter-terminal communication according to the information related to the conflict.

8. The terminal according to claim 7, wherein, The control unit controls at least one of re-selection of the resource and discard of the resource according to the resource allocation mode of the second terminal.

9. A terminal, which is the first terminal, has: A receiving unit that receives first reservation information for reserving a first resource from a second terminal, where the first resource is used for transmitting a shared channel for inter-terminal communication to the first terminal; and A transmitting unit that, when the first terminal is scheduled to transmit through a second resource that overlaps with the first resource in the time domain, transmits information related to a conflict between the first resource and the second resource to the second terminal.

10. A communication method, wherein The following steps are performed by the first terminal: Receive the first reservation information for reserving the first resource from the second terminal and receive the second reservation information for reserving the second resource from the third terminal; Determine whether specific conditions based on a first time and a second time are satisfied, where the first time is the time from the reception of the first reservation information to the transmission of information related to the conflict between the first resource and the second resource, and the second time is the time from the transmission of the information related to the conflict to the resource where the conflict occurs; And Transmit the information related to the conflict when the specific conditions are satisfied.

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