Terminal and transmission method

Abstract

Provided is a terminal comprising: a receiver that receives resource allocation information for sidelink transmission from a base station; a controller that determines whether to perform sidelink transmission using a resource allocated by the base station on the basis of a sidelink signal received from a terminal that autonomously selects resources; and a transmitter that performs the sidelink transmission using the resource when it is determined to perform the sidelink transmission using the resource.

Description

[Technical Field]

[0001] The present invention relates to a terminal and a base station in a wireless communication system. [Background technology]

[0002] LTE (Long Term Evolution) and its successor systems (e.g., LTE-A (LTE Advanced) and NR (New Radio) (also known as 5G)) have introduced D2D technology, which enables terminals to communicate directly with each other without going through a base station.

[0003] D2D reduces traffic between terminals and base stations and enables communication between terminals even when the base station becomes unavailable due to a disaster, etc. In addition, since 3GPP (3rd Generation Partnership Project) refers to D2D as "sidelink," this specification also basically uses the term sidelink.

[0004] Sidelink communication can be broadly divided into discovery, which is used to find other terminals with which it can communicate, and communication for direct communication between terminals (also called D2D direct communication, terminal-to-terminal direct communication, etc.). Hereinafter, when there is no particular distinction between communication, discovery, etc., it will simply be referred to as sidelink. Various use cases for services related to V2X (Vehicle to Everything) in NR are being considered. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TS 38.331 V16.1.0(2020-07) [Non-patent document 2] 3GPP TS 38.214 V16.2.0(2020-06) [Non-patent document 3] 3GPP TS 38.321 V16.1.0(2020-07) Summary of the Invention [Problem to be solved by the invention]

[0006] In sidelink services, it is expected that terminals that perform sidelink transmission using resources allocated by a base station and terminals that perform sidelink transmission by autonomously selecting resources will coexist in the same area.

[0007] In a mode in which a base station allocates resources for sidelink transmission to terminals, in an environment in which terminals autonomously select resources for sidelink transmission as described above exist, uncontrollable sidelink transmissions may occur, which may result in collisions of sidelink transmissions between terminals.

[0008] The present invention has been made in consideration of the above points, and aims to provide a technique that makes it possible to avoid collisions in sidelink transmissions between a terminal that performs sidelink transmissions using resources allocated by a base station and a terminal that performs sidelink transmissions by autonomously selecting resources. [Means for solving the problem]

[0009] According to the disclosed technology, a receiver that receives resource allocation information for sidelink transmission from a base station; a control unit that determines whether to perform sidelink transmission using resources allocated from the base station based on a sidelink signal received from a terminal that autonomously selects resources; a transmitting unit that performs sidelink transmission using the resource when it is determined to perform sidelink transmission using the resource, a plurality of resources for sidelink transmission are allocated to the terminal; the controller selects an available resource from the plurality of resources based on the sidelink signal; The control unit is configured to The last resource in time or the first resource in time determining a resource for feedback to be transmitted to the base station based on the resource; A terminal is provided. [Effects of the Invention]

[0010] The disclosed technology provides a technology that enables avoidance of collisions in sidelink transmissions between a terminal that performs sidelink transmissions using resources allocated by a base station and a terminal that performs sidelink transmissions by autonomously selecting resources. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram for explaining V2X. [Figure 2] FIG. 1 is a diagram for explaining an example (1) of a V2X transmission mode. [Figure 3] FIG. 10 is a diagram for explaining an example (2) of a V2X transmission mode. [Figure 4] FIG. 10 is a diagram illustrating an example (3) of a V2X transmission mode. [Figure 5] FIG. 10 is a diagram illustrating an example (4) of a V2X transmission mode. [Figure 6] FIG. 10 is a diagram illustrating an example (5) of a V2X transmission mode. [Figure 7] FIG. 1 is a diagram for explaining an example (1) of a V2X communication type. [Figure 8] FIG. 10 is a diagram for explaining an example (2) of a V2X communication type. [Figure 9] FIG. 10 is a diagram for explaining an example (3) of a V2X communication type. [Figure 10] FIG. 1 is a sequence diagram showing an operation example (1) of V2X. [Figure 11] FIG. 10 is a sequence diagram showing an operation example (2) of V2X. [Figure 12] FIG. 10 is a sequence diagram showing an operation example (3) of V2X. [Figure 13] FIG. 10 is a sequence diagram showing an operation example (4) of V2X. [Figure 14] FIG. 10 is a diagram illustrating an example of a sensing operation. [Figure 15] FIG. 10 is a diagram illustrating an example of a partial sensing operation. [Figure 16] 10 is a flowchart illustrating an example of reevaluation. [Figure 17] FIG. 10 is a diagram illustrating an example of reevaluation. [Figure 18] 10 is a flowchart illustrating an example of preemption. [Figure 19] FIG. 10 is a diagram for explaining mode 1. [Figure 20] FIG. 10 is a diagram for explaining mode 1. [Figure 21] FIG. 10 is a diagram for explaining mode 1. [Figure 22] FIG. 1 is a diagram for explaining a first embodiment. [Figure 23] FIG. 1 is a diagram for explaining a first embodiment. [Figure 24] FIG. 10 is a diagram for explaining a second embodiment. [Figure 25] FIG. 10 is a diagram for explaining a second embodiment. [Figure 26] FIG. 10 is a diagram for explaining a third embodiment. [Figure 27] FIG. 10 is a diagram for explaining a third embodiment. [Figure 28] FIG. 10 is a diagram for explaining a third embodiment. [Figure 29] FIG. 10 is a diagram for explaining a third embodiment. [Figure 30] FIG. 10 is a diagram for explaining a fourth embodiment. [Figure 31] FIG. 10 is a diagram for explaining a fourth embodiment. [Figure 32] 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. [Figure 33] FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to the embodiment of the present invention. [Figure 34] 2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0013] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are used as appropriate. However, the existing technologies are, for example, existing NR (for example, the technologies disclosed in Non-Patent Documents 1 to 3) or existing LTE, but are not limited to existing NR or existing LTE. Furthermore, the term "LTE" used in this specification has a broad meaning including LTE-Advanced, systems subsequent to LTE-Advanced (e.g., NR), or wireless LAN (Local Area Network), unless otherwise specified.

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

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

[0016] In the following description, the operation of an upper layer (e.g., MAC layer) and a lower layer (e.g., PHY layer) in a terminal will be described as an example. However, the functional division between the upper layer and the lower layer is an example, and the operation described below may be performed without distinguishing between the upper layer and the lower layer.

[0017] Figure 1 is a diagram for explaining V2X. 3GPP is studying the realization of V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functions, and is currently working on specifications. As shown in Figure 1, V2X is part of ITS (Intelligent Transport Systems) and is a collective term for V2V (Vehicle to Vehicle), which refers to a form of communication between vehicles; V2I (Vehicle to Infrastructure), which refers to a form of communication between vehicles and roadside units (RSUs) installed on the side of the road; V2N (Vehicle to Network), which refers to a form of communication between vehicles and ITS servers; and V2P (Vehicle to Pedestrian), which refers to a form of communication between vehicles and mobile terminals carried by pedestrians.

[0018] Additionally, 3GPP is studying V2X using LTE or NR cellular communications and device-to-device communications. V2X using cellular communications is also called cellular V2X. NR V2X is being studied to achieve high capacity, low latency, high reliability, and quality of service (QoS) control.

[0019] It is expected that future studies of LTE or NR V2X will be conducted beyond the 3GPP specifications, including ensuring interoperability, reducing costs through implementation of higher layers, using or switching between multiple RATs (Radio Access Technologies), complying with regulations in each country, and methods for acquiring, distributing, managing databases, and using data from LTE or NR V2X platforms.

[0020] In the embodiments of the present invention, a communication device (which may also be called a terminal) is mainly assumed to be mounted on a vehicle, but the embodiments of the present invention are not limited to this. For example, the communication device may be a terminal held by a person, a device mounted on a drone or an aircraft, or a base station, an RSU, a relay station (relay node), a terminal with scheduling capability, etc. Here, a vehicle mounted with a communication device may also be called a terminal.

[0021] Note that SL (Sidelink) may be distinguished from UL (Uplink) or DL ​​(Downlink) based on any one or a combination of the following 1) to 4). SL may also be called by other names. 1) Time domain resource allocation 2) Frequency domain resource allocation 3) Reference synchronization signal (including SLSS (Sidelink Synchronization Signal)) 4) Reference signal used for path loss measurement for transmission power control

[0022] Furthermore, with regard to SL or UL Orthogonal Frequency Division Multiplexing (OFDM), any of Cyclic-Prefix OFDM (CP-OFDM), Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM), non-transform precoded OFDM, and transform precoded OFDM may be applied.

[0023] In the LTE SL, Mode 3 and Mode 4 are defined for SL resource allocation to terminal 20. In Mode 3, transmission resources are dynamically allocated by DCI (Downlink Control Information) transmitted from base station 10 to terminal 20. Also, in Mode 3, SPS (Semi Persistent Scheduling) is possible. In Mode 4, terminal 20 autonomously selects transmission resources from a resource pool.

[0024] In NR SL, Mode 1 and Mode 2 are specified for SL resource allocation to terminal 20. In Mode 1, transmission resources are allocated by DCI transmitted from base station 10 to terminal 20. In Mode 2, terminal 20 autonomously selects transmission resources from a resource pool.

[0025] The term "slot" in the embodiments of the present invention may be interpreted as a symbol, a minislot, a subframe, a radio frame, or a TTI (Transmission Time Interval). The term "cell" in the embodiments of the present invention may be interpreted as a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), or the like.

[0026] In the embodiment of the present invention, the terminal 20 is not limited to a V2X terminal, and may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a terminal carried by a user, such as a smartphone, or may be an IoT (Internet of Things) device, such as a smart meter. Furthermore, the terminal may be referred to as a "UE."

[0027] (Example of basic system configuration and basic operation)

[0028] 2 to 13 described below show an example of the system configuration in this embodiment, and also show an example of the basic operation of the system according to this embodiment.

[0029] As shown in Fig. 2, the wireless communication system according to this embodiment includes terminal 20A, terminal 20B, and base station 10. Although in reality there are many terminals, Fig. 2 shows terminal 20A and terminal 20B as examples.

[0030] Hereinafter, when there is no particular distinction between terminals 20A, 20B, etc., they will be simply referred to as "terminal 20" or "UE." In Fig. 2, as an example, a case where terminal 20A and terminal 20B are both within the coverage of a cell is shown, but the operation in this embodiment can also be applied to a case where terminal 20 is outside the coverage.

[0031] The terminal 20 does not need to be a device in a single housing. For example, even if various sensors are distributed and arranged inside a vehicle, the terminal 20 may be a device including the various sensors.

[0032] Furthermore, the processing of sidelink transmission data by terminal 20 is basically the same as the processing of UL transmission in LTE or NR. For example, terminal 20 may scramble and modulate codewords of transmission data to generate complex-valued symbols, map the complex-valued symbols (transmission signals) to one or two layers, and perform precoding. Then, terminal 20 maps the symbols to resource elements to generate transmission signals (e.g., complex-valued time-domain SC-FDMA signals), which are then transmitted from each antenna port.

[0033] The base station 10 has a cellular communication function as a base station in LTE or NR, and a function for enabling communication of the terminal 20 in this embodiment (e.g., resource pool configuration, resource allocation, etc.). The base station 10 may also be an RSU (gNB type RSU). The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of the wireless signal are defined in the time domain and the frequency domain, and the time domain may be defined by the number of OFDM symbols, and the frequency domain may be defined by the number of subcarriers or the number of resource blocks. The TTI (Transmission Time Interval) in the time domain may be a slot, a subframe, or a symbol.

[0034] Furthermore, in the wireless communication system according to this embodiment, the signal waveform used by terminal 20 for SL or UL may be OFDMA, SC-FDMA, or another signal waveform.

[0035] In the example shown in FIG. 2, the transmitting terminal 20A may be referred to as TX-UE, and the receiving terminal 20B may be referred to as RX-UE.

[0036] FIG. 2 is also a diagram for explaining an example of operation in an example (1) of the V2X transmission mode. In the transmission mode of sidelink communication shown in FIG. 2, in step 1, the base station 10 transmits sidelink scheduling information to the terminal 20A. Next, based on the received scheduling information, the terminal 20A transmits control information via a PSCCH (Physical Sidelink Control Channel) and transmits data (which may be control information) to the terminal 20B via a PSSCH (Physical Sidelink Shared Channel) (step 2). Note that transmitting control information via the PSCCH may be expressed as "transmitting the PSCCH," and transmitting data (which may be control information) via the PSSCH may be expressed as "transmitting the PSSCH."

[0037] The transmission mode of sidelink communication shown in FIG. 2 may be referred to as sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu is the radio interface between a Universal Terrestrial Radio Access Network (UTRAN) and a User Equipment (UE). The transmission mode of sidelink communication shown in FIG. 2 may be referred to as sidelink transmission mode 1 in NR.

[0038] FIG. 3 is a diagram illustrating an example of operation in an example (2) of a V2X transmission mode. In the transmission mode of sidelink communication illustrated in FIG. 3, in step 1, the terminal 20A transmits the PSCCH and the PSSCH to the terminal 20B using autonomously selected resources. The transmission mode of sidelink communication illustrated in FIG. 3 may be referred to as sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the terminal 20A itself performs resource selection. The transmission mode of sidelink communication illustrated in FIG. 3 may be referred to as sidelink transmission mode 2 in NR. In sidelink transmission mode 2 in NR, the terminal 20A itself performs resource selection.

[0039] FIG. 4 is a diagram illustrating an example of operation in an example (3) of a V2X transmission mode. In the transmission mode of sidelink communication shown in FIG. 4, in step 1, the terminal 20A transmits the PSCCH and the PSSCH to the terminal 20B using autonomously selected resources. Similarly, the terminal 20B transmits the PSCCH and the PSSCH to the terminal 20A using autonomously selected resources (step 1). The transmission mode of sidelink communication shown in FIG. 4 may be referred to as sidelink transmission mode 2 or transmission mode 2a in NR. In sidelink transmission mode 2 in NR, the terminal 20 itself performs resource selection.

[0040] FIG. 5 is a diagram illustrating an example of operation in an example (4) of a V2X transmission mode. In the transmission mode of sidelink communication illustrated in FIG. 5, in step 0, the base station 10 transmits a sidelink resource pattern to the terminal 20A via RRC (Radio Resource Control) configuration. Alternatively, the sidelink resource pattern is configured in advance in the terminal 20A. Subsequently, the terminal 20A transmits a PSSCH to the terminal 20B based on the received or configured resource pattern (step 1). The transmission mode of sidelink communication illustrated in FIG. 5 may be referred to as a sidelink transmission mode 2c in NR.

[0041] Fig. 6 is a diagram for explaining an example of operation in an example (5) of a V2X transmission mode. In the transmission mode of sidelink communication shown in Fig. 6, in step 1, terminal 20A transmits sidelink scheduling information to terminal 20B via a PSCCH. Subsequently, terminal 20B transmits a PSSCH based on the received scheduling information to terminal 20A (step 2). The transmission mode of sidelink communication shown in Fig. 6 may be referred to as a sidelink transmission mode 2d in NR.

[0042] Fig. 7 is a diagram for explaining an example of operation in an example (1) of V2X communication type. The sidelink communication type shown in Fig. 7 is unicast. Terminal 20A transmits a PSCCH and a PSSCH to terminal 20. In the example shown in Fig. 7, terminal 20A unicasts to terminal 20B and also unicasts to terminal 20C.

[0043] Fig. 8 is a diagram for explaining an example of operation in an example (2) of V2X communication type. The sidelink communication type shown in Fig. 8 is groupcast. Terminal 20A transmits PSCCH and PSSCH to a group to which one or more terminals 20 belong. In the example shown in Fig. 8, the group includes terminal 20B and terminal 20C, and terminal 20A performs groupcast to the group.

[0044] FIG. 9 is a diagram for explaining an example of operation in the example (3) of V2X communication type. The sidelink communication type shown in FIG. 9 is broadcast. Terminal 20A transmits PSCCH and PSSCH to one or more terminals 20. In the example shown in FIG. 9, terminal 20A broadcasts to terminal 20B, terminal 20C, and terminal 20D. Note that terminal 20A shown in FIGS. 7 to 9 may be referred to as a header UE (header-UE).

[0045] In addition, NR-V2X supports Hybrid Automatic Repeat Request (HARQ) for sidelink unicast and groupcast. Furthermore, NR-V2X defines Sidelink Feedback Control Information (SFCI) including an HARQ response. The SFCI is transmitted via the Physical Sidelink Feedback Channel (PSFCH).

[0046] In the following description, the PSFCH is used for transmitting the HARQ-ACK on the side link, but this is just an example. For example, the HARQ-ACK may be transmitted on the side link using the PSCCH, the PSSCH, or another channel.

[0047] For convenience, information reported by terminal 20 in HARQ will be generally referred to as HARQ-ACK below. This HARQ-ACK may also be referred to as HARQ-ACK information. More specifically, a codebook applied to HARQ-ACK information reported from terminal 20 to base station 10 or the like will be referred to as a HARQ-ACK codebook. The HARQ-ACK codebook defines the bit string of the HARQ-ACK information. Note that in addition to ACK, NACK is also transmitted using "HARQ-ACK".

[0048] FIG. 10 is a sequence diagram showing an operation example (1) related to HARQ-ACK of V2X.

[0049] In step S101, terminal 20A autonomously selects resources to be used for PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window may be set in terminal 20 by base station 10. Note that the resource selection involves a resource identification process for determining a set of candidates and a resource selection process for selecting resources from the set.

[0050] In steps S102 and S103, terminal 20A transmits SCI (Sidelink Control Information) via PSCCH (or PSSCH) using the resources autonomously selected in step S101, and also transmits SL data via PSSCH. For example, terminal 20A may transmit PSCCH using frequency resources adjacent to the frequency resources of PSSCH in the same time resources as at least a part of the time resources of PSSCH.

[0051] Terminal 20B receives the SCI (PSCCH or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The received SCI may include information on the PSFCH resource for terminal 20B to transmit a HARQ-ACK in response to reception of the data. Terminal 20A may transmit information on autonomously selected resources (resource reservation information) by including it in the SCI.

[0052] In step S104, the terminal 20B uses the PSFCH resource determined from the received SCI to transmit a HARQ-ACK for the received data to the terminal 20A.

[0053] In step S105, if the HARQ-ACK received in step S104 indicates a request for retransmission, that is, if it is a NACK (negative acknowledgement), the terminal 20A retransmits the PSCCH and PSSCH to the terminal 20B. The terminal 20A may retransmit the PSCCH and PSSCH using autonomously selected resources.

[0054] If HARQ feedback control is not performed, steps S104 and S105 may not be performed.

[0055] 11 is a sequence diagram showing an operation example (2) related to HARQ-ACK in V2X. Blind retransmission without HARQ feedback control may be performed to improve the transmission success rate or reach.

[0056] In step S201, the terminal 20A autonomously selects resources to be used for the PSCCH and the PSSCH from a resource selection window having a predetermined period. The resource selection window may be set to the terminal 20 by the base station 10.

[0057] In steps S202 and S203, terminal 20A transmits SCI over PSCCH (or PSSCH) and transmits SL data over PSSCH using the resources autonomously selected in step S201. For example, terminal 20A may transmit PSCCH using the same time resource as at least a part of the time resource of PSSCH and using frequency resources adjacent to the frequency resource of PSSCH.

[0058] In step S204, the terminal 20A uses the resource autonomously selected in step S201 to retransmit the SCI via the PSCCH or PSSCH and the SL data via the PSSCH to the terminal 20B. The retransmission in step S204 may be performed multiple times.

[0059] If blind retransmission is not performed, step S204 does not have to be performed.

[0060] 12 is a sequence diagram showing an operation example (3) related to HARQ-ACK of V2X. Base station 10 may perform sidelink scheduling. That is, base station 10 may determine sidelink resources to be used by terminal 20 and transmit information indicating these resources to terminal 20. Furthermore, when HARQ control is applied, base station 10 may transmit information indicating PSFCH resources to terminal 20.

[0061] In step S301, the base station 10 performs SL scheduling by transmitting DCI (Downlink Control Information) via the PDCCH to the terminal 20 A. For convenience, the DCI for SL scheduling is referred to as SL scheduling DCI.

[0062] Furthermore, in step S301, the base station 10 may transmit DCI for DL ​​scheduling (which may also be called DL allocation) to the terminal 20A via the PDCCH. For convenience, the DCI for DL ​​scheduling is called DL scheduling DCI. The terminal 20A that has received the DL scheduling DCI receives DL data via the PDSCH using resources specified in the DL scheduling DCI.

[0063] In steps S302 and S303, terminal 20A transmits SCI (Sidelink Control Information) by PSCCH (or PSSCH) using resources specified in the SL scheduling DCI, and also transmits SL data by PSSCH. Note that only PSSCH resources may be specified in the SL scheduling DCI. In this case, for example, terminal 20A may transmit PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, in the same time resources as at least a part of the time resources of the PSSCH.

[0064] The terminal 20B receives the SCI and SL data (PSSCH) transmitted from the terminal 20A. The SCI received via the PSCCH or PSSCH includes information about the PSFCH resource used by the terminal 20B to transmit a HARQ-ACK in response to reception of the data.

[0065] The resource information may be included in the DL scheduling DCI or SL scheduling DCI transmitted from the base station 10 in step S301, or the terminal 20A may acquire the resource information from the DL scheduling DCI or SL scheduling DCI and include it in the SCI. Alternatively, the resource information may not be included in the DCI transmitted from the base station 10, and the terminal 20A may autonomously include the resource information in the SCI and transmit it.

[0066] In step S304, the terminal 20B uses the PSFCH resource determined from the received SCI to transmit a HARQ-ACK for the received data to the terminal 20A.

[0067] In step S305, the terminal 20A transmits a HARQ-ACK, for example, at a timing (for example, slot-unit timing) specified by the DL scheduling DCI (or the SL scheduling DCI) using a PUCCH (Physical uplink control channel) resource specified by the DL scheduling DCI (or the SL scheduling DCI), and the base station 10 receives the HARQ-ACK.

[0068] If HARQ feedback control is not performed, at least one of step S304 and step S305 may not be performed.

[0069] FIG. 13 is a sequence diagram showing an operation example (4) related to V2X HARQ-ACK. As described above, in the NR sidelink, it is supported that the HARQ response is transmitted on the PSFCH. Note that the PSFCH format can be, for example, the same format as PUCCH (Physical Uplink Control Channel) format 0. That is, the PSFCH format may be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified by differences in sequence or cyclic shift (or both). The PSFCH format is not limited to this. The PSFCH resource may be allocated to the last symbol or the last multiple symbols of a slot. Furthermore, a periodicity N is set or predefined for the PSFCH resource. The periodicity N may be set or predefined on a slot-by-slot basis.

[0070] In FIG. 13, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. The PSCCH may be allocated to the first symbol of a slot, or to multiple symbols from the first, or to multiple symbols from symbols other than the first. The PSFCH may be allocated to the last symbol of a slot, or to multiple symbols from the last. Note that the "first slot" may refer to the first symbol of a slot, where X symbols are symbols usable for the side link among multiple symbols constituting one slot, or may refer to the first symbol among the symbols excluding the first symbol of the X symbols. Similarly, the "last slot" may refer to the last symbol of the X symbols, or may refer to the last symbol among the symbols excluding the last symbol of the X symbols. In the example shown in FIG. 13, three subchannels are configured in the resource pool, and two PSFCHs are allocated three slots after the slot in which the PSSCH is allocated. The arrow from the PSSCH to the PSFCH indicates an example of a PSFCH associated with the PSSCH.

[0071] Fig. 13 shows an example of groupcast option 2 in which an ACK or a NACK is transmitted as a HARQ response in NR-V2X groupcast. As shown in Fig. 13, in step S401, terminal 20A, which is a transmitting terminal 20, executes groupcast via SL-SCH to terminals 20B, 20C, and 20D, which are receiving terminals 20. In the following step S402, terminal 20B uses PSFCH#B, terminal 20C uses PSFCH#C, and terminal 20D uses PSFCH#D to transmit a HARQ response to terminal 20A. Note that in groupcast option 1, only a NACK is transmitted as a HARQ response, and an ACK is not transmitted.

[0072] FIG. 14 is a diagram showing an example of sensing operation as a basic operation example of the system in this embodiment. Here, an example of sensing operation in LTE is shown as an example. When partial sensing is not configured by a higher layer in the LTE sidelink, terminal 20 selects resources and performs transmission as shown in FIG. 14. As shown in FIG. 14, terminal 20 performs sensing in a sensing window within a resource pool. By sensing, terminal 20 receives a resource reservation field included in an SCI transmitted from another terminal 20, and identifies available resource candidates within a resource selection window within the resource pool based on the field. Next, terminal 20 randomly selects a resource from the available resource candidates. Sensing all resources within the sensing window may be referred to as full sensing.

[0073] 14, the resource pool configuration may have a period. For example, the period may be a period of 10240 milliseconds. SL From subframe t Tmax SL In this example, the resource pool is set up to the period. The resource pool within the period may have its area set by, for example, a bitmap.

[0074] Also, as shown in FIG. 14, the transmission trigger in terminal 20 occurs in subframe n, and the priority of the transmission is p TX The terminal 20 receives the data in subframe t n-10×Pstep SL From subframe t n-1 SL In the sensing window up to, for example, another terminal 20 receives a signal with priority p RX When an SCI is detected within the sensing window and the RSRP is greater than a threshold, the resource in the resource selection window corresponding to the SCI is excluded. When an SCI is detected within the sensing window and the RSRP is less than a threshold, the resource in the resource selection window corresponding to the SCI is not excluded. The threshold is, for example, a value determined by the priority p TX and priority p RX A threshold Th is set or defined for each resource in the sensing window based on pTX,pRX may be.

[0075] Also, subframe t shown in FIG. Z SL As such, resources in the resource selection window that correspond to resources in the sensing window that were not monitored, e.g., for transmission, are excluded.

[0076] In the resource selection window from subframe n+T1 to subframe n+T2, resources occupied by other UEs are identified as shown in Figure 14, and the resources excluding these resources are used to form a set of available resource candidates. The set of available resource candidates is denoted as S A Then, S A If the resource selection window is less than 20% of the resources, the threshold Th set for each resource in the sensing window is used. pTX,pRX Increase the value by 3 dB and perform resource identification again.

[0077] That is, the threshold value Th pTX,pRXBy increasing S and re-identifying resources, the number of resources that are not excluded because their RSRP is below the threshold is increased. A Measure the RSSI of each resource in the set S and select the resources with the smallest RSSI. B Add to the set of resource candidates S B S until is greater than or equal to 20% of the resource selection window. A The resource with the smallest RSSI included in B Repeat the process of adding to.

[0078] The lower layer of the terminal 20 is S B The upper layer of the terminal 20 reports S B The terminal 20 performs random selection for the resource to be used. The terminal 20 performs sidelink transmission using the determined resource. After securing the resource once, the terminal 20 may select the resource a predetermined number of times (e.g., C resel The resource may be used periodically without sensing for a certain period of time (times).

[0079] FIG. 15 is a diagram showing an example of partial sensing operation. When partial sensing is configured by a higher layer in the LTE sidelink, terminal 20 selects resources and performs transmission as shown in FIG. 15. As shown in FIG. 15, terminal 20 performs partial sensing on a part of the sensing window in the resource pool. With partial sensing, terminal 20 receives a resource reservation field included in an SCI transmitted from another terminal 20, and identifies available resource candidates in the resource selection window in the resource pool based on the field. Then, terminal 20 randomly selects a resource from the available resource candidates.

[0080] 15, the resource pool configuration may have a period. For example, the period may be a period of 10240 milliseconds. SL From subframe t Tmax SLIn this example, the resource pool is set up to the period. The resource pool within the period may have its area set by, for example, a bitmap.

[0081] As shown in FIG. 15, the transmission trigger in terminal 20 occurs in subframe n, and the priority of the transmission is p TX In the example of FIG. 15, among the subframes n+T1 to n+T2, the subframe t y SL From subframe t y+Y SL 15, the transmission trigger in terminal 20 occurs in subframe n, and the priority of the transmission is p TX Let us assume that:

[0082] The terminal 20 receives a subframe t y-k×Pstep SL From subframe t y+Y-k×Pstep SL In one or more sensing windows up to the end of the period, for example, the other terminal 20 receives a signal with a priority p RX It is possible to detect that the subframe t is transmitting. k may be, for example, a 10-bit bitmap. In FIG. 15, an example is shown in which the third and sixth bits of the bitmap k are set to "1", which indicates that partial sensing is being performed. That is, in FIG. 15, y-6×Pstep SL From subframe t y+Y-6×Pstep SL Up to and subframe t y-3×Pstep SL From subframe t y+Y-3×Pstep SL As mentioned above, the i-th bit of bitmap k is set to the subframe t y-i×Pstep SL From subframe t y+Y-i×Pstep SL It supports a sensing window up to

[0083] If an SCI is detected in one or more sensing windows and the RSRP is greater than a threshold, the resource in the resource selection window corresponding to the SCI is excluded. Also, if an SCI is detected in a sensing window and the RSRP is less than a threshold, the resource in the resource selection window corresponding to the SCI is not excluded. The threshold may be, for example, a priority p TX and priority p RX A threshold Th is set or defined for each resource in the sensing window based on pTX,pRX may be.

[0084] In the resource selection window in which the Y subframe is set, the terminal 20 identifies resources occupied by other UEs, and the resources excluding these resources become available resource candidates. The set of available resource candidates is denoted as S A Then, S A If the resource selection window is less than 20% of the resources, the threshold Th set for each resource in the sensing window is used. pTX,pRX The threshold value Th is increased by 3 dB and resource identification is performed again. pTX,pRX By increasing S and re-identifying resources, the number of resources that are not excluded because their RSRP is below the threshold is increased. A Measure the RSSI of each resource in the set S and select the resources with the smallest RSSI. B Add to the set of resource candidates S B S until is greater than or equal to 20% of the resource selection window. A The resource with the smallest RSSI included in B Repeat the process of adding to.

[0085] The lower layer of the terminal 20 is S B The upper layer of the terminal 20 reports S B The terminal 20 may determine the resource to be used by randomly selecting the resource. The terminal 20 may perform sidelink transmission using the determined resource. Note that after securing the resource once, the terminal 20 may select the resource a predetermined number of times (e.g., C reselThe resource may be used periodically without sensing for a certain period of time (times).

[0086] The above-mentioned Figures 14 and 15 explain the operation of the transmitting terminal 20, but the receiving terminal 20 detects data transmission from another terminal 20 based on the results of sensing or partial sensing, and receives data from the other terminal 20.

[0087] The resource selection operation in NR (for example, Non-Patent Documents 2 and 3) is basically the same as the resource selection operation in LTE.

[0088] That is, the TX-UE selects all resources in the resource pool within the resource selection window (referred to as M total First, let's start with M total =S A ) and denote the specific resource detected based on the sensing in the sensing window as S A The specific resources are resources reserved by the SCI received by the TX-UE, and include resources for which the RSRP (received power) for the SCI is higher than a threshold, resources that were not sensed, etc.

[0089] The amount of identified resources (S A If the amount of resources (amount of resources) is less than X% of the amount of all resources in the resource selection window in the resource pool, the above process is repeated while increasing the threshold by 3 dB until this becomes X% or more. X is, for example, 20. Note that one resource is, for example, "1 slot x (one or more subchannels)" resources. Furthermore, RSRP may be a value measured by DM-RS of the PSCCH resources that transmit SCI, or may be a value measured by DM-RS of the PSSCH resources that are indicated (reserved) by SCI.

[0090] In TX-UE, the determined S A is reported to the upper layer, and the upper layer randomly selects S AIn NR, power saving based on partial sensing as described above may be performed.

[0091] On the other hand, in the NR Release 16 sidelink, a preemption confirmation and re-evaluation function is adopted, and the terminal 20 in this embodiment can perform preemption confirmation and re-evaluation. The preemption confirmation and re-evaluation are functions for resource allocation mode 2 in which the terminal 20 autonomously selects resources to transmit, but in this embodiment, they may also be used in mode 1.

[0092] FIG. 16 is a flowchart for explaining an example of re-evaluation. FIG. 17 is a diagram showing an example of re-evaluation. In step S501, the terminal 20 performs sensing in a sensing window. When the terminal 20 performs a power-saving operation, the sensing may be performed in a predefined limited period. Next, the terminal 20 identifies each resource in the resource selection window based on the sensing result and generates a set S of resource candidates. A Next, the terminal 20 determines a set of resource candidates S A The resource set (r_0, r_1, . . . ) is selected from the resource set (r_0, r_1, . . . ) (S503). This resource set may be resources selected in a higher layer and intended to be used for transmission.

[0093] In step S504, the terminal 20 re-identifies each resource in the resource selection window based on the sensing result, for example, at the timing T(r_0)-T3 shown in FIG. 17, and generates a set of resource candidates S A Next, the terminal 20 determines S A If resource r_i is not included in the resource set, r_i is excluded from the resource set (S505), the resource set is updated, and the re-evaluation is terminated. In the upper layer, a resource is selected from the resource set after the re-evaluation.

[0094] In the example of re-evaluation shown in FIG. 17, of the resources r_0 and r_1, r_1 is re-evaluated as S A Therefore, the terminal 20 performs transmission using the resource r_0.

[0095] FIG. 18 is a sequence diagram showing an example of preemption confirmation. The operation will be explained by replacing "reevaluation" with "preemption confirmation" and "r_0" and "r_1" with "r'_0" and "r'_1" in FIG. 17. In step S601, the terminal 20 performs sensing in the sensing window. When the terminal 20 performs power saving operation, sensing may be performed in a predefined limited period. Next, the terminal 20 identifies each resource in the resource selection window based on the sensing result and creates a set S of resource candidates. A Next, the terminal 20 determines a set of resource candidates S A The resource set (r'_0, r'_1, . . . ) is selected from the resource set (r'_0, r'_1, . . . ) (S603). This resource set may be resources selected in a higher layer and intended to be used for transmission.

[0096] In step S604, the terminal 20 re-identifies each resource in the resource selection window based on the sensing result and priority at the timing T(r_0)-T3 shown in FIG. 17 to generate a set S of resource candidates. A For example, r′_1 shown in FIG. 17 is determined by resensing and is added to the set S A be included in.

[0097] When preemption is enabled, if the value prio_RX indicating the priority of the SCI transmitted from another terminal 20 is lower than the value prio_TX indicating the priority of the transport block transmitted from the terminal itself, the terminal 20 allocates the resource r′_1 to S AThe lower the value indicating the priority, the higher the priority. In other words, if the value prio_RX indicating the priority of the SCI transmitted from another terminal 20 is higher than the value prio_TX indicating the priority of the transport block transmitted from the terminal itself, the terminal 20 allocates the resource r′_1 to S A Do not exclude from.

[0098] Hereinafter, when the priority is referred to as "high," it means that the priority is high.

[0099] In step S605, the terminal 20 A If resource r′_i is not included in the resource set S, r′_i is excluded from the resource set (S605) and the resource set S A In this case, it is determined that r'_i is unavailable based on the upper layer parameters and prio_TX and prio_RX, and the preemption check is terminated. A Select a sending resource from

[0100] (Regarding Mode 1) The technology described in this embodiment is not limited to a specific wireless system such as NR or LTE, or a specific mode. However, as an example, it is assumed that NR mode 1 (resource allocation mode 1) is used together with the above-mentioned mode 2, and therefore an overview of mode 1 will be described here.

[0101] As described with reference to Fig. 2 etc., in mode 1, SL transmission resources are allocated from base station 10 to terminal 20. That is, as shown in Fig. 19, SL transmission resources (i.e., PSCCH) are allocated to terminal 20 by the PDCCH (specifically, DCI) received from base station 10, and terminal 20 performs SL transmission using those resources.

[0102] More specifically, the allocation of SL transmission from the base station 10 to the terminal 20 includes a dynamic grant (DG), a configurewd grant (CG) type 1, and a CG type 2. In mode 1, DCI format 3_0 is used for DG and CG type 2. Note that the monitoring opportunity for DCI format 3_0 is set separately from the other formats.

[0103] Fig. 20 shows an example of the fields of DCI format 3_0. As shown in Fig. 20, information notified by DCI format 3_0 includes information on resources to be scheduled, information on initial transmission / retransmission, and information on feedback. With regard to the information on initial transmission / retransmission, transmitting terminal 20A manages the relationship between the HPN (HARQ Process Number) specified in DCI format 3_0 and the HPN in the SCI.

[0104] Furthermore, feedback is as explained with reference to Fig. 12 etc. Fig. 21 shows resources in the case explained in Fig. 12. As shown in Fig. 21, it is possible to feed back HARQ-ACK fed back to terminal 20A on PSFCH to base station 10 on PUCCH.

[0105] (About the assignment) A situation is assumed in which terminal 20 operating in NR mode 1 and terminal 2 operating in NR mode 2, as described above, coexist. When SL communication is performed in mode 1 in an environment in which terminal 20 operating in mode 2 exists, uncontrollable SL transmission may occur on the NW (base station 10) side, resulting in a collision.

[0106] As specific examples of techniques for solving the above problems, Examples 1 to 4 will be described below. Examples 1 to 4 can be implemented in any combination.

[0107] Example 1 <Basic operation> First, a description will be given of Example 1. In Example 1, a terminal 20 whose SL transmission has been scheduled by the NW determines whether the scheduled SL transmission is possible or the transmittable resources based on signals received from other terminals 20.

[0108] That is, the terminal 20 in mode 1 scheduled for SL transmission avoids signal collision with the terminal 20 in mode 2 based on information learned from the SL signal received from the terminal 20 in mode 2. Basically, in the first embodiment, the terminal 20 scheduled for SL transmission avoids collision by sensing the SL signal transmitted from the terminal 20 in mode 2, similar to the sensing of mode 2 described above.

[0109] A specific example will be described with reference to Fig. 22. As shown in Fig. 22, it is assumed that a base station 10, a terminal 20-1 that operates in mode 1, and a terminal 20-2 that operates in mode 2 exist.

[0110] For terminal 20-1, SL transmission scheduling is performed by scheduling #1 from base station 10, and terminal 20-2 transmits an SL signal using autonomously selected resources. Terminal 20-1 receives the SL signal. Based on the SL signal received from terminal 20-2, terminal 20-1 determines whether or not the resources allocated in scheduling #1 can be used.

[0111] For example, terminal 20-1 receives an SCI as an SL signal from terminal 20-2 and determines from the SCI that the resource indicated by A in Fig. 23 has been reserved. On the other hand, terminal 20-1 has been assigned the resource indicated by B as the SL transmission resource by scheduling #1.

[0112] When terminal 20-1 detects that the resource reserved by terminal 20-2 conflicts with resource B allocated to itself, it determines that resource B cannot be used and does not transmit an SL signal using resource B. This makes it possible to avoid collision (interference) of SL transmission resources.

[0113] In the above example, terminal 20-1 determines whether or not it is possible to use the resources allocated to it based on the resource reservation information received from terminal 20-2, but this is just an example. Terminal 20-1 may also determine whether or not it is possible to use the resources allocated to it based on either or both of the information indicated in the time resource assignment field and the information indicated in the resource reservation period field in the SCI received from terminal 20-2.

[0114] Furthermore, terminal 20-1 may determine whether or not resources allocated from base station 10 are available based on the received power of an SL signal received from terminal 20-2. For example, when the received power of a certain resource received from terminal 20-2 is equal to or greater than a threshold and part or all of the resource overlaps with part or all of the resources allocated from base station 10, terminal 20-1 may determine that the resource is unavailable.

[0115] Furthermore, when determining whether or not the resources allocated by the base station 10 can be used, the terminal 20-1 may regard the resources allocated by the base station 10 as resources selected by itself in mode 2, and may perform the same operation as the re-evaluation or pre-emption confirmation described above.

[0116] <Resource selection operation> In the above example, terminal 20-1 determines whether or not the resources allocated by base station 10 can be used based on the SL signal received from terminal 20-2 in mode 2, but as a more detailed operation, terminal 20-1 may perform the resource selection operation described below.

[0117] In the resource-to-be-used selection operation, multiple resources are allocated to terminal 20-1 as resources available for SL transmission from base station 10. Based on the SL signal received from terminal 20-2, terminal 20-1 selects an available resource from the multiple resources and performs SL transmission using the selected resource.

[0118] For example, suppose that terminal 20-1 is allocated four resources A, B, C, and D as resources available for SL transmission by base station 10. When terminal 20-1 determines, based on the SL signal received from terminal 20-2, that resources A and B are being used (including being reserved) by terminal 20-2, it performs SL transmission using either or both of resources C and D.

[0119] The multiple resources allocated by the base station 10 may be allocated by multiple DCIs or may be allocated by one DCI at a time. The multiple resources allocated at a time may be four or more resources.

[0120] Alternatively, multiple resources may be treated as a set, and a certain set among the sets may be instructed from base station 10 to terminal 20-1.

[0121] For example, if base station 10 specifies set 1 having four resources A, B, C, and D as a set of available resources to terminal 20-1, terminal 20-1 selects a resource to use from resources A, B, C, and D included in set 1.

[0122] Furthermore, in the utilization resource selection operation in which multiple resources are allocated from the base station 10 to the terminal 20-1, the terminal 20-1 may provide feedback to the base station 10, as described in Fig. 12. In this case, the terminal 20-1 may determine the resource for feedback (e.g., time resource, frequency resource, or time-frequency resource) based on a specific resource (e.g., "last in time" or "first in time") among the multiple resources. The resource for feedback does not have to be based on the resource actually used for SL transmission.

[0123] For example, suppose that terminal 20-1 is assigned resources A, B, C, and D as multiple resources and performs SL transmission using resource A. Furthermore, if resource D is the last resource in terms of time among resources A, B, C, and D, terminal 20-1 transmits feedback regarding the SL transmission using resource A to base station 10 in a slot that is a predetermined number of slots after the slot of resource D.

[0124] <Reporting to the base station> For example, if the terminal 20-1 has not performed SL transmission using the resources allocated by the base station 10 based on the signal received from the terminal 20-2, the terminal 20-1 may transmit a NACK to the base station 10.

[0125] Furthermore, in the above-described operation of selecting resources to be used, the terminal 20-1 may report to the base station 10 the resources that have not been used for SL transmission, among the multiple resources allocated by the base station 10.

[0126] <Effects of Example 1> It is assumed that the terminal 20 operating in mode 1 also supports operation in mode 2. In the first embodiment, the terminal 20 performs operations similar to sensing in mode 2 and re-evaluation or pre-emption confirmation, thereby avoiding signal collisions with the terminal 20 in mode 2. This has the effect of preventing collisions between terminals in mode 1 and mode 2 while suppressing the implementation of additional terminals.

[0127] Example 2 Next, a description will be given of Example 2. Example 2 may be implemented without relying on Example 1 as a premise, or may be implemented in combination with Example 1.

[0128] In the second embodiment, the terminal 20 operating in mode 1 receives a signal from the terminal 20 operating in mode 2 and reports information based on the signal to the base station 10. This allows, for example, the base station 10 to receive information related to the terminal 20 in mode 2 (e.g., resources used for SL transmission) from the terminal 20 in mode 1. This allows the base station 10 to allocate resources for SL transmission to the terminal 20 operating in mode 1 based on the information, for example, so as not to collide with resources used by the terminal 20 in mode 2.

[0129] A specific example will be described with reference to Fig. 24. In the example of Fig. 24, there exists a base station 10, a terminal 20-1 that executes an operation in mode 1 under the control of the base station 10, and a terminal 20-2 that executes an operation in mode 2.

[0130] Terminal 20-2 in mode 2 performs SL transmission using autonomously selected resources. Terminal 20-1 receives the SL signal and reports information based on the SL signal to base station 10. The information based on the SL signal may be an SCI received by the SL signal, a resource included in the SCI to be used for SL transmission, or a resource included in the SCI reserved for SL transmission. Furthermore, the information based on the SL signal may be information on a resource whose received power is equal to or greater than a threshold.

[0131] The base station 10 that has received the information based on the SL signal allocates, for example, resources that are not being used by the terminal 20-2 in mode 2 to the terminal 20-1 as resources for SL transmission.

[0132] In the above example, terminal 20-1 reports information based on the SL signal from terminal 20-2 in mode 2 to base station 10, but this is just an example, and terminal 20-1 may transmit information to base station 10 based on the SL signal received from other terminals 20, not just terminal 20-2 in mode 2. In the following, as an example, the situation in FIG. 24 is assumed, and the other terminal 20 is described as terminal 20-2. Furthermore, terminal 20-2 in the following description of Example 2 may be a terminal that is not operating in mode 2, unless otherwise specified.

[0133] <How to send information> When terminal 20-1 receives an SL signal from terminal 20-2, it may always transmit information based on the SL signal to base station 10, or it may determine whether a predetermined condition is met and transmit only if it is determined that the predetermined condition is met. The predetermined condition is, for example, that transmission is scheduled to occur at a predetermined time (e.g., slot or time window).

[0134] As an example, when terminal 20-1 is scheduled to perform UL transmission between the time when it receives the SL signal (for example, slot k) and the time n slots later (i.e., slot k+n), it transmits information based on the SL signal, for example, at the timing of the UL transmission. "Scheduled to perform UL transmission" means, for example, that UL transmission has been scheduled for terminal 20-1, or that terminal 20-1 is scheduled to perform UL transmission using resources it has autonomously selected.

[0135] The predetermined condition may be either (1) or (2) below.

[0136] (1) The terminal 20-1 detected that at least a part of the resources allocated to the terminal 20-1 from the base station 10 was reserved for the terminal 20-2.

[0137] (2) The terminal 20-1 detected that at least a part of the resources allocated to the terminal 20-1 from the base station 10 was reserved for the terminal 20-2, and at least one of the priority and RSRP satisfied the second predetermined condition. The second predetermined condition is, for example, that the priority of the terminal 20-2 is higher than the priority of the terminal 20-1. Also, the second predetermined condition may be, for example, that the received power (RSRP) of the SL signal received from the terminal 20-2 is greater than or equal to a certain threshold.

[0138] The terminal 20-1 may transmit information based on the SL signal using periodic resources, or may receive an allocation of aperiodic resources from the base station 10 and use the aperiodic resources for transmission.

[0139] The signal including information based on the SL signal transmitted by the terminal 20-1 may be transmitted on a data channel, a control channel, a feedback channel, or a dedicated channel other than these.

[0140] Also, the signal including information based on the SL signal transmitted by the terminal 20-1 may be UCI. When using UCI, the format of UCI or PUCCH including UCI may be any format. Also, a format dedicated to UCI or PUCCH including UCI in which information based on the SL signal is included may be used as the format of UCI or PUCCH including UCI.

[0141] Also, the signal including information based on the SL signal transmitted by the terminal 20-1 may be transmitted by upper layer signaling (e.g., MAC CE, RRC signal).

[0142] <Regarding information based on the SL signal> The information based on the SL signal transmitted by terminal 20-1 may be information about resources that terminal 20-1 cannot use, or may be information about resources that are scheduled to be used by terminal 20-2. In other words, the information based on the SL signal transmitted by terminal 20-1 may be information about resources at a future time.

[0143] Furthermore, the information based on the SL signal transmitted by terminal 20-1 may be information about resources that terminal 20-1 was unable to use due to a conflict with resources of terminal 20-2, or may be information about resources that were used by terminal 20-2. In other words, the information based on the SL signal transmitted by terminal 20-1 may be information about resources at a past point in time.

[0144] The information based on the SL signal transmitted by terminal 20-1 may be limited to information on terminals 20 operating in mode 2 (e.g., information related to resources used by or that have been used by terminals 20 operating in mode 2). In other words, terminal 20-1 may not transmit to base station 10 information based on the SL signal received from terminals 20 not operating in mode 2 (e.g., terminals 20 operating in mode 1).

[0145] To enable the above operation, terminal 20 may include, in the SCI that it transmits, information indicating whether the resource usage information or resource reservation information by that SCI is information relating to Mode 1 or whether the resource usage information or resource reservation information by that SCI is information relating to Mode 2. Terminal 20-1 identifies, based on the information received from other terminals 20, whether other terminals 20 are operating in Mode 2, and, if it detects that other terminals 20 are operating in Mode 2, reports information based on the SL signal to base station 10.

[0146] <sequence> An example sequence will be described with reference to Fig. 25. Here, it is assumed that terminal 20-1 operates in mode 1 and terminal 20-2 operates in mode 2. In S11, terminal 20-1 receives an SL signal from terminal 20-2. In S12, terminal 20-1 transmits information based on the received SL signal to base station 10. For example, base station 10 uses the information based on the SL signal to determine the resources used by terminal 20-2, determines resources that avoid collision with those resources, and in S13 transmits allocation information of the determined resources to terminal 20-1.

[0147] Furthermore, for example, when resources for SL transmission have already been allocated to terminal 20-1, if base station 10 determines from information based on the SL signal that some or all of the resources (including reserved) used by terminal 20-2 overlap with some or all of the resources already allocated to terminal 20-1, it may transmit to terminal 20-1 a command to stop SL transmission using the already allocated resources. Terminal 20-1, having received this command, stops the corresponding SL transmission.

[0148] <Effects of Example 2> According to the second embodiment, the base station 10 can know the resource usage status of the terminal 20 in mode 2, and based on that, the terminal 20 in mode 1 operating under the control of the base station 10 can perform operations to avoid transmission collisions.

[0149] Example 3 Next, a description will be given of Example 3. Example 3 may be implemented without relying on Examples 1 and 2, or may be implemented in combination with any one or all of Examples 1 and 2.

[0150] In the third embodiment, the terminal 20 operating in mode 2 connects to the same base station 10 as the base station 10 to which the terminal 20 operating in mode 1 is connected. Here, the side link resource pool used by the terminal 20 operating in mode 2 and the side link resource pool used by the terminal 20 operating in mode 1 may be the same or may partially overlap.

[0151] That is, in the third embodiment, it is assumed that the terminal 20 in mode 2 is also in-coverage, and the terminal 20 in mode 2 operates based on scheduling information for the terminal 20 in mode 1. This allows the terminal 20 in mode 2 to perform SL transmission operation so as to avoid collision with the terminal 20 in mode 1.

[0152] In addition, in Example 3, "terminal 20 connects to base station 10" includes not only establishing a connection by RRC or the like, but also "terminal 20 receives a signal from base station 10 without establishing a connection by RRC or the like."

[0153] In addition, in the third embodiment, a resource group (e.g., resource pool, CC, serving cell) that can be used only by the terminal 20 in mode 1 and the terminal 20 in mode 2 connected to the same base station 10 as the terminal 20 in mode 1 connected to may be configured for these terminals 20.

[0154] A specific example will be described with reference to Figures 26 and 27. In Figure 26, terminal 20-1 in mode 1 receives resource allocation information (scheduling #1) from base station 10. Terminal 20-2 in mode 2 also receives scheduling #1 from base station 10. In other words, scheduling information can be shared.

[0155] 27, for example, terminal 20-2 can detect that part of the resources indicated by A that it has selected (reserved) is the resource allocated to terminal 20-1 in mode 1. In this case, for example, terminal 20-2 can determine not to use the resources indicated by A.

[0156] Below, more specific examples will be described from the viewpoints of a method of connecting with a base station, a scheduling method, a method of receiving scheduling information, transmission control, and the like.

[0157] <Example of how to connect to a base station> Here, as in the case shown in FIG. 26, a case is assumed in which base station 10, terminal 20-1 in mode 1, and terminal 20-2 in mode 2 exist.

[0158] An example of a connection method in this case will be described with reference to Fig. 28. In S21, terminal 20-1 establishes an RRC connection with base station 10. On the other hand, no RRC connection is established between terminal 20-2 and base station 10, and in S22, terminal 20-2 receives an SSB and system information transmitted from base station 10. The SSB or system information may include information about resources for receiving information (e.g., DCI) transmitted from base station 10 in S24, which will be described later.

[0159] In S23, terminal 20-1 receives resource information (scheduling information) related to scheduling addressed to itself from base station 10. This scheduling information may include resource allocation information for terminals 20 other than terminal 20-1. In S24, terminal 20-2 also receives the scheduling information.

[0160] In S25, terminal 20-2 performs transmission control. Specifically, terminal 20-2 may perform a predetermined operation when some or all of the resources selected (including reserved) by itself in the operation of Mode 2 overlap with some or all of the resources received in S24 (e.g., resources allocated to one or more terminals 20).

[0161] The predetermined operation by the terminal 20-2 is, for example, stopping SL transmission using the resource selected by itself.

[0162] Alternatively, the predetermined operation by terminal 20-2 may be to perform SL transmission using the resource selected by itself with increased transmission power, or may be to perform SL transmission using the resource selected by itself as usual.

[0163] Which of the above operations (stop transmission, increase transmission power, normal transmission) to perform may be determined based on at least one of the priority of the selected resource, the resource allocation order, and whether the resource can be reserved. As an example, assuming that the priority types of the selected resource are high, medium, and low, if priority=high, increase transmission power; if priority=medium, normal transmission; and if priority=low, stop transmission.

[0164] Another example will be described with reference to Fig. 29. In S31, the terminal 20-1 establishes an RRC connection with the base station 10.

[0165] On the other hand, the terminal 20-2 receives an SSB from the base station 10 in S32, and performs PRACH transmission in S33. The PRACH resource (e.g., sequence) used in this PRACH transmission may be different from the PRACH resource used in PRACH transmission for the RRC connection.

[0166] After transmitting the PRACH, in S34, the terminal 20-2 receives, from the base station 10, setting information related to reception of the PDCCH from the base station 10. The setting information may include, for example, any one or more or all of a monitoring occasion, a CORESET, a search space, an aggregation level, and an RNTI value for reception of the PDCCH.

[0167] In S35, terminal 20-1 receives resource information (scheduling information) related to scheduling addressed to itself from base station 10. In S36, terminal 20-2 also receives the scheduling information. In S37, terminal 20-2 performs transmission control in the same manner as in S25 described above.

[0168] <Scheduling method> In the third embodiment, the scheduling of resources (SL resources) for SL transmission from the base station 10 to the terminals 20 in mode 1 may be performed by a signal addressed to a single terminal 20 (e.g., a UE-specific signal) or by a signal addressed to multiple terminals 20 (e.g., a Group-common signal).

[0169] A signal addressed to multiple terminals 20 may include information on SL resources allocated to each terminal 20. Furthermore, a signal addressed to multiple terminals 20 may include information related to feedback to base station 10 (e.g., PUCCH slot, PUCCH resource, SAI, DAI, etc.). Furthermore, a signal addressed to multiple terminals 20 may include both information on SL resources allocated to each terminal 20 and information related to feedback to base station 10.

[0170] As described above, when a signal addressed to multiple terminals 20 includes scheduling information (such as information on SL resources) to be allocated to each terminal 20, a terminal 20 in mode 1 may determine the scheduling information addressed to itself based on at least one of the following (1) to (3):

[0171] (1) Determination is made based on the RNTI by which the CRC of the DCI is scrambled. For example, if the terminal 20 can decode the DCI using a specific RNTI, the terminal 20 determines that the DCI is addressed to itself.

[0172] (2) Terminal 20 determines that the X-th scheduling information is the scheduling information addressed to itself among N (N≧0) pieces of scheduling information included in a signal addressed to multiple terminals 20. Here, X may be specified by base station 10 to terminal 20 by a higher layer parameter such as an RRC signal or MAC CE, for example.

[0173] (3) The determination is made based on the UE-ID included in the signal addressed to multiple terminals 20. For example, if terminal 20's own UE-ID is included in a signal addressed to multiple terminals 20, terminal 20 determines that the scheduling information in the signal is addressed to itself.

[0174] In a signal addressed to multiple terminals 20, predetermined parameters may be common to the multiple terminals 20. Here, the predetermined parameters are, for example, MCS, time-domain resource, and the like.

[0175] Furthermore, terminal 20 in mode 1 may receive multiple DCIs related to different RNTIs from base station 10. At this time, terminal 20 may determine that the scheduling information other than that addressed to itself is scheduling information addressed to another terminal 20 and that this scheduling information cannot be used.

[0176] For example, base station 10 transmits multiple DCIs, each with multiple RNTI values ​​set to be received by multiple terminals 20. For example, base station 10 transmits DCI set to RNTI-A, which is to be received by terminal 20-1, and DCI set to RNTI-B, which is to be received by another terminal, terminal 21-1. Note that although an example using multiple RNTIs is shown here, a single RNTI may be set, and scheduling information addressed to itself may be identified by something other than the RNTI.

[0177] When a terminal 20 in mode 2 receives a plurality of DCIs relating to different RNTIs, it may determine that all of the received DCIs correspond to scheduling information addressed to other terminals 20 and cannot be used.

[0178] In addition, the mode 2 terminal 20 may operate based on information received from the base station 10 (e.g., resource allocation information for the mode 1 terminal 20) in either or both of resource identification and resource selection.

[0179] For example, the terminal 20 in mode 2 performs either or both of resource identification and resource selection, excluding resources indicated by information received from the base station 10. Furthermore, the terminal 20 in mode 2 may determine whether to exclude resources indicated by information received from the base station 10 based on the priority of the resource. For example, the terminal 20 in mode 2 may not exclude the resources selected by itself from candidates for SL transmission resources when the priority of the resources selected by itself is higher than the priority of the resources indicated by information received from the base station 10.

[0180] <Example of expected reception> In both mode 1 and mode 2, it may be assumed that terminal 20 always receives signals addressed to multiple terminals 20 from base station 10 in each PDCCH monitoring occasion.

[0181] If terminal 20 does not receive signals addressed to multiple terminals 20 in a PDCCH monitoring occasion that is expected to be received, terminal 20 may determine not to perform SL transmission using the SL resource corresponding to that occasion. Also, if an SL resource corresponding to that occasion has been selected or reserved, transmission using that SL resource may be stopped. This is because if an SL resource corresponding to that occasion is allocated, there is a possibility that a collision will occur with SL transmission performed using that SL resource, and it is expected that the reception quality of the SL signal will deteriorate.

[0182] Furthermore, when a predetermined parameter set is notified from the base station 10 to a terminal 20 in mode 1, it may mean that SL resource allocation is not performed for the terminal 20 in mode 1.

[0183] <Effects of Example 3> According to the third embodiment, the terminal 20 in mode 2 can know the SL allocation status of the terminal 20 in mode 1, and can apply an operation to avoid transmission collisions based on the information.

[0184] Example 4 Next, a description will be given of Example 4. Example 4 may be implemented without relying on Examples 1 to 3, or may be implemented in combination with any one, any plurality, or all of Examples 1 to 3.

[0185] In the fourth embodiment, a terminal 20 operating in mode 2 transmits certain data (e.g., a TB (transport block)) using predetermined resources for the first transmission of the data or for the transmission of certain data using unreserved resources. Hereinafter, the above-mentioned "first transmission" and "transmission using unreserved resources" are collectively referred to as "transmission A." Note that transmission A is not limited to these, and any transmission that cannot be known in advance by other terminals 20 may also be referred to as transmission A.

[0186] In this way, the terminal 20 in mode 2 uses predetermined resources in transmission A, and can distinguish non-reserved resources (resources for transmission A) from other resources, thereby avoiding collisions between modes 1 and 2 related to resources for transmission A. Note that, by applying embodiment 1, reserved resources can be detected by sensing, re-evaluation / pre-emption check, etc., and collisions can be avoided.

[0187] <Resources available for transmission A> Resources that a terminal 20 in mode 2 can use for transmission A (referred to as transmission A available resources) may be specified by prior configuration of the terminal 20. This configuration may be performed from the base station 10 to the terminal 20 by RRC signaling, MAC CE, DCI, or the like.

[0188] Regarding the resources to be set above, time resources may be specified as a range of resources that can be used for transmission A. For example, one or more slots in a resource pool for SL transmission or SL reception may be specified.

[0189] Furthermore, for the resources to be set, frequency resources may be specified as a range of resources that can be used for transmission A. For example, one or more sub-channels in a resource pool for SL transmission or SL reception may be specified.

[0190] It should be noted that the terminal 20 in mode 2 may use any resource in the resource pool for transmissions other than transmission A.

[0191] <Selection of resources to be used for transmission A> The terminal 20 in mode 2 uses resources from the available resources for transmission A when actually performing transmission A. Specifically, for example, either of the following methods (1) or (2) can be used.

[0192] (1) A terminal 20 in mode 2 performs resource identification in the same manner as for transmission resources other than transmission A, and when selecting resources to actually use for transmission from the identification result (identified set), selects resources included in the transmission A available resources.

[0193] (2) The terminal 20 in mode 2 performs resource identification from among the resources available for transmission A, and selects the resources to be actually used for transmission from the identified set.

[0194] <Operation of terminal 20 in mode 1> A mode 1 terminal 20 may assume that for its first transmission of some data or for transmission in unreserved resources, it will use resources other than the above-mentioned predetermined resources for a mode 2 terminal 20.

[0195] For example, the base station 10 may allocate resources other than the above-mentioned transmission A available resources to the terminal 20 in mode 1 as resources for the initial transmission of data or as resources for transmission using unreserved resources.

[0196] Furthermore, the terminal 20 in mode 1 may perform the operation of the first or second embodiment based on at least the SL signal (resource reservation signal) transmitted from the terminal 20 in mode 2 using the above-mentioned predetermined resource.

[0197] <Other examples> In the fourth embodiment, the terminal 20 may transmit only a part of the data (TB) or may transmit only reservation information in non-reserved resources (for example, the above-mentioned "predetermined resources" are examples of non-reserved resources). Also, the number of frequency resources for initial transmission and retransmission may be different.

[0198] <Example> An example of the sequence will be described with reference to Fig. 30. In Fig. 30, there is a base station 10, a terminal 20-1 in mode 1, and a terminal 20-2 in mode 2.

[0199] In S41, the base station 10 allocates resources for the first SL transmission to the terminal 10-1. The resources are, for example, resources other than the transmission A available resources. This makes it possible to avoid collision between the first SL transmission transmitted by the terminal 20-1 and the transmission A by another terminal 20.

[0200] Here, in S42, terminal 20-1 receives from terminal 20-2 the SL signal by transmission A. For example, the SL signal by transmission A includes reservation information by terminal 20-2, and this allows transmission control of subsequent SL transmissions (S43) to be performed in the same manner as in the first embodiment.

[0201] Another example will be described with reference to Fig. 31. In the example of Fig. 31, similarly to the case of Fig. 29, it is assumed that there are base station 10, terminal 20-1 in mode 1, and terminal 20-2 in mode 2.

[0202] As shown in Fig. 31 as "Resource for initial TX and reTX of a TB from mode 1 UE," an upper portion of the resource pool is set as resources for initial transmission and retransmission of data for terminal 20-1 in mode 1. Also, as shown as "Resource for reTX of a TB from any UE," a central portion of the resource pool is set as resources for retransmission from any terminal. Also, as shown as "Resource for initial TX and reTX of a TB from mode 2 UE," a lower portion of the resource pool is set as resources for initial transmission and retransmission of data for terminal 20-2 in mode 2.

[0203] Under such settings, as shown in FIG. 31, each terminal 20 can avoid resource collisions and perform initial SL transmission and subsequent SL transmissions based on reservations.

[0204] <Effects of Example 4> According to the fourth embodiment, it is possible to avoid collisions between the terminal 20 in mode 1 and the terminal 20 in mode 2. Furthermore, in the fourth embodiment, additional implementation can be limited.

[0205] (Other examples) In all of the first to fourth embodiments, mode 1 is a mode in which the NW (base station 10) schedules SL resources to the terminal 20, and mode 2 is a mode in which the terminal 20 autonomously selects resources. However, the mode in which the NW (base station 10) schedules SL resources to the terminal 20 may be called by a name other than mode 1, and the mode in which the terminal 20 autonomously selects resources may be called by a name other than mode 2.

[0206] In any of the first to fourth embodiments, the base station 10 may be replaced with a terminal 20 other than the terminal 20 under the control of the base station 10, and the first to fourth embodiments may be implemented. That is, in any of the first to fourth embodiments, the technology of the embodiment may be applied to an operation in which one terminal 20 sets (or allocates) a transmission resource for another terminal 20.

[0207] In any of the first to fourth embodiments, the terminal 20 may be any terminal, and may be a V2X terminal or a terminal other than a V2X terminal that performs D2D.

[0208] Furthermore, in any of the first to fourth embodiments, the operation may be performed only in a specific resource pool. For example, in any of the first to fourth embodiments, the operation may be performed only in a resource pool that can be used by the terminal 20 of Rel-17 or later.

[0209] (Device configuration) Next, a description will be given of an example of the functional configuration of the base station 10 and the terminal 20 that execute the processes and operations described above. The base station 10 and the terminal 20 include functions for implementing the above-mentioned embodiments 1 to 4. However, the base station 10 and the terminal 20 may each be provided with only the functions of any one of embodiments 1 to 4.

[0210] <Base station 10> Fig. 32 is a diagram showing an example of the functional configuration of the base station 10. As shown in Fig. 32, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 32 is merely an example. The names of the functional divisions and functional units may be any as long as they can perform the operations related to the embodiment of the present invention. The transmitting unit 110 and the receiving unit 120 may be called a communication unit.

[0211] The transmitter 110 has a function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiver 120 has a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signals. The transmitter 110 also has a function of transmitting, to the terminal 20, an NR-PSS, an NR-SSS, an NR-PBCH, a DL / UL control signal, DL data, etc.

[0212] The setting unit 130 stores in a storage device setting information that is set in advance and various setting information to be transmitted to the terminal 20, and reads out the setting information from the storage device as needed. The setting information is read out from the setting unit 130 and transmitted to the terminal 20 by the transmission unit 110.

[0213] The control unit 140 performs, for example, resource allocation and overall control of the base station 10. Note that the functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120. Furthermore, the transmitting unit 110 and the receiving unit 120 may be called a transmitter and a receiver, respectively.

[0214] <Terminal 20> Fig. 33 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 33, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 33 is merely an example. The names of the functional divisions and functional units may be any as long as they can execute the operations related to the embodiment of the present invention. The transmitting unit 210 and the receiving unit 220 may be called a communication unit.

[0215] The transmitter 210 generates a transmission signal from transmission data and transmits the transmission signal wirelessly. The receiver 220 receives various signals wirelessly and acquires higher layer signals from the received physical layer signals.

[0216] The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220 in a storage device and reads it out from the storage device as needed. The setting unit 230 also stores setting information that is set in advance. The control unit 240 executes control such as determining whether or not SL transmission is possible using the allocated resources.

[0217] Note that the functional units in control unit 240 related to signal transmission may be included in transmitting unit 210, and the functional units in control unit 240 related to signal reception may be included in receiving unit 220. Furthermore, transmitting unit 210 and receiving unit 220 may be called a transmitter and a receiver, respectively.

[0218] According to the present embodiment, at least the terminal, base station, and transmission method described in the following items are provided. Each related embodiment will be described below.

[0219] <Examples 1 and 4> (Section 1) a receiving unit configured to receive resource allocation information for sidelink transmission from a base station; a control unit that determines whether to perform sidelink transmission using resources allocated from the base station based on a sidelink signal received from a terminal that autonomously selects resources; a transmitting unit that performs sidelink transmission using the resource when it is determined that sidelink transmission using the resource is to be performed; A terminal comprising: (Section 2) a plurality of resources for sidelink transmission are allocated to the terminal; The controller selects an available resource from the plurality of resources based on the sidelink signal. 1. The terminal described in paragraph 1. (Section 3) The control unit determines a resource for feedback to be transmitted to the base station based on a specific resource among the plurality of resources. 2. The terminal described in paragraph 2. (Section 4) The sidelink signal transmitted by the terminal that autonomously selects resources is transmitted by a resource selected from a predetermined range of resources when transmitting data on non-reserved resources. 2. A terminal according to claim 1 or 2. (Section 5) The transmitter performs sidelink transmission using resources other than the predetermined range of resources in transmitting data using non-reserved resources. 4. A terminal as described in paragraph 4. (Section 6) receiving resource allocation information for sidelink transmission from a base station; determining whether to perform sidelink transmission using resources allocated by the base station based on a sidelink signal received from a terminal that autonomously selects resources; performing sidelink transmission using the resource when it is determined to perform sidelink transmission using the resource; A transmission method performed by a terminal, comprising:

[0220] Any of the first to sixth clauses provides a technique that enables collision avoidance of sidelink transmission between a terminal that performs sidelink transmission using resources allocated by a base station and a terminal that performs sidelink transmission by autonomously selecting resources. In particular, the second clause enables flexible control by allowing a certain resource to be selected from multiple resources. The third clause clarifies the feedback resource (e.g., timing). The fourth clause enables collision avoidance even when transmission is performed using non-reserved resources. The fifth clause enables collision avoidance even when transmission is performed using non-reserved resources.

[0221] <Example 2> (Section 1) a receiver for receiving a sidelink signal from a terminal that autonomously selects resources; a transmitter configured to transmit information based on the sidelink signal to a base station; A terminal comprising: (Section 2) a control unit that determines whether to transmit information based on the sidelink signal to the base station by comparing resource allocation information for sidelink transmission received from the base station with information on resources used by the terminal that autonomously selects resources; 2. The terminal according to claim 1, comprising: (Section 3) The transmitter transmits, to the base station, information on resources that will be unavailable in the future or information on resources that were unavailable in the past, as information based on the sidelink signal. 2. A terminal according to claim 1 or 2. (Section 4) a receiving unit that receives information based on a sidelink signal transmitted from a first terminal that autonomously selects resources from a second terminal via an uplink; a control unit that schedules sidelink transmission to the second terminal based on information based on the sidelink signal; A base station comprising: (Section 5) a transmitter that transmits a sidelink transmission stop command to the second terminal based on the resources allocated to the second terminal and information based on the sidelink signal; 5. The base station of claim 4, comprising: (Section 6) receiving a sidelink signal from a terminal that autonomously selects resources; transmitting information based on the sidelink signal to a base station; A transmission method performed by a terminal, comprising:

[0222] Any of the above items 1 to 6 provides a technique that enables avoiding collisions of sidelink transmissions between a terminal that performs sidelink transmission using resources allocated by a base station and a terminal that performs sidelink transmission by autonomously selecting resources. In particular, the above item 2 enables transmission of only information necessary for control at the base station. The above item 3 enables control based on resource information at a future or past point in time. The above item 5 enables stopping SL transmissions that may cause interference.

[0223] Example 3 (Section 1) a receiving unit for receiving resource allocation information for sidelink transmission from a base station; a control unit that determines whether to perform sidelink transmission using autonomously selected resources based on the resource allocation information; and a transmitting unit that performs the sidelink transmission when it is determined that the sidelink transmission is to be performed; A terminal comprising: (Section 2) After the PRACH transmission is performed by the transmitter to the base station, the receiver receives setting information for receiving the resource allocation information from the base station. 1. The terminal described in paragraph 1. (Section 3) The control unit performs an operation of autonomously selecting a resource by excluding resources indicated in the resource allocation information from candidates. 2. A terminal according to claim 1 or 2. (Section 4) The receiver is assumed to receive signals addressed to multiple terminals from the base station at each PDCCH monitoring opportunity, and if signals addressed to multiple terminals are not received at a certain PDCCH monitoring opportunity, the transmitter does not perform sidelink transmission using resources corresponding to the certain PDCCH monitoring opportunity. A terminal according to any one of paragraphs 1 to 3. (Section 5) receiving, from a base station, resource allocation information for sidelink transmission; determining whether to perform sidelink transmission using autonomously selected resources based on the resource allocation information; performing the sidelink transmission when it is determined that the sidelink transmission is to be performed; A transmission method performed by a terminal, comprising:

[0224] Any of the above items 1 to 5 provides a technique that enables avoiding collisions of sidelink transmissions between a terminal that performs sidelink transmission using resources allocated from a base station and a terminal that performs sidelink transmission by autonomously selecting resources. In particular, the above item 2 enables receiving configuration information from a base station without an RRC connection. The above item 3 enables efficient autonomous resource selection. The above item 4 enables, for example, SL transmission to be performed in a state with good wireless quality.

[0225] (Hardware configuration) The block diagrams (FIGS. 32 and 33) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are connected directly or indirectly (for example, by wire, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining the single device or the multiple devices with software.

[0226] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0227] For example, the base station 10, the terminal 20, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 34 is a diagram illustrating an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 described above may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0228] In the following description, the term "apparatus" can be read as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0229] Each function in the base station 10 and the terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

[0230] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0231] Furthermore, the processor 1001 reads programs (program codes), software modules, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes in accordance with the programs. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 140 of the base station 10 shown in FIG. 32 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. Furthermore, for example, the control unit 240 of the terminal 20 shown in FIG. 33 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. While the above-described various processes have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0232] The storage device 1002 is a computer-readable recording medium and may be configured, for example, by at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to an embodiment of the present disclosure.

[0233] The secondary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. The secondary storage device 1003 may also be referred to as an secondary storage device. The above-mentioned storage medium may be, for example, a database, a server, or other appropriate medium including at least one of the storage device 1002 and the secondary storage device 1003.

[0234] The communication device 1004 is hardware (transmission / reception 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, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated.

[0235] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0236] Furthermore, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0237] Furthermore, base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, processor 1001 may be implemented using at least one of these pieces of hardware.

[0238] (Supplementary explanation of the embodiment) Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention; two or more items may be combined as needed, and items described in one item may apply to items described in another item (unless inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries between physical components. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of the processing steps described in the embodiments may be reversed as long as there is no contradiction. For convenience of processing description, the base station 10 and terminal 20 have been described using functional block diagrams. However, such devices may be implemented using hardware, software, or a combination thereof. The software operated by the processor of the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor of the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0239] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0240] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark), IEEE 802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), or other appropriate systems, and next-generation systems extended based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G, etc.) may also be applied.

[0241] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be changed unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

[0242] In this specification, a specific operation that is described as being performed by the base station 10 may also be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and another network node other than the base station 10 (such as, but not limited to, an MME or an S-GW). Although the above example illustrates a case where there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (such as an MME and an S-GW).

[0243] The information, signals, etc. described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0244] Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be sent to another device.

[0245] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0246] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0247] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0248] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0249] Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0250] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0251] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or other corresponding information. For example, a radio resource may be indicated by an index.

[0252] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUSCH, PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0253] In this 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," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0254] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0255] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0256] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0257] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, or the mobile body itself. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0258] Furthermore, a base station in the present disclosure may be read as a terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a terminal is replaced with communication between a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0259] Similarly, the term "terminal" in the present disclosure may be read as "base station." In this case, the base station may be configured to have the functions of the terminal described above.

[0260] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0261] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0262] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0263] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0264] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0265] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0266] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0267] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0268] Numerology may be communication parameters that apply to at least one of transmission and reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

[0269] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may be a time unit based on numerology.

[0270] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0271] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0272] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0273] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0274] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0275] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0276] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0277] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0278] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0279] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0280] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0281] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0282] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0283] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0284] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0285] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0286] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0287] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0288] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0289] In the present disclosure, an SS block or a CSI-RS is an example of a synchronization signal or a reference signal.

[0290] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0291] 10 base station 110 Transmitter 120 Receiver 130 Setting section 140 Control Unit 20 terminals 210 Transmitter 220 Receiving unit 230 Setting Section 240 Control Unit 1001 processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication equipment 1005 Input Device 1006 Output Device

Claims

1. a receiving unit configured to receive resource allocation information for sidelink transmission from a base station; a control unit that determines whether to perform sidelink transmission using resources allocated from the base station based on a sidelink signal received from a terminal that autonomously selects resources; a transmitting unit that performs sidelink transmission using the resource when it is determined to perform sidelink transmission using the resource, a plurality of resources for sidelink transmission are allocated to the terminal; the controller selects an available resource from the plurality of resources based on the sidelink signal; The control unit determines a resource for feedback to be transmitted to the base station based on a temporally last resource or a temporally first resource among the plurality of resources. Terminal.

2. The sidelink signal transmitted by the terminal that autonomously selects resources is transmitted by a resource selected from a predetermined range of resources when transmitting data on non-reserved resources. The terminal according to claim 1 .

3. The transmitter performs sidelink transmission using resources other than the predetermined range of resources in transmitting data using non-reserved resources. The terminal according to claim 2.

4. receiving resource allocation information for sidelink transmission from a base station; a control step of determining whether to perform sidelink transmission using resources allocated by the base station based on a sidelink signal received from a terminal that autonomously selects resources; and when it is determined that sidelink transmission using the resource is to be performed, performing the sidelink transmission using the resource, a plurality of resources for sidelink transmission are allocated to the terminal; In the control step, selecting an available resource from the plurality of resources based on the sidelink signal; In the control step, a resource for feedback to be transmitted to the base station is determined based on the last resource in time or the first resource in time among the plurality of resources. Sending method.

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