Terminal and Communication Method

Abstract

This terminal includes: a control unit that determines a sensing target on the basis of a resource selection window set in a resource pool and periodicity for reserving a resource; a reception unit that performs sensing of the determined sensing target and detects control information for performing periodic resource reservation transmitted from another terminal; and a transmission unit that uses the result of the sensing as a basis to select a resource from the resource selection window and transmits the control information for performing periodic resource reservation.

Description

Technical Field

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

Background Art

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

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

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

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As an enhancement of NR side link, power saving is being considered. For example, in Resource allocation mode 2 where the terminal autonomously selects resources, the terminal performs partial sensing by sensing limited resources within the sensing window, and based on the result, selects available resource candidates from the resource selection window.

[0007] On the other hand, in the periodic resource reservation in NR side link, compared with LTE, the shortest configurable periodicity is shorter and a greater variety of periodic resource reservations are possible. Therefore, it is necessary to sense many resources, which hinders power-saving operation.

[0008] The present invention has been made in view of the above points, and aims to efficiently detect the transmission of other terminals in direct communication between terminals.

Means for Solving the Problems

[0009] According to the disclosed technology, based on a candidate slot to be a resource selection target and a periodicity set for the terminal, a control unit determines, as a target for partial sensing, a immediately preceding section corresponding to the periodicity before the candidate slot or a plurality of sections corresponding to the periodicity before the candidate slot, a control unit that selects a resource from among the candidate slots based on the result of the partial sensing in the determined section, and a control channel for inter-terminal communication using the selected resource or at least one of the shared channels A transmitting unit that transmits, is provided and the control unit determines which of a directly preceding section corresponding to the periodicity before the candidate slot or a plurality of sections corresponding to the periodicity before the candidate slot is to be the target of the partial sensing, based on a specific parameter A terminal is provided.

Advantages of the Invention

[0010] According to the disclosed technology, in direct communication between terminals, the transmission of other terminals can be efficiently detected.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

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

[0013] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are appropriately used. However, the existing technology is, for example, existing LTE, but is not limited to existing LTE. Further, the term "LTE" used in this specification has a broad meaning including LTE-Advanced, and systems after LTE-Advanced (e.g., NR), or wireless LAN (Local Area Network) unless otherwise specified.

[0014] Also, in the embodiment of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or another method (e.g., Flexible Duplex, etc.).

[0015] Also, in the embodiment of the present invention, that a radio parameter or the like is "configured" may mean that a predetermined value is pre-configured, or that a radio parameter notified from the base station 10 or the terminal 20 is configured.

[0016] Figure 1 is a diagram for explaining V2X. In 3GPP, it is being studied to realize V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending the D2D function, and standardization is underway. As shown in Figure 1, V2X is a part of ITS (Intelligent Transport Systems), and means V2V (Vehicle to Vehicle), which is a communication form carried out between vehicles, V2I (Vehicle to Infrastructure), which is a communication form carried out between a vehicle and a roadside unit (RSU) installed beside the road, V2N (Vehicle to Network), which is a communication form carried out between a vehicle and an ITS server, and V2P (Vehicle to Pedestrian), which is a communication form carried out between a vehicle and a mobile terminal held by a pedestrian.

[0017] Also, in 3GPP, V2X using LTE or NR cellular communication and device-to-device communication is being studied. V2X using cellular communication is also called cellular V2X. In NR V2X, studies are underway to achieve large capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0018] Regarding LTE or NR V2X, it is assumed that studies will be carried out not limited to future 3GPP specifications. For example, ensuring interoperability, reducing costs by implementing upper layers, methods of using or switching between multiple RATs (Radio Access Technologies), compliance with regulations in each country, data acquisition, distribution, database management, and utilization methods of the LTE or NR V2X platform are assumed to be studied.

[0019] In the embodiments of the present invention, a form in which a communication device is mounted on a vehicle is mainly assumed, but the embodiments of the present invention are not limited to such a form. For example, the communication device may be a terminal held by a person, or the communication device may be a device mounted on a drone or an aircraft, or the communication device may be a base station, an RSU, a relay station (relay node), a terminal having scheduling capabilities, etc.

[0020] Note that SL (Sidelink) may be distinguished from UL (Uplink) or DL (Downlink) based on any one or a combination of the following 1)-4). Also, SL may have another name. 1) Resource allocation in the time domain 2) Resource allocation in the frequency domain 3) Synchronization signal to be referred to (including SLSS (Sidelink Synchronization Signal)) 4) Reference signal used for path loss measurement for transmission power control

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

[0022] In LTE SL, Mode3 and Mode4 are defined regarding the resource allocation of SL to terminal 20. In Mode3, transmission resources are dynamically allocated by DCI (Downlink Control Information) transmitted from base station 10 to terminal 20. Also, SPS (Semi Persistent Scheduling) is possible in Mode3. In Mode4, terminal 20 autonomously selects transmission resources from a resource pool.

[0023] Note that the slot in the embodiment of the present invention may be read as a symbol, a mini-slot, a subframe, a radio frame, a TTI (Transmission Time Interval). Also, the cell in the embodiment of the present invention may be read as a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including wireless LAN), etc.

[0024] Note that 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 owned by a user such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

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

[0026] FIG. 3 is a diagram for explaining an example (2) of the transmission mode of V2X. In the transmission mode of sidelink communication shown in FIG. 3, in step 1, terminal 20A transmits PSCCH and PSSCH to terminal 20B using the autonomously selected resources. The transmission mode of sidelink communication shown in FIG. 3 may be referred to as sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0027] FIG. 4 is a diagram for explaining an example (3) of the transmission mode of V2X. In the transmission mode of sidelink communication shown in FIG. 4, in step 1, terminal 20A transmits PSCCH and PSSCH to terminal 20B using the autonomously selected resources. Similarly, terminal 20B transmits PSCCH and PSSCH to terminal 20A using the autonomously selected resources (step 1). The transmission mode of sidelink communication shown in FIG. 4 may be referred to as sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, the terminal 20 itself performs resource selection.

[0028] FIG. 5 is a diagram for explaining an example (4) of the transmission mode of V2X. In the transmission mode of sidelink communication shown in FIG. 5, in step 0, base station 10 transmits a sidelink grant to terminal 20A via RRC (Radio Resource Control) configuration. Subsequently, terminal 20A transmits PSSCH to terminal 20B based on the received resource pattern (step 1). The transmission mode of sidelink communication shown in FIG. 5 may be referred to as sidelink transmission mode 2c in NR.

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

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

[0031] FIG. 8 is a diagram for explaining an example (2) of the communication type of V2X. The communication type of sidelink 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.

[0032] FIG. 9 is a diagram for explaining an example (3) of the communication type of V2X. The communication type of sidelink 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 performs broadcast 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).

[0033] Also, in NR-V2X, it is assumed that HARQ (Hybrid Automatic Repeat Request) is supported for unicast and groupcast of sidelink. Further, in NR-V2X, SFCI (Sidelink Feedback Control Information) including HARQ response is defined. Further, it is being considered that SFCI is transmitted via PSFCH (Physical Sidelink Feedback Channel).

[0034] Note that in the following description, it is assumed that PSFCH is used for transmitting HARQ-ACK in sidelink, but this is just an example. For example, it may be possible to use PSCCH to transmit HARQ-ACK in sidelink, or it may be possible to use PSSCH to transmit HARQ-ACK in sidelink, or it may be possible to use other channels to transmit HARQ-ACK in sidelink.

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

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

[0037] Hereinafter, when the terminals 20A, 20B, etc. are not particularly distinguished, they are simply described as "terminal 20" or "user device". FIG. 10 shows, as an example, a case where both the terminal 20A and the terminal 20B are within the coverage of a cell. However, the operations in the embodiments of the present invention can also be applied when the terminal 20B is outside the coverage.

[0038] As described above, in the present embodiment, the terminal 20 is, for example, a device mounted on a vehicle such as an automobile, and has a cellular communication function as a UE in LTE or NR, and a sidelink function. The terminal 20 may be a general mobile terminal (such as a smartphone). Also, the terminal 20 may be an RSU. The RSU may be a UE type RSU having the function of a UE, or a gNB type RSU having the function of a base station device.

[0039] Note that the terminal 20 does not necessarily have to be a device in one housing. For example, even when various sensors are distributed and arranged in a vehicle, the device including the various sensors may be the terminal 20.

[0040] Also, the processing content of the sidelink transmission data of the terminal 20 is basically the same as the processing content of UL transmission in LTE or NR. For example, the terminal 20 scrambles the codewords of the transmission data, modulates them to generate complex-valued symbols, maps the complex-valued symbols (transmission signals) to 1 or 2 layers, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate a transmission signal (e.g., complex-valued time-domain SC-FDMA signal), which is transmitted from each antenna port.

[0041] Note that the base station 10 has the functions of cellular communication as a base station in LTE or NR, and the functions for enabling the communication of the terminal 20 in the present embodiment (e.g., resource pool setting, resource allocation, etc.). Further, the base station 10 may be an RSU (gNB type RSU).

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

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

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

[0045] The terminal 20B receives the SCI (PSCCH and / or PSSCH) and the SL data (PSSCH) transmitted from the terminal 20A. The received SCI may include information on the resources of the PSFCH for the terminal 20B to transmit the HARQ-ACK for the reception of the data. The terminal 20A may include the information on the resources autonomously selected in the SCI and transmit it.

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

[0047] In step S105, when the HARQ-ACK received in step S104 indicates a retransmission request, that is, when it is a NACK (negative response), 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.

[0048] Note that if HARQ control with HARQ feedback is not executed, steps S104 and S105 may not be executed.

[0049] FIG. 11 is a sequence diagram showing an operation example (2) of V2X. Blind retransmission not based on HARQ control for improving the transmission success rate or the reach distance may be executed.

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

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

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

[0053] Note that if blind retransmission is not executed, step S204 may not be executed.

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

[0055] In step S301, the base station 10 performs sidelink scheduling by sending DCI (Downlink Control Information) to the terminal 20A by PDCCH. Hereinafter, for convenience, the DCI for sidelink scheduling is referred to as sidelink scheduling DCI.

[0056] Also, in step S301, it is assumed that the base station 10 also transmits DCI for DL scheduling (which may be called DL allocation) to the terminal 20A by PDCCH. Hereinafter, for convenience, the DCI for DL scheduling is referred to as DL scheduling DCI. The terminal 20A that has received the DL scheduling DCI receives DL data by PDSCH using the resources specified by the DL scheduling DCI.

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

[0058] The terminal 20B receives the SCI (PSCCH and / or PSSCH) and the SL data (PSSCH) transmitted from the terminal 20A. The SCI received by means of the PSCCH and / or PSSCH includes information on the resources of the PSFCH for the terminal 20B to transmit the HARQ-ACK for the reception of the data.

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

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

[0061] In step S305, the terminal 20A transmits HARQ-ACK at a timing (e.g., timing in slot units) specified by, for example, DL scheduling DCI (or SL scheduling DCI), using the 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. The codebook of the HARQ-ACK may include ARQ-ACK generated based on the HARQ-ACK received from the terminal 20B or the PSFCH not received, and HARQ-ACK for DL data. However, when there is no allocation of DL data, etc., HARQ-ACK for DL data is not included. In NR Rel.16, the codebook of the HARQ-ACK does not include HARQ-ACK for DL data.

[0062] Note that if HARQ control involving HARQ feedback is not executed, step S304 and / or step S305 may not be executed.

[0063] FIG. 13 is a sequence diagram showing an operation example (4) of V2X. As described above, in the NR side link, it is supported that the HARQ response is transmitted by the PSFCH. Note that, for example, a format similar to the PUCCH (Physical Uplink Control Channel) format 0 can be used as the format of the PSFCH. That is, the format of the PSFCH 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 sequences and / or cyclic shifts. The format of the PSFCH is not limited to this. The resource of the PSFCH may be arranged in the last symbol or a plurality of last symbols of the slot. Also, a period N is set or predefined for the PSFCH resource. The period N may be set or predefined in slot units.

[0064] In FIG. 13, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. The PSCCH may be arranged in one symbol at the slot start, in a plurality of symbols from the start, or in a plurality of symbols from symbols other than the start. The PSFCH may be arranged in one symbol at the slot end or in a plurality of symbols at the slot end. Note that the above "slot start" and "slot end" may omit consideration of symbols for AGC (Automatic Gain Control) and symbols for transmission / reception switching. That is, for example, when one slot is composed of 14 symbols, the "slot start" and "slot end" may mean the first and last symbols in the 12 symbols excluding the first and last symbols. In the example shown in FIG. 13, three sub-channels are set in the resource pool, and two PSFCHs are arranged three slots after the slot in which the PSSCH is arranged. The arrow from the PSSCH to the PSFCH indicates an example of the PSFCH associated with the PSSCH.

[0065] When the groupcast option 2 in which the HARQ response in NR-V2X groupcast transmits ACK or NACK, it is necessary to determine the resources used for transmission and reception of the PSFCH. As shown in FIG. 13, in step S401, the terminal 20A which is the transmitting-side terminal 20 executes groupcast to the terminals 20B, 20C, and 20D which are the receiving-side terminals 20 via the SL-SCH. In the subsequent step S402, the terminal 20B uses the PSFCH#B, the terminal 20C uses the PSFCH#C, and the terminal 20D uses the PSFCH#D to transmit the HARQ response to the terminal 20A. Here, as shown in the example of FIG. 13, when the number of available PSFCH resources is less than the number of receiving-side terminals 20 belonging to the group, it is necessary to determine how to allocate the PSFCH resources. Note that the transmitting-side terminal 20 may know the number of receiving-side terminals 20 in the groupcast. Note that in groupcast option 1, only NACK is transmitted as the HARQ response, and ACK is not transmitted.

[0066] FIG. 14 is a diagram showing an example of a sensing operation. When partial sensing is not set from the upper layer in the LTE side link, as shown in FIG. 14, the terminal 20 selects a resource and performs transmission. As shown in FIG. 14, the terminal 20 executes sensing in a sensing window within a resource pool. By sensing, the terminal 20 receives a resource reservation field included in the SCI transmitted from another terminal 20, and based on the field, identifies available resource candidates within a resource selection window in the resource pool. Subsequently, the terminal 20 randomly selects a resource from the available resource candidates. The resource selection window is a set of resources that are candidates for use set within the resource pool. The resource selection window may be called by other names, for example, settings related to resource selection, target intervals for selecting resources, etc. The sensing window in LTE may be an interval from a predetermined time point before a trigger such as packet generation to immediately before the trigger. Performing sensing on all resources within the sensing window may be called full sensing. Note that the sensing window may be another name indicating the interval for performing sensing.

[0067] Also, as shown in FIG. 14, the setting of the resource pool may have a period. For example, the period may be a period of 10240 milliseconds. FIG. 14 shows subframe t 0 SL to subframe t Tmax SL as an example of being set as a resource pool. The resource pool within the period may have its area set, for example, by a bitmap.

[0068] Also, as shown in FIG. 14, the transmission trigger in the terminal 20 occurs in subframe n, and the priority of the transmission is p TX Let it be. The terminal 20 is in subframe t n-10×Pstep SL from subframe tn-1 SL In the sensing window up to, for example, when it is detected that another terminal 20 is performing transmission with priority p RX . If an SCI is detected within the sensing window and the RSRP (Reference Signal Received Power) exceeds the threshold, the resources within the resource selection window corresponding to the SCI are excluded. Also, if an SCI is detected within the sensing window and the RSRP is less than the threshold, the resources within the resource selection window corresponding to the SCI are not excluded. The threshold may be, for example, a threshold Th TX set or defined for each resource within the sensing window based on the priority p RX and the priority p pTX,pRX .

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

[0070] Subframe n + T 1 to subframe n + T 2 As shown in FIG. 14, the resource selection window from to has the resources occupied by other UEs identified, and the resources from which the occupied resources are excluded become candidate available resources. Let the set of candidate available resources be S A . Then, if S A is less than 20% of the resources of the resource selection window, the threshold Th pTX,pRX set for each resource of the sensing window may be increased by 3 dB and the resource identification may be performed again. That is, by increasing the threshold Th pTX,pRX and performing the resource identification again, the resources that are not excluded because the RSRP is less than the threshold may be increased. Further, S AMeasure the RSSI (Received Signal Strength Indicator) of each resource, and add the resource with the minimum RSSI to the set S B It may be added to. The set S of resource candidates B Repeat the operation of adding the resource with the minimum RSSI included in S to S until S becomes 20% or more of the resource selection window A It may be repeated. The lower layer of the terminal 20 may report S B to the upper layer. The upper layer of the terminal 20 may perform random selection on S to determine the resource to be used. The terminal 20 may perform sidelink transmission using the determined resource. Note that after the terminal 20 secures a resource, it may periodically use the resource without performing sensing for a predetermined number of times (for example, C

[0071] times). B Figure 15 is a diagram showing an example of the partial sensing operation. When partial sensing is set from the upper layer in the LTE sidelink, as shown in Figure 15, the terminal 20 selects a resource and performs transmission. As shown in Figure 15, the terminal 20 performs partial sensing on a part of the sensing window in the resource pool. The resource on which partial sensing is performed may be called a sensing target, a sensing object, a sensing subframe, or a sensing slot. By partial sensing, the terminal 20 receives the resource reservation field included in the SCI transmitted from another terminal 20, and based on the field, identifies the available resource candidates within the resource selection window in the resource pool. Subsequently, the terminal 20 randomly selects a resource from the available resource candidates B . resel In addition, as shown in Figure 15, the setting of the resource pool may have a period. For example, the period may be a period of 10240 milliseconds. Figure 15 shows subframe t

[0072] from subframe t

[0073] to subframe t 0 SL ​Tmax SL The above is an example of being set as a resource pool. The resource pool within a period may have its target area set by, for example, a bitmap.

[0074] As shown in FIG. 15, the transmission trigger in the terminal 20 occurs in subframe n, and the priority of the transmission is p TX Let's assume so. As shown in FIG. 15, from subframe n+T 1 to subframe n+T 2 Among them, the Y subframes from subframe t y SL to subframe t y+Y-1 SL may be set as a resource selection window. Further, as shown in FIG. 15, the transmission trigger in the terminal 20 occurs in subframe n, and the priority of the transmission is p TX Let's assume so.

[0075] The terminal 20 can detect, for example, that another terminal 20 is performing a transmission with priority p y-k×Pstep SL in one or more sensing targets from subframe t y+Y-k×Pstep-1 SL to subframe t RX k may be, for example, a 10-bit bitmap. FIG. 15 shows an example where the 3rd and 6th bits of the bitmap k are set to "1" indicating partial sensing. That is, in FIG. 15, subframes from subframe t y-6×Pstep SL to subframe t y+Y-6×Pstep-1 SL and subframes from subframe t y-3×Pstep SL to subframe t y+Y-3×Pstep-1 SL are set as sensing targets. As described above, the i-th bit of the bitmap k may correspond to the sensing targets from subframe t y-i×Pstep SL to subframe t y+Y-i×Pstep-1 SL up to.

[0076] Note that y is an index within the Y subframe, k is set with a 10-bit bitmap or predefined in advance, and P step is 100 ms. However, when performing SL communication on DL and UL carriers, P step is (U / (D + S + U)) * 100 ms. U corresponds to the number of UL slots, D corresponds to the number of DL slots, and S corresponds to the number of special slots.

[0077] When an SCI is detected within one or more of the above sensing targets and the RSRP exceeds the threshold, the resources within the resource selection window corresponding to the resource reservation field of the SCI are excluded. Also, when an SCI is detected within the sensing target and the RSRP is less than the threshold, the resources within the resource selection window corresponding to the resource reservation field of the SCI are not excluded. The threshold may be, for example, the threshold Th TX set or defined for each resource within the sensing window based on the priority p RX and the priority p pTX,pRX and may be.

[0078] As shown in FIG. 15, within the resource selection window where the Y subframe is set in the interval [n + T 1 , n + T 2 , the terminal 20 identifies the resources occupied by other UEs, and the resources excluding the identified resources become candidate available resources. Note that the Y subframes may not be continuous. Let the set of candidate available resources be S A . If S A is less than 20% of the resources in the resource selection window, the threshold Th pTX,pRX set for each resource in the sensing window may be increased by 3 dB and the resource identification may be performed again. That is, by increasing the threshold Th pTX,pRX and performing the resource identification again, the resources not excluded due to the RSRP being less than the threshold may be increased. Further, the RSSI of each resource in S A is measured, and the resource with the minimum RSSI is set as the set SB may be added to the set S of resource candidates. Until the set S B becomes 20% or more of the resource selection window, the operation of adding the resource with the minimum RSSI included in S A to S B may be repeated.

[0079] The lower layer of the terminal 20 may report S B to the upper layer. The upper layer of the terminal 20 may determine the resource to be used by performing random selection on S B and use it. The terminal 20 may perform sidelink transmission using the determined resource. Note that after the terminal 20 secures a resource once, it may use the resource periodically without performing sensing for a predetermined number of times (for example, C resel times).

[0080] In FIGS. 14 and 15 described above, the operation of the transmitting terminal 20 was described. However, the receiving terminal 20 may detect data transmission from another terminal 20 based on the result of sensing or partial sensing and receive data from the other terminal 20.

[0081] In the NR Release 17 sidelink, power saving based on the above random resource selection and partial sensing is being considered. For example, for power saving, the random resource selection and partial sensing of the sidelink in LTE Release 14 may be applied to the resource allocation mode 2 of the NR Release 16 sidelink. The terminal 20 to which partial sensing is applied performs reception and sensing only in specific slots within the sensing window.

[0082] In addition, in the NR Release 17 side link, enhanced Ultra Reliable Low Latency Communication (eURLLC) is being considered with inter-UE coordination as the baseline. For example, terminal 20A may share information indicating a resource set with terminal 20B, and terminal 20B may consider this information in resource selection for transmission.

[0083] For example, the reservation periodicity of resources that can be indicated in the resource pool where LTE's P2V is performed is {100, 200,..., 1000} ms. The resource pool is the resource pool used by partial sensing UEs. Here, since P step is 100 ms, the reservation periodicity can be expressed as P step *k. Therefore, the Y slot of the resource selection window is guaranteed to be reserved at t y-k×Pstep SL . When Pstep is (U / (D + S + U)) * 100, the reservation periodicity is corrected in the same way. Hereinafter, although the correction with Pstep being (U / (D + S + U)) * 100 will be omitted from being specified, it is assumed that the correction is applicable to the embodiments of the present invention in the same way as in LTE.

[0084] On the other hand, in NR, the reservation periodicity that can be indicated by Release 16 UEs is {1, 2,..., 98, 99, 100, 200,..., 900, 1000} ms. That is, the reservation periodicity can be set in units of 1 ms from 1 ms to 100 ms, and can be set in units of 100 ms from 100 ms to 1000 ms. Applying the above-described LTE partial sensing method, it is necessary to set P step to 1 ms, and it is necessary to sense a very large number of resources. Therefore, the power saving effect is reduced.

[0085] Therefore, in the resource pool available for the terminal 20 that performs power-saving operation, sensing slots may be determined based on a predetermined method for periodic resource reservation based on a predetermined period or periodicity. In this embodiment, "period" and "periodicity" may be interchangeable.

[0086] FIG. 16 is a diagram showing an example (1) of the sensing operation in the embodiment of the present invention. For example, in the resource pool available for the terminal 20 that performs power-saving operation, the value of the periodicity available for periodic resource reservation may be restricted. Also, the parameter (e.g., P step ) for determining the sensing slot in partial sensing may be determined based on the set periodicity. Also, for each set periodicity, the sensing slot may be determined based on different parameters. Also, for each set periodicity, only the immediately preceding period may be the sensing target.

[0087] Note that the sensing window in NR is an interval from a predetermined time point n-T 0 before the selection trigger n such as packet generation to immediately before n-T proc,0 which is T proc,0 corresponding to the processing time from the selection trigger.

[0088] Note that the parameters k and P step in the partial sensing shown in FIG. 16 may be parameters for determining the sensing slot corresponding to the Y slot when the resource selection window is the Y slot. FIG. 16 is an example of calculating A from P step and determining the sensing slot of the Y slot length using A and k. A may be P step or a value calculated based on P step . Also, similar to LTE, the Y slot may be discontinuous. Also, for non-periodic resource reservation, i.e., reservation based only on the time / frequency resource allocation field, the corresponding sensing target may be set separately from the periodic resource reservation.

[0089] As described above, in the resource pool where the terminal 20 performing the power-saving operation can be used, the periodic value that can be used in the periodic resource reservation may be restricted. For example, the periodic value may be restricted as shown in the following 1)-4).

[0090] 1) Among {1, 2,..., 98, 99, 100, 200,..., 900, 1000} ms, only values of 100 ms or more can be set.

[0091] 2) Among {1, 2,..., 98, 99, 100, 200,..., 900, 1000} ms, only multiples of a specific value X can be set. For example, when X = 10 ms, {10, 20,..., 80, 90, 100, 200,..., 900, 1000} ms may be settable.

[0092] 3) Among {1, 2,..., 98, 99, 100, 200,..., 900, 1000} ms, some or all of the values whose greatest common divisor is Y or more can be set. For example, when Y = 20 ms, {80, 200, 1000} ms may be settable. Note that Y may be the parameter Y used in FIG. 16.

[0093] 4) Among {1, 2,..., 98, 99, 100, 200,..., 900, 1000} ms, some or all of the values whose greatest common divisor of the k - multiplied value is Y or more can be set. Note that k and Y may be the parameters k and Y used in FIG. 16.

[0094] X and Y may be given as upper - layer parameters, or may be defined in advance in the specification. k may be given as an upper - layer parameter, or may be indicated by a bitmap. Also, depending on the priority, the periodic values that can be used in the periodic resource reservation may be different.

[0095] As described above, in the resource pool available for the terminal 20 that performs power-saving operation, by limiting the periodic value that can be used for periodic resource reservation, it is possible to limit the sensing target and improve the power-saving effect.

[0096] Also, as described above, a parameter (for example, P used in FIG. 16) for determining the sensing slot in partial sensing step ) may be determined based on the periodicity set for the periodic resource reservation. For example, the parameter may be set as shown in the following 1)-4).

[0097] 1) Use the minimum value among the set periodicities.

[0098] 2) Use a value based on the settable periodicity or parameters (for example, X, Y) for determining the sensing slot. For example, P step may be set as X, or Y may be set as the parameter Y used in FIG. 16.

[0099] 3) Use the greatest common divisor of the set periodicities. For example, when the periodicities are {80, 200, 1000}, P step may be set as 40 ms.

[0100] 4) Use the greatest common divisor of the values obtained by multiplying the set periodicities by k. For example, when the periodicities are {80, 200, 1000} and the second and fourth bits of k are 1, the greatest common divisor 80 ms of {80 * 2, 80 * 4, 200 * 2, 200 * 4, 1000 * 2, 1000 * 4} may be P step . That is, P step may be the product of the greatest common divisor of the set periodicities and the greatest common divisor of the bit numbers of k that are 1.

[0101] Moreover, a method for limiting the periodicity value that can be used in the periodic resource reservation in the resource pool available to the terminal 20 that performs the above-described power-saving operation and a parameter for determining the sensing slot in partial sensing may be combined with a method for determining based on the periodicity set in the periodic resource reservation.

[0102] As described above, by determining the parameter for determining the sensing slot in partial sensing based on the periodicity set in the periodic resource reservation, it is possible to appropriately set the sensing target by sensing the slots that require sensing and not performing sensing on the slots that do not require sensing.

[0103] Also, as described above, for each set periodicity, the sensing slot may be determined based on different parameters. For example, as shown in the following 1)-4), the sensing slot may be determined.

[0104] 1) Set P step for each periodicity. P step may be the P used in FIG. 16. step 2) Set k for each periodicity. k may be the k used in FIG. 16. 3) Classify the periodicity into several groups and set P step for each group. Furthermore, a method for limiting the periodicity value that can be used in the periodic resource reservation in the resource pool available to the terminal 20 that performs the above-described power-saving operation, or a method for determining the parameter for determining the sensing slot in the above-described partial sensing based on the periodicity set in the periodic resource reservation may be applied for each group. ​4) Classify the periodicities into several groups and set k for each group. Further, a method of restricting the value of the periodicity available for periodic resource reservation in the resource pool available for the terminal 20 performing the above power saving operation, or a parameter for determining the sensing slot in the above partial sensing may be determined based on the periodicity set for the periodic resource reservation, and may be applied for each group.

[0105] As described above, by determining the sensing slot based on different parameters for each set periodicity, the settable periodicity can be further increased. Also, when the greatest common divisor of the set periodicities is small, it is possible to set so as not to sense the slots where sensing is unnecessary.

[0106] FIG. 17 is a diagram showing an example (2) of the sensing operation in the embodiment of the present invention. As described above, for each set periodicity, an interval corresponding only to the period immediately before the resource selection window may be set as the sensing target. That is, as shown in FIG. 17, P step is each periodicity, and the first bit of k may be 1. In FIG. 17, an example is shown where the periodicity, that is, P step is {15, 100, 500} ms. At this time, A = {15, 100, 500} slots, and the SCS may be 15 kHz. As shown in FIG. 17, the sensing target is the interval corresponding to the periodicity of 15 ms from t y-15 SL to t y+Y-15-1 SL ; the interval corresponding to the periodicity of 100 ms is from t y-100 SL to t y+Y-100-1 SL ; and the interval corresponding to the periodicity of 500 ms is from t y-500 SL to t y+Y-500-1 SL . Note that the corresponding resource selection window as shown in FIG. 17 is from t y SL to t y+Y-1 SLThat's all.

[0107] Furthermore, the transmitting terminal 20A that has reserved periodic resources by the resource reservation field may continue periodic transmission. For example, when the transmitting terminal 20A stops periodic transmission, it may be considered that the resources after the next period are not reserved by the transmitting terminal 20A. Also, when the SCI transmitted from the transmitting terminal 20A notifies the reservation of periodic resources by the resource reservation field, the receiving terminal 20B may consider that the periodic resources are reserved as long as it receives the reservation signal of the periodic resources from the transmitting terminal 20A for each period. Also, when the reservation signal of the periodic resources is not received continuously N times from the transmitting terminal 20A, the receiving terminal 20B may consider that the periodic resources are released (not reserved hereafter). For example, N may be 1.

[0108] Whether the method of setting the sensing target to the section corresponding only to the period immediately before the resource selection window for each of the set periodicities described above is applied, or the method of setting the sensing target to the section over a specific plurality of periods is applied may be determined according to specific conditions. For example, which method is applied may be determined by the parameters set for each periodicity.

[0109] The method of sensing only the period immediately before the resource selection window for each set periodicity can be arbitrarily combined with the method of restricting the value of the periodicity available for periodic resource reservation in the resource pool available to the terminal 20 performing the above-described power saving operation, the method of determining the sensing slot in the above-described partial sensing based on the periodicity set for the periodic resource reservation, and the method of determining the sensing slot in the partial sensing based on the period set for the periodic resource reservation. For example, for some periodicities, the method of sensing only the period immediately before the resource selection window for each set periodicity is applied, and for other periodicities, the method of restricting the value of the periodicity available for periodic resource reservation in the resource pool available to the terminal 20 performing the above-described power saving operation, the method of determining the sensing slot in the above-described partial sensing based on the periodicity set for the periodic resource reservation, or the method of determining the sensing slot in the partial sensing based on the periodicity set for the periodic resource reservation may be applied.

[0110] As described above, by sensing only the period immediately before the resource selection window for each set periodicity, the number of sensing targets can be reduced. In addition, the probability of occurrence of resource collisions can be reduced.

[0111] Note that the terminal 20 (Power saving UE) performing the power saving operation may be any one of the following 1) to 4). 1) The terminal 20 set to perform partial sensing. 2) The terminal 20 performing a sensing method different from the full sensing defined in Release 16. Note that full sensing may be sensing all resources within the sensing window. The sensing window is the slot section [n - T 0 , n - T proc,0It may be defined by [], and n may be a slot corresponding to the packet arrival timing. 3) The terminal 20 that does not perform sensing. For example, the terminal 20 that is set to perform random resource selection. 4) The terminal 20 that does not perform reception and / or transmission only within a limited time.

[0112] Note that "when performing at least one of the transmission, reception, and sensing operations only at a specific timing" may be replaced with "when power saving-related settings are made".

[0113] Note that the UE or the terminal 20 may be a plurality of UEs or terminals 20 and may belong to the same group.

[0114] Among the terminals 20 performing sidelink communication, some of the terminals 20 may be UEs performing power saving operations, or all of the terminals 20 may be UEs performing power saving operations.

[0115] The above embodiments are not limited to V2X terminals and may be applied to terminals performing D2D communication.

[0116] Note that the terminal 20 may know the reception possible timing and / or the transmission possible timing of other terminals 20. It may know by determining the timing in the specification or pre-setting, or may know by receiving a notification from other terminals 20.

[0117] Note that in the above embodiments, the timing, that is, the time resource, may be replaced with a frequency resource. The timing may be a period.

[0118] According to the above embodiments, the terminal 20 can appropriately set the sensing target in partial sensing based on the periodicity of resource reservation, so as to efficiently set the sensing target and enhance the power saving effect.

[0119] That is, in direct communication between terminals, the transmission of other terminals can be efficiently detected.

[0120] (Device Configuration) Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described so far will be described. The base station 10 and the terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and the terminal 20 may each be provided with only some of the functions in the embodiments.

[0121] <Base Station 10> FIG. 18 is a diagram showing an example of the functional configuration of the base station 10. As shown in FIG. 18, the base station 10 includes a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in FIG. 18 is merely an example. As long as the operations according to the embodiments of the present invention can be executed, the functional division and the names of the functional units may be any.

[0122] The transmission unit 110 includes a function of generating a signal to be transmitted to the terminal 20 side and wirelessly transmitting the signal. The reception unit 120 includes a function of receiving various signals transmitted from the terminal 20 and obtaining information of, for example, a higher layer from the received signals. Further, the transmission unit 110 has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0123] The setting unit 130 stores setting information set in advance and various setting information to be transmitted to the terminal 20 in a storage device and reads it out from the storage device as necessary. The content of the setting information is, for example, information related to the setting of D2D communication.

[0124] As described in the embodiments, the control unit 140 performs processing related to the settings for the terminal 20 to perform D2D communication. Further, the control unit 140 transmits scheduling of D2D communication and DL communication to the terminal 20 via the transmission unit 110. Further, the control unit 140 receives information related to HARQ responses of D2D communication and DL communication from the terminal 20 via the reception unit 120. A functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the reception unit 120.

[0125] <Terminal 20> FIG. 19 is a diagram showing an example of the functional configuration of the terminal 20. As shown in FIG. 19, the terminal 20 includes a transmission unit 210, a reception unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in FIG. 19 is merely an example. As long as the operations according to the embodiments of the present invention can be executed, the functional division and the names of the functional units may be any.

[0126] The transmission unit 210 creates a transmission signal from transmission data and wirelessly transmits the transmission signal. The reception unit 220 wirelessly receives various signals and obtains signals of higher layers from the received physical layer signals. Further, the reception unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, reference signals, etc. transmitted from the base station 10. Further, for example, as D2D communication, the transmission unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to another terminal 20, and the reception unit 220 receives PSCCH, PSSCH, PSDCH, PSBCH, etc. from another terminal 20.

[0127] The setting unit 230 stores various setting information received from the base station 10 or the terminal 20 by the receiving unit 220 in the storage device, and reads it out from the storage device as necessary. Further, the setting unit 230 also stores preset setting information. The content of the setting information is, for example, information related to the setting of D2D communication and the like.

[0128] As described in the embodiments, the control unit 240 controls D2D communication for establishing an RRC connection with other terminals 20. Further, the control unit 240 performs processing related to power saving operation. Further, the control unit 240 performs processing related to HARQ of D2D communication and DL communication. Further, the control unit 240 transmits information related to HARQ responses of D2D communication and DL communication to other terminals 20 scheduled by the base station 10 to the base station 10. Further, the control unit 240 may schedule D2D communication for other terminals 20. Further, the control unit 240 may autonomously select resources to be used for D2D communication from a resource selection window based on the result of sensing, or may perform re-evaluation or preemption. Further, the control unit 240 performs processing related to power saving in transmission and reception of D2D communication. Further, the control unit 240 performs processing related to terminal cooperation in D2D communication. A functional unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and a functional unit related to signal reception in the control unit 240 may be included in the receiving unit 220.

[0129] (Hardware Configuration) The block diagrams (FIGS. 18 and 19) used in the description of the above embodiments show blocks of functional units. These functional blocks (constituent parts) are realized by an arbitrary combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly (for example, using wired, wireless, etc.) connected and realized using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0130] Functions include, but are not limited to, judgment, decision-making, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection determination, establishment, comparison, assumption, expectation, assumption, notification (broadcasting), notification (notifying), communication, forwarding, configuration, reconfiguration, allocation (allocating, mapping), assignment, etc. For example, a functional block (component) that enables transmission is called a transmitting unit or a transmitter. As described above, the implementation method is not particularly limited.

[0131] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure may function as a computer that performs the processing of the wireless communication method of the present disclosure. FIG. 20 is a diagram showing an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. Physically, the above-described base station 10 and terminal 20 may be configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0132] In the following description, the term "device" 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 each device shown in the figure, or may be configured without including some devices.

[0133] Each function in the base station 10 and the terminal 20 is realized by causing the processor 1001 to perform calculations and control communication by the communication device 1004, or to control at least one of reading and writing data in the storage device 1002 and the auxiliary storage device 1003, by loading a predetermined software (program) onto hardware such as the processor 1001 and the storage device 1002.

[0134] Processor 1001 controls the entire computer by operating, for example, an operating system. Processor 1001 may be composed of a central processing unit (CPU: Central Processing Unit) including an interface with peripheral devices, a control device, an arithmetic device, registers, etc. For example, the above-described control unit 140, control unit 240, etc. may be realized by processor 1001.

[0135] Further, processor 1001 reads a program (program code), software module, data, etc. from at least one of auxiliary storage device 1003 and communication device 1004 into storage device 1002, and executes various processes according to these. As the program, a program for causing a computer to execute at least a part of the operations described in the above-described embodiments is used. For example, the control unit 140 of the base station 10 shown in FIG. 18 may be stored in storage device 1002 and realized by a control program operating on processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in FIG. 19 may be stored in storage device 1002 and realized by a control program operating on processor 1001. Although it has been described that the above-described various processes are executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be mounted by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

[0136] The memory device 1002 is a computer-readable recording medium and may be constituted by at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The memory device 1002 may be referred to as a register, a cache, a main memory (main storage device), etc. The memory device 1002 can store a program (program code), a software module, etc. executable for implementing the communication method according to an embodiment of the present disclosure.

[0137] The auxiliary storage device 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, 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 (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-described storage medium may be, for example, a database, a server, or other appropriate medium including at least one of the memory device 1002 and the auxiliary storage device 1003.

[0138] The communication device 1004 is hardware (a transceiver device) for performing communication between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transceiver antenna, an amplifier unit, a transceiver unit, a transmission line interface, etc. may be implemented by the communication device 1004. The transceiver unit may be physically or logically separated into a transmission unit and a reception unit.

[0139] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an external input. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs an output to the outside. Note that the input device 1005 and the output device 1006 may have an integrated configuration (e.g., a touch panel).

[0140] Also, 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 for each device.

[0141] Further, the base station 10 and the 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), and a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0142] (Summary of Embodiment) As described above, according to the embodiment of the present invention, a control unit that determines a sensing target based on a resource selection window set in a resource pool and a periodicity of reserving resources, a receiving unit that senses the determined sensing target and detects control information for making a periodic resource reservation transmitted from another terminal, and a transmitting unit that selects a resource from the resource selection window based on the result of the sensing and transmits control information for making a periodic resource reservation are provided.

[0143] With the above configuration, the terminal 20 can appropriately set the sensing target in partial sensing based on the periodicity of resource reservation, thereby efficiently setting the sensing target and enhancing the power saving effect. That is, in direct communication between terminals, the transmission of other terminals can be efficiently detected.

[0144] The control unit may determine, as the sensing target, a section corresponding to the periodicity of reserving the resource immediately before the resource selection window. With this configuration, the terminal 20 can appropriately set the sensing target in partial sensing based on the periodicity of resource reservation.

[0145] The control unit may limit the periodicity of reserving the resource. With this configuration, the terminal 20 can limit the sensing target and enhance the power saving effect.

[0146] The control unit may set the periodicity of reserving the resource as the greatest common divisor of the configurable periodicities. With this configuration, the terminal 20 can efficiently limit the sensing target according to the assumed periodicity of resource reservation and enhance the power saving effect.

[0147] The control unit may determine the sensing target for each group of the periodicities of reserving one or more of the resources. With this configuration, the terminal 20 can limit the sensing target and enhance the power saving effect.

[0148] Also, according to an embodiment of the present invention, a communication method is provided in which a terminal executes a control procedure for determining a sensing target based on a resource selection window set in a resource pool and a periodicity of reserving a resource, a reception procedure for sensing the determined sensing target and detecting control information for performing periodic resource reservation transmitted from another terminal, and a transmission procedure for selecting a resource from the resource selection window based on the result of the sensing and transmitting control information for performing periodic resource reservation.

[0149] With the above configuration, the terminal 20 can appropriately set the sensing target in partial sensing based on the periodicity of resource reservation, thereby efficiently setting the sensing target and enhancing the power saving effect. That is, in direct communication between terminals, the transmission of other terminals can be efficiently detected.

[0150] (Supplement of the embodiment) The embodiments of the present invention have been described above. However, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, corrections, alternatives, substitutions, etc. Although specific numerical examples have been used for the purpose of facilitating understanding of the invention, unless otherwise specified, those numerical values are merely examples, and any appropriate values may be used. The classification of items in the above description is not essential to the present invention, and matters described in two or more items may be used in combination as necessary, or matters described in one item may be applied to matters described in another item (as long as there is no contradiction). The boundaries of the functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. The operations of a plurality of functional units may be physically performed by one component, or the operation of one functional unit may be physically performed by a plurality of components. Regarding the processing procedures described in the embodiments, the order of processing may be changed as long as there is no contradiction. For the sake of convenience in explaining the processing, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software that operates by the processor included in the base station 10 according to the embodiment of the present invention and the software that operates by the processor included in the terminal 20 according to the embodiment of the present invention may be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), an EPROM, an EEPROM, a register, a hard disk drive (HDD), a removable disk, a CD-ROM, a database, a server, or any other appropriate storage medium, respectively.

[0151] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and other methods may be used. For example, the notification of information may be implemented by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, notification information (MIB (Master Information Block), SIB (System Information Block)), other signals or combinations thereof. Also, the RRC signaling may be referred to as an RRC message, and for example, it may be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0152] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), other suitable systems, and next-generation systems extended based thereon. Also, a plurality of systems may be combined (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) and applied.

[0153] The processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this specification may be rearranged as long as there is no contradiction. For example, regarding the methods described in this disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0154] The specific operations assumed to be performed by the base station 10 in this specification may, in some cases, be performed by its upper node. 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 can be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, but not limited to, MME or S-GW, etc.). Although the case where there is one other network node other than the base station 10 is exemplified above, the other network node may be a combination of a plurality of other network nodes (for example, MME and S-GW).

[0155] The information or signals, etc. described in this disclosure can be output from an upper layer (or lower layer) to a lower layer (or upper layer). They may also be input and output via a plurality of network nodes.

[0156] The input and output information, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. The input and output information, etc. can be overwritten, updated, or appended. The output information, etc. may be deleted. The input information, etc. may be transmitted to other devices.

[0157] The determination in this disclosure may be made by a value represented by 1 bit (0 or 1), or by a Boolean value (true or false), or by a numerical comparison (for example, comparison with a predetermined value).

[0158] Software should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether called software, firmware, middleware, microcode, a hardware description language, or by any other name.

[0159] Also, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technologies (such as infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0160] 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., which may be referred to throughout the above description, may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0161] Note that terms described 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). Also, a signal may be a message. Also, a component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0162] The terms "system" and "network" used in this disclosure are used interchangeably.

[0163] In addition, the information, parameters, etc. described in the present disclosure may be represented using absolute values, relative values from a predetermined value, or using other corresponding information. For example, radio resources may be indicated by an index.

[0164] The names used for the above-described parameters are not limiting names in any way. Furthermore, mathematical formulas, etc. using these parameters may be different from those explicitly disclosed in the present disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting names in any way.

[0165] In the present disclosure, terms such as "base station (BS: Base Station)", "radio base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. The base station may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0166] A base station can accommodate one or more (e.g., three) cells. When the base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services 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 whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services in this coverage.

[0167] In the present disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" can be used interchangeably.

[0168] A mobile station may also be called by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terms.

[0169] At least one of the base station and the mobile station may also be called a transmitting device, a receiving device, a communication device, etc. Note that at least one of the base station and the mobile station may also be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves without a driver (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanoid or non-humanoid). Note that at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0170] Also, the base station in the present disclosure may be replaced by a user terminal. For example, for a configuration in which communication between the base station and the user terminal is replaced with communication between a plurality of terminals 20 (which may be referred to as, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.), each aspect / embodiment of the present disclosure may be applied. In this case, the functions of the above-described base station 10 may be configured to be functions of the terminal 20. Also, terms such as "uplink" and "downlink" may be replaced with terms corresponding to inter-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be replaced with a side channel.

[0171] Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, the functions of the above-described user terminal may be configured to be functions of the base station.

[0172] The terms "determining" and "deciding" as used in this disclosure may encompass a wide variety of actions. "Determining" and "deciding" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up (e.g., searching in a table, database, or another data structure), ascertaining, and considering something as having been "determined" or "decided". Also, "determining" and "deciding" may include considering something as having been "determined" or "decided" based on receiving (e.g., receiving information), transmitting (e.g., transmitting information), inputting, outputting, accessing (e.g., accessing data in a memory), etc. Further, "determining" and "deciding" may include considering something as having been "determined" or "decided" based on resolving, selecting, choosing, establishing, comparing, etc. That is, "determining" and "deciding" may include considering that some action has been "determined" or "decided". Also, "determining (deciding)" may be read as "assuming", "expecting", "considering", etc.

[0173] The terms "connected" or "coupled", or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed". As used in this disclosure, two elements can be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as, by way of some non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region.

[0174] The reference signal can also be abbreviated as RS (Reference Signal) and may be called a Pilot according to the applicable standard.

[0175] As used in this disclosure, the description "based on" does not mean "based only on" unless otherwise specified. In other words, the description "based on" means both "based only on" and "based at least on".

[0176] Any reference to an element using designations such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements can be employed, or that the first element must precede the second element in any form.

[0177] The "means" in the configuration of each of the above devices may be replaced with a "section", "circuit", "device", etc.

[0178] In the present disclosure, when terms such as "include", "including" and their variants are used, these terms are intended to be inclusive, similar to the term "comprising". Further, the term "or" used in the present disclosure is not intended to be an exclusive disjunction.

[0179] A wireless 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 referred to as 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) independent of numerology.

[0180] Numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. Numerology may indicate, for example, at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, wireless frame configuration, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by a transceiver in the time domain, etc.

[0181] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on numerology.

[0182] The slot may include a plurality of mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. Also, the mini-slot may be called a sub-slot. The mini-slot may be composed of a smaller number of symbols than the slot. The PDSCH (or PUSCH) transmitted in a time unit larger than the mini-slot may be called PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the mini-slot may be called PDSCH (or PUSCH) mapping type B.

[0183] The radio frame, sub-frame, slot, mini-slot, and symbol all represent time units for transmitting signals. Different names corresponding to each of them may be used.

[0184] For example, one sub-frame may be called a Transmission Time Interval (TTI), or a plurality of consecutive sub-frames may be called a TTI, or one slot or one mini-slot may be called a TTI. That is, at least one of the sub-frame and the TTI may be the sub-frame (1 ms) in the existing LTE, or a period shorter than 1 ms (e.g., 1 - 13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, a mini-slot, etc. instead of a sub-frame.

[0185] Here, the TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate radio resources (such as the frequency bandwidth and transmission power that can be used in each terminal 20) to each terminal 20 in TTI units. Note that the definition of the TTI is not limited to this.

[0186] The TTI may be a transmission time unit such as a channel-coded data packet (transport block), a code block, a codeword, etc., or may be a processing unit such as for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) in which an actual transport block, code block, codeword, etc. is mapped may be shorter than the TTI.

[0187] Note that when one slot or one mini-slot is called a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may be the minimum time unit for scheduling. Also, the number of slots (number of mini-slots) constituting the minimum time unit for the scheduling may be controlled.

[0188] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel.8 - 12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial TTI, a shortened subframe, a short subframe, a mini-slot, a sub-slot, a slot, etc.

[0189] Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be read as a TTI having a time length exceeding 1 ms, or a short TTI (e.g., a shortened TTI, etc.) may be read as a TTI having a TTI length less than that of a long TTI and not less than 1 ms.

[0190] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and in the frequency domain, it may include one or a plurality of consecutive subcarriers. The number of subcarriers included in an RB may be the same regardless of the numerology, for example, it may be 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0191] Also, the time domain of the RB may include one or more symbols, and may have the length of 1 slot, 1 mini-slot, 1 sub-frame, or 1 TTI. 1 TTI, 1 sub-frame, etc. may each be composed of one or more resource blocks.

[0192] Note that one or more RBs may be referred to as physical resource blocks (PRBs), sub-carrier groups (SCGs), resource element groups (REGs), PRB pairs, RB pairs, etc.

[0193] Also, a resource block may be composed of one or more resource elements (REs). For example, 1 RE may be a radio resource area of 1 sub-carrier and 1 symbol.

[0194] A bandwidth part (BWP) (which may also be called a partial bandwidth, etc.) may represent a subset of consecutive common resource blocks (common RBs) for a certain numerology in a certain carrier. Here, the common RB may be specified by the index of the RB based on the common reference point of the carrier. A PRB is defined in a certain BWP and may be numbered within the BWP.

[0195] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be set within one carrier for the terminal 20.

[0196] At least one of the set BWPs may be active, and the terminal 20 may not be assumed to transmit and receive a predetermined signal / channel outside the active BWP. Note that "cell", "carrier", etc. in the present disclosure may be read as "BWP".

[0197] The structures such as the above-described radio frames, sub-frames, slots, mini-slots, and symbols are merely examples. For example, the number of sub-frames included in a radio frame, the number of slots per sub-frame or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of sub-carriers included in an RB, and the number of symbols, symbol length, cyclic prefix (CP) length, etc. within a TTI can be changed in various ways.

[0198] In the present disclosure, for example, when articles are added by translation like a, an, and the in English, the present disclosure may include that the nouns following these articles are in the plural form.

[0199] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". Note that the term may also mean "A and B are each different from C". Terms such as "separate", "coupled", etc. may also be interpreted in the same way as "different".

[0200] In the present disclosure, each aspect / embodiment described may be used alone, in combination, or switched and used during execution. Also, the notification of predetermined information (for example, the notification of "being X") is not limited to being explicitly performed, and may be performed implicitly (for example, by not performing the notification of the predetermined information).

[0201] Note that in the present disclosure, SCI is an example of control information.

[0202] As described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and changed 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 for illustrative purposes only and has no restrictive meaning for the present disclosure.

Explanation of Signs

[0203] 10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

1. A control unit that determines, based on candidate slots to be resource selection targets and a periodicity set for a terminal, a immediately preceding section corresponding to the periodicity before the candidate slot or a plurality of sections corresponding to the periodicity before the candidate slot as targets for partial sensing; and a control unit that selects a resource from among the candidate slots based on the result of the partial sensing in the determined section; A transmission unit that transmits at least one of a control channel or a shared channel for inter-terminal communication using the selected resource; The terminal has; The control unit determines which of the immediately preceding section corresponding to the periodicity before the candidate slot or the plurality of sections corresponding to the periodicity before the candidate slot is to be the target of the partial sensing based on a specific parameter. Terminal.

2. The periodicity is a value of periodicity available for periodic resource reservation restricted using a higher layer parameter. The terminal according to claim 1.

3. The terminal according to claim 1 or 2, further comprising a receiving unit that detects control information transmitted from another terminal by the partial sensing in the determined section. The terminal according to claim 1 or 2.

4. A procedure for determining, based on candidate slots to be resource selection targets and a periodicity set for a terminal, a immediately preceding section corresponding to the periodicity before the candidate slot or a plurality of sections corresponding to the periodicity before the candidate slot as targets for partial sensing, and selecting a resource from among the candidate slots based on the result of the partial sensing in the determined section; A procedure for transmitting at least one of a control channel or a shared channel for inter-terminal communication using the selected resource; A procedure for determining which of the immediately preceding section corresponding to the periodicity before the candidate slot or the plurality of sections corresponding to the periodicity before the candidate slot is to be the target of the partial sensing based on a specific parameter; A communication method for a terminal that executes.

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