Terminal and communication method

Abstract

The terminal includes: a control unit that randomly selects resources from a resource pool set for random selection without monitoring according to specific conditions; and a transmission unit that performs transmission using the resources.

Description

Technical Field

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

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

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

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

[0005] Prior art literature

[0006] Non-patent literature

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

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

[0009] Problems to be solved by the invention

[0010] As an enhancement to the NR sidelink, power conservation is being studied. For example, in Resource Allocation Mode 2, where the terminal autonomously selects resources, the terminal performs partial sensing of limited resources within a monitoring window and, based on the results, selects available resource candidates from the resource selection window.

[0011] Here, in resource allocation pattern 2, when random resource selection is performed in the resource pool without monitoring, the probability of resource conflict increases. Therefore, for example, it is difficult to apply random resource selection without monitoring to services requiring high reliability.

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the reliability of communication during autonomous resource selection in inter-terminal direct communication.

[0013] Means for solving problems

[0014] According to the disclosed technology, a terminal is provided including: a control unit that randomly selects resources from a resource pool set for random selection according to specific conditions without monitoring; and a transmission unit that performs transmission using the resources.

[0015] Effects of the Invention

[0016] According to the disclosed technology, in inter-terminal direct communication, the reliability of communication during autonomous resource selection can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram used to explain V2X.

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

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

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

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

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

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

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

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

[0026] Figure 10 This is a timing diagram showing an operation example (1) of V2X.

[0027] Figure 11 This is a timing diagram showing an operation example (2) of V2X.

[0028] Figure 12 This is a timing diagram showing an operation example (3) of V2X.

[0029] Figure 13 This is a timing diagram showing an operation example (4) of V2X.

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

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

[0032] Figure 16 1 is a diagram showing an example of a preemption operation.

[0033] Figure 17 This is a diagram showing an example of priorities applied to resources in an embodiment of the present invention.

[0034] Figure 18 This is a diagram showing an example of the functional configuration of the base station 10 in the embodiment of the present invention.

[0035] Figure 19 This is a diagram showing an example of the functional configuration of the terminal 20 in the embodiment of the present invention.

[0036] Figure 20 This is a diagram showing an example of the hardware configuration of the base station 10 or the terminal 20 in the embodiment of the present invention. DETAILED DESCRIPTION

[0037] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0038] When operating the wireless communication system according to the embodiments of the present invention, existing technologies are appropriately used. However, this existing technology is, for example, existing LTE, but is not limited to existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning that includes LTE-Advanced and post-LTE-Advanced systems (for example, NR) or wireless LANs (Local Area Networks).

[0039] Furthermore, in the embodiment of the present invention, the duplexing method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, flexible duplex, etc.).

[0040] Furthermore, in the embodiment of the present invention, “configuring” wireless parameters and the like may be pre-configuring predetermined values, or may be configuring wireless parameters notified from the base station 10 or the terminal 20 .

[0041] Figure 1 This is a diagram for explaining V2X. 3GPP is researching technologies to implement V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality and is promoting standardization. Figure 1 As shown, V2X is a part of ITS (Intelligent Transport Systems), and is a general term for V2V (Vehicle to Vehicle) which represents the communication between vehicles, V2I (Vehicle to Infrastructure) which represents the communication between vehicles and roadside equipment (RSU: Road-Side Unit) installed next to the road, V2N (Vehicle to Network) which represents the communication between vehicles and ITS servers, and V2P (Vehicle to Pedestrian) which represents the communication between vehicles and mobile terminals held by pedestrians.

[0042] Furthermore, 3GPP is researching V2X, which utilizes cellular communications and inter-device communications using LTE or NR. V2X using cellular communications is also referred to as cellular V2X. Research is progressing on achieving high capacity, low latency, high reliability, and QoS (Quality of Service) control in NR-based V2X.

[0043] Regarding LTE and NR V2X, research is envisioned to continue beyond 3GPP specifications. For example, research is envisioned to ensure interoperability, reduce costs associated with high-level installation, integrate and switch between multiple RATs (Radio Access Technologies), support regulations in various countries, and acquire, publish, manage, and utilize data from LTE and NR V2X platforms.

[0044] While the embodiments of the present invention primarily envision the communication device being mounted on a vehicle, the embodiments of the present invention are not limited to this configuration. For example, the communication device may be a terminal held by a person, a device mounted on a drone or aircraft, or a base station, RSU, relay node, or terminal with scheduling capabilities.

[0045] In addition, SL (Sidelink) can also be distinguished by UL (Uplink) or DL ​​(Downlink) and any one or a combination of the following 1) to 4). In addition, SL can also be other names.

[0046] 1) Time Domain Resource Allocation

[0047] 2) Frequency Domain Resource Allocation

[0048] 3) Reference synchronization signal (including SLSS (Sidelink Synchronization Signal))

[0049] 4) Reference signal used for path loss measurement for transmit power control

[0050] In addition, for OFDM (Orthogonal Frequency Division Multiplexing) of SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding can also be used.

[0051] LTE's SL specifies Mode 3 and Mode 4 for SL resource allocation to terminal 20. In Mode 3, transmission resources are dynamically allocated using DCI (Downlink Control Information) sent from base station 10 to terminal 20. Mode 3 also supports Semi-Persistent Scheduling (SPS). In Mode 4, terminal 20 autonomously selects transmission resources from a resource pool.

[0052] In addition, the time slot in the embodiments of the present invention may be replaced by a symbol, a mini-slot, a subframe, a radio frame, or a TTI (Transmission Time Interval). Furthermore, the cell in the embodiments of the present invention may be replaced by a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), or the like.

[0053] Furthermore, in the embodiments of the present invention, the terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a user-held terminal such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0054] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode. Figure 2In the transmission mode of the sidelink communication shown in FIG, in step 1, the base station 10 sends the sidelink scheduling information to the terminal 20A. Then, the terminal 20A sends the PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to the terminal 20B based on the received scheduling information (step 2). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, sidelink scheduling based on Uu is performed. Uu refers to the radio interface between UTRAN (Universal Terrestrial Radio Access Network) and UE (User Equipment). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 1 in NR.

[0055] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode. Figure 3 In the transmission mode of the side link communication shown in FIG, in step 1, the terminal 20A transmits the PSCCH and PSSCH to the terminal 20B using the resources selected autonomously. Figure 3 The transmission mode of the sidelink communication shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0056] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode. Figure 4 In the transmission mode of the sidelink communication shown in FIG, in step 1, the terminal 20A uses the resources selected autonomously to transmit the PSCCH and PSSCH to the terminal 20B. Similarly, the terminal 20B uses the resources selected autonomously to transmit the PSCCH and PSSCH to the terminal 20A (step 1). Figure 4 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, the terminal 20 performs resource selection itself.

[0057] Figure 5 This is a diagram for explaining example (4) of the V2X transmission mode. Figure 5In the transmission mode of the sidelink communication shown in FIG, in step 0, the base station 10 sets the resource mode of the sidelink to the terminal 20A via RRC (Radio Resource Control) or pre-sets the resource mode of the sidelink. Then, the terminal 20A transmits the PSSCH to the terminal 20B according to the resource mode (step 1). Figure 5 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2c in NR.

[0058] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode. Figure 6 In the transmission mode of the side link communication shown in FIG, in step 1, terminal 20A transmits the scheduling information of the side link to terminal 20B via PSCCH. Then, terminal 20B transmits PSSCH to terminal 20A based on the received scheduling information (step 2). Figure 6 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2d in NR.

[0059] Figure 7 This is a diagram for explaining example (1) of the V2X communication type. Figure 7 The communication type of the side link shown is unicast. Terminal 20A sends PSCCH and PSSCH to terminal 20. Figure 7 In the example shown, the terminal 20A performs unicast to the terminal 20B, and also performs unicast to the terminal 20C.

[0060] Figure 8 This is a diagram for explaining example (2) of the V2X communication type. Figure 8 The communication type of the side link shown is multicast. Terminal 20A sends PSCCH and PSSCH to the group to which one or more terminals 20 belong. Figure 8 In the example shown, the group includes the terminal 20B and the terminal 20C, and the terminal 20A performs multicast for the group.

[0061] Figure 9 This is a diagram for explaining example (3) of the V2X communication type. Figure 9 The communication type of the side link shown is broadcast. Terminal 20A sends PSCCH and PSSCH to one or more terminals 20. Figure 9 In the example shown, terminal 20A broadcasts to terminal 20B, terminal 20C, and terminal 20D. Figures 7 to 9 The terminal 20A shown is referred to as a head UE (header-UE).

[0062] Furthermore, NR-V2X envisions supporting HARQ (Hybrid Automatic Repeat Request) in both unicast and multicast on the sidelink. Furthermore, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Furthermore, research is underway to transmit SFCI via the Physical Sidelink Feedback Channel (PSFCH).

[0063] In the following description, it is assumed that the PSFCH is used for transmission of HARQ-ACK on the sidelink. However, this is only an example. For example, HARQ-ACK on the sidelink may be transmitted using the PSCCH, the PSSCH, or other channels.

[0064] For convenience, all information reported by terminal 20 in HARQ will be referred to below as HARQ-ACK. This HARQ-ACK may also be referred to as HARQ-ACK information. Furthermore, more specifically, the codebook used for HARQ-ACK information reported from terminal 20 to base station 10, etc., is referred to as the HARQ-ACK codebook. The HARQ-ACK codebook defines the bit string of the HARQ-ACK information. Furthermore, HARQ-ACK allows NACKs to be transmitted in addition to ACKs.

[0065] Figure 10 This is a timing diagram showing an example of V2X operation (1). Figure 10 As shown, the wireless communication system according to the embodiment of the present invention may include a terminal 20A and a terminal 20B. In addition, there are actually multiple user devices, but Figure 10 The terminal 20A and the terminal 20B are shown as examples.

[0066] Hereinafter, when the terminals 20A and 20B are not particularly distinguished, they are simply referred to as "terminal 20" or "user device". Figure 10 In the embodiment, the case where both the terminal 20A and the terminal 20B are within the coverage of the cell is shown as an example, but the operation in the embodiment of the present invention can also be applied to the case where the terminal 20B is outside the coverage.

[0067] As described above, in this embodiment, the terminal 20 is a device mounted on a vehicle, such as an automobile, and has cellular communication functions and sidelink functions as a UE in LTE or NR. The terminal 20 may also be a general portable terminal (such as a smartphone). Furthermore, the terminal 20 may also be an RSU. This RSU may be a UE-type RSU (UE type RSU) that has UE functions, or a gNB-type RSU (gNB type RSU) that has base station functions.

[0068] Furthermore, the terminal 20 does not need to be a device having a single housing. For example, even when various sensors are dispersedly arranged in a vehicle, the terminal 20 may be a device including these various sensors.

[0069] Furthermore, the processing of sidelink transmit data by terminal 20 is essentially the same as that of UL transmission in LTE or NR. For example, terminal 20 scrambles the codewords of transmit data, modulates them, and generates complex-valued symbols. These complex-valued symbols (transmit signals) are mapped to layer 1 or layer 2 and precoded. The precoded complex-valued symbols are then mapped to resource elements to generate a transmit signal (e.g., a complex-valued time-domain SC-FDMA signal), which is then transmitted from each antenna port.

[0070] The base station 10 also has cellular communication functions as a base station in LTE or NR, as well as functions for enabling communication with the terminal 20 in this embodiment (e.g., resource pool configuration, resource allocation, etc.). Furthermore, the base station 10 may also be an RSU (gNB-type RSU).

[0071] In addition, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 in the SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.

[0072] In step S101, terminal 20A autonomously selects resources to be used for PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may also be set by base station 10 for terminal 20. The predetermined duration of the resource selection window may be defined based on terminal installation conditions such as processing time or maximum permissible packet delay, or may be pre-defined by a specification. The predetermined duration may also be referred to as an interval in the time domain.

[0073] In steps S102 and S103, the terminal 20A uses the resources autonomously selected in step S101 to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. For example, the terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH in the same time resources as at least a portion of the time resources of the PSSCH.

[0074] Terminal 20B receives the SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The received SCI may include information about the PSFCH resource used by terminal 20B to transmit the HARQ-ACK for the received data. Terminal 20A may include information about the autonomously selected resource in the SCI and transmit it.

[0075] In step S104 , the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the PSFCH resources determined by the received SCI.

[0076] If the HARQ-ACK received in step S104 is a NACK (negative acknowledgement) indicating a retransmission request, terminal 20A retransmits PSCCH and PSSCH to terminal 20B in step S105. Terminal 20A can retransmit PSCCH and PSSCH using autonomously selected resources.

[0077] In addition, when HARQ control with HARQ feedback is not performed, steps S104 and S105 may not be performed.

[0078] Figure 11 This is a timing diagram showing an example of V2X operation (2). Blind retransmissions may be performed independently of HARQ control for improving the transmission success rate or the reach distance.

[0079] In step S201 , the terminal 20A autonomously selects resources to be used for the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0080] In steps S202 and S203, terminal 20A uses the resources autonomously selected in step S201 to transmit SCI using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. For example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH in the same time resources as at least a portion of the time resources of the PSSCH.

[0081] In step S204, the terminal 20A retransmits the SCI based on the PSCCH and / or PSSCH and the SL data based on the PSSCH to the terminal 20B using the resources autonomously selected in step S201. The retransmission in step S204 may be performed multiple times.

[0082] In addition, when blind retransmission is not performed, step S204 may not be performed.

[0083] Figure 12 This is a sequence diagram illustrating an example of V2X operation (3). The base station 10 can perform sidelink scheduling. Specifically, the base station 10 can determine the sidelink resources used by the terminal 20 and transmit information indicating the resources to the terminal 20. Furthermore, when HARQ control with HARQ feedback is applied, the base station 10 can transmit information indicating PSFCH resources to the terminal 20.

[0084] In step S301, the base station 10 transmits DCI (Downlink Control Information) to the terminal 20A using the PDCCH, thereby performing SL scheduling. Hereinafter, for convenience of explanation, the DCI for SL scheduling is referred to as SL scheduling DCI.

[0085] Furthermore, the following scenario is envisioned: in step S301, the base station 10 also transmits DCI for DL ​​scheduling (also referred to as DL allocation) to the terminal 20A using the PDCCH. Hereinafter, for convenience, the DCI for DL ​​scheduling is referred to as DL scheduling DCI. Upon receiving the DL scheduling DCI, the terminal 20A receives DL data using the PDSCH using the resources specified by the DL scheduling DCI.

[0086] In steps S302 and S303, terminal 20A uses the resources specified by the SL scheduling DCI to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. Alternatively, the SL scheduling DCI may specify only PSSCH resources. In this case, for example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, within the same time resources as at least a portion of the time resources of the PSSCH.

[0087] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The SCI received using PSCCH and / or PSSCH includes information on the resource of the PSFCH used by terminal 20B to transmit HARQ-ACK for receiving the data.

[0088] The resource information is included in the DL scheduling DCI or SL scheduling DCI transmitted from the base station 10 in step S301. The terminal 20A obtains the resource information from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, if the DCI transmitted from the base station 10 does not include the resource information, the terminal 20A autonomously includes the resource information in the SCI and transmits it.

[0089] In step S304 , the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the PSFCH resources determined by the received SCI.

[0090] In step S305, the terminal 20A, for example, sends a HARQ-ACK using the PUCCH (Physical uplink control channel) resource specified by the DL scheduling DCI (or the SL scheduling DCI) at the timing (e.g., timing in time slots) specified by the DL scheduling DCI (or the SL scheduling DCI), and the base station 10 receives the HARQ-ACK. The HARQ-ACK codebook may include a HARQ-ACK generated based on the HARQ-ACK received from the terminal 20B or based on the unreceived PSFCH, and a HARQ-ACK for DL ​​data. However, in the case where there is no allocation of DL data, the HARQ-ACK for DL ​​data is not included. In Rel.16 of NR, the HARQ-ACK codebook does not include a HARQ-ACK for DL ​​data.

[0091] In addition, when HARQ control accompanied by HARQ feedback is not performed, step S304 and / or step S305 may not be performed.

[0092] Figure 13 This is a timing diagram showing an example of V2X operation (4). As described above, the side link of NR supports the case of sending HARQ responses through PSFCH. In addition, the format of PSFCH can use the same format as PUCCH (Physical Uplink Control Channel) format 0 (PUCCH format 0), for example. That is, regarding the format of PSFCH, it can be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified based on the difference in timing and / or cyclic shift. The format of PSFCH is not limited to this. The resources of PSFCH can be configured as a codeword at the end of the time slot or multiple codewords at the end. In addition, a period N is set or predefined for the PSFCH resources. The period N can be set or predefined in units of time slots.

[0093] exist Figure 13 In the figure, the vertical axis corresponds to the frequency domain, and the horizontal axis corresponds to the time domain. PSCCH can be configured in one codeword at the start of the time slot, or in multiple codewords starting from the start, or in multiple codewords starting from a codeword other than the start. PSFCH can be configured in one codeword at the end of the time slot, or in multiple codewords at the end of the time slot. In addition, the above-mentioned "start of the time slot" and "end of the time slot" can also omit the consideration of the codewords used for AGC (Automatic Gain Control) and the codewords used for transmission / reception switching. That is, for example, in the case where 1 time slot is composed of 14 codewords, "start of the time slot" and "end of the time slot" can mean the codewords of the start and end respectively among the 12 codewords excluding the codewords at the start and end. In Figure 13 In the example shown, three subchannels are set in the resource pool, and two PSFCHs are allocated three slots after the slot where the PSSCH is allocated. The arrow from the PSSCH to the PSFCH shows an example of the PSFCH associated with the PSSCH.

[0094] When the HARQ response in NR-V2X multicast is multicast option 2 of sending ACK or NACK, it is necessary to determine the resources used for PSFCH transmission and reception. Figure 13As shown, in step S401, terminal 20A as the transmitting terminal 20 performs multicast via SL-SCH to terminal 20B, terminal 20C and terminal 20D as the receiving terminal 20. In the next step S402, terminal 20B uses PSFCH#B to send a HARQ response to terminal 20A, terminal 20C uses PSFCH#C to send a HARQ response to terminal 20A, and terminal 20D uses PSFCH#D to send a HARQ response to terminal 20A. Figure 13 As shown in the example, when the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to determine how to allocate the PSFCH resources. Furthermore, the transmitting terminal 20 can understand the number of receiving terminals 20 in the multicast. Furthermore, in multicast option 1, only NACK is transmitted as the HARQ response, and ACK is not transmitted.

[0095] Figure 14 is a diagram showing an example of monitoring operation in NR. In resource allocation mode 2, the terminal 20 selects resources for transmission. Figure 14 As shown, terminal 20 monitors within a monitoring window within a resource pool. Through monitoring, terminal 20 receives the resource reservation field or resource assignment field contained in the SCI sent from other terminals 20. Based on this field, terminal 20 identifies available resource candidates within a resource selection window within the resource pool. Terminal 20 then randomly selects a resource from the available resource candidates.

[0096] In addition, if Figure 14 As shown, the resource pool setting may have a period, for example, the period may be a period of 10240 milliseconds. Figure 14 is time slot t0 SL To time slot t Tmax SL The resource pool area in each cycle can be set by, for example, a bitmap.

[0097] In addition, if Figure 14 As shown, assuming that the transmission trigger in terminal 20 occurs in time slot n, the priority of the transmission is p TX The terminal 20 can detect the time from time slot n-T0 to time slot nT proc，0 In the monitoring window up to the immediately preceding time slot, for example, other terminals 20 are performing priority p RXWhen SCI is detected in the monitoring window and RSRP (Reference Signal Received Power) is greater than the threshold, the resources in the resource selection window corresponding to the SCI are excluded. In addition, when SCI is detected in the monitoring window and RSRP is less than the threshold, the resources in the resource selection window corresponding to the SCI are not excluded. The threshold can also be, for example, based on the priority p TX and priority p RX The threshold value Th is set or defined according to each resource in the monitoring window. pTX，pRX .

[0098] In addition, if Figure 14 The time slot t shown m SL In this way, for example, resources within the resource selection window for transmission corresponding to resources within the monitoring window that are not monitored are excluded as candidates for resource reservation information.

[0099] like Figure 14 As shown, in the resource selection window from time slot n+T1 to time slot n+T2, the resources occupied by other UEs are identified, and the resources after the resources are excluded become the available resource candidates. When the set of available resource candidates is set to S A When S A If the resource selection window is less than 20%, the threshold value Th set for each resource in the monitoring window can be set to pTX，pRX The resource identification is performed again by increasing the threshold Th by 3dB. pTX，pRX The resource identification is performed again to increase the number of resources that are not excluded because the RSRP is less than the threshold, and the set of resource candidates S A Become more than 20% of the resource selection window. A If the resource selection window is less than 20%, the threshold value Th set for each resource in the monitoring window can be repeatedly adjusted. pTX，pRX The resource identification operation is performed again by increasing the value by 3dB.

[0100] The lower layer of terminal 20 can A Report to the upper layer. The upper layer of terminal 20 can report to S A The resource to be used is determined by performing random selection, and the terminal 20 can perform sidelink transmission using the determined resource.

[0101] In the above Figure 14 In the description, the operation of the transmitting terminal 20 is described, but the receiving terminal 20 may detect data transmission from another terminal 20 based on the result of monitoring or partial monitoring, and receive data from the other terminal 20.

[0102] Figure 15 is a flowchart showing an example of preemption in NR. Figure 16 is a diagram showing an example of preemption in NR. In step S501, the terminal 20 performs monitoring in the monitoring window. When the terminal 20 performs power saving operation, the monitoring can be performed during a predefined limited period. Then, the terminal 20 identifies each resource in the resource selection window based on the monitoring results and determines a set of resource candidates S. A (S502) Next, the terminal 20 selects a set of resource candidates S A A resource set (r_0, r_1, ...) is selected from the set (S503).

[0103] In step S504, the terminal 20 Figure 16 The timing of T(r_0)-T3 shown in the figure is used to identify the resources in the resource selection window again based on the monitoring results, and the set of resource candidates S is determined. A , and then determine the preemption based on the priority. For example, Figure 16 The r_1 shown in FIG. 1 detects the SCI sent from the other terminal 20 through the second monitoring and is not included in the S A In the case where preemption is enabled, when the value prio_RX indicating the priority of the SCI sent from another terminal 20 is lower than the value prio_TX indicating the priority of the transport block sent from the terminal itself, the terminal 20 determines that the resource r_1 is preempted. In addition, if the value indicating the priority is a lower value, the priority becomes higher. That is, when the value prio_RX indicating the priority of the SCI sent from another terminal 20 is higher than the value prio_TX indicating the priority of the transport block sent from the terminal itself, the terminal 20 does not preempt the resource r_1 from the SCI. A Resource r_1 is excluded from the preemption. Alternatively, if preemption is enabled only for a specific priority level (for example, if sl-PreemptionEnable is any of pl1, pl2, ..., pl8), the priority level is set to prio_pre. In this case, if the value prio_RX indicating the priority of the SCI sent from another terminal 20 is lower than prio_pre, and prio_RX is lower than the value prio_TX indicating the priority of the transport block sent from the terminal itself, the terminal 20 determines that resource r_1 is preempted.

[0104] In step S505 , if the terminal 20 determines that preemption has occurred in step S504 , the terminal 20 notifies the upper layer of the preemption, reselects resources in the upper layer, and ends the preemption.

[0105] In the NR Release 17 sidelink, power saving based on the aforementioned random resource selection and partial monitoring is being studied. For example, for power saving, the random resource selection and partial monitoring of the LTE Release 14 sidelink can be applied to the resource allocation mode 2 of the NR Release 16 sidelink. Terminals 20 to which partial monitoring is applied perform reception and monitoring only in specific time slots within the monitoring window.

[0106] Furthermore, in the sidelink of NR Release 17, research is underway on enhanced Ultra Reliable Low Latency Communication (eURLLC), using inter-UE coordination as a baseline. For example, terminal 20A and terminal 20B share information indicating resource sets, allowing terminal 20B to consider this information when selecting resources for transmission.

[0107] In LTE, in resource allocation modes where the terminal 20 autonomously selects resources, in addition to full sensing and partial sensing, random selection without monitoring is also supported. The resource selection method to be executed can be configured in the resource pool. Furthermore, random selection and random resource selection can be distinguished, or not. For example, random resource selection without monitoring can be referred to as random selection.

[0108] When random selection is configured for a transmission by a higher layer, the time and frequency resources for a transmission opportunity are randomly selected from the resource pool based on the amount of frequency resources. In random selection, the selectable candidates are selected with equal probability.

[0109] Alternatively, when the transmission based on random selection is set by the higher layer and further set to use a resource pool across multiple carriers, the terminal 20 may perform the following 1)-5).

[0110] 1) Set up the resource selection window.

[0111] 2) The resource collection S A Set to all resources within the window.

[0112] 3) Let S B =S A .

[0113] 4) According to the simultaneous transmission capability between carriers, B Exclude unusable resources from .

[0114] 5) S B Report to senior management.

[0115] In the LTE sidelink, in resource pools configured with random selection, there are no conditions or restrictions on the application of random selection without monitoring. Terminal 20 selects resources and transmits without monitoring, resulting in a very high probability of resource conflicts. This reduces the reliability of resource pools configured with random selection, and resources can only be used for limited services.

[0116] On the other hand, the NR sidelink assumes the existence of services requiring higher reliability and responds to various requirements. Therefore, the same random selection method without monitoring as the LTE sidelink should be avoided.

[0117] Therefore, the terminal 20 that performs random resource selection without monitoring can perform specific selection and transmission operations according to specific constraints. Hereinafter, "random resource selection without monitoring" will be referred to as "random selection."

[0118] For example, the terminal 20 can perform a random selection action in a resource pool that has been set or pre-set with parameters related to random selection. For example, it can be limited to a resource pool that does not have a resource allocation mode set for "the base station 10 notifies the terminal 20 of the transmission resources." In addition, for example, the terminal 20 can perform specific selection actions and transmission actions based on priority. In addition, for example, the terminal 20 can only perform transmission based on random selection in specific resources. In addition, for example, the terminal 20 can also perform random selection and transmission based on a specific transmission frequency. In addition, for example, the terminal 20 can also impose restrictions on the functions to which random selection and transmission can be applied. In addition, for example, the terminal 20 can also perform specific selection actions and transmission actions based on information received in specific resources.

[0119] As described above, the terminal 20 in the embodiment of the present invention can perform specific selection and transmission actions based on priority. For example, in the case of transmissions with a priority higher than a specific priority (i.e., a value indicating a priority lower than a specific priority), random selection can be performed. In addition, in the case of transmissions with a priority higher than a specific priority (i.e., a value indicating a priority lower than a specific priority), random selection can also be performed.

[0120] Furthermore, for example, in the case of transmissions with a priority lower than a specific one (ie, a value indicating a priority being larger), monitoring may necessarily be applied, and random selection may not be performed.

[0121] Regarding the above-mentioned specific priority, parameters for determination can be set or predefined. In addition, the above-mentioned specific priority can also be defined by a specification. In addition, the above-mentioned specific priority can also be a priority at which other terminals 20 can perform preemption. When preemption is not set in the other terminals 20, it can be set so that random selection cannot be set. In addition, in a resource pool with random selection set, the conditions for preemption performed by other terminals 20 may be different from those of a resource pool without random selection set. For example, in a resource pool with random selection set, when the other terminal 20 makes a preemption judgment, when receiving reservation information based on a priority higher than the above-mentioned specific priority through the selected resource, the other terminal 20 may not be able to use the resource regardless of the received RSRP and / or the priority of the transmission.

[0122] Figure 17 This figure shows an example of priority applied to resources in an embodiment of the present invention. For example, a priority may be determined for each time and / or frequency resource, and whether random selection can be performed is determined based on the priority. Figure 17 This is an example of setting priority 0 for two sub-channels on the higher frequency side and setting priority 2 for two sub-channels on the lower frequency side among frequency resources in the resource selection window set in the resource pool.

[0123] In the case of transmissions with a higher priority than the priority set for each time and / or frequency resource (i.e., a smaller value indicating the priority), random selection may be performed. Furthermore, in the case of transmissions with a priority higher than the priority set for each time and / or frequency resource (i.e., a value indicating the priority lower than the priority set for each time and / or frequency resource), random selection may also be performed. Furthermore, for example, in the case of transmissions with a lower priority than the priority set for each time and / or frequency resource (i.e., a value indicating the priority higher than the priority set for each time and / or frequency resource), monitoring may be required or random selection may not be performed.

[0124] For example, in Figure 17 In the case of transmission with priority 1, the terminal 20 may not perform random selection among resources set with priority 0, but may perform random selection among resources set with priority 2.

[0125] When priorities are determined for each time and / or frequency resource in the resource pool, other terminals 20 that select resources based on monitoring can also perform transmission operations based on these priorities. For example, when the priority for transmitting a transport block is X, only resources with a priority value smaller than X, which indicates the priority set for each resource, can be set as candidates. In other words, candidate resources can be preempted.

[0126] By setting the priority for each resource as described above, the resources used by the terminal 20 that does not perform random selection or selects resources based on monitoring can be changed, thereby reducing the probability of conflict.

[0127] As described above, the terminal 20 in the embodiment of the present invention may only be able to perform transmission based on random selection in specific resources. The specific resource may be any one of the resources shown in 1) to 4) below.

[0128] 1) It can be a resource that is not configured as a PSFCH in the same time resource as the PSFCH opportunity. When using this resource, the PSCCH / PSSCH can apply either TDM (Time Division Multiplexing) or FDM (Frequency Division Multiplexing). The DM-RS (Demodulation Reference Signal) can be shared between the PSCCH / PSSCH or transmitted per channel. The shared or per-channel DM-RS can be FDMed with the information transmission resources in each channel.

[0129] 2) It can be a specific frequency resource. For example, a specific frequency resource can be specified by a subchannel. In addition, a specific frequency resource can also be a specific subchannel in a subchannel of a resource pool. In addition, with respect to a specific frequency resource, for example, when the subchannel size shared by multiple subchannels in a resource pool is set to A, it can be a subchannel set with a subchannel size other than A. In addition, with respect to a specific frequency resource, when the number of PRBs in a set resource pool or CBW (Channel bandwidth) is set to P and the subchannel size set in the resource pool is set to Q, it can also be PN×Q PRBs. Wherein, N is the largest integer where N×Q does not exceed P.

[0130] 3) It can be N_reserved time slots. N_reserved time slots can be {10240×2^μ-N_SSSB-N_nonSL} mod L_bitmap. In addition, μ is a parameter corresponding to the subcarrier spacing, N_SSSB is a parameter indicating the number of time slots used for sidelink SSB transmission, N_nonSL is a parameter indicating the number of time slots not used for the sidelink, and L_bitmap is a parameter indicating the bitmap length of the parameter represented by the bitmap specifying the valid time slots.

[0131] 4) It can be a specific time resource. For example, it can be a time resource determined based on at least one of higher-layer parameters, SFN (System Frame Number), DFN (Direct Frame Number), PSFCH period, and PSFCH opportunity. Alternatively, it can be a time resource that specifies "a time slot to a time slot within a resource pool or resource selection window."

[0132] By enabling only transmission based on random selection in specific resources as described above, collision between transmission based on random selection and transmission based on monitoring can be avoided.

[0133] As described above, the terminal 20 in the embodiment of the present invention can perform random selection and transmission according to a specific transmission frequency. For example, the terminal 20 can perform random selection and transmission in a manner that the transmission frequency does not exceed a specific value. Whether it exceeds the specific value can be determined according to each transmission, or according to each resource selection, or according to each transmission block. In addition, the specific value can be set as a parameter for determination, or can be pre-specified, or defined by a specification, or can be specified according to each priority. The transmission frequency can be, for example, the channel occupancy ratio, or the number of transmissions in a specific time interval, or the number of transmission blocks sent in a specific time interval.

[0134] By performing random selection and transmission based on the transmission frequency as described above, it is possible to avoid a situation where transmission based on random selection is frequent and thus easily causes collisions.

[0135] As described above, the terminal 20 in the embodiment of the present invention can impose restrictions on the functions to which random selection and transmission can be applied. For example, the functions shown in the following 1) to 6) can be restricted.

[0136] 1) Random selection may be applied to transmissions for which HARQ feedback is invalid. On the other hand, random selection may not be applied to transmissions for which HARQ feedback is valid.

[0137] 2) The random selection may be applied to broadcast and / or multicast transmissions. On the other hand, the random selection may not be applied to multicast and / or unicast transmissions.

[0138] 3) The random selection may be applied to transmissions with periodic reservations. On the other hand, the random selection may not be applied to transmissions with aperiodic reservations.

[0139] 4) The random selection may be applied to transmissions that are scheduled aperiodically. On the other hand, the random selection may not be applied to transmissions that are scheduled periodically.

[0140] 5) It may be configured that random selection cannot be applied to transmissions related to the PC5-RRC connection. For example, transmissions related to the PC5-RRC connection include PC5-RRC connection setup, CSI reporting, and MIMO-related parameter indication.

[0141] 6) It can be set to prioritize the transmission of random selection and UL transmission, and UL transmission does not necessarily have priority.

[0142] By limiting the functions to which random selection and transmission are applied as described above, random selection can be prevented from being applied to functions to which transmission based on random selection is not desired, thereby avoiding degradation of system performance.

[0143] As described above, the terminal 20 in the embodiment of the present invention can perform specific selection actions and sending actions according to the information received in the specific resource.

[0144] For example, signals from other terminals 20 can be received during specific time and / or frequency resources. Signal reception can be an action other than monitoring. Other terminals 20 capable of monitoring can transmit information related to or based on monitoring results within specific resources, and can also transmit location information of the other terminals 20. Furthermore, terminals 20 capable of monitoring within a resource pool containing specific resources can transmit this information using these resources based on specific conditions. These specific conditions can, for example, include a transmission obligation occurring at a specific frequency or probability.

[0145] Terminal 20 can limit resource candidates and perform random selection based on the information received from other terminals 20. For example, resource exclusion can be performed by receiving monitoring results from other terminals 20. Furthermore, the decision to limit resource candidates based on the RSRP of information received from other terminals 20 (e.g., whether it exceeds a specific value) can be made. Furthermore, the decision to limit resource candidates based on location information received from other terminals 20 (e.g., whether it is within a specific distance) can be made.

[0146] As described above, by receiving information from other terminals 20 in a specific resource, resource exclusion and transmission collision avoidance can be performed even without performing monitoring.

[0147] According to the above embodiment, the terminal 20 can reduce the probability of transmission collision when selecting random resources without monitoring.

[0148] That is, in inter-terminal direct communication, the reliability of communication during autonomous resource selection can be improved.

[0149] (Device Structure)

[0150] Next, the functional configuration examples of the base station 10 and terminal 20 that perform the above-described processing and operations are described. The base station 10 and terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and terminal 20 may each include only a portion of the functions described in the embodiments.

[0151] <Base Station 10>

[0152] Figure 18 1 is a diagram showing an example of the functional configuration of the base station 10. Figure 18 As shown, the base station 10 includes a transmitting unit 110 , a receiving unit 120 , a setting unit 130 , and a control unit 140 . Figure 18 The functional configuration shown is merely an example, and any functional divisions and names of functional units may be used as long as the operations according to the embodiments of the present invention can be executed.

[0153] The transmitter 110 includes a function of generating a signal to be transmitted to the terminal 20 and wirelessly transmitting the signal. The receiver 120 includes a function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher-layer information from the received signals. Furthermore, the transmitter 110 includes a function of transmitting the NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, and the like to the terminal 20.

[0154] The setting unit 130 stores pre-set setting information and various setting information to be sent to the terminal 20 in a storage device, and reads the setting information from the storage device as needed. The content of the setting information is, for example, information related to the setting of D2D communication.

[0155] As described in the embodiments, the control unit 140 performs processing related to the configuration for the terminal 20 to perform D2D communication. Furthermore, the control unit 140 transmits the schedule for D2D communication and DL communication to the terminal 20 via the transmission unit 110. Furthermore, the control unit 140 receives information related to HARQ responses for D2D communication and DL communication from the terminal 20 via the reception unit 120. Functional units related to signal transmission within the control unit 140 may be included in the transmission unit 110, while functional units related to signal reception within the control unit 140 may be included in the reception unit 120.

[0156] <Terminal 20>

[0157] Figure 19 2 is a diagram showing an example of the functional structure of the terminal 20. Figure 19 As shown, the terminal 20 includes a transmitting unit 210 , a receiving unit 220 , a setting unit 230 , and a control unit 240 . Figure 19 The functional configuration shown is merely an example, and any functional divisions and names of functional units may be used as long as the operations according to the embodiments of the present invention can be executed.

[0158] The transmitting unit 210 generates a transmission signal based on the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 receives various signals wirelessly and obtains higher-layer signals from the received physical layer signals. In addition, the receiving unit 220 has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals transmitted from the base station 10. In addition, for example, as D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0159] The configuration unit 230 stores various configuration information received by the receiving unit 220 from the base station 10 or the terminal 20 in a storage device and reads it from the storage device as needed. Furthermore, the configuration unit 230 also stores pre-set configuration information. This configuration information may include, for example, information related to D2D communication configuration.

[0160] As described in the embodiment, the control unit 240 controls D2D communication that establishes an RRC connection with another terminal 20. In addition, the control unit 240 performs processing related to power saving operations. In addition, the control unit 240 performs processing related to HARQ of D2D communication and DL communication. In addition, the control unit 240 sends to the base station 10 information related to HARQ responses for D2D communication and DL communication scheduled from the base station 10 to other terminals 20. In addition, the control unit 240 can also schedule D2D communication for other terminals 20. In addition, the control unit 240 can autonomously select resources used in D2D communication from the resource selection window based on the monitoring results, and can also perform re-evaluation or preemption. In addition, the control unit 240 performs processing related to power saving in the transmission and reception of D2D communication. In addition, the control unit 240 performs processing related to inter-terminal coordination in D2D communication. The functional units related to signal transmission in the control unit 240 may be included in the transmitting unit 210 , and the functional units related to signal reception in the control unit 240 may be included in the receiving unit 220 .

[0161] (Hardware Structure)

[0162] The block diagram used in the description of the above embodiment ( Figure 18 and Figure 19 ) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a device that is physically or logically combined, or it can be implemented by connecting two or more physically or logically separated devices directly or indirectly (for example, using wired or wireless connections) and using these multiple devices. The functional block can also be implemented by combining software with the above-mentioned one device or the above-mentioned multiple devices.

[0163] Functionally, these include, but are not limited to, judging, deciding, determining, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, resolving, selecting, choosing, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning. For example, a functional block (structural unit) that enables the transmission function is called a transmitting unit or a transmitter. In short, as described above, there is no particular limitation on the implementation method.

[0164] For example, the base station 10 , the terminal 20 , and the like in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 20 This figure shows an example of the hardware configuration of a base station 10 and a terminal 20 according to one embodiment of the present disclosure. The base station 10 and the terminal 20 described above can also be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0165] In the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and the terminal 20 may include one or more of the devices shown in the figures, or may exclude some of the devices.

[0166] The various functions in the base station 10 and the terminal 20 are implemented by reading predetermined software (programs) into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs calculations and controls the communication of the communication device 1004 or controls at least one of the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0167] Processor 1001 controls the entire computer by, for example, running an operating system. Processor 1001 may also be comprised of a central processing unit (CPU) that includes interfaces with peripheral devices, a control device, a computing device, registers, and the like. For example, control unit 140 and control unit 240 described above may also be implemented by processor 1001.

[0168] In addition, the processor 1001 reads a program (program code), a software module, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and performs various processes based on the program. As a program, a program that causes the computer to execute at least a part of the actions described in the above embodiment is used. For example, Figure 18 The control unit 140 of the base station 10 shown may also be implemented by a control program stored in the storage device 1002 and executed in the processor 1001. Figure 19The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and executed by the processor 1001. Regarding the various processes described above, although they are described as being executed by a single processor 1001, they can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be implemented on one or more chips. Furthermore, the program can be transmitted from a network via a telecommunications line.

[0169] The storage device 1002 is a computer-readable recording medium and may be composed of, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and RAM (Random Access Memory). The storage device 1002 may also be referred to as a register, cache, or main memory (main storage device). The storage device 1002 can store executable programs (program code), software modules, and the like for implementing the communication method according to one embodiment of the present disclosure.

[0170] The auxiliary storage device 1003 is a computer-readable recording medium, and can be composed of at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (for example, a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic stripe, etc. The above-mentioned storage medium can be, for example, a database, a server, or other appropriate medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0171] Communication device 1004 is hardware (a transceiver) used to communicate between computers via at least one of a wired network and a wireless network. It is also referred to as a network device, network controller, network card, or communication module. Communication device 1004 may include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, communication device 1004 may also implement a transceiver antenna, an amplifier, a transceiver, a transmission path interface, and the like. The transceiver may also be physically or logically separated from the transmitter and receiver.

[0172] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to the outside (e.g., a display, speaker, LED light, etc.). Alternatively, the input device 1005 and the output device 1006 may be integrally formed (e.g., a touch panel).

[0173] Furthermore, the processor 1001, the storage device 1002, and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured as a single bus or may be configured as different buses between devices.

[0174] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array), and may implement some or all of the functional blocks using this hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0175] (Summary of Implementation Methods)

[0176] As described above, according to an embodiment of the present invention, there is provided a terminal including: a control unit that randomly selects resources from a resource pool set for random selection without monitoring according to specific conditions; and a transmission unit that performs transmission using the resources.

[0177] According to the above configuration, the terminal 20 can reduce the probability of transmission collision when selecting random resources without monitoring. In other words, in inter-terminal direct communication, the reliability of communication during autonomous resource selection can be improved.

[0178] The control unit can randomly select resources without monitoring based on the priority set for the transmission or the priority set for the resources. According to this structure, the terminal 20 can reduce the probability of transmission collision when randomly selecting resources without monitoring based on priority.

[0179] The control unit may randomly select a resource without monitoring when the resource is a predetermined specific resource. According to this configuration, the terminal 20 can reduce the probability of transmission collision when randomly selecting a resource without monitoring.

[0180] The control unit may randomly select resources without monitoring when the transmission frequency is lower than a threshold value. According to this configuration, the terminal 20 can reduce the probability of transmission collision when randomly selecting resources without monitoring.

[0181] The control unit may randomly select resources without monitoring when the transmission is of a predetermined type. With this configuration, the terminal 20 can reduce the probability of transmission collisions when randomly selecting resources without monitoring according to the transmission type.

[0182] In addition, according to an embodiment of the present invention, a communication method is provided, wherein the terminal performs the following steps: a control step, in which resources are randomly selected in a resource pool set with random selection according to specific conditions without monitoring; and a sending step, in which the resources are used for sending.

[0183] According to the above configuration, the terminal 20 can reduce the probability of transmission collision when selecting random resources without monitoring. In other words, in inter-terminal direct communication, the reliability of communication during autonomous resource selection can be improved.

[0184] (Supplementary Implementation Methods)

[0185] The above describes the embodiments of the present invention, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, substitutions, and replacements. Specific numerical examples are used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate value may be used. The distinction between the items in the above description is not essential to the present invention. Matters recorded in two or more items may be combined and used as needed, and matters recorded in one item may be applied to matters recorded in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. The actions of multiple functional units may be performed by one physical component, or the actions of one functional unit may be performed by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing may be reversed if there is no contradiction. For the convenience of explaining the processing, the base station 10 and the terminal 20 are described using functional block diagrams, but such devices may also be implemented using hardware, software, or a combination thereof. The software that operates by the processor of the base station 10 according to the embodiment of the present invention and the software that operates by the processor of the terminal 20 according to the embodiment of the present invention can also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server and any other appropriate storage medium.

[0186] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information can be implemented through physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), high-layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals or a combination thereof. In addition, RRC signaling may also be referred to as an RRC message, for example, it may also be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0187] Each form / embodiment described in this disclosure may also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems derived therefrom. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G) may also be applied.

[0188] The processing procedures, timings, and flows of each form / implementation described in this specification may be performed in a different order unless there is a conflict. For example, the methods described in this disclosure use an illustrative order to present the elements of various steps, but are not limited to the specific order presented.

[0189] In this specification, specific operations performed by base station 10 may also be performed by its upper node depending on the situation. In a network consisting of one or more network nodes including base station 10, various operations performed to communicate with terminal 20 can be performed by at least one of base station 10 and other network nodes other than base station 10 (e.g., MME or S-GW, but not limited to these). While the above example illustrates a single other network node other than base station 10, the other network node may also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0190] The information or signals described in this disclosure can be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), and can also be input or output via multiple network nodes.

[0191] Input or output information can be stored in a specific location (e.g., memory) or managed using a management table. Input or output information can be overwritten, updated, or appended. Output information can also be deleted. Input information can also be sent to other devices.

[0192] The determination in the present disclosure may be performed using a value represented by one bit (0 or 1), a Boolean value (Boolean: true or false), or a comparison of numerical values ​​(for example, comparison with a predetermined value).

[0193] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to instructions, sets of instructions, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0194] Furthermore, software, commands, information, and the like may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of a wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and a wireless technology (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0195] The information, signals, etc. described in this disclosure may also be represented using any of a variety of different technologies. For example, data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be referred to in the entire description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0196] In addition, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0197] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0198] In addition, the information, parameters, etc. described in this disclosure may be represented by absolute values, relative values ​​relative to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0199] The names used for the above parameters are not limiting in any way. Furthermore, the formulas and the like using these parameters may sometimes differ from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting in any way.

[0200] In this disclosure, terms such as "base station (BS)," "wireless base station," "base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" are used interchangeably. Base stations are sometimes also referred to as macrocells, small cells, femtocells, and picocells.

[0201] A base station can accommodate one or more (for example, three) cells. When a base station accommodates multiple cells, the base station's overall coverage area can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (for example, a small base station for indoor use (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a portion or the entire coverage area of ​​at least one of the base station and base station subsystem that provide communication services within the coverage area.

[0202] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0203] For mobile stations, those skilled in the art sometimes also use the following terms to refer to them: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client or some other appropriate terms.

[0204] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a means of transportation (e.g., a car, an airplane, etc.), a mobile body that moves unmanned (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0205] In addition, the base station in the present disclosure can also be replaced by a user terminal. For example, regarding a structure in which the communication between the base station and the user terminal is replaced by the communication between multiple terminals 20 (for example, it can also be called D2D (Device-to-Device: device to device), V2X (Vehicle-to-Everything: vehicle to everything system), etc.), the various forms / implementations of the present disclosure can also be applied. In this case, it can also be set as a structure in which the terminal 20 has the functions of the above-mentioned base station 10. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (such as "side"). For example, uplink channels, downlink channels, etc. can also be replaced by side channels.

[0206] Likewise, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station may also have the functions of the user terminal described above.

[0207] As used in this disclosure, terms such as “determining” and “determining” sometimes also include a variety of actions. “Determining” and “judging” may, for example, include considering matters such as judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (for example, searching in a table, database or other data structure), and ascertaining as matters that have been “determined” or “determined”. In addition, “determining” and “receiving” (for example, receiving information), transmitting (for example, sending information), inputting, outputting, accessing (for example, accessing data in a memory) as matters that have been “determined” or “determined”. In addition, “determining” and “resolving” may include matters such as selecting, choosing, establishing, and comparing as matters that have been “determined” or “determined”. That is, "judgment" and "decision" can include matters that are considered to have "judged" or "decided" any action. In addition, "judgment (decision)" can also be replaced by "assuming (assuming)," "expecting (expecting)", "considering (considering)" and the like.

[0208] The terms "connected", "coupled" or any variation of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include situations where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used instead of "connection". As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the wireless frequency domain, microwave region and optical (visible and invisible) region may be used to "connect" or "couple" to each other.

[0209] The reference signal may be referred to as RS (Reference Signal) for short, or may be called a pilot signal depending on the applied standard.

[0210] The phrase "according to" used in this disclosure does not mean "only according to" unless otherwise expressly stated. In other words, the phrase "according to" means both "only according to" and "at least according to."

[0211] Any reference to an element using the terms "first," "second," etc., as used in this disclosure, does not necessarily limit the number or order of these elements. These terms can be used as a convenient way to distinguish between two or more elements in this disclosure. Therefore, a reference to a first element and a second element does not imply that only two elements can be used or that the first element must precede the second element in any manner.

[0212] The “unit” in the configuration of each of the above-mentioned devices may be replaced with a “section,” “circuit,” “device,” or the like.

[0213] When the terms "include," "including," and variations thereof are used in this disclosure, these terms, like the term "comprising," are intended to be inclusive. Furthermore, the term "or" used in this disclosure does not mean an exclusive or.

[0214] A radio frame can be composed of one or more frames in the time domain. In the time domain, one or more frames can be called a subframe. A subframe can be further composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) that is independent of the numerology.

[0215] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a signal or channel. For example, the parameter set may represent at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by the transceiver in the frequency domain, specific windowing performed by the transceiver in the time domain, and the like.

[0216] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0217] A time slot may contain multiple mini-slots. Each mini-slot may consist of one or more symbols in the time domain. Furthermore, a mini-slot may also be referred to as a sub-slot. A mini-slot may consist of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in time units larger than a mini-slot may be referred to as PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as PDSCH (or PUSCH) mapping type B.

[0218] Radio frame, subframe, time slot, mini-time slot, and symbol all represent time units for signal transmission. Radio frame, subframe, time slot, mini-time slot, and symbol may be referred to by other corresponding names.

[0219] For example, a subframe can also be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and a slot or a mini-slot can also be called a TTI. That is, at least one of a subframe and a TTI can be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. Furthermore, the unit representing a TTI may be called a slot, a mini-slot, or the like, rather than a subframe.

[0220] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communications. For example, in the LTE system, a base station schedules each terminal 20 by allocating wireless resources (such as the frequency bandwidth and transmit power available to each terminal 20) in units of TTI. The definition of TTI is not limited to this.

[0221] The TTI can be the time unit for transmitting data packets (transport blocks), code blocks, code words, etc. after channel coding, and can also be the processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the time interval (for example, the number of symbols) to which the transport blocks, code blocks, code words, etc. are actually mapped can be shorter than the TTI.

[0222] In addition, when one time slot or one mini-time slot is referred to as a TTI, one or more TTIs (i.e., one or more time slots or one or more mini-time slots) can constitute the minimum time unit for scheduling. In addition, the number of time slots (the number of mini-time slots) constituting the minimum time unit for scheduling can be controlled.

[0223] A TTI with a time length of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a time slot, etc.

[0224] In addition, for long TTI (for example, normal TTI, subframe, etc.), it can be replaced with a TTI with a time length of more than 1ms, and for short TTI (for example, shortened TTI, etc.), it can be replaced with a TTI length that is smaller than long TTI (longTTI) and has a TTI length of more than 1ms.

[0225] A resource block (RB) is a unit of resource allocation in the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers contained in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers contained in an RB can also be determined by the parameter set.

[0226] In addition, the time domain of an RB may include one or more symbols and may be the length of one slot, one mini-slot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0227] In addition, one or more RBs may be referred to as a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, and the like.

[0228] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0229] A bandwidth part (BWP) (also known as a fractional bandwidth) can represent a subset of contiguous common resource blocks (RBs) used for a parameter set within a carrier. Common RBs can be identified by their index relative to the common reference point of the carrier. PRBs can be defined within a BWP and numbered within that BWP.

[0230] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for the terminal 20 within one carrier.

[0231] At least one of the set BWPs may be active, and it is not assumed that the terminal 20 transmits or receives predetermined signals / channels outside the active BWP. In addition, "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

[0232] The above-described structures of radio frames, subframes, slots, mini-slots, and symbols are merely examples. For example, various modifications may be made to the structures, such as the number of subframes in a radio frame, the number of slots per subframe or radio frame, the number of mini-slots in a slot, the number of symbols and RBs in a slot or mini-slot, the number of subcarriers in an RB, the number of symbols in a TTI, the symbol length, and the cyclic prefix (CP) length.

[0233] In the present disclosure, when an article is added by translation, such as a, an, and the in English, the present disclosure may also include cases where the noun following the article is in a plural form.

[0234] In this disclosure, the phrase "A is different from B" may also mean "A and B are different from each other." Alternatively, the phrase may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

[0235] Each form / implementation described in this disclosure may be used individually or in combination, and may be switched between them depending on the execution. Furthermore, notification of scheduled information is not limited to being performed explicitly (e.g., a notification of "yes X") but may also be performed implicitly (e.g., not notifying the scheduled information).

[0236] While the present disclosure has been described in detail above, it should be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in various modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes only and does not have any limiting meaning on the present disclosure.

[0237] Label Description

[0238] 10: base station;

[0239] 110: Sending department;

[0240] 120: receiving unit;

[0241] 130: Setting department;

[0242] 140: Control Department;

[0243] 20: terminal;

[0244] 210: Sending department;

[0245] 220: receiving unit;

[0246] 230: Setting department;

[0247] 240: Control Department;

[0248] 1001: processor;

[0249] 1002: storage device;

[0250] 1003: auxiliary storage device;

[0251] 1004: Communication device;

[0252] 1005: input device;

[0253] 1006: Output device.

Claims

1. A terminal comprising: a control unit that randomly selects resources from a resource pool set to be randomly selected, without performing monitoring, according to specific conditions; and a sending unit, which uses the resource to send, The control unit randomly selects a resource from among the resources for which the priority of the resource is set, without monitoring, when the priority of the transmission is higher than the priority of the resource, based on the priority of the resource set for each time and / or frequency resource.

2. The terminal according to claim 1, wherein When the resource is a predetermined specific resource, the control unit randomly selects a resource without performing monitoring.

3. The terminal according to claim 1, wherein: When the transmission frequency is lower than a threshold value, the control unit randomly selects a resource without performing monitoring. The terminal according to claim 1 , wherein: When the transmission is of a predetermined type, the control unit randomly selects a resource without performing monitoring.

5. A communication method performed by a terminal, wherein: The communication method comprises the following steps: A control step of randomly selecting resources from a resource pool configured for random selection without monitoring according to specific conditions; and a sending step, using the resource to send, In the control step, based on the priority of the resource set according to each time and / or frequency resource, in the case of a transmission with a priority higher than the priority of the resource, a resource is randomly selected from the resources with the priority of the resource set without monitoring.

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