Terminal and communication method

Abstract

The terminal has a reception section that receives information on inter-terminal direct communication for avoiding collision of resources from other terminals, a control section that identifies a candidate of resources and selects a resource to be used in accordance with the information, and a transmission section that performs transmission in inter-terminal direct communication using the selected resource.

Description

Technical Field

[0001] This invention relates to terminals and communication methods in wireless communication systems. Background Technology

[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 enables direct communication between terminals without going through a base station, is being researched (e.g., non-patent literature 1).

[0003] D2D reduces the traffic load between terminals and base stations, enabling communication between terminals even when base stations cannot communicate, such as during disasters. Furthermore, in 3GPP (3rd Generation Partnership Project), D2D is referred to as a "sidelink," but in this specification, the more general term D2D is used. However, in the description of the implementation methods described later, "sidelink" may also be used as needed.

[0004] D2D communication can be broadly divided into D2D discovery (also known as D2D discovery), used to discover other terminals capable of communication, and D2D direct communication (also known as D2D communication, direct communication between terminals, etc.), used for direct communication between terminals. Hereinafter, without specifically distinguishing between D2D communication and D2D discovery, it will be simply referred to as D2D. Furthermore, signals sent and received via D2D are referred to as D2D signals. Various use cases related to V2X (Vehicle to Everything) services in NR are being investigated (e.g., non-patent literature 2).

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent document 1: 3GPP TS 38.211V16.0.0 (2019-12)

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

[0009] The problem that the invention aims to solve

[0010] Imagine a scenario where, in direct communication between terminals, one terminal receives information from other terminals, such as information about resources to be used, and performs resource selection based on that information, thereby improving communication quality. However, the details of the information to be shared between terminals and the methods for using that information to improve communication quality are still unclear.

[0011] The present invention was made in view of the above, and its object is to improve the communication quality in direct communication between terminals based on information notified from other terminals.

[0012] Methods for solving problems

[0013] According to the disclosed technology, a terminal is provided, comprising: a receiving unit that receives information related to direct inter-terminal communication for avoiding resource conflicts from other terminals; a control unit that identifies candidate resources and selects the resource to be used based on the information; and a transmitting unit that uses the selected resource to perform transmission in direct inter-terminal communication.

[0014] Invention Effects

[0015] According to publicly available technology, in direct communication between terminals, communication quality can be improved based on information notified from other terminals. Attached Figure Description

[0016] Figure 1 This is a diagram used to illustrate V2X.

[0017] Figure 2 This is a diagram used to illustrate the transmission mode of V2X (1).

[0018] Figure 3 This is a diagram used to illustrate the transmission mode of V2X (2).

[0019] Figure 4 This is a diagram used to illustrate the transmission mode of V2X (3).

[0020] Figure 5 This is a diagram used to illustrate the transmission mode of V2X (4).

[0021] Figure 6 This is a diagram used to illustrate the transmission mode of V2X (5).

[0022] Figure 7 This is a diagram illustrating example (1) of the communication types in V2X.

[0023] Figure 8 This is a diagram used to illustrate example (2) of the V2X communication type.

[0024] Figure 9 This is a diagram used to illustrate the communication type of V2X (3).

[0025] Figure 10 This is a timing diagram showing the action example (1) of V2X.

[0026] Figure 11 This is a timing diagram showing the action example (2) of V2X.

[0027] Figure 12 This is a timing diagram showing the action example (3) of V2X.

[0028] Figure 13 This is a timing diagram showing the action example (4) of V2X.

[0029] Figure 14 This is a diagram illustrating an example (1) of information related to a synchronization source in an embodiment of the present invention.

[0030] Figure 15 This is a diagram illustrating example (2) of information related to the synchronization source in an embodiment of the present invention.

[0031] Figure 16 This is a diagram illustrating an example (1) of information related to HARQ response in an embodiment of the present invention.

[0032] Figure 17 This is a diagram illustrating an example (2) of information related to HARQ response in an embodiment of the present invention.

[0033] Figure 18 This is a diagram illustrating an example (1) of information related to transmission power reduction in an embodiment of the present invention.

[0034] Figure 19 This is a diagram illustrating an example (1) of information related to transmission power reduction in an embodiment of the present invention.

[0035] Figure 20 This is a diagram illustrating an example of information related to unused resources in an embodiment of the present invention.

[0036] Figure 21 This is a diagram illustrating an example of the functional structure of base station 10 in an embodiment of the present invention.

[0037] Figure 22 This is a diagram illustrating an example of the functional structure of terminal 20 in an embodiment of the present invention.

[0038] Figure 23 This is a diagram illustrating an example of the hardware structure of a base station 10 or a terminal 20 in an embodiment of the present invention. Detailed Implementation

[0039] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are merely examples, and the application of the present invention is not limited to the following embodiments.

[0040] When the wireless communication system according to the embodiments of the present invention is in operation, existing technologies are appropriately used. However, such existing technologies are, for example, existing LTE, but are not limited to existing LTE. Furthermore, unless otherwise stated, the term "LTE" as used in this specification has a broad meaning that includes LTE-Advanced and LTE-Advanced and later methods (e.g., NR) or wireless LAN (Local Area Network).

[0041] Furthermore, in embodiments of the present invention, the duplex mode can be TDD (Time Division Duplex), FDD (Frequency Division Duplex), or other modes (e.g., Flexible Duplex).

[0042] Furthermore, in embodiments of the present invention, the "configure" wireless parameters can be pre-configured predetermined values, or wireless parameters notified from base station 10 or terminal 20, or pre-defined according to specifications.

[0043] Figure 1 This diagram illustrates V2X. Within 3GPP, technologies for implementing V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality are being researched and standardized. Figure 1As shown, V2X is a part of ITS (Intelligent Transport Systems). It is a collective term for V2V (Vehicle to Vehicle), V2I (Vehicle to Infrastructure), V2N (Vehicle to Network), and V2P (Vehicle to Pedestrian), which are communication forms between vehicles, roadside units (RSUs) located beside the road.

[0044] Furthermore, 3GPP is researching V2X using LTE or NR cellular communication and inter-terminal communication. V2X using cellular communication is also referred to as cellular V2X. In NR V2X, research is underway to achieve high capacity, low latency, high reliability, and QoS (Quality of Service) control.

[0045] Regarding V2X for LTE or NR, it is envisioned that future research could be advanced beyond 3GPP specifications. For example, research is envisioned on ensuring interoperability, reducing costs incurred due to higher-level installations, methods for the concurrent use or handover of multiple RATs (Radio Access Technologies), regulatory support in various countries, and methods for data acquisition, distribution, database management, and usage on LTE or NR V2X platforms.

[0046] In the embodiments of the present invention, the communication device is primarily envisioned to be mounted on a vehicle, but the embodiments of the present invention are not limited to this method. For example, the communication device can be a terminal held by a person, a device mounted on a drone or aircraft, or a base station, RSU, relay station (Relay Node), terminal with scheduling capabilities, etc.

[0047] Additionally, SL (Sidelink) can also be distinguished by UL (Uplink) or DL ​​(Downlink) and any one or a combination of 1)-4) below. Furthermore, SL can also be other names.

[0048] 1) Resource allocation in the time domain

[0049] 2) Frequency domain resource allocation

[0050] 3) Reference synchronization signals (including SLSS (Sidelink Synchronization Signal))

[0051] 4) Reference signal used in path loss measurement for transmission power control

[0052] In addition, for SL or UL OFDM (Orthogonal Frequency Division Multiplexing), any of the following can be used: CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding.

[0053] In LTE's SL (Send-On) architecture, two modes, Mode 3 and Mode 4, are specified for 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. Furthermore, SPS (Semi-Persistent Scheduling) is also possible in Mode 3. In Mode 4, terminal 20 autonomously selects transmission resources from the resource pool.

[0054] In addition, the slot in the embodiments of the present invention can also be replaced by symbol, mini slot, subframe, radio frame, or TTI (Transmission Time Interval). Furthermore, the cell in the embodiments of the present invention can also be replaced by cell group, carrier component, BWP, resource pool, resource, RAT (Radio Access Technology), system (including wireless LAN), etc.

[0055] Furthermore, in embodiments of the present invention, terminal 20 is not limited to a V2X terminal, but can be any type of terminal performing D2D communication. For example, terminal 20 can be a user-owned terminal such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0056] Figure 2 This is a diagram used to illustrate example (1) of the V2X transmission mode. In Figure 2 In the sidelink communication transmission mode shown, in step 1, base station 10 sends sidelink scheduling information to terminal 20A. Then, terminal 20A, based on the received scheduling information, sends PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to terminal 20B (step 2). Alternatively... Figure 2 The sidelink communication transmission mode shown is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 of LTE, sidelink scheduling is performed based on Uu. Uu refers to the radio interface between the UTRAN (Universal Terrestrial Radio Access Network) and the UE (User Equipment). Alternatively, it can also be... Figure 2 The sidelink communication transmission mode shown is called sidelink transmission mode 1 in NR.

[0057] Figure 3 This is a diagram illustrating example (2) of the V2X transmission mode. In Figure 3 In the side-link communication transmission mode shown, in step 1, terminal 20A uses autonomously selected resources to send PSCCH and PSSCH to terminal 20B. Alternatively... Figure 3 The sidelink communication transmission mode shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0058] Figure 4 This is a diagram used to illustrate example (3) of the V2X transmission mode. In Figure 4 In the side-link communication transmission mode shown, in step 1, terminal 20A uses autonomously selected resources to send PSCCH and PSSCH to terminal 20B. Similarly, terminal 20B uses autonomously selected resources to send PSCCH and PSSCH to terminal 20A (step 1). Alternatively... Figure 4 The sidelink communication transmission mode shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2a in NR, terminal 20 performs resource selection itself. In NR, the mode in which terminal 20 selects resources for sidelink transmission can also be called resource allocation mode 2.

[0059] Figure 5This is a diagram used to illustrate example (4) of the V2X transmission mode. In Figure 5 In the sidelink communication transmission mode shown, in step 0, base station 10 sends a sidelink grant to terminal 20A via RRC (Radio Resource Control). Then, terminal 20A sends a PSSCH to terminal 20B according to the received resource mode (step 1). Alternatively... Figure 5 The sidelink communication transmission mode shown is called sidelink transmission mode 2c in NR.

[0060] Figure 6 This is a diagram used to illustrate example (5) of the V2X transmission mode. In Figure 6 In the sidelink communication transmission mode shown, in step 1, terminal 20A sends information related to sidelink scheduling to terminal 20B via PSCCH. Then, terminal 20B sends PSSCH to terminal 20A based on the received scheduling information (step 2). Alternatively... Figure 6 The sidelink communication transmission mode shown is called sidelink transmission mode 2d in NR. In NR, the mode in which base station 10 allocates resources to terminal 20 and performs sidelink transmission can also be called resource allocation mode 1.

[0061] Figure 7 This is a diagram illustrating example (1) of the communication types in V2X. 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, terminal 20A unicasts to terminal 20B and unicasts to terminal 20C.

[0062] Figure 8 This is a diagram used to illustrate example (2) of the V2X communication type. Figure 8 The sidelink communication type 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 terminal 20B and terminal 20C, and terminal 20A multicasts to the group.

[0063] Figure 9 This is a diagram used to illustrate the communication type of V2X (3). 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 terminals 20B, 20C, and 20D. Alternatively, it can also... Figures 7-9 The terminal 20A shown is called the header UE.

[0064] Furthermore, NR-V2X envisions supporting HARQ (Hybrid Automatic Repeat Request) in unicast and multicast on sidelinks. Additionally, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Moreover, the transmission of SFCI via PSFCH (Physical Sidelink Feedback Channel) is under investigation.

[0065] Furthermore, in the following description, it is assumed that PSFCH is used for HARQ-ACK transmission in the side link, but this is only one example. For example, PSCCH, PSSCH, and other channels can be used for HARQ-ACK transmission in the side link.

[0066] For ease of explanation, all information reported by terminal 20 in HARQ will be referred to as HARQ-ACK. This HARQ-ACK can also be called HARQ-ACK information. More specifically, the codebook used for the HARQ-ACK information reported from terminal 20 to base station 10, etc., is called the HARQ-ACK codebook. The HARQ-ACK codebook specifies the bit string of the HARQ-ACK information. In addition to ACK, NACK is also sent using "HARQ-ACK".

[0067] Figure 10 This is a timing diagram illustrating the action example (1) of V2X. For example... Figure 10 As shown, the wireless communication system of this embodiment of the invention can have terminal 20A and terminal 20B. In addition, multiple user devices are actually present, but... Figure 10 Terminals 20A and 20B are shown as examples.

[0068] Hereinafter, without specifically distinguishing between terminals 20A, 20B, etc., they will simply be referred to as "Terminal 20" or "User Equipment". Figure 10 As an example, the example shows a situation where both terminal 20A and terminal 20B are within the coverage area of ​​the cell. However, the actions in this embodiment of the invention can also be applied to situations where terminal 20B is outside the coverage area.

[0069] As described above, in this embodiment, terminal 20 is, for example, a device mounted in a vehicle such as an automobile, and has cellular communication functions as a UE in LTE or NR, as well as sidelink functions. Terminal 20 can also be a general portable terminal (such as a smartphone). Furthermore, terminal 20 can also be an RSU. This RSU can be a UE-type RSU with UE functions, or a gNB-type RSU with base station functions.

[0070] In addition, the terminal 20 does not need to be a device with a housing. For example, even if various sensors are distributed throughout the vehicle, the device including these various sensors can also be the terminal 20.

[0071] Furthermore, the processing of data transmitted via the sidelink of terminal 20 is essentially the same as that of UL transmission in LTE or NR. For example, terminal 20 scrambles and modulates the codewords of the transmitted data to generate complex-valued symbols, maps these complex-valued symbols (transmitted signals) to layer 1 or layer 2, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate a transmitted signal (e.g., complex-valued time-domain SC-FDMA signal) and transmitted from each antenna port.

[0072] Furthermore, regarding base station 10, it has cellular communication functions as a base station in LTE or NR, and functions for enabling terminal 20 in this embodiment to communicate (e.g., resource pool setting, resource allocation, etc.). Additionally, base station 10 can also be an RSU (gNB type RSU).

[0073] Furthermore, in the wireless communication system of the present invention, the signal waveform used by the terminal 20 in SL or UL can be OFDMA, SC-FDMA, or other signal waveforms.

[0074] In step S101, terminal 20A autonomously selects the resources to be used in PSCCH and PSSCH from a resource selection window with a predetermined period. The resource selection window can also be set by base station 10 for terminal 20.

[0075] In steps S102 and S103, terminal 20A uses the resources autonomously selected in step S101 to transmit SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and also transmits SL data using PSSCH. For example, terminal 20A can transmit PSCCH using frequency resources adjacent to the frequency resources of PSSCH within at least a portion of the time resources that are the same as the time resources of PSSCH.

[0076] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from terminal 20A. The received SCI may contain information about the resources used by terminal 20B to send a HARQ-ACK for the received data via PSFCH. Terminal 20A may include information about resources it autonomously selects in the SCI and send it.

[0077] In step S104, terminal 20B uses the resources of PSFCH determined by the received SCI to send HARQ-ACK for the received data to terminal 20A.

[0078] If the HARQ-ACK received in step S104 is a NACK (negative acknowledgment) indicating a request for retransmission, then in step S105, terminal 20A retransmits the PSCCH and PSSCH to terminal 20B. Terminal 20A may use resources it autonomously selects to retransmit the PSCCH and PSSCH.

[0079] Alternatively, steps S104 and S105 can be omitted if HARQ control is not performed.

[0080] Figure 11 This is a timing diagram illustrating a V2X action example (2). Blind retransmissions can also be performed, independent of HARQ control used to improve transmission success rate or arrival distance.

[0081] In step S201, terminal 20A autonomously selects the resources to be used in PSCCH and PSSCH from a resource selection window with a predetermined period. The resource selection window can also be set by base station 10 for terminal 20.

[0082] In steps S202 and S203, terminal 20A uses the resources autonomously selected in step S201 to transmit SCI using PSCCH and / or PSSCH, and transmit SL data using PSSCH. For example, terminal 20A can transmit PSCCH using frequency resources adjacent to the frequency resources of PSSCH in at least a portion of the time resources that are the same as the time resources of PSSCH.

[0083] In step S204, terminal 20A uses the resources autonomously selected in step S201 to retransmit SCI data based on PSCCH and / or PSSCH and SL data based on PSSCH to terminal 20B. The retransmission in step S204 can be performed multiple times.

[0084] Alternatively, step S204 can be omitted if blind retransmission is not performed.

[0085] Figure 12 This is a timing diagram illustrating an example of V2X operation (3). Base station 10 can perform sidelink scheduling. That is, base station 10 can determine the resources of the sidelink used by terminal 20 and send information representing those resources to terminal 20. Furthermore, when HARQ control is applied, base station 10 can send information representing the resources of the PSFCH to terminal 20.

[0086] In step S301, base station 10 uses PDCCH to send DCI (Downlink Control Information) to terminal 20A, thereby performing SL scheduling. For ease of explanation, the DCI used for SL scheduling will be referred to as SL scheduling DCI.

[0087] Furthermore, the following scenario is envisioned: In step S301, base station 10 also sends a DCI for DL ​​scheduling (also known as DL allocation) to terminal 20A using PDCCH. For ease of explanation, the DCI for DL ​​scheduling will be referred to as DL scheduling DCI. Terminal 20A, upon receiving the DL scheduling DCI, uses the resources specified by the DL scheduling DCI to receive DL data using PDSCH.

[0088] In steps S302 and S303, terminal 20A uses the resources specified by the SL scheduling DCI to transmit SCI (Sidelink Control Information) using PSCCH and / or PSSCH, and also transmits SL data using PSSCH. Alternatively, the SL scheduling DCI may specify only the resources for PSSCH. In this case, for example, terminal 20A may transmit PSCCH using frequency resources adjacent to the frequency resources of PSSCH, within at least a portion of the time resources that are identical to the time resources of PSSCH.

[0089] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) sent from terminal 20A. The SCI received using PSCCH and / or PSSCH contains information about the resources of PSFCH for terminal 20B to send HARQ-ACK for the received data.

[0090] The information about the resource is included in the DL scheduling DCI or SL scheduling DCI sent from base station 10 in step S301. Terminal 20A obtains the information about the resource from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, assuming that the DCI sent from base station 10 does not contain the information about the resource, terminal 20A autonomously includes the information about the resource in the SCI and sends it.

[0091] In step S304, terminal 20B uses the resources of PSFCH determined by the received SCI to send HARQ-ACK for the received data to terminal 20A.

[0092] In step S305, terminal 20A, for example, at a timing specified by the DL scheduling DCI (or SL scheduling DCI) (e.g., timing in time slots), uses the PUCCH (Physical uplink control channel) resources specified by the DL scheduling DCI (or the SL scheduling DCI) to send a HARQ-ACK, and base station 10 receives the HARQ-ACK. The codebook of this HARQ-ACK may contain the HARQ-ACK received from terminal 20B, or an HARQ-ACK generated based on an unreceived PSFCH, and a HARQ-ACK for DL ​​data. However, in cases where no DL data is allocated, etc., it does not contain a HARQ-ACK for DL ​​data. In Rel. 16 of NR, the codebook of this HARQ-ACK does not contain a HARQ-ACK for DL ​​data.

[0093] Alternatively, steps S304 and S305 can be omitted if HARQ control is not performed.

[0094] Figure 13 This is a timing diagram illustrating a V2X operation example (4). As described above, the transmission of HARQ responses via PSFCH is supported in the NR side link. Furthermore, the PSFCH format can, for example, be the same as PUCCH (Physical Uplink Control Channel) format 0. That is, the PSFCH format can be a sequence-based format where the PRB (Physical Resource Block) size is 1, and ACK and NACK are identified based on sequence differences. The PSFCH format is not limited to this. PSFCH resources can be configured in symbols at the end of a time slot or multiple symbols at the end. Furthermore, a period N is set or predefined for the PSFCH resources. The period N can be set or predefined in units of time slots.

[0095] exist Figure 13 In the diagram, the vertical axis corresponds to the frequency domain, and the horizontal axis corresponds to the time domain. The PSCCH can be configured with one symbol at the beginning of a time slot, or with multiple symbols starting from the beginning, or with multiple symbols starting from symbols other than the beginning. The PSFCH can be configured with one symbol at the end of a time slot, or with multiple symbols at the end of a time slot. Figure 13 In the example shown, three sub-channels are configured in the resource pool, and two PSFCHs are configured after the three time slots configured with PSSCHs. The arrows from PSSCH to PSFCHs indicate an example of a PSFCH associated with a PSSCH.

[0096] In NR-V2X multicast, where the HARQ response is option 2 (either ACK or NACK), the resources used for PSFCH transmission and reception need to be determined. For example... Figure 13 As shown, in step S401, terminal 20A, acting as the transmitting terminal 20, performs multicast to terminals 20B, 20C, and 20D, acting as the receiving terminal 20, via SL-SCH. In the following step S402, terminal 20B sends a HARQ response to terminal 20A using PSFCH#B, terminal 20C sends a HARQ response to terminal 20A using PSFCH#C, and terminal 20D sends a HARQ response to terminal 20A using PSFCH#D. Here, as... Figure 13As the example illustrates, when the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to decide how to allocate the PSFCH resources. Additionally, the sending terminal 20 can ascertain the number of receiving terminals 20 in the multicast.

[0097] Here, sidelink enhancements are being investigated in future versions (e.g., NR Release 17). For example, regarding power reduction, enhancements are being studied based on random resource selection and partial listening in LTE Release 14. Furthermore, enhancements are being studied, for example, as enhanced Ultra-Reliable and Low-Latency Communications (URLLC), based on inter-UE coordination in the NR sidelink research phase. As an example of inter-UE coordination, terminal 20A and terminal 20B share a resource set, and terminal 20B can consider this resource set in resource selection.

[0098] It is believed that by sending various information from terminal 20A to terminal 20B, and having terminal 20B act accordingly, communication quality can be improved. That is, it is believed that sharing not only resource sets but also other information among the terminals 20 is effective. However, it is unclear what kind of information should be shared among the terminals 20. Furthermore, it is unclear how the information shared among the terminals 20 should be used.

[0099] Therefore, terminal 20A can send at least one of the following information A)-D) to terminal 20B.

[0100] A) Information related to the synchronization source

[0101] B) Information related to scheduled PSFCH transmission and reception opportunities.

[0102] C) Information related to transmit power reduction due to in-device coexistence

[0103] D) Information relating to reserved but unused resources

[0104] Here, terminal 20B can be a single terminal 20 or multiple terminals 20. That is, terminal 20A can multicast the above information, and terminal 20A can also broadcast the above information. The "intra-device coexistence" in C) above can correspond to the case where multiple channels in terminal 20A overlap at least in the time domain.

[0105] Furthermore, terminal 20A can perform resource selection for terminal 20B based on at least one of A)-D) above.

[0106] By implementing resource selection that utilizes the additional information shown in A)-D) above, higher reliability or communication quality can be ensured.

[0107] Figure 14 This is a diagram illustrating an example (1) of information related to the synchronization source in an embodiment of the present invention. The information related to the synchronization source in A) above can be based on S-SSB (Sidelink-SS / PBCH block) information received by terminal 20. S-SSB refers to a signal containing synchronization signals and broadcast information in the sidelink transmitted by terminal 20. Additionally, S-SSB_TX indicates that an S-SSB signal has been transmitted.

[0108] like Figure 14 As shown, terminal 20A receives S-SSB_TX(i) from terminal 20C. On the other hand, terminal 20A sets the S-SSB_TX received from terminal 20B as a synchronization source. Here, terminal 20A can send information related to S-SSB_TX(i) received from terminal 20C, which is a synchronization source other than the one currently in use, to terminal 20B. For example, the information related to S-SSB_TX(i) could be the RSRP (Reference Signal Received Power) value. Furthermore, for example, the information related to S-SSB_TX(i) could also be the time difference (e.g., Xms) between the S-SSB_TX from terminal 20B, which is the synchronization source currently in use, and the S-SSB_TX(i) from terminal 20C, which is a synchronization source that has not been standardized.

[0109] In addition, terminal 20A can also send the RSRP value of S-SSB_TX received from terminal 20B, which is set as the synchronization source, to terminal 20B.

[0110] in addition, Figure 14Examples of synchronization source priorities are shown. Base station 10, the highest priority gNB / eNB, corresponds to priority P0. Terminal 20D, the second highest priority UE directly synchronized with the gNB / eNB, corresponds to priority P1. Terminal 20B, with an even higher priority and indirect synchronization with the gNB / eNB, corresponds to priority P2. GNSS 30, with an even higher priority, corresponds to priority P3. Terminal 20E, a UE directly synchronized with the GNSS, corresponds to priority P4. Terminal 20F, a UE indirectly synchronized with the GNSS, corresponds to priority P5. Terminals 20A, 20C, and 20G, the lowest priority UEs, correspond to priority P6.

[0111] Figure 15 This is a diagram illustrating example (2) of information related to the synchronization source in an embodiment of the present invention. Figure 14 The terminal 20B shown can also perform resource allocation actions based on the information related to S-SSB sent by terminal 20C and received from terminal 20A.

[0112] For example, terminal 20B can also decode the SCI in PSCCH / PSSCH and perform listening based on the S-SSB-related information received from terminal 20A and sent by terminal 20C.

[0113] In addition, for example, such as Figure 15 As shown, the time difference of the synchronization source can be calculated based on the S-SSB-related information received from terminal 20C and received from terminal 20A. This time difference can correspond to the time difference between the resource pool based on the synchronization source-related information received from other UEs and the resource pool based on the synchronization source in use. Terminal 20B can detect power based on the aforementioned synchronization source time difference. For example, if a power change exceeding a predetermined value is detected by monitoring the aforementioned synchronization source time difference, terminal 20B can determine that some transmissions exist regardless of the success or failure of SCI decoding.

[0114] Terminal 20B can identify resources based on the time difference of the aforementioned synchronization source, determine unusable resources, and exclude them from the candidate resource group that is expected to be usable. For example, terminal 20B can exclude resources determined based on the time resource assignment field and / or resource reservation period field of the decoded SCI from the candidate resource group that is expected to be usable. Furthermore, for example, if it is determined that a transmission exists by listening to the time difference of the aforementioned synchronization source, resources determined based on the time resource assignment field and / or resource reservation period field indicated by the transmission can be excluded from the candidate resource group that is expected to be usable.

[0115] Furthermore, for example, terminal 20B can determine whether to suspend transmission based on the time difference and / or power detection of the synchronization sources described above. For example, if terminal 20B detects transmissions based on different synchronization sources, it can suspend sidelink transmissions in the associated resources.

[0116] As described above, by selecting or allocating resources based on information related to the synchronization source obtained from other terminals 20, resources can be selected so as not to conflict with the transmissions of terminals 20 that are operating based on other synchronization sources.

[0117] Figure 16 This is a diagram illustrating an example (1) of information related to HARQ responses in an embodiment of the present invention. The information related to the predetermined PSFCH opportunity described in B) above can be information related to the transmission and reception of PSFCH associated with communication with any terminal. The information related to the PSFCH opportunity can, for example, be information in the time domain and / or frequency domain and / or code domain indicating that a PSFCH opportunity has been set. For example, it can also be the information related to the PSFCH opportunity shown in 1)-4) below.

[0118] 1) PSFCH opportunity corresponding to the PSCCH / PSSCH received by terminal 20

[0119] 2) PSFCH opportunity corresponding to the resource indicated by the time resource allocation field contained in the SCI of the PSCCH / PSSCH received by terminal 20.

[0120] 3) The PSFCH opportunity corresponding to the resource indicated by the resource reservation period field contained in the SCI of the PSCCH / PSSCH received by terminal 20.

[0121] 4) PSFCH opportunities corresponding to resources selected for transmission in terminal 20 (i.e., unreserved resources).

[0122] exist Figure 16 The image shows an example corresponding to 2) above, where terminal 20B notifies terminal 20C of information related to the PSFCH opportunity corresponding to the PSCCH / PSSCH received from terminal 20A. Additionally, Figure 16 The duration of the initial number of symbols for PSCCH / PSSCH shown illustrates an example of the time required for a sidelink transmit / receive switch. For example... Figure 16 As shown, terminal 20A sends a PSCCH / PSSCH to terminal 20B. Information related to the PSFCH opportunities corresponding to the two resources indicated by the time resource allocation field notified to terminal 20B by the PSCCH / PSSCH can be notified from terminal 20B to terminal 20C.

[0123] Furthermore, the priority can be notified together with information related to the PSFCH opportunity or notified independently. This priority can be a priority in the SCI or a higher-layer priority (e.g., the priority of the logical channel associated with the corresponding PSCCH / PSSCH). Additionally, for the PSFCH opportunities shown in 1)-4) above, "receive" can be replaced with "transmit". For example, information related to the PSFCH opportunity corresponding to the PSCCH / PSSCH transmitted by terminal 20 can be notified to other terminals 20. Furthermore, the terminal 20 shown in 1)-4) above can be replaced with any terminal 20. For example, Figure 16 The terminal 20A shown can send information to the terminal 20C related to the scheduled PSFCH opportunity.

[0124] As described above, by notifying other terminals 20 of the information related to PSFCH received or sent by terminal 20, it is possible to predict conflicts between the PSFCH received and sent by the terminal and the PSFCH received and sent by the terminal itself, and to avoid conflicts as needed.

[0125] Figure 17 This is a diagram illustrating example (2) of information related to HARQ responses in an embodiment of the present invention. Terminal 20 can perform resource allocation operations based on information related to PSFCH opportunities received from other terminals. Figure 17 In, such as Figure 16 As shown, assume that terminal 20C receives information from terminal 20B related to the PSFCH opportunity corresponding to the PSCCH / PSSCH sent from terminal 20A to terminal 20B.

[0126] like Figure 17 As shown, terminal 20C performs at least one of the actions shown in 1)-3) below based on the information related to the PSFCH opportunity received from terminal 20B.

[0127] 1) Terminal 20C can determine the PSCCH / PSSCH resources corresponding to the PSFCH opportunity used by terminal 20B and exclude them from the available candidate resource group (i.e., resource selection window). This exclusion can be applied only if terminal 20C intends to retransmit based on HARQ response. Furthermore, it can be applied only if, among the PSFCH opportunities used by terminal 20B, the priority of the PSFCH sent or received by terminal 20B is higher than a specific value. This specific value can, for example, refer to the priority corresponding to a predetermined PSCCH / PSSCH sent by terminal 20C to terminal 20B. Additionally, this exclusion can be applied only if terminal 20C transmits to one or more terminals 20 including terminal 20B. Furthermore, the aforementioned PSFCH opportunity used by terminal 20B can be either a PSFCH opportunity in which terminal 20B can perform PSFCH transmission or a PSFCH opportunity in which terminal 20B can perform PSFCH reception.

[0128] 2) Only when there is a PSFCH opportunity for terminal 20B to send PSFCH, or when the number of PSFCH transmissions in that PSFCH opportunity is more than the predetermined number, or when the number of transmissions exceeds the predetermined number, terminal 20C may decide on the PSCCH / PSSCH resources corresponding to the PSFCH opportunity used by terminal 20B and exclude them from the available candidate resource group (i.e., resource selection window).

[0129] 3) Only when there is a PSFCH opportunity that terminal 20B can receive PSFCH, or when the number of PSFCH received in that PSFCH opportunity is more than the predetermined number, or when the number of PSFCH received is greater than the predetermined number, terminal 20C may decide on the PSCCH / PSSCH resources corresponding to the PSFCH opportunity used by terminal 20B and exclude them from the available candidate resource group (i.e., resource selection window).

[0130] As described above, by notifying other terminals 20 of the information related to PSFCH received or sent by terminal 20, resources other than those that cannot be expected to be sent from the receiving terminal via PSFCH can be selected, thus ensuring HARQ feedback.

[0131] Figure 18This is a diagram illustrating an example (1) of information related to transmission power reduction in an embodiment of the present invention. The information above (C) related to transmission power reduction due to in-device coexistence may be information related to transmission power reduction caused by the overlap of SL transmission and UL transmission in either terminal 20 at least in the time domain. Alternatively, SL transmission and UL transmission may be replaced by a first SL transmission and a second SL transmission, where the first SL transmission may be an SL transmission in NR and the second SL transmission may be an SL transmission in LTE. Hereinafter, SL transmission and UL transmission will be described as examples. For example, information related to transmission power reduction may be the fact that UL transmission takes precedence over SL transmission and the transmission power of SL transmission is reduced. For example, information related to transmission power reduction may be the amount of transmission power reduction when UL transmission takes precedence over SL transmission and the transmission power of SL transmission is reduced. Specific granularity may also be applied to this amount of transmission power reduction.

[0132] like Figure 18 As shown, when the transmission power of an SL transmission is reduced due to a PUSCH transmission that overlaps with an SL transmission reserved through the time resource allocation field in the time domain, the terminal 20 of the SL transmission source can notify the terminal 20 of the SL transmission destination or other terminals 20 of the information related to the transmission power reduction.

[0133] Figure 19 This is a diagram illustrating an example (1) of information related to transmission power reduction in an embodiment of the present invention. For example... Figure 19 As shown, when the transmission power of an SL transmission is reduced due to a UL transmission (PUSCH) that overlaps with the transmitted SL transmission resources in the time domain, the terminal 20 of the SL transmission source can notify the terminal 20 of the SL transmission destination or other terminals 20 of the information related to the reduction in transmission power.

[0134] At least one of the aforementioned UL and SL transmissions can be a transmission scheduled via dynamic grant. Furthermore, at least one of the aforementioned UL and SL transmissions can also be a transmission configured or indicated as semi-persistent. That is, at least one of the aforementioned UL and SL transmissions can also be a transmission scheduled by configured grant type 1 and configured grant type 2.

[0135] As described above, terminal 20 notifies other terminals 20 of information related to the reduction of transmission power, thereby enabling other terminals 20 to grasp a more accurate picture of resource utilization.

[0136] Terminal 20 can perform resource allocation actions based on information received from other terminals 20 related to the reduction in transmission power caused by in-device coexistence.

[0137] As an action based on information relating to the reduction of transmission power from resources reserved in other terminals 20, terminal 20 may perform the actions shown in 1)-3) below.

[0138] 1) In the resource identification process, the resource indicated by the SCI received from other terminals 20 is taken as the object. If the other terminals 20 receive information about the aforementioned power reduction due to coexistence within the device, terminal 20 determines that the resource with reduced power can be used. If the other terminals 20 do not receive information about the aforementioned power reduction due to coexistence within the device, it can be determined that the corresponding resource cannot be used and it is excluded from the resource candidate group that can use the resource. That is, terminal 20 can decide whether the resource can be used based on the information related to power reduction received from other terminals 20.

[0139] 2) Terminal 20 determines that it can use the resource with reduced transmission power only if the power value (e.g., RSRP) of the PSCCH / PSSCH received from other terminals 20 is lower than or below a predetermined value. If the power value (e.g., RSRP) of the PSCCH / PSSCH received from other terminals 20 is higher than or above a predetermined value, terminal 20 can exclude the corresponding resource from the available resource candidate group. That is, terminal 20 can decide whether the resource can be used based on the power value received from other terminals 20.

[0140] 3) In the resource identification operation, taking the resource indicated by the SCI received from other terminals 20 as the object, terminal 20 can subtract the aforementioned transmission power reduction caused by coexistence within the device (e.g., subtracting 3dB from the power value if a 3dB reduction is notified) from the power value of PSCCH / PSSCH received from other terminals 20, and use the subtracted transmission power value to determine whether the resource can be used.

[0141] As an action based on information relating to the reduction of transmission power in resources already transmitted from other terminals 20, terminal 20 may perform the actions shown in 1)-3) below.

[0142] 1) In the resource identification process, taking the resources indicated by the SCI received from other terminals 20 as the object, if other terminals 20 receive information about the aforementioned transmission power reduction due to coexistence within the device, terminal 20 can determine that the resource with reduced transmission power can be used. If other terminals 20 do not receive information about the aforementioned transmission power reduction due to coexistence within the device, it can determine that the corresponding resource cannot be used and exclude it from the resource candidate group that can use the resource. That is, terminal 20 can decide whether the resource can be used based on the information related to transmission power reduction received from other terminals 20.

[0143] 2) Terminal 20 may determine that it can use the resource corresponding to the resource with reduced transmission power only if the power value (e.g., RSRP) of the PSCCH / PSSCH received from other terminals 20 is lower than or below a predetermined value. If the power value (e.g., RSRP) of the PSCCH / PSSCH received from other terminals 20 is higher than or above a predetermined value, terminal 20 may also exclude the corresponding resource from the candidate group of usable resources. That is, terminal 20 can decide whether a resource can be used based on the power value received from other terminals 20.

[0144] 3) In the resource identification operation, taking the resource indicated by the SCI received from other terminals 20 as the object, terminal 20 adds the power value (e.g. RSRP) of the PSCCH / PSSCH received from other terminals 20 to the aforementioned power reduction caused by coexistence within the device (e.g., if a 3dB reduction is notified, the power value is added by 3dB), and uses the added power value to determine whether the resource can be used.

[0145] Additionally, resource identification can also be the action of determining unusable resources and excluding them from the group of available candidate resources. Furthermore, the aforementioned terminal 20 may not be limited to the SL transmission destination of other terminals 20, but may also be the object of multicast or broadcast based on other terminals 20.

[0146] As described above, terminal 20 can perform resource selection based on the predicted value of the actual received power after the transmission power reduction, which can improve the performance of collision avoidance.

[0147] The information in D) above concerning reserved but unused resources can be information about resources that are available but not used, or information about resources that are unusable. For example, the processing of the above information can also be applied to the situations shown in 1)-5) below.

[0148] 1) Cases where resource reservation is made but the transport block is successfully sent (i.e., ACK is received) without retransmission.

[0149] 2) Cases where, despite resource reservation, the retransmission of the first transport block is suspended or delayed due to the occurrence of further significant SL data.

[0150] 3) Situation where resources were reserved but were pre-empted by other terminals 20.

[0151] 4) Cases where, despite resource reservations, transmission is suspended or delayed due to overlap with UL transmission, at least in the time domain.

[0152] 5) Although resource reservation was implemented, the decision formula (Σ) in congestion control was used. i≧ k CR(i)≦CR Limit (k) and the situation where the transmission is suspended or delayed.

[0153] Additionally, CR (channel occupancy ratio) is an indicator related to the resources used by this device, while CBR (channel busy ratio) is an indicator related to the resources used by other devices. CR(i) is the CR evaluation value in slot nN used in the PSSCH transmission with priority field i in the SCI. Limit (k) corresponds to the higher-level parameter sl-CR-Limit, which is associated with the range of CBR, including priority k and the CBR measured in time slot nN. N is the processing time for congestion control. Furthermore, pre-emption can mean the following: for resources reserved by terminal 20, terminal 20 receives a signal from other terminals 20 notifying it of the resources.

[0154] Furthermore, the information regarding the reserved but unused resources mentioned above can be information indicating the unused resources or information indicating the reason for not using them. Additionally, the aforementioned resource reservation can be made based on the indication of the time resource allocation field in the SCI, or it can be made based on the indication of the resource reservation period field.

[0155] As described above, by receiving information from other terminals 20 regarding reserved but unused resources, a more accurate understanding of resource utilization can be obtained.

[0156] Figure 20 This diagram illustrates an example of information related to unused resources in an embodiment of the present invention. Terminal 20 can perform resource allocation operations based on information received from other terminals 20 regarding reserved but unused pre-allocated resources.

[0157] For example, such as Figure 20 As shown, if terminal 20C, based on a notification from terminal 20A or terminal 20B, sets the resource indicated by the SCI received from terminal 20A as an object, and subsequently receives a notification from terminal 20A or terminal 20B that it will not use the resource, terminal 20C can determine that it can use the resource and will not exclude it from the group of available candidate resources. If it does not receive a notification from terminal 20A or terminal 20B that it will not use the resource, terminal 20C can determine that it cannot use the resource and will perform resource exclusion.

[0158] Furthermore, terminal 20C can determine whether it can use the resource without excluding it from the group of available candidate resources based on the priority in the SCI received from terminal 20A and / or the priority in the predetermined SCI sent by terminal 20C.

[0159] As described above, by receiving information from other terminals 20 regarding reserved but unused resources, terminals 20 are able to utilize the unused resources, thereby improving resource utilization efficiency.

[0160] According to the above embodiments, terminal 20 can perform resource selection actions based on information notified from other terminals 20, thereby reducing the probability of resource conflicts and improving resource utilization efficiency.

[0161] That is, in direct communication between terminals, the communication quality can be improved based on information notified from other terminals.

[0162] (Device Structure)

[0163] Next, an example of the functional structure of the base station 10 and terminal 20 performing the processes and actions described above will be explained. The base station 10 and terminal 20 include the functions implemented in the above embodiments. However, the base station 10 and terminal 20 may each have only a portion of the functions described in the embodiments.

[0164] <Base Station 10>

[0165] Figure 21 This is a diagram illustrating an example of the functional structure of base station 10. (As shown...) Figure 21 As shown, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130 and a control unit 140. Figure 21 The functional structure shown is only one example. As long as the actions involved in the embodiments of the present invention can be performed, the functional distinctions and names of the functional parts can be arbitrary.

[0166] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher-level information from the received signals. In addition, the transmitting unit 110 has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, etc. to the terminal 20.

[0167] The setting unit 130 stores preset setting information and various setting information sent to the terminal 20 into a storage device, and reads it from the storage device as needed. The content of the setting information includes, for example, information related to D2D communication settings.

[0168] As described in the embodiment, the control unit 140 performs processing related to the settings for D2D communication by the terminal 20. Furthermore, the control unit 140 sends the scheduling of D2D and DL communication to the terminal 20 via the transmitting unit 110. Additionally, the control unit 140 receives information related to HARQ responses for D2D and DL communication from the terminal 20 via the receiving unit 120. Alternatively, the signal transmission-related functions of the control unit 140 may be included in the transmitting unit 110, and the signal reception-related functions of the control unit 140 may be included in the receiving unit 120.

[0169] Terminal 20

[0170] Figure 22 This is a diagram illustrating an example of the functional structure of terminal 20. (As shown...) Figure 22 As shown, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. Figure 22 The functional structure shown is only one example. As long as the actions involved in the embodiments of the present invention can be performed, the functional distinctions and names of the functional parts can be arbitrary.

[0171] The transmitting unit 210 generates a transmission signal based on the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and obtains higher-layer signals from the received physical layer signals. Furthermore, 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. Additionally, 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 from other terminals 20.

[0172] The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or the terminal 20 into a storage device, and reads it from the storage device as needed. In addition, the setting unit 230 also stores preset setting information. The content of the setting information includes, for example, information related to D2D communication settings.

[0173] As described in the embodiment, the control unit 240 controls D2D communication with other terminals 20. Furthermore, the control unit 240 performs HARQ processing related to D2D and DL communication. Additionally, the control unit 240 sends information scheduled from the base station 10 related to HARQ responses for D2D and DL communication to other terminals 20. Furthermore, the control unit 240 can also schedule D2D communication with other terminals 20. Furthermore, the control unit 240 can autonomously select resources used in D2D communication from a resource selection window based on monitoring results. Furthermore, the control unit 240 performs PSBCH transmission and reception processing related to D2D communication. Alternatively, the signal transmission-related functions of the control unit 240 can be included in the transmitting unit 210, and the signal reception-related functions of the control unit 240 can be included in the receiving unit 220.

[0174] (Hardware Structure)

[0175] The block diagram used in the description of the above embodiments ( Figure 21 and Figure 22The diagram illustrates blocks organized by function. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Furthermore, there are no particular limitations on the implementation method of each functional block. That is, each functional block can be implemented using a single device that is physically or logically combined, or by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. Functional blocks can also be implemented by combining software with one or more of the aforementioned devices.

[0176] Functionally, it includes functions such as judgment, decision, determination, calculation, calculation, processing, derivation, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but is not limited to these. For example, the functional block (structural part) that enables sending is called the transmitting unit or transmitter. In short, as mentioned above, there are no particular limitations on the implementation method.

[0177] For example, in one embodiment of this disclosure, the base station 10, terminal 20, etc., can also function as a computer for processing the wireless communication method of this disclosure. Figure 23 This is a diagram illustrating an example of the hardware structure of a base station 10 and a terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 described above may 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, etc.

[0178] Additionally, in the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware structure of base station 10 and terminal 20 can be configured to include one or more of the devices shown in the figures, or it can be configured to not include any of them.

[0179] The functions of 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 reading out and writing data in the storage device 1002 and the auxiliary storage device 1003.

[0180] The processor 1001 controls the computer as a whole, for example, by enabling the operating system to function. The processor 1001 may also be a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc. For example, the aforementioned control unit 140, control unit 240, etc., can also be implemented using the processor 1001.

[0181] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage devices 1003 and communication devices 1004, and performs various processes accordingly. As a program, a program is used that causes the computer to perform at least a portion of the actions described in the above embodiments. For example, Figure 21 The control unit 140 of the base station 10 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Furthermore, for example, Figure 22 The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Regarding the various processes described above, although it has been stated that the various processes are executed by one processor 1001, the various processes can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be installed using more than one chip. Furthermore, the program can also be transmitted from a network via a telecommunications line.

[0182] Storage device 1002 is a computer-readable recording medium, and may be composed of at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. Storage device 1002 may also be referred to as a register, cache, main memory (main storage device), etc. Storage device 1002 can store programs (program code), software modules, etc., that are executable for implementing the communication method according to one embodiment of this disclosure.

[0183] The auxiliary storage device 1003 is a computer-readable recording medium, such as at least one of the following: CD-ROM (CompactDisc ROM), hard disk drive, floppy disk, magneto-optical disk (e.g., compact disk, digital multipurpose disk, Blu-ray disk, smart card, flash memory (e.g., card, stick, key drive), floppy disk, magnetic stripe, etc.). The aforementioned storage medium may be, for example, a database, server, or other suitable media that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0184] Communication device 1004 is hardware (transceiver) used for communication 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 interface card (NIC), communication module, etc. Communication device 1004 may, for example, be configured to include high-frequency switches, duplexers, filters, frequency synthesizers, etc., to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, transceiver antennas, amplifiers, transceiver units, transmission path interfaces, etc., can also be implemented using communication device 1004. The transceiver unit may also be physically or logically separated into a transmitting unit and a receiving unit.

[0185] Input device 1005 is an input device that accepts input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, LED, etc.). Alternatively, input device 1005 and output device 1006 can also be integrated (e.g., a touch panel).

[0186] Furthermore, the processor 1001 and storage device 1002, among other devices, are connected via a bus 1007 for communicating information. The bus 1007 can be configured using a single bus or by using different buses between each device.

[0187] Furthermore, the base station 10 and the terminal 20 can 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 a FPGA (Field Programmable Gate Array), and can also use this hardware to implement part or all of the functional blocks. For example, the processor 1001 can also be implemented using at least one of these hardware components.

[0188] (Summary of Implementation Methods)

[0189] As described above, according to an embodiment of the present invention, a terminal is provided, comprising: a receiving unit that receives information related to direct inter-terminal communication for avoiding resource conflicts from other terminals; a control unit that identifies candidate resources and selects a resource to be used based on the information; and a transmitting unit that uses the selected resource to perform transmission in direct inter-terminal communication.

[0190] Based on the above structure, terminal 20 can perform resource selection actions according to information notified from other terminals 20, thereby reducing the probability of resource conflicts and improving resource utilization efficiency. That is, in direct communication between terminals, communication quality can be improved based on information notified from other terminals.

[0191] The information may also be related to the synchronization source of the other terminals. According to this structure, terminal 20 can perform resource selection actions based on information notified from other terminals 20, thereby reducing the probability of resource conflicts.

[0192] The control unit can also detect power based on the time difference between the timing of the signal received by the other terminal (including synchronization signals and broadcast information) and the timing of the synchronization source used by the current terminal, as indicated by information related to the synchronization source of the other terminal. According to this structure, terminal 20 can perform resource selection actions based on information notified from other terminals 20, thereby reducing the probability of resource conflicts.

[0193] The information may also be channel-related information concerning responses to transmit / retransmit and retransmission control. According to this structure, terminal 20 can perform resource selection actions based on information notified from other terminals 20, thereby reducing the probability of resource conflicts.

[0194] The control unit can also exclude resources from the pool of available resources that correspond to transmission opportunities of channels configured to receive and transmit responses related to retransmission control, based on information related to the channel for receiving and transmitting responses related to retransmission control. According to this structure, terminal 20 can perform resource selection actions based on information notified from other terminals 20, thereby reducing the probability of resource conflicts.

[0195] Furthermore, according to an embodiment of the present invention, a communication method executed by a terminal is provided, wherein the terminal performs the following steps: a receiving step, receiving information related to direct inter-terminal communication for avoiding resource conflicts from other terminals; a controlling step, identifying candidate resources and selecting a resource to be used based on the information; and a sending step, using the selected resource to perform sending in direct inter-terminal communication.

[0196] Based on the above structure, terminal 20 can perform resource selection actions according to information notified from other terminals 20, thereby reducing the probability of resource conflicts and improving resource utilization efficiency. That is, in direct communication between terminals, communication quality can be improved based on information notified from other terminals.

[0197] (Supplement to the implementation method)

[0198] The embodiments of the present invention have been described above, but the disclosed invention is not limited to these embodiments. Those skilled in the art should understand various modifications, alterations, substitutions, and replacements. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these values ​​are merely examples, and any appropriate values ​​may be used. The distinctions between items in the above description are not essential to the present invention; items described in two or more items may be combined as needed, and items described in one item may be applied to items described 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. Multiple functional units may be operated by a single physical component, or a single functional unit may be operated by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing may be interchanged unless there is a contradiction. For ease of explanation, the base station 10 and terminal 20 have been described using functional block diagrams, but this device may also be implemented in hardware, software, or a combination thereof. The software operating via the processor of the base station 10 according to an embodiment of the present invention and the software operating via the processor of the terminal 20 according to an embodiment of the present invention can also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server and other suitable storage media, respectively.

[0199] Furthermore, the notification of information is not limited to the forms / implementations described in this disclosure, and other methods may also be used. For example, information notification may be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, RLC (Radio Link Control) signaling, PDCP (Packet Data Convergence Protocol) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. Additionally, RRC signaling may also be referred to as an RRC message, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc. Furthermore, information notification may be performed using certain channels, such as PSCCH, PSSCH, PSFCH, PSBCH.

[0200] The various forms / implementations described in this disclosure can also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-Wide Band), Bluetooth (registered trademark), systems using other suitable systems, and next-generation systems extended therefrom. Furthermore, multiple systems can be combined (e.g., a combination of at least one of LTE and LTE-A with 5G, etc.) for application.

[0201] The processing procedures, timing, and flow of the various forms / implementations described in this specification may be changed in order, provided there is no contradiction. For example, the elements of various steps are indicated using an illustrative order for the methods described in this disclosure, but are not limited to the specific order indicated.

[0202] In this specification, certain actions purported to be performed by base station 10 may sometimes be performed through its upper node, depending on the circumstances. In a network consisting of one or more network nodes including base station 10, it is obvious that various actions performed to communicate with terminal 20 can be performed by at least one of base station 10 and other network nodes besides base station 10 (e.g., considering MME or S-GW, but not limited to these). The above example illustrates the case where there is only one other network node besides base station 10, but other network nodes can also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0203] The information or signals described in this disclosure can be output from a higher (or lower) layer to a lower (or higher) layer. They can also be input or output via multiple network nodes.

[0204] 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.

[0205] The determination in this disclosure can be made by a value represented by 1 bit (0 or 1), by a Boolean value (Boolean: true or false), or by a comparison of numerical values ​​(e.g., a comparison with a predetermined value).

[0206] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted as commands, command sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0207] Furthermore, software, commands, and information can be sent and received via a transmission medium. For example, when software is sent from a website, server, or other remote source using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technologies (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0208] The information, signals, etc., described in this disclosure can also be represented using any of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc., that may be involved in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0209] Furthermore, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms that have the same or similar meanings. For example, at least one of the channel and symbol may also be a signal (signaling). Additionally, a signal may also be a message. Furthermore, a component carrier (CC) may also be referred to as a carrier frequency, cell, frequency carrier, etc.

[0210] The terms “system” and “network” as used in this disclosure are used interchangeably.

[0211] Furthermore, the information, parameters, etc., described in this disclosure may be represented using absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0212] The names used for the above parameters are not limiting in any way. Furthermore, the formulas, etc., using these parameters sometimes differ from those explicitly disclosed in this disclosure. Since a wide variety of channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by all appropriate names, the various names assigned to these wide variety of channels and information elements are not limiting in any way.

[0213] In this disclosure, the terms "base station (BS)," "wireless 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. Sometimes, terms such as macro cell, small cell, femtocell, and picocell are also used to refer to base stations.

[0214] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, its coverage area can be divided into several smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base station and base station subsystem providing communication services within that coverage area.

[0215] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" are used interchangeably.

[0216] For mobile stations, those skilled in the art sometimes also use the following terms: 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, handheld device, user agent, mobile client, client, or some other appropriate terms.

[0217] At least one of the base station and mobile station can also be referred to as a transmitting device, receiving device, communication device, etc. Furthermore, at least one of the base station and mobile station can be a device mounted on a mobile body, the mobile body itself, etc. The mobile body can be a vehicle (e.g., a car, an airplane, etc.), a mobile body moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Additionally, at least one of the base station and mobile station also includes devices that do not necessarily move during communication. For example, at least one of the base station and mobile station can be an IoT (Internet of Things) device such as a sensor.

[0218] Furthermore, the base station in this disclosure can also be replaced by a user terminal. For example, various forms / implementations of this disclosure can be applied to a structure that replaces the communication between the base station and the user terminal with communication between multiple terminals 20 (e.g., also referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminal 20 can also be configured to have the functions of the base station 10 described above. In addition, terms such as "uplink" and "downlink" can be replaced with terms corresponding to inter-terminal communication (e.g., "side"). For example, uplink channel, downlink channel, etc., can also be replaced with side channel.

[0219] Similarly, the user terminal in this disclosure can be replaced by a base station. In this case, the base station can also be configured to have the functions of the user terminal described above.

[0220] The terms "determining" and "determining" as used in this disclosure sometimes encompass a variety of actions. For example, "determining" and "determining" can include actions such as judging, calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), and ascertaining, which are considered as actions of "determining" and "determining." Furthermore, "determining" and "determining" can include actions such as receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, and accessing (e.g., accessing data in memory), which are considered as actions of "determining" and "determining." Additionally, "determining" and "determining" can include actions such as resolving, selecting, choosing, establishing, and comparing, which are considered as actions of "determining" and "determining." That is, "judgment" and "decision" can include matters that are considered to have been "judged" or "decided" to take any action. In addition, "judgment (decision)" can also be replaced by "assuming", "expecting", "considering", etc.

[0221] The terms “connected,” “coupled,” or any variations thereof are intended to indicate any direct or indirect connection or combination between two or more elements, including cases where there is one or more intermediate elements between the two elements that are “connected” or “coupled.” The combination or connection between elements can be physical, logical, or a combination of these. For example, “access” can be used instead of “connected.” In the context of this disclosure, it can be understood that two elements are “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, using electromagnetic energy with wavelengths in the wireless frequency domain, microwave region, and light (both visible and invisible) region to “connect” or “couple” to each other.

[0222] The reference signal can be simply referred to as RS (Reference Signal), or, depending on the standard applied, as a pilot.

[0223] As used in this disclosure, the word "based on" does not mean "based on only" unless otherwise expressly stated. In other words, the word "based on" means both "based on only" and "based on at least" both.

[0224] Any reference to elements using the designations "first," "second," etc., as used in this disclosure does not necessarily limit the number or order of these elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Therefore, references to the first element and the second element do not imply that only two elements can be taken or that in any form the first element must precede the second element.

[0225] Alternatively, the term "unit" in the structure of the above devices can be replaced with "section," "circuit," "equipment," etc.

[0226] When the terms "include," "including," and their variations are used in this disclosure, these terms, like the term "comprising," imply inclusion. Furthermore, the term "or" as used in this disclosure does not refer to XOR.

[0227] A radio frame can consist of one or more frames in the time domain. Each frame in the time domain can be called a subframe. A subframe can further consist of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) independent of the parameter set (numerology).

[0228] A parameter set can be communication parameters applied to at least one of the transmission and reception of a signal or channel. For example, a parameter set can 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 processing performed by the transceiver in the frequency domain, and specific windowing processing performed by the transceiver in the time domain.

[0229] In the time domain, a time slot can be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A time slot can be a time unit based on a set of parameters.

[0230] A time slot can contain multiple mini-time slots. Each mini-time slot can consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can consist of fewer symbols than a time slot. PDSCH (or PUSCH) transmitted in time units larger than mini-time slots can be called PDSCH (or PUSCH) mapping type (type) A. PDSCH (or PUSCH) transmitted using mini-time slots can be called PDSCH (or PUSCH) mapping type (type) B.

[0231] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can also be referred to by their respective alternative names.

[0232] For example, a subframe can also be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and a time slot or a mini-time slot can also be called a TTI. That is, at least one of a subframe and a TTI can be a subframe in the existing LTE (1ms), a period shorter than 1ms (e.g., symbols 1-13), or a period longer than 1ms. In addition, the unit representing TTI may not be called a subframe, but a time slot, mini-time slot, etc.

[0233] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules the allocation of radio resources (bandwidth, transmit power, etc., available to each terminal 20) on a TTI basis. However, the definition of TTI is not limited to this.

[0234] The Time Interval (TTI) can be the transmission time unit for channel-coded data packets (transmission blocks), code blocks, codewords, etc., or it can be a processing unit for scheduling, link adaptation, etc. Furthermore, when a TTI is given, the actual time interval (e.g., the number of symbols) in which the transmission block, code block, codeword, etc., are mapped can be shorter than that TTI.

[0235] Furthermore, when one time slot or one mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can constitute the minimum time unit for scheduling. Moreover, the number of time slots constituting this minimum time unit for scheduling (the number of mini-time slots) can be controlled.

[0236] A TTI with a duration of 1ms can also be referred to as a normal TTI (TTI in LTE Rel.8-12), a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI can be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini time slot, a sub-time slot, a time slot, etc.

[0237] Additionally, for long TTIs (e.g., regular TTIs, subframes, etc.), they can be replaced with TTIs with a duration of more than 1ms. For short TTIs (e.g., shortened TTIs, etc.), they can be replaced with TTIs with a duration of less than long TTIs and a duration of more than 1ms.

[0238] A resource block (RB) is a unit of resource allocation in both 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 based on the parameter set.

[0239] Furthermore, the temporal domain of an RB can contain one or more symbols, and can be 1 time slot, 1 mini-time slot, 1 subframe, or 1 TTI in length. 1 TTI, 1 subframe, etc., can each be composed of one or more resource blocks.

[0240] In addition, one or more RBs can be called Physical Resource Block (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB Pair, RB Pair, etc.

[0241] Furthermore, a resource block can consist of one or more resource elements (REs). For example, 1 RE can be a radio resource area consisting of 1 subcarrier and 1 symbol.

[0242] The Bandwidth Part (BWP) (which may also be referred to as partial bandwidth, etc.) can represent a subset of contiguous common resource blocks (RBs) used for a certain parameter set in a given carrier. Here, common resource blocks can be determined by indexing RBs based on a common reference point of that carrier. PRBs can be defined and numbered within a BWP.

[0243] A BWP can include a UL BWP and a DL BWP. One or more BWPs can be configured for terminal 20 within one carrier.

[0244] At least one of the configured BWPs can be active, and it is not assumed that the terminal 20 will transmit or receive predetermined signals / channels outside of an active BWP. Furthermore, the terms "cell," "carrier," etc., used in this disclosure can be replaced with "BWP."

[0245] The structures of radio frames, subframes, time slots, mini-time slots, and symbols described above are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained in a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc., can be varied in many ways.

[0246] In this disclosure, for example, in cases where articles are added through translation, such as in English (e.g., a, an, and the), this disclosure may also include cases where the noun following these articles is in a plural form.

[0247] In this disclosure, the phrase "A is different from B" can also mean "A and B are not the same." Furthermore, this phrase can also mean "A and B are each different from C." Terms such as "separate" and "combined" can also be interpreted in the same way as "different."

[0248] The various forms / implementations described in this disclosure can be used individually or in combination, and can be switched depending on the execution. Furthermore, the notification of predetermined information is not limited to explicit notification (e.g., a "Yes X" notification) but can also be implicit notification (e.g., not notifying the predetermined information).

[0249] Additionally, the PSFCH in this disclosure is an example of a channel for receiving and transmitting responses related to retransmission control. PSCCH / PSSCH is an example of a control channel and a data channel.

[0250] The present disclosure has been described in detail above, but it will 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 as modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the present disclosure is for illustrative purposes only and is not intended to be limiting.

[0251] Label Explanation

[0252] 10: Base station;

[0253] 110: Dispatch Department;

[0254] 120: Receiving Unit;

[0255] 130: Setting Department;

[0256] 140: Control Department;

[0257] 20: Terminal;

[0258] 210: Sending Department;

[0259] 220: Receiving unit;

[0260] 230: Setting Department;

[0261] 240: Control Unit;

[0262] 30: GNSS;

[0263] 1001: Processor;

[0264] 1002: Storage device;

[0265] 1003: Auxiliary storage device;

[0266] 1004: Communication device;

[0267] 1005: Input device;

[0268] 1006: Output device.

Claims

1. A terminal, wherein, The terminal has: a reception section that receives control information from a first terminal via a control channel; and a transmission section that transmits, to a second terminal, information about a feedback channel for avoiding a collision of a first resource with a second resource, the first resource being a resource indicated by the control information and being a resource used by the first terminal in transmission of a shared channel, the second resource being a resource used by the second terminal in transmission of the shared channel, the feedback channel being used for transmission of HARQ-ACK information and collision information.

2. The terminal according to claim 1, wherein the second resource is selected by the second terminal in accordance with the information about the feedback channel for avoiding the collision.

3. The terminal according to claim 2, wherein the second resource is included in resources after at least a part of the first resource is removed from a group of candidate resources that can be used.

4. The terminal according to claim 1, wherein the transmission section transmits, to the second terminal, the information about the feedback channel for avoiding the collision in a transmission opportunity for a feedback channel corresponding to a time slot of reception of the control information via the control channel.

5. The terminal according to claim 1, wherein the transmission section transmits, to the second terminal, the information about the feedback channel for avoiding the collision in a transmission opportunity for a feedback channel corresponding to the first resource indicated by the control information.

6. A communication method, wherein, The following steps are performed by a terminal: receiving control information from a first terminal via a control channel; and transmitting, to a second terminal, information about a feedback channel for avoiding a collision of a first resource with a second resource, the first resource being a resource indicated by the control information and being a resource used by the first terminal in transmission of a shared channel, the second resource being a resource used by the second terminal in transmission of the shared channel, the feedback channel being used for transmission of HARQ-ACK information and collision information.

Images