Terminal and communication method

Abstract

A terminal has a reception section that receives data from another terminal, a control section that controls an acknowledgement relating to retransmission processing of the data in accordance with which of a power saving state and a normal state, and a transmission section that transmits the acknowledgement relating to the retransmission processing of the data to the other terminal.

Description

TECHNICAL FIELD

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

[0002] In LTE (Long Term Evolution) and a successor system of LTE (for example, LTE-A (LTE-Advanced), NR (New Radio) (also referred to as 5G)), a D2D (Device to Device) technology in which terminals directly communicate without going through a base station is being researched (for example, Non-Patent Literature 1).

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

[0004] D2D communication is roughly classified into D2D discovery (also referred to as D2D discovery) for discovering other terminals with which communication can be performed, and D2D communication (also referred to as D2D direct communication, D2D communication, inter-terminal direct communication, and the like) for directly communicating between terminals. Hereinafter, when D2D communication (D2D communication), D2D discovery (D2D discovery), and the like are not particularly distinguished, D2D is simply referred to. Furthermore, a signal transmitted and received by D2D is referred to as a D2D signal. Various use cases of services related to V2X (Vehicle to Everything) in NR are being researched (for example, Non-Patent Literature 2).

[0005] PRIOR ART LITERATURE

[0006] NON-PATENT LITERATURE

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

[0008] Non-Patent Literature 2: 3GPP TR 22.886 V15.1.0 (2017-03) SUMMARY

[0009] Problem to be Solved by the Invention

[0010] In inter-terminal direct communication in NR, an operation of reporting a HARQ (Hybrid automatic repeat request) response of a sidelink to a base station is supported. Further, in inter-terminal direct communication in NR, a power saving operation is being studied with respect to random resource selection or partial sensing in a case where a terminal selects a resource. However, with respect to an operation related to a HARQ response, an operation related to power saving has not been specified in power saving of a sidelink.

[0011] The present invention was achieved in view of the above-described circumstances, and an object thereof is to reduce power consumption of an operation related to a HARQ (Hybrid automatic repeat request) response in inter-terminal direct communication.

[0012] Means for Solving the Problem

[0013] According to the disclosed technology, a terminal is provided with a reception section that receives data from another terminal, a control section that controls a response related to retransmission processing of the data in accordance with which one of a power saving state and a normal state, and a transmission section that transmits the response related to the retransmission processing of the data to the other terminal.

[0014] Effects of the Invention

[0015] According to the disclosed technology, it is possible to reduce power consumption of an operation related to a HARQ (Hybrid automatic repeat request) response in inter-terminal direct communication. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a diagram for explaining V2X.

[0017] Figure 2 is a diagram for explaining an example (1) of a transmission mode of V2X.

[0018] Figure 3 is a diagram for explaining an example (2) of a transmission mode of V2X.

[0019] Figure 4 is a diagram for explaining an example (3) of a transmission mode of V2X.

[0020] Figure 5 is a diagram for explaining an example (4) of a transmission mode of V2X.

[0021] Figure 6 is a diagram for explaining an example (5) of a transmission mode of V2X.

[0022] Figure 7 is a diagram for explaining example (1) of a communication type of V2X.

[0023] Figure 8 is a diagram for explaining example (2) of a communication type of V2X.

[0024] Figure 9 is a diagram for explaining example (3) of a communication type of V2X.

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

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

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

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

[0029] Figure 14 is a diagram showing example (1) of HARQ response in the embodiment of the present application.

[0030] Figure 15 is a diagram showing example (2) of HARQ response in the embodiment of the present application.

[0031] Figure 16 is a diagram showing an example of resource pool in the embodiment of the present application.

[0032] Figure 17 is a diagram showing an example of functional structure of the base station 10 in the embodiment of the present application.

[0033] Figure 18 is a diagram showing an example of functional structure of the terminal 20 in the embodiment of the present application.

[0034] Figure 19 is a diagram showing an example of hardware structure of the base station 10 or the terminal 20 in the embodiment of the present application. DETAILED DESCRIPTION

[0035] Hereinafter, an embodiment of the present application will be described with reference to the drawings. In addition, the embodiment described below is only an example, and the embodiment to which the present application is applied is not limited to the embodiment described below.

[0036] In the wireless communication system of the embodiment of the present application, the related art is appropriately used. However, the related art is, for example, the existing LTE, but is not limited to the existing LTE. Further, unless otherwise specified, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and LTE-Advanced beyond (for example, NR) or wireless LAN (Local Area Network) in addition.

[0037] Further, in the embodiment of the present application, the duplexing (Duplex) method can be a TDD (Time Division Duplex) method, can be an FDD (Frequency Division Duplex) method, or can be a method other than these (for example, a flexible duplexing (Flexible Duplex) method, etc.).

[0038] Further, in the embodiment of the present application, the "Configure" wireless parameters and the like can be to pre-configure a predetermined value, or can be to configure a wireless parameter notified from the base station 10 or the terminal 20.

[0039] Figure 1 is a diagram for explaining V2X. In 3GPP, a technology for realizing V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending the D2D function is being studied, and standardization is being promoted. As shown in Figure 1 indicated, V2X is a part of ITS (Intelligent Transport Systems), and is a general term of V2V (Vehicle to Vehicle) indicating a communication form between vehicles, V2I (Vehicle to Infrastructure) indicating a communication form between a vehicle and a road side unit (RSU: Road-Side Unit) provided on the side of a road, V2N (Vehicle to Network) indicating a communication form between a vehicle and an ITS server, and V2P (Vehicle to Pedestrian) indicating a communication form between a vehicle and a mobile terminal held by a pedestrian.

[0040] Further, in 3GPP, V2X using LTE or NR for cellular communication and inter-terminal communication is being studied. V2X using cellular communication is also referred to as cellular V2X. In V2X of NR, research for achieving large capacity, low latency, high reliability, and QoS (Quality of Service) control is being promoted.

[0041] With respect to V2X of LTE or NR, it is envisaged that research not limited to 3GPP specifications will also be promoted in the future. For example, it is envisaged that research for ensuring interoperability, reducing costs due to installation of higher layers, a method for combining or switching multiple RATs (Radio Access Technologies), support for regulations in each country, data acquisition, distribution, database management, and usage methods for a V2X platform of LTE or NR will be conducted.

[0042] In the embodiments of the present application, a mode in which a communication device is mounted on a vehicle is mainly envisaged, but the embodiments of the present application are not limited to this mode. For example, the communication device can be a terminal held by a person, the communication device can also be a device mounted on a drone or an aircraft, the communication device can also be a base station, an RSU, a Relay Node, a terminal having a scheduling capability, or the like.

[0043] In addition, SL (Sidelink) can also be distinguished according to any one or a combination of UL (Uplink) or DL (Downlink) and 1) to 4) described below. Further, SL can also be another name.

[0044] 1) Resource configuration in time domain

[0045] 2) Resource configuration in frequency domain

[0046] 3) Reference of synchronization signal (including SLSS (Sidelink Synchronization Signal))

[0047] 4) Reference signal used in path loss measurement for transmission power control

[0048] Furthermore, as the OFDM (Orthogonal Frequency Division Multiplexing) for SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, and OFDM with transform precoding can be employed.

[0049] In the SL of LTE, as for the resource allocation of the SL to the terminal 20, Mode 3 and Mode 4 are defined. In Mode 3, the transmission resource is dynamically allocated by the DCI (Downlink Control Information) transmitted from the base station 10 to the terminal 20. Furthermore, in Mode 3, SPS (Semi-Persistent Scheduling) is also possible. In Mode 4, the terminal 20 autonomously selects the transmission resource from a resource pool.

[0050] In addition, the slot in the embodiment of the present application can be replaced with a symbol, a mini-slot, a subframe, a radio frame, a TTI (Transmission Time Interval), and the like. Furthermore, the cell in the embodiment of the present application can be replaced with a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), and the like.

[0051] In addition, in the embodiment of the present application, the terminal 20 is not limited to the V2X terminal, and can be any kind of terminal that performs D2D communication. For example, the terminal 20 can be a terminal held by a user such as a smartphone, and can be an IoT (Internet of Things) device such as a smart meter.

[0052] Figure 2 is a diagram for explaining Example (1) of the transmission mode of V2X. In Figure 2The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode. Figure 2 The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode. Figure 2 The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode.

[0053] Figure 3 FIG. 11 is a diagram for explaining example (2) of the transmission mode of V2X. In the transmission mode of sidelink communication shown in FIG. 11, in step 1, the terminal 20A transmits a PSCCH and a PSSCH to the terminal 20B using a resource autonomously selected by the terminal 20A. In addition, the terminal 20B transmits a PSCCH and a PSSCH to the terminal 20A using a resource autonomously selected by the terminal 20B (step 1). The transmission mode of sidelink communication shown in FIG. 11 can also be called sidelink transmission mode 4 in LTE. Figure 3 The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode. Figure 3 The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode.

[0054] Figure 4 FIG. 12 is a diagram for explaining example (3) of the transmission mode of V2X. In the transmission mode of sidelink communication shown in FIG. 12, in step 1, the terminal 20A transmits a PSCCH and a PSSCH to the terminal 20B using a resource autonomously selected by the terminal 20A. Also, the terminal 20B transmits a PSCCH and a PSSCH to the terminal 20A using a resource autonomously selected by the terminal 20B (step 1). The transmission mode of sidelink communication shown in FIG. 12 can also be called sidelink transmission mode 2a or sidelink resource allocation mode 2 in NR. Figure 4 The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode. Figure 4 The transmission mode of sidelink communication shown in FIG. 10 is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, Uu-based sidelink scheduling is performed. Uu refers to a radio interface between a UTRAN (Universal Terrestrial Radio Access Network) and a UE (User Equipment). In addition, the transmission mode can also be called a resource allocation mode.

[0055] Figure 5 FIG. 13 is a diagram for explaining example (4) of the transmission mode of V2X. In the transmission mode of sidelink communication shown in FIG. 13, in step 1, the terminal 20A transmits a PSCCH and a PSSCH to the terminal 20B using a resource autonomously selected by the terminal 20A. Also, the terminal 20B transmits a PSCCH and a PSSCH to the terminal 20A using a resource autonomously selected by the terminal 20B (step 1). The transmission mode of sidelink communication shown in FIG. 13 can also be called sidelink transmission mode 2b or sidelink resource allocation mode 3 in NR. Figure 5The transmission mode of the sidelink communication illustrated in FIG. 10 is called sidelink transmission mode 2a in NR. Figure 5 The transmission mode of the sidelink communication illustrated in FIG. 11 is called sidelink transmission mode 2b in NR.

[0056] Figure 6 FIG. 12 is a diagram for explaining example (5) of the transmission mode of V2X. Figure 6 The transmission mode of the sidelink communication illustrated in FIG. 12 is called sidelink transmission mode 2c in NR. Figure 6

[0057] Figure 7 FIG. 13 is a diagram for explaining example (1) of the communication type of V2X. Figure 7 The communication type of the sidelink illustrated in FIG. 13 is unicast. The terminal 20A transmits the PSCCH and the PSSCH to the terminal 20. Figure 7 In the example illustrated in FIG. 13, the terminal 20A unicasts to the terminal 20B and unicasts to the terminal 20C.

[0058] Figure 8 FIG. 14 is a diagram for explaining example (2) of the communication type of V2X. Figure 8 The communication type of the sidelink illustrated in FIG. 14 is groupcast. The terminal 20A transmits the PSCCH and the PSSCH to a group to which one or a plurality of terminals 20 belong. Figure 8 In the example illustrated in FIG. 14, the group includes the terminal 20B and the terminal 20C, and the terminal 20A groupcasts to the group.

[0059] Figure 9 FIG. 15 is a diagram for explaining example (3) of the communication type of V2X. Figure 9 The communication type of the sidelink illustrated in FIG. 15 is broadcast. The terminal 20A transmits the PSCCH and the PSSCH to one or a plurality of terminals 20. Figure 9 In the example illustrated in FIG. 15, the terminal 20A broadcasts to the terminal 20B, the terminal 20C, and the terminal 20D. In addition, the terminal 20A illustrated in FIG. 15 can be called a header-UE. Figures 7-9

[0060] ​​Further, in the NR-V2X, it is assumed that HARQ (Hybrid automatic repeat request) is supported in unicast and groupcast of the sidelink. Also, in the NR-V2X, SFCI (Sidelink Feedback Control Information) including a HARQ response is defined. Also, it is under study that the SFCI is transmitted via a PSFCH (Physical Sidelink Feedback Channel).

[0061] Further, in the following description, it is assumed that the PSFCH is used in transmission of the HARQ-ACK in the sidelink, but this is only an example. For example, the PSCCH can be used for transmission of the HARQ-ACK in the sidelink, the PSSCH can be used for transmission of the HARQ-ACK in the sidelink, or another channel can be used for transmission of the HARQ-ACK in the sidelink.

[0062] Hereinafter, for convenience of explanation, all the information reported by the terminal 20 in the HARQ is referred to as HARQ-ACK. The HARQ-ACK can also be referred to as HARQ-ACK information. Further, more specifically, a codebook applied to the information of the HARQ-ACK reported from the terminal 20 to the base station 10 or the like is referred to as a HARQ-ACK codebook. The HARQ-ACK codebook specifies a bit string of the HARQ-ACK information. In addition, with the "HARQ-ACK", in addition to the ACK, the NACK is also transmitted.

[0063] Figure 10 is a diagram showing an example (1) of a structure and an operation of a wireless communication system in an embodiment of the present application. As shown in Figure 10 The wireless communication system of the embodiment of the present application has a terminal 20A and a terminal 20B. In addition, in reality, there are a plurality of user devices, but Figure 10 The terminal 20A and the terminal 20B are shown as examples.

[0064] Hereinafter, without particularly distinguishing the terminal 20A, 20B, or the like, only "terminal 20" or "user device" is written. In Figure 10 In the example, the case where both the terminal 20A and the terminal 20B are in the coverage of the cell, but the operation in the embodiment of the present application can also be applied to the case where the terminal 20B is out of the coverage.

[0065] As described above, in the present embodiment, the terminal 20 is, for example, a device mounted on a vehicle such as an automobile, and has a function of cellular communication as a UE in LTE or NR and a sidelink function. The terminal 20 can also be a general portable terminal (smartphone or the like). In addition, the terminal 20 can also be an RSU. The RSU can be a UE type RSU (UE type RSU) having the function of a UE, or a gNB type RSU (gNB type RSU) having the function of a base station device.

[0066] In addition, the terminal 20 need not be a device of one housing, and for example, even in a case where various sensors are arranged dispersedly in a vehicle, a device including the various sensors is the terminal 20.

[0067] In addition, the processing content of the transmission data of the sidelink of the terminal 20 is basically the same as that of the UL transmission in LTE or NR. For example, the terminal 20 scrambles a codeword of the transmission data, performs modulation to generate complex-valued symbols, maps the complex-valued symbols (transmission signal) to layer 1 or layer 2, and performs precoding. Then, the precoded complex-valued symbols are mapped to resource elements to generate a transmission signal (for example, a complex-valued time-domain SC-FDMA signal), and are transmitted from each antenna port.

[0068] In addition, with respect to the base station 10, it has a function of cellular communication as a base station in LTE or NR, and a function for enabling the terminal 20 in the present embodiment to perform communication (for example, resource pool setting, resource allocation, and the like). In addition, the base station 10 can also be an RSU (gNB type RSU).

[0069] In addition, in the wireless communication system of the present embodiment, the signal waveform used in the SL or UL by the terminal 20 can be OFDMA, can be SC-FDMA, or can be another signal waveform.

[0070] In step S101, the terminal 20A autonomously selects resources used in the PSCCH and the PSSCH from a resource selection window having a predetermined period. The resource selection window can also be set to the terminal 20 by the base station 10.

[0071] In step S102 and step S103, the terminal 20A transmits SCI (Sidelink Control Information) using PSCCH and transmits SL data using PSSCH using the resources autonomously selected in step S101. For example, the terminal 20A can transmit SCI (PSCCH) using frequency resources adjacent to frequency resources of PSSCH in the same time resources as the time resources of PSSCH.

[0072] The terminal 20B receives the SCI (PSCCH) and the SL data (PSSCH) transmitted from the terminal 20A. In the SCI received using PSCCH, information of resources of PSFCH for the terminal 20B to transmit HARQ-ACK for the reception of the data can be included. The terminal 20A can include information of the autonomously selected resources in the SCI and transmit the same.

[0073] In step S104, the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the resources of PSFCH specified by the received SCI.

[0074] When the HARQ-ACK received in step S104 is NACK (negative acknowledgement) indicating a case where retransmission is requested, the terminal 20A retransmits PSCCH and PSSCH to the terminal 20B in step S105. The terminal 20A can retransmit PSCCH and PSSCH using the autonomously selected resources.

[0075] In addition, step S104 and step S105 can not be performed without performing HARQ control.

[0076] Figure 11 FIG. 2 is a diagram illustrating an example (2) of a structure and operation of a wireless communication system in an embodiment of the present application. Blind retransmission can be performed regardless of HARQ control for improving a success rate of transmission or a distance of arrival.

[0077] In step S201, the terminal 20A autonomously selects resources used in PSCCH and PSSCH from a resource selection window having a predetermined period. The resource selection window can be set to the terminal 20 by the base station 10.

[0078] In step S202 and step S203, the terminal 20A transmits SCI using PSCCH and transmits SL data using PSSCH using the resources autonomously selected in step S201. For example, the terminal 20A can transmit SCI (PSCCH) using frequency resources adjacent to frequency resources of PSSCH in the same time resources as the time resources of PSSCH.

[0079] In step S204, the terminal 20A retransmits the SCI based on the PSCCH and the SL data based on the PSSCH to the terminal 20B using the resource autonomously selected in step S201. The retransmission in step S204 can be performed multiple times.

[0080] In addition, in a case where the blind retransmission is not performed, step S204 can not be performed.

[0081] Figure 12 FIG. 3 is a diagram illustrating an example (3) of a structure and operation of a wireless communication system in an embodiment of the present application. The base station 10 can perform scheduling of a sidelink. That is, the base station 10 can decide a resource of a sidelink used by the terminal 20, and transmit information indicating the resource to the terminal 20. Also, in a case where HARQ control is applied, the base station 10 can transmit information indicating a resource of a PSFCH to the terminal 20.

[0082] In step S301, the base station 10 transmits a DCI (Downlink Control Information) to the terminal 20A using a PDCCH, thereby performing SL scheduling. Hereinafter, for convenience of explanation, the DCI for SL scheduling will be referred to as SL scheduling DCI.

[0083] Further, a case is assumed where, in step S301, the base station 10 transmits a DCI for DL scheduling (which can also be referred to as DL assignment) to the terminal 20A using a PDCCH. Hereinafter, for convenience of explanation, the DCI for DL scheduling will be referred to as DL scheduling DCI. The terminal 20A that has received the DL scheduling DCI receives DL data using a PDSCH using a resource specified by the DL scheduling DCI.

[0084] In steps S302 and S303, the terminal 20A transmits SCI (Sidelink Control Information) using a PSCCH and transmits SL data using a PSSCH using a resource specified by the SL scheduling DCI. In addition, in the SL scheduling DCI, only a resource of the PSSCH can be specified. In this case, for example, the terminal 20A can transmit the SCI (PSCCH) using a frequency resource adjacent to a frequency resource of the PSSCH in a same time resource as the time resource of the PSSCH.

[0085] The terminal 20B receives the SCI (PSCCH) and the SL data (PSSCH) transmitted from the terminal 20A. In the SCI received with the PSCCH, information of a resource of the PSFCH for the terminal 20B to transmit a HARQ-ACK for the reception of the data is included.

[0086] The information of the resource is included in the DL scheduling DCI or the SL scheduling DCI transmitted from the base station 10 in step S301, and the terminal 20A can also acquire the information of the resource from the DL scheduling DCI or the SL scheduling DCI and include it in the SCI. Alternatively, assuming that the information of the resource is not included in the DCI transmitted from the base station 10, the terminal 20A autonomously includes the information of the resource in the SCI and transmits it.

[0087] In step S304, the terminal 20B transmits a HARQ-ACK for the received data to the terminal 20A using the resource of the PSFCH specified by the received SCI.

[0088] In step S305, the terminal 20A transmits a HARQ-ACK using a PUCCH resource specified by the DL scheduling DCI (or the SL scheduling DCI) at a timing (for example, a timing in units of slots) specified by the DL scheduling DCI (or the SL scheduling DCI), for example, and the base station 10 receives the HARQ-ACK. The codebook of the HARQ-ACK can include the HARQ-ACK received from the terminal 20B and a HARQ-ACK for DL data. However, in a case where there is no allocation of DL data, or the like, a HARQ-ACK for DL data is not included.

[0089] In addition, in a case where HARQ control is not performed, step S304 and step S305 can also not be performed.

[0090] Figure 13is a diagram illustrating an example of the operation (4) in the embodiment of the present application. As described above, in the sidelink of NR, a case where HARQ acknowledgement is transmitted by PSFCH is supported. In addition, the format of PSFCH can use the same format as PUCCH (Physical Uplink Control Channel) format 0 (PUCCH format 0). That is, as for the format of PSFCH, it can be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified according to the difference in sequence. As the format of PSFCH, it is not limited thereto. The resource of PSFCH can be configured in the symbol at the end of the slot or a plurality of symbols at the end. Further, a period N is set or predetermined for the PSFCH resource. The period N can be set or predetermined in units of slots.

[0091] In Figure 13 , the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. The PSCCH can be configured in one symbol at the start of the slot, can be configured in a plurality of symbols from the start, and can be configured in a plurality of symbols from a symbol other than the start. The PSFCH can be configured in one symbol at the end of the slot, or can be configured in a plurality of symbols at the end of the slot. In Figure 13 , three subchannels are set in the resource pool, and two PSFCHs are configured after three slots in which the PSSCH is configured. The arrow from the PSSCH to the PSFCH shows an example of the PSFCH associated with the PSSCH.

[0092] In the case of option 2 where ACK or NACK is transmitted in the HARQ acknowledgement in the groupcast of NR-V2X, it is necessary to decide the resource used in the transmission and reception of PSFCH. As Figure 13 indicated, in step S401, the terminal 20A as the transmitting side terminal 20 performs groupcast on the terminal 20B, the terminal 20C, and the terminal 20D as the receiving side terminals 20 via the SL-SCH. In the next step S402, the terminal 20B transmits HARQ acknowledgement to the terminal 20A using PSFCH #B, the terminal 20C transmits HARQ acknowledgement to the terminal 20A using PSFCH #C, and the terminal 20D transmits HARQ acknowledgement to the terminal 20A using PSFCH #D. Here, as Figure 13 indicated in the example, in the case where the number of available resources of PSFCH is less than the number of receiving side terminals 20 belonging to the group, it is necessary to decide how to allocate the resources of PSFCH. In addition, the transmitting side terminal 20 can grasp the number of receiving side terminals 20 in the groupcast.

[0093] Here, as a sidelink enhancement of NR, power saving is being studied. Random resource selection in LTE and partial sensing, resource allocation mode 2 in NR are taken as a baseline related to power saving actions.

[0094] However, HARQ response in sidelink is a function not supported in LTE, and power saving related to actions related to HARQ response is not considered. Not only the power saving of sensing and the like in resource allocation is promoted, but also the power saving of PSFCH which transmits and receives HARQ response is promoted, whereby the power saving as a whole system can be achieved.

[0095] Therefore, in the case where a specific parameter is set or predetermined, at least one of A) to D) shown below can be applied. In addition, the specific parameter can be set by the other terminal through RRC signaling of the sidelink. For example, the specific parameter can be a parameter that reduces the sensing object and / or selection candidate. Furthermore, for example, the specific parameter can also be a parameter that indicates that a specific action such as PSCCH decoding is not performed. Furthermore, for example, the specific parameter can also be a parameter that indicates a transition to a power saving state. Furthermore, for example, it can also be a parameter that notifies that the receiving side UE is in a power saving state. The parameter can be replaced with a signal, and the setting can be replaced with the reception.

[0096] In addition, regarding the state, there are a power saving state and a normal state, and the terminal 20 can perform an action that reduces power consumption more in the power saving state than in the normal state, that is, at least one of A) to D). Furthermore, the power saving state can also be referred to as a power saving mode.

[0097] A) Apply only NACK feedback action

[0098] Figure 14 is a figure showing an example (1) of HARQ response in the embodiment of the present application. As Figure 14 indicated, in the case where the terminal 20A transmits a groupcast, the terminal 20B and the terminal 20D fail to receive the groupcast, and therefore, NACK is fed back to the terminal 20A via the resource A. On the other hand, the terminal 20B which normally successfully receives the groupcast does not feed back ACK to the terminal 20A.

[0099] Figure 15 is a figure showing an example (2) of HARQ response in the embodiment of the present application. As Figure 15As illustrated, in a case where the terminal 20A transmits a unicast to the terminal 20B and the terminal 20B successfully receives the unicast, the terminal 20B does not feedback an ACK to the terminal 20A. On the other hand, in a case where the terminal 20C transmits a unicast to the terminal 20D and the terminal 20D fails to receive the unicast, the terminal 20D feedbacks a NACK to the terminal 20C. In addition, in a case of NACK, m_CS for calculating the cyclic shift a of the PSFCH format 0 can be specified as 0.

[0100] As described above, in a case of successful reception of a sidelink, no feedback can be performed, and in a case of failed reception of a sidelink, a NACK can be fed back. As for the action of feeding back only a NACK, validity and invalidity can be notified by RRC signaling of a sidelink. In addition, distance-based feedback can or can not be applied. The distance-based feedback refers to an action of not transmitting feedback in a case where a distance between terminals 20 is detected to be separated by a predetermined distance or more.

[0101] By applying the action illustrated in A) described above, it is possible to reduce the number of times of transmission of a PSFCH, and it is possible to achieve power saving.

[0102] B) Transmitting and / or receiving a PSFCH only at a specific timing

[0103] The timing of transmitting and / or receiving a PSFCH can be notified by RRC signaling of a sidelink. Figure 16 is a diagram illustrating an example of a resource pool of an embodiment of the present application. As illustrated in Figure 16 , a resource pool can be configured, for example, with a superframe of 10240 ms as one cycle. As illustrated in Figure 16 , a terminal 20 in a power saving state can also use every Mth PSFCH opportunity for each N time slots. That is, a terminal 20 in a power saving state can transmit a PSFCH in every N*Mth PSFCH opportunity. Figure 16 is an example of N=4 and M=2. A PSCCH and a PSSCH corresponding to a PSFCH opportunity to be used can be used as a resource candidate for HARQ-based retransmission. Therefore, a transmitting-side terminal 20 can select a resource candidate for HARQ-based retransmission from a resource selection window in a case where the terminal 20 intends to perform HARQ-based retransmission. Also, a specific offset can be set for each terminal 20, and the specific offset can be set to different values for each cycle of a resource pool. In addition, the above-described parameters N or M can be notified by RRC signaling by another terminal 20. In addition, a terminal 20 in a normal state can transmit and / or receive a PSFCH using all PSFCH opportunities illustrated in Figure 16 .

[0104] Further, for example, a value of N > 4 can be set or predetermined, and a PSFCH opportunity of each N slot is set within the resource pool. This N can be a value that is referred to only by the terminal 20 in the power saving state.

[0105] Further, for example, N of the PSFCH opportunity for transmission and N of the PSFCH opportunity for reception can be set separately. Also, a specific offset amount can be set for each terminal 20, and the specific offset amount can be set to different values for each cycle of the resource pool.

[0106] By applying the action shown in B) described above, the number of times of transmission of the PSFCH can be reduced, and power saving can be achieved.

[0107] C) No HARQ feedback

[0108] It can be set / instructed that HARQ feedback is not requested. Further, even in a case where HARQ feedback is requested, the receiving side terminal 20 can set / determine that HARQ feedback is not performed. Further, it can be set / determined that only broadcast is allowed.

[0109] By applying the action shown in C) described above, power consumption related to transmission and reception of the PSFCH can be reduced, and power saving can be achieved.

[0110] D) Reporting to the base station 10 that the terminal 20 at the transmission destination is in a power saving state

[0111] The terminal 20 can report to the base station 10 that the terminal 20 at the transmission destination is in a power saving state by different SR (Scheduling request) resources. Further, the terminal 20 can report to the base station 10 that the terminal 20 at the transmission destination is in a power saving state using a BSR (Buffer status report). Further, the terminal 20 can report to the base station 10 information related to the PSFCH opportunity that the terminal 20 at the transmission destination can transmit.

[0112] By applying the action shown in D) described above, HARQ-based retransmission can be effectively used in the power saving state.

[0113] According to the above-described embodiment, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state compared to the normal state.

[0114] That is, power consumption of an action related to HARQ (Hybrid automatic repeat request) response in inter-terminal direct communication can be reduced.

[0115] (Apparatus structure)

[0116] Next, a functional configuration example of the base station 10 and the terminal 20 that execute the above-described processing and operation will be described. The base station 10 and the terminal 20 include the functions of the above-described embodiments. However, the base station 10 and the terminal 20 can each have only a part of the functions of the embodiments.

[0117] <BASE STATION 10>

[0118] Figure 17 is a diagram showing an example of the functional configuration of the base station 10. As shown in Figure 17 , the base station 10 has a transmission section 110, a reception section 120, a setting section 130, and a control section 140. Figure 17 The functional configuration shown in the drawing is merely an example. The functional division and the names of the functional sections can be arbitrary as long as the operation related to the embodiments of the present application can be executed.

[0119] The transmission section 110 includes a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal in a wireless manner. The reception section 120 includes a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, higher layer information from the received signals. Further, the transmission section 110 has a function of transmitting an NR-PSS, an NR-SSS, an NR-PBCH, a DL / UL control signal, a DL reference signal, and the like to the terminal 20.

[0120] The setting section 130 stores setting information set in advance and various setting information transmitted to the terminal 20 in a storage device and reads out the setting information from the storage device as necessary. The content of the setting information is, for example, information related to the setting of D2D communication and the like.

[0121] As described in the embodiments, the control section 140 performs processing related to the setting for the terminal 20 to perform D2D communication. Further, the control section 140 transmits scheduling of D2D communication and DL communication to the terminal 20 via the transmission section 110. Further, the control section 140 receives information related to HARQ response of D2D communication and DL communication from the terminal 20 via the reception section 120. The functional section in the control section 140 related to signal transmission can be included in the transmission section 110, and the functional section in the control section 140 related to signal reception can be included in the reception section 120.

[0122] <TERMINAL 20>

[0123] Figure 18 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Figure 18 , the terminal 20 has a transmission section 210, a reception section 220, a setting section 230, and a control section 240. Figure 18 The functional configuration shown in the drawing is merely an example. The functional division and the names of the functional sections can be arbitrary as long as the operation related to the embodiments of the present application can be executed.

[0124] The transmission section 210 generates a transmission signal in accordance with transmission data and transmits the transmission signal in a wireless manner. The reception section 220 receives various signals in a wireless manner and acquires higher layer signals from the received physical layer signals. Further, the reception section 220 has a function of receiving an NR-PSS, an NR-SSS, an NR-PBCH, a DL / UL / SL control signal, or a reference signal, or the like, transmitted from the base station 10. Further, for example, as D2D communication, the transmission section 210 transmits a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), or the like, to other terminals 20, and the reception section 220 receives a PSCCH, a PSSCH, a PSDCH, or a PSBCH, or the like, from other terminals 20.

[0125] The setting section 230 stores various setting information received by the reception section 220 from the base station 10 or the terminal 20 in a storage device and reads out as necessary from the storage device. Further, the setting section 230 also stores setting information set in advance. The content of the setting information is, for example, information related to the setting of D2D communication and power saving, or the like.

[0126] As explained in the embodiment, the control section 240 controls D2D communication with other terminals 20 and a power saving state. Further, the control section 240 performs processing related to HARQ of D2D communication and DL communication. Further, the control section 240 transmits, to the base station 10, information related to HARQ response of D2D communication and DL communication scheduled by the base station 10 to other terminals 20. Further, the control section 240 can also perform scheduling of D2D communication to other terminals 20. Further, the control section 240 can autonomously select resources used in D2D communication from a resource selection window in accordance with the result of sensing. Further, the control section 240 performs processing related to MCS in transmission and reception of D2D communication. The functional section in the control section 240 related to signal transmission can be included in the transmission section 210, and the functional section in the control section 240 related to signal reception can be included in the reception section 220.

[0127] (Hardware structure)

[0128] The block diagram used in the explanation of the above-described embodiment Figure 17 andFigure 18 )The functional blocks (structural units) are shown in units of functions. These functional blocks (structural units) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block can be realized by one device that is physically or logically integrated, or two or more devices that are physically or logically separated can be directly or indirectly (for example, using wired, wireless, or the like) connected and realized using the plurality of devices. Each functional block can also be realized by combining software with the one device or the plurality of devices.

[0129] have judgment, decision, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, election, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, and the like, but are not limited thereto. For example, a functional block (structural unit) that causes transmission to function is referred to as a transmitting unit or a transmitter. In any case, as described above, the method of realization is not particularly limited.

[0130] For example, the base station 10, the terminal 20, and the like in one embodiment of the present disclosure can also function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 19 is a diagram illustrating an example of a hardware structure of the base station 10 and the terminal 20 of one embodiment of the present disclosure. The above-described base station 10 and terminal 20 can also be physically configured as a computer device including a processor 1001, a storage 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0131] In addition, in the following description, the expression "device" can be replaced with "circuit", "equipment", "unit", and the like. The hardware structure of the base station 10 and the terminal 20 can be configured to include one or more of each device illustrated, or can be configured not to include a part of the device.

[0132] Each function in the base station 10 and the terminal 20 is realized by reading a predetermined software (program) into a hardware such as the processor 1001, the storage 1002, and causing the processor 1001 to perform an operation and control at least one of communication of the communication device 1004 or reading and writing of data in the storage 1002 and the auxiliary storage 1003.

[0133] The processor 1001 controls the entire computer, for example, by causing an operating system to operate. The processor 1001 can also be constituted by a central processing device (CPU: Central Processing Unit) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like. For example, the control section 140, the control section 240, and the like described above can also be realized by the processor 1001.

[0134] Further, the processor 1001 reads a program (program code), a software module, or data, and the like from at least one of the auxiliary storage 1003 and the communication device 1004 to the storage 1002, and performs various processes based on the same. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiments is used. For example, Figure 17 The control section 140 of the base station 10 illustrated can also be realized by a control program stored to the storage 1002 and operated in the processor 1001. Further, for example, Figure 18 The control section 240 of the terminal 20 illustrated can also be realized by a control program stored to the storage 1002 and operated in the processor 1001. As for the above-described various processes, although it is described that the above-described various processes are executed by one processor 1001, the above-described various processes can also be executed by two or more processors 1001 simultaneously or sequentially. The processor 1001 can also be mounted by one or more chips. In addition, the program can also be transmitted from a network via a telecommunication line.

[0135] The storage 1002 is a computer-readable recording medium, and can also be constituted by at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), and the like. The storage 1002 can also be referred to as a register, a cache, a main storage (main storage device), and the like. The storage 1002 can hold a program (program code), a software module, and the like that can be executed in order to implement the communication method related to one embodiment of the present disclosure.

[0136] The auxiliary storage device 1003 is a computer-readable recording medium such as at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk, an intelligent disk, a flash memory (for example, a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic stripe, and the like. The above-described storage medium can be, for example, a database, a server, and other appropriate medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0137] The communication device 1004 is hardware (a transceiver device) for communication between computers via at least one of a wired network and a wireless network, also referred to as a network device, a network controller, a network card, a communication module, and the like. The communication device 1004 can also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transceiving antenna, an amplification section, a transceiving section, a transmission path interface, and the like can also be implemented by the communication device 1004. The transceiving section can also be installed physically or logically by a transmission section and a reception section.

[0138] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, and the like) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, and the like) that implements output to the outside. In addition, the input device 1005 and the output device 1006 can also be integrally configured (for example, a touch panel).

[0139] Furthermore, the processor 1001 and each device such as the storage device 1002 are connected by a bus 1007 for communication of information. The bus 1007 can be configured using a single bus, or can be configured using different buses for each device.

[0140] Furthermore, the base station 10 and the terminal 20 can be configured to include a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), or the like, and a part or all of the functional blocks can be implemented by the hardware. For example, the processor 1001 can be implemented by using at least one of these hardware.

[0141] (SUMMARY OF EMBODIMENTS)

[0142] As described above, according to the embodiment of the present application, there is provided a terminal having a reception section that receives data from another terminal, a control section that controls a response related to retransmission processing of the data in accordance with which of a power saving state and a normal state the state is, and a transmission section that transmits the response related to the retransmission processing of the data to the another terminal.

[0143] According to the above-described structure, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state than in the normal state. That is, it is possible to reduce the power consumption of the operation related to the HARQ (Hybrid automatic repeat request) response in the inter-terminal direct communication.

[0144] The reception section can also receive an instruction to shift to the power saving state from the other terminal, and the control section can shift the state to the power saving state in accordance with the instruction. According to this structure, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state than in the normal state.

[0145] The control section can also decide not to transmit the response related to the retransmission processing of the data in a case where the response related to the retransmission processing of the data is an ACK. According to this structure, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state than in the normal state.

[0146] The control section can also reduce the number of candidates of channels on which the response related to the retransmission processing is configured to be transmitted in the case where the state is the power saving state than in the case where the state is the normal state. According to this structure, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state than in the normal state.

[0147] The receiving section can also receive the retransmission of the data using a channel corresponding to the data of the "candidate of a channel of a response related to the configuration of the retransmission processing in the case where the state is the power saving state". According to this configuration, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state compared to the normal state.

[0148] Further, according to an embodiment of the present application, there is provided a communication method performed by a terminal, wherein the terminal performs the steps of: receiving data from another terminal; controlling a response related to retransmission processing of the data in accordance with which of a power saving state and a normal state; and transmitting the response related to the retransmission processing of the data to the another terminal.

[0149] According to the above-described configuration, the terminal 20 can reduce the number of times of transmission of the PSFCH in the power saving state compared to the normal state. That is, it is possible to reduce the power consumption of the operation related to the HARQ (Hybrid automatic repeat request) response in the direct communication between terminals.

[0150] (Supplement to Embodiments)

[0151] The above describes an embodiment of the present application, but the disclosed application is not limited to such an embodiment, and a person skilled in the art will understand various modifications, alterations, alternatives, substitutions, and the like. A specific numerical example is described in order to facilitate understanding of the application, but as long as there is no specific indication, these values are only one example, and any appropriate value can be used. The division of items in the above description is not essential to the present application, and items described in two or more items can be used in combination as needed, or items described in one item can be applied to items described in another item (as long as there is no contradiction). The boundary of a functional block or a processing block in a functional block diagram does not necessarily correspond to the boundary of a physical component. The operation of a plurality of functional blocks can be performed by one physical component, or the operation of one functional block can be performed by a plurality of physical components. As for the processing procedure described in the embodiments, the order of the processing can be changed without contradiction. The base station 10 and the terminal 20 are described using a functional block diagram for convenience of description of the processing, but such an apparatus can also be implemented in hardware, in software, or in a combination thereof. Software that operates by a processor possessed by the base station 10 according to the embodiment of the present application and software that operates by a processor possessed by the terminal 20 according to the embodiment of the present application can each be stored in a random access memory (RAM), a flash memory, a read only memory (ROM), an EPROM, an EEPROM, a register, a hard disk (HDD), a removable disk, a CD-ROM, a database, a server, and another appropriate arbitrary storage medium.

[0152] Further, the notification of the information is not limited to the forms / embodiments described in the present disclosure, and can be performed using other methods. For example, the notification of the information can be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. Further, the RRC signaling can also be referred to as an RRC message, for example, can be an RRC connection setup message, an RRC connection reconfiguration message, or the like.

[0153] The forms / embodiments described in the present disclosure can also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), a system using other appropriate systems, and a next-generation system extended therefrom. Further, a plurality of systems (e.g., at least one of LTE and LTE-A and 5G, etc.) can also be combined and applied.

[0154] For the processes, timings, flows, and the like of the forms / embodiments described in this specification, the order can be changed without contradiction. For example, for the methods described in this disclosure, the elements of the various steps are prompted using the exemplified order, but are not limited to the specific order prompted.

[0155] In this specification, specific actions performed by the base station 10 are sometimes performed by an upper node thereof according to the situation. In a network constituted by one or a plurality of network nodes having the base station 10, it is obvious that various actions performed for communication with the terminal 20 can be performed by at least one of the base station 10 and other network nodes (for example, consider MME or S-GW, or the like, but not limited to these) other than the base station 10. In the above, a case where the other network nodes than the base station 10 is one is exemplified, but the other network nodes can also be a combination of a plurality of other network nodes (for example, MME and S-GW).

[0156] The information or the like described in this disclosure can be output from a higher layer (or a lower layer) to a lower layer (or a higher layer). It can also be input or output via a plurality of network nodes.

[0157] The information or the like input or output can be saved in a specific location (for example, a memory), and can be managed using a management table. The information or the like input or output can be rewritten, updated, or appended. The information or the like output can also be deleted. The information or the like input can also be transmitted to other devices.

[0158] The determination in this disclosure can be performed by a value (0 or 1) represented by 1 bit, by a Boolean value (true or false), or by comparison of numerical values (for example, comparison with a predetermined value).

[0159] For software, regardless of being called software, firmware, middleware, microcode, hardware description language, or by another name, it should be broadly interpreted as referring to commands, command sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and the like.

[0160] Moreover, software, commands, information, and so on can be transmitted via transmission media. For example, if the software is transmitted from a website, server, or other remote source using at least one of wired (e.g., coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or the like) and / or wireless (e.g., infrared, microwave, or the like) technologies, then at least one of wired or wireless technologies is included in the definition of transmission media.

[0161] The information, signals, and so on described in the disclosure can be represented using any of a variety of different technologies and techniques. For example, data, commands, instructions, information, signals, bits, symbols, chips, and so on that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0162] In addition, for the terms and the terms required for understanding the disclosure described in the disclosure, terms having the same or similar meanings can be substituted. For example, at least one of a channel and a symbol can also be a signal (signaling). Furthermore, a signal can also be a message. Furthermore, a component carrier (CC) can also be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

[0163] The terms "system" and "network" used in the disclosure can be used interchangeably.

[0164] Furthermore, the information, parameters, and so on described in the disclosure can be represented using absolute values, can be represented using relative values from predetermined values, and can be represented using corresponding other information. For example, a radio resource can also be indicated by an index.

[0165] The names used for the above-described parameters are non-limiting in any respect. Furthermore, the formulas and so on using these parameters are sometimes different from the content explicitly disclosed in the disclosure. Since a variety of channels (e.g., PUCCH, PDCCH, and so on) and information elements can be identified by all appropriate names, a variety of names assigned to the variety of channels and information elements are non-limiting in any respect.

[0166] In the present disclosure, the terms "base station (BS)", "wireless base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", and the like can be used interchangeably. The base station is sometimes also referred to by the terms macro cell, small cell, femto cell, pico cell, and the like.

[0167] A base station can accommodate one or plural (for example, 3) cells. In a case where a base station accommodates plural cells, the coverage area of the base station as a whole can be divided into plural smaller areas, and each of the smaller areas can also be provided with communication services by a base station subsystem (for example, a small base station for indoor use (RRH: Remote Radio Head)). The terms "cell" or "sector" refer to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services in the coverage range.

[0168] In the present disclosure, the terms "mobile station (MS)", "user terminal", "user equipment (UE)", "terminal", and the like can be used interchangeably.

[0169] For a mobile station, the skilled person in the art also sometimes refers to it by the 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, handset, user agent, mobile client, client, or some other suitable terminology.

[0170] At least one of the base station and the mobile station can also be referred to as a transmission device, a reception device, a communication device, or the like. In addition, at least one of the base station and the mobile station can be a device mounted on a mobile body, the mobile body itself, or the like. The mobile body can be a vehicle (for example, an automobile, an airplane, or the like), can be a mobile body that moves in an unmanned manner (for example, a drone, a self-driving automobile, or the like), or can be a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move when performing communication. For example, at least one of the base station and the mobile station can be a sensor or the like IoT (Internet of Things) device.

[0171] Furthermore, the base station in the present disclosure can also be replaced with a user terminal. For example, with respect to a structure in which communication between a base station and a user terminal is replaced with communication between a plurality of terminals 20 (for example, also referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), or the like), each form / embodiment of the present disclosure can also be applied. In this case, a structure in which the terminal 20 has the functions of the base station 10 described above can also be provided. Furthermore, the expressions "uplink" and "downlink" and the like can also be replaced with expressions corresponding to inter-terminal communication (for example, "side"). For example, the uplink channel, the downlink channel, and the like can also be replaced with a side channel.

[0172] Likewise, the user terminal in the present disclosure can also be replaced with a base station. In this case, a structure in which the base station has the functions of the user terminal described above can also be provided.

[0173] The terms "determining" and "deciding" as used in the present disclosure also include a variety of actions. For example, "determining" or "deciding" can include "determining" or "deciding" that an item has been judged, calculated, computed, processed, derived, investigated, searched (e.g., searched in a table, a database, or other data structure), ascertained, or the like. In addition, "determining" or "deciding" can include "determining" or "deciding" that an item has been received (e.g., received information), transmitted (e.g., transmitted information), input, output, accessed (e.g., accessed data in a memory), or the like. Furthermore, "determining" or "deciding" can include "determining" or "deciding" that an item has been resolved, selected, chosen, established, compared, or the like. That is, "determining" or "deciding" can include "determining" or "deciding" that any action has been performed. In addition, "determining" or "deciding" can be replaced by "assuming", "expecting", "considering", or the like.

[0174] The terms "connected" and "coupled" or all modifications thereof are intended to mean all possible direct or indirect connections or couplings between two or more elements. Such a connection or coupling between elements can include one or more intervening elements. The coupling or connection between elements can be physical or logical, or a combination thereof. For example, "connected" can be replaced by "accessed". In the present disclosure, it can be considered that two elements are "connected" or "coupled" to each other using at least one of a wire, a cable, and a printed electrical connection, and as some non-limiting and non-inclusive examples, electromagnetic energy having a wavelength in the radio frequency region, the microwave region, and the light (both visible and invisible) region is used to "connect" or "couple" to each other.

[0175] A reference signal can be simply referred to as RS (Reference Signal), and can be referred to as a pilot according to the applied standard.

[0176] The expression "based on" as used in the present disclosure is not "only based on", unless explicitly noted otherwise. In other words, the expression "based on" means both "only based on" and "at least based on".

[0177] Any reference to elements using the expressions "1st", "2nd", and the like used in the present disclosure does not necessarily limit the number or order of the elements. These expressions can be used in the present disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a 1st element and a 2nd element does not mean that only two elements can be taken or that in any form the 1st element must precede the 2nd element.

[0178] The expression "unit" in the structure of each of the above-described apparatuses can be replaced with the expression "part", "circuit", "device", or the like.

[0179] When the expressions "include", "including", and variations thereof are used in the present disclosure, these expressions mean the same as the expression "comprising". Also, the expression "or" used in the present disclosure does not mean the exclusive or.

[0180] A radio frame can be composed of one or more frames in the time domain. In the time domain, one or more frames can be referred to as a subframe. A subframe can be further composed of one or more slots in the time domain. A subframe can also be a fixed length of time (e.g., 1 ms) independent of numerology.

[0181] A numerology can be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. The numerology can indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), a number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, a specific windowing process performed by a transceiver in the time domain, and the like.

[0182] A slot can be constituted by one or a plurality of symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, and the like) in the time domain. A slot can be a time unit based on a numerology.

[0183] A slot can include a plurality of mini-slots. Each mini-slot can be constituted by one or a plurality of symbols in the time domain. Further, a mini-slot can also be referred to as a sub-slot. A mini-slot can be constituted by a smaller number of symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-slot can be referred to as PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot can be referred to as PDSCH (or PUSCH) mapping type B.

[0184] A radio frame, a subframe, a slot, a mini-slot, and a symbol each represent a time unit in transmission of a signal. A radio frame, a subframe, a slot, a mini-slot, and a symbol can each be referred to by other names.

[0185] For example, 1 subframe can also be referred to as a transmission time interval (TTI), a plurality of consecutive subframes can also be referred to as a TTI, 1 slot or 1 mini-slot can also be referred to as a TTI. That is, at least one of a subframe and a TTI can be a subframe (1 ms) in the existing LTE, can be a period shorter than 1 ms (for example, 1-13 symbols), or can be a period longer than 1 ms. In addition, a unit representing a TTI can not be referred to as a subframe, but can be referred to as a slot, a mini-slot, or the like.

[0186] Here, a TTI, for example, refers to a minimum time unit of scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling in which a radio resource (a frequency bandwidth, a transmission power, and the like, which can be used in each terminal 20) is allocated to each terminal 20 in units of a TTI. In addition, the definition of a TTI is not limited thereto.

[0187] A TTI can be a transmission time unit of a data packet (a transport block) after channel coding, a code block, a codeword, and the like, or can be a processing unit of scheduling, link adaptation, and the like. In addition, when a TTI is given, a time interval (for example, a number of symbols) in which a transport block, a code block, a codeword, and the like are actually mapped can be shorter than the TTI.

[0188] In addition, in a case where 1 slot or 1 mini-slot is referred to as a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) can constitute a minimum time unit of scheduling. Further, the number of slots (the number of mini-slots) constituting the minimum time unit of scheduling can be controlled.

[0189] A TTI having a time length of 1 ms can also be referred to as a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than the 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-slot, a sub-slot, a slot, etc.

[0190] In addition, for a long TTI (e.g., a normal TTI, a subframe, etc.), a TTI having a time length longer than 1 ms can be replaced, and for a short TTI (e.g., a shortened TTI, etc.), a TTI having a TTI length shorter than the long TTI (long TTI) and having a TTI length of 1 ms or more can be replaced.

[0191] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and in the frequency domain, can include one or more contiguous subcarriers. The number of subcarriers included in the RB can be the same regardless of the numerology, for example, can be 12. The number of subcarriers included in the RB can also be determined according to the numerology.

[0192] In addition, the time domain of the RB can include one or more symbols, and can be the length of 1 slot, 1 mini-slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. can each be constituted by one or more resource blocks.

[0193] In addition, one or more RBs can be referred to as a physical resource block (PRB), a subcarrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0194] In addition, a resource block can be constituted by one or more resource elements (REs). For example, 1 RE can be a wireless resource area of 1 subcarrier and 1 symbol.

[0195] A bandwidth part (BWP) (may be referred to as a partial bandwidth, etc.) can mean a subset of contiguous common RBs for a certain numerology in a certain carrier. Here, the common RBs can be determined by the index of the RBs from a common reference point of the carrier. The PRB can be defined in a certain BWP and numbered within the BWP.

[0196] A BWP can include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs can be configured for the terminal 20 within one carrier.

[0197] At least one of the configured BWPs can be active, and a case in which the terminal 20 transmits / receives a predetermined signal / channel outside the active BWP can not be assumed. In addition, "cell", "carrier", etc. in the present disclosure can be replaced with "BWP".

[0198] The structures of the radio frame, the subframe, the slot, the mini-slot, the symbol, etc. described above are merely examples. For example, the number of subframes included in the radio frame, the number of slots per subframe or radio frame, the number of mini-slots included in the slot, the number of symbols and RBs included in the slot or mini-slot, the number of subcarriers included in the RB, the number of symbols in the TTI, the symbol length, the cyclic prefix (CP) length, etc. in the structure of the radio frame, the subframe, the slot, the mini-slot, the symbol, etc. can be variously changed.

[0199] In the present disclosure, for example, in a case where an article is added by translation like a, an, and the in English, the present disclosure can also include a case where the article following these articles is plural.

[0200] In the present disclosure, the expression "A is different from B" can also mean "A and B are mutually different". In addition, the expression can also mean "A and B are each different from C". The expressions "separate", "combine", etc. can also be interpreted as "different" as well.

[0201] Each form / implementation described in the present disclosure can be used alone, can be used in combination, and can also be switched in use according to execution. In addition, the notification of the predetermined information is not limited to be performed explicitly (for example, the notification of "X is") and can also be performed implicitly (for example, the notification of the predetermined information is not performed).

[0202] In addition, the PSFCH in the present disclosure is an example of a channel that transmits / receives a response related to a retransmission process. The PSFCH opportunity is an example of a candidate that configures a channel that transmits / receives a response related to a retransmission process. The PSSCH is an example of data.

[0203] The present disclosure has been described in detail above, but it should be understood that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in various modified and changed forms without departing from the spirit and scope of the present disclosure defined by the claims. Therefore, the purpose of the present disclosure is to illustrate, and the present disclosure is not intended to have any limiting meaning.

[0204] Label Explanation

[0205] 10: base station;

[0206] 110: transmission section;

[0207] 120: reception section;

[0208] 130: setting section;

[0209] 140: control section;

[0210] 20: terminal;

[0211] 210: transmission section;

[0212] 220: reception section;

[0213] 230: setting section;

[0214] 240: control section;

[0215] 1001: processor;

[0216] 1002: storage device;

[0217] 1003: auxiliary storage device;

[0218] 1004: communication device;

[0219] 1005: input device;

[0220] 1006: output device.

Claims

1. A terminal having: a control section that controls transmission of a shared channel for inter-terminal communication to another terminal based on a schedule for the inter-terminal communication received from a base station; a reception section that receives a HARQ response from the other terminal via a feedback channel for the inter-terminal communication; and a transmission section that transmits a parameter related to a power saving state of the other terminal to the base station, the control section determines a parameter related to timing of transmission of the shared channel based on the parameter related to the power saving state, and the reception section receives the HARQ response at other timing corresponding to the timing.

2. The terminal according to claim 1, wherein the reception section receives the parameter related to the power saving state from the other terminal.

3. A base station having: a transmission section that transmits a schedule for inter-terminal communication to a terminal, and the terminal transmits a shared channel for the inter-terminal communication to another terminal based on the schedule, the terminal receives a HARQ response from the other terminal via a feedback channel for the inter-terminal communication, determines a parameter related to timing of transmission of the shared channel based on a parameter related to a power saving state, and receives the HARQ response at other timing corresponding to the timing.

4. A terminal having: a transmission section that transmits a parameter related to a power saving state to another terminal, and a reception section that receives a shared channel at timing of transmission of the shared channel determined by the other terminal based on the parameter related to the power saving state, the transmission section transmits a HARQ response to the other terminal via a feedback channel for inter-terminal communication at other timing corresponding to the timing.

5. A communication method comprising, by a terminal: a control step of controlling transmission of a shared channel for inter-terminal communication to another terminal based on a schedule for the inter-terminal communication received from a base station; a reception step of receiving a HARQ response from the other terminal via a feedback channel for the inter-terminal communication; and a transmission step of transmitting a parameter related to a power saving state of the other terminal to the base station, in the control step, a parameter related to timing of transmission of the shared channel is determined based on the parameter related to the power saving state, and in the reception step, the HARQ response is received at other timing corresponding to the timing. ​ ​ ​ ​ ​ ​ a receiving section that receives from the terminal a parameter relating to the power saving state of the other terminal, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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