Terminal, Communication Method, and Integrated Circuit

Abstract

To improve efficiency of resource allocation in wireless communication.SOLUTION: A terminal includes a control circuit that sets a time resource interval to be reserved from a plurality of time resource interval candidate values, and a transmission circuit that transmits sidelink control information (SCI) including first information for notifying a user of the time resource interval to be reserved. The plurality of time resource interval candidate values includes a multiplication value of a first value, which is an integer value, and a second value that is variable in two patterns, and the second information indicating the plurality of time resource interval candidate values is notified by a higher layer.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a terminal, a communication method, and an integrated circuit.

Background Art

[0002] A communication system called the fifth-generation mobile communication system (5G) is being studied. In 5G, it is being considered to flexibly provide functions for each use case that requires an increase in high-speed communication traffic, an increase in the number of connected terminals, high reliability, and low latency. The 3rd Generation Partnership Project (3GPP), which is an international standardization organization, is studying the advancement of communication systems from both aspects of the advancement of the Long Term Evolution (LTE) system and New Radio (NR).

[0003] In 3GPP, the support for vehicle to everything (V2X) has been studied in the LTE system. Support for V2X is also being studied in NR, which can use a wider bandwidth than the LTE system (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, there is room for study on a method for improving the efficiency of resource (for example, at least one of time resource and frequency resource) allocation in wireless communication.

[0006] Non-limiting embodiments of the present disclosure contribute to providing a terminal, a communication method, and an integrated circuit that can improve the efficiency of resource allocation in wireless communication.

Means for Solving the Problems

[0007] A terminal according to an embodiment of the present disclosure includes a control circuit that determines first information including a second value obtained by dividing an interval of reserved time resources by a first value, and second information indicating an association between the second value and the first information and one of at least one candidate when there are a plurality of candidates for at least one of them, and a transmission circuit that transmits the first information and the second information.

[0008] These general or specific aspects may be implemented in a system, apparatus, method, integrated circuit, computer program, or recording medium, or may be implemented in any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

Advantages of the Invention

[0009] According to an embodiment of the present disclosure, the efficiency of resource allocation in wireless communication can be improved.

[0010] Further advantages and effects in an embodiment of the present disclosure will be clarified from the specification and drawings. Such advantages and / or effects are provided by some embodiments and the features described in the specification and drawings, respectively, but not necessarily all are provided in order to obtain one or more identical features.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0013] <5G NR System Architecture and Protocol Stack> 3GPP is continuing work towards the next release of 5th generation mobile phone technology (also simply referred to as "5G"), including the development of new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which enables the prototyping and commercial deployment of terminals (e.g., smartphones) compliant with the 5G NR standard.

[0014] For example, the system architecture as a whole assumes an NG-RAN (Next Generation - Radio Access Network) with a gNB. The gNB provides the UE-side termination of the protocols for the user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) of NG radio access. The gNBs are connected to each other by the Xn interface. Also, the gNB is connected to the NGC (Next Generation Core) by the Next Generation (NG) interface, more specifically, to the AMF (Access and Mobility Management Function) (e.g., a specific core entity performing the AMF) by the NG-C interface, and to the UPF (User Plane Function) (e.g., a specific core entity performing the UPF) by the NG-U interface. The NG-RAN architecture is shown in FIG. 1 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0015] The protocol stack of the user plane of NR (see, for example, 3GPP TS 38.300, section 4.4.1) includes the PDCP (Packet Data Convergence Protocol, see section 6.4 of TS 38.300) sublayer, the RLC (Radio Link Control, see section 6.3 of TS 38.300) sublayer, and the MAC (Medium Access Control, see section 6.2 of TS 38.300) sublayer, which are terminated on the network side at the gNB. Also, a new sublayer of the access stratum (AS), the SDAP (Service Data Adaptation Protocol), is introduced on top of the PDCP (see, for example, section 6.5 of 3GPP TS 38.300). Also, the protocol stack of the control plane is defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of the layer 2 functions is described in section 6 of TS 38.300. The functions of the PDCP sublayer, the RLC sublayer, and the MAC sublayer are listed in sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in section 7 of TS 38.300.

[0016] For example, the Medium-Access-Control layer handles the multiplexing of logical channels and scheduling and scheduling-related functions, including handling various numerologies.

[0017] For example, the physical layer (PHY) is responsible for encoding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. Also, the physical layer handles the mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. The physical channel corresponds to a set of time-frequency resources used for the transmission of a specific transport channel, and each transport channel is mapped to the corresponding physical channel. For example, the physical channels include, as uplink physical channels, PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), and as downlink physical channels, PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), PBCH (Physical Broadcast Channel).

[0018] The use cases / deployment scenarios of NR may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communication (mMTC) with diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in the downlink and 10 Gbps in the uplink) and effective (user-experienced) data rates about three times that provided by IMT-Advanced. On the other hand, in the case of URLLC, more stringent requirements are for ultra-low latency (0.5 ms each for UL and DL in terms of user plane latency) and high reliability (1 - 10 within 1 ms) -5is imposed on. Finally, in mMTC, preferably a high connection density (1,000,000 devices / km in an urban environment 2 ), wide coverage in harsh environments, and extremely long-lived batteries (15 years) for low-cost devices may be required.

[0019] Therefore, a new numerology of OFDM suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may not be effective for other use cases. For example, for low-latency services, preferably, the symbol length is shorter (and thus the subcarrier spacing is larger) than that of mMTC services and / or the number of symbols per scheduling interval (also referred to as TTI) may be required to be smaller. Further, in a deployment scenario where the channel delay spread is large, preferably, the CP length may be required to be longer than in a scenario where the delay spread is short. The subcarrier spacing may be optimized according to the situation so that a similar CP overhead is maintained. The value of the subcarrier spacing supported by NR may be one or more. Correspondingly, currently, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz... are being considered. Symbol length T u and subcarrier spacing Δf are directly related by the formula Δf = 1 / T u . Similar to the LTE system, the term "resource element" can be used to mean the smallest resource unit composed of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0020] In the new radio system 5G-NR, for each numerology and each carrier, a resource grid of subcarriers and OFDM symbols is defined for each of the uplink and downlink. Each element of the resource grid is called a resource element and is specified based on the frequency index in the frequency domain and the symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0021] <Functional Separation between NG-RAN and 5GC in 5G NR> Figure 2 shows the functional separation between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0022] For example, gNB and ng-eNB host the following main functions: - Functions of radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic allocation (scheduling) of resources to the UE in both the uplink and downlink; - IP header compression, encryption, and integrity protection of data; - Selection of AMF at UE attachment when the routing to AMF from the information provided by the UE cannot be determined; - Routing of user plane data towards UPF; - Routing of control plane information towards AMF; - Setup and release of connections; - Scheduling and transmission of paging messages; - Scheduling and transmission of system information messages (source is AMF or operation, admission, maintenance function (OAM)); - Configuration of measurements and measurement reports for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Support for network slicing; - Management of QoS flows and mapping to data radio bearers; - Support for UEs in the RRC_INACTIVE state; - Delivery function for NAS messages; - Sharing of the radio access network; - Dual connectivity; - Tight cooperation between NR and E-UTRA.

[0023] The Access and Mobility Management Function (AMF) hosts the following main functions: - Function to terminate Non-Access Stratum (NAS) signaling; - Security of NAS signaling; - Security control of the Access Stratum (AS); - Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; - Reachability of idle-mode UEs (including control and execution of paging retransmission); - Management of the registration area; - Support for in-system mobility and inter-system mobility; - Access authentication; - Access authorization including checking of roaming rights; - Mobility management control (subscription and policy); - Support for network slicing; - Selection of the Session Management Function (SMF).

[0024] Furthermore, the User Plane Function (UPF) hosts the following main functions: - Anchor point for intra-RAT mobility / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) session point for interconnection with the data network; - Packet routing and forwarding; - Packet inspection and policy rule enforcement in the user plane part; - Reporting of traffic usage; - Uplink classifier for supporting routing of traffic flows to the data network; - Branching Point for supporting multi-homed PDU session; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping to QoS flows of SDF); - Downlink packet buffering and trigger function for downlink data notification.

[0025] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Policy enforcement and QoS in the control part; - Notification of downlink data.

[0026] <Procedures for RRC connection setup and reconfiguration> Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entity) when the UE in the NAS part transitions from RRC_IDLE to RRC_CONNECTED (see TS 38.300 v15.6.0).

[0027] RRC is the upper layer signaling (protocol) used for the configuration of the UE and gNB. With this transition, the AMF prepares UE context data (which includes, for example, PDU session context, security keys, UE Radio Capability, UE Security Capabilities, etc.) and sends it to the gNB together with an INITIAL CONTEXT SETUP REQUEST. Then, the gNB activates AS security with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE and the UE responding to the gNB with a SecurityModeComplete message. After that, the gNB sends an RRCReconfiguration message to the UE, and upon receiving the RRCReconfigurationComplete from the UE in response, performs a reconfiguration to set up Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For a signaling-only connection, since SRB2 and DRB are not set up, the steps related to RRCReconfiguration are skipped. Finally, the gNB notifies the AMF in an INITIAL CONTEXT SETUP RESPONSE that the setup procedure is complete.

[0028] Therefore, in the present disclosure, there is provided an entity (e.g., AMF, SMF, etc.) of a 5th Generation Core (5GC) including a control circuit that establishes a Next Generation (NG) connection with a gNodeB during operation, and a transmission unit that transmits an initial context setup message to the gNodeB via the NG connection during operation so that a signaling radio bearer between the gNodeB and a user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling including a resource allocation setting information element (IE) to the UE via the signaling radio bearer. Then, the UE performs transmission on the uplink or reception on the downlink based on the resource allocation setting.

[0029] <IMT Usage Scenarios After 2020> FIG. 4 shows some of the use cases for 5G NR. In the 3rd generation partnership project new radio (3GPP NR), three use cases envisioned by IMT-2020 to support a variety of services and applications are being considered. The formulation of the first-phase specifications for enhanced mobile-broadband (eMBB) has been completed. Current and future work includes, in addition to expanding the support for eMBB, standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). FIG. 4 shows some examples of the envisioned usage scenarios of IMT after 2020 (see, for example, ITU-R M.2083, FIG. 2).

[0030] URLLC use cases have strict requirements for performance such as throughput, latency (delay), and availability. The URLLC use cases are envisioned as one of the enabling technologies to realize these future applications such as wireless control of industrial production processes or manufacturing processes, remote medical surgery, automation of power transmission and distribution in smart grids, and traffic safety. The ultra-high reliability of URLLC is supported by identifying technologies that meet the requirements set by TR 38.913. In NR URLLC in Release 15, important requirements include that the target user plane latency is 0.5 ms in UL (uplink) and 0.5 ms in DL (downlink). The general URLLC requirement for a single packet transmission is that the block error rate (BLER) is 1E-5 for a packet size of 32 bytes when the user plane latency is 1 ms.

[0031] From the perspective of the physical layer, reliability can be improved in many ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, repetition of PDCCH, etc. However, this room can expand for the realization of ultra-high reliability as NR becomes more stable and more developed (regarding the important requirements of NR URLLC). Specific use cases of NR URLLC in Release 15 include extended reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0032] In addition, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable numerology, non-slot-based scheduling by flexible mapping, grant-free uplink (set grant), slot-level repetition in the data channel, and pre-emption in the downlink. Pre-emption means that a transmission for which resources have already been allocated is stopped, and the already allocated resources are used for other transmissions with lower latency / higher priority requirements requested later. Therefore, an already permitted transmission is replaced by a later transmission. Pre-emption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be replaced by a transmission of service type B (such as eMBB). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5.

[0033] The characteristics of the use cases of mMTC (massive machine type communication) are typically that there are a very large number of connected devices that transmit relatively small amounts of data and are not easily affected by latency. The devices are required to be low-cost and have a very long battery life. From the perspective of NR, using a very narrow bandwidth part is one solution that can save power from the UE's perspective and enable a long battery life.

[0034] As described above, the scope of reliability improvement in NR is expected to become wider. One of the important requirements for all cases, for example, the important requirements for URLLC and mMTC are high reliability or ultra-high reliability. Several mechanisms can improve reliability from the wireless perspective and the network perspective. Generally, there are two to three important areas that may help improve reliability. These areas include compact control channel information, repetition of data channels / control channels, and diversity regarding the frequency domain, time domain, and / or spatial domain. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0035] Regarding NR URLLC, additional use cases with more stringent requirements, such as factory automation, transportation, and power distribution, are envisioned. Stringent requirements mean high reliability (reliability up to 10 -6 levels), high availability, packet size up to 256 bytes, time synchronization up to about several μs (depending on the use case, the value can be set to 1 μs or several μs according to the frequency range and short latency of about 0.5 ms to 1 ms, for example, 0.5 ms latency in the target user plane), and latency of about 0.5 ms to 1 ms.

[0036] Furthermore, for NR URLLC, several technical enhancements may be possible from the perspective of the physical layer. These technical enhancements include enhancements to the PDCCH (Physical Downlink Control Channel) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. Also, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Additionally, enhancements to the PUSCH related to mini-slot level hopping and enhancements to retransmission / repetition may be possible. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0037] <QoS Control> The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flow) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flow). Therefore, at the NAS level, a QoS flow is the finest-grained QoS classification in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI) that is carried in an encapsulation header via the NG-U interface.

[0038] For each UE, the 5GC establishes one or more PDU sessions. For each UE, in accordance with the PDU session, the NG-RAN establishes at least one Data Radio Bearer (DRB) as shown above with reference to, for example, Figure 3. Also, additional DRBs for the QoS flows of that PDU session can be set later (it depends on the NG-RAN when to set). The NG-RAN maps the packets belonging to various PDU sessions to various DRBs. While NAS-level packet filters in the UE and 5GC associate UL packets and DL packets with QoS flows, AS-level mapping rules in the UE and NG-RAN associate UL QoS flows and DL QoS flows with DRBs.

[0039] Figure 5 shows the 5G NR non-roaming reference architecture (see TS 23.501 v16.1.0, section 4.23). The Application Function (AF) (for example, an external application server hosting 5G services as illustrated in Figure 4) communicates with the 3GPP core network to provide services. For example, accessing the Network Exposure Function (NEF) or interacting with the policy framework for policy control (for example, QoS control) (see Policy Control Function (PCF)) to support applications that affect traffic routing. Based on operator deployment, Application Functions considered to be trusted by the operator can communicate directly with the relevant Network Functions. Application Functions not permitted by the operator to directly access Network Functions communicate with the relevant Network Functions using the external exposure framework via the NEF.

[0040] FIG. 5 further shows additional functional units of the 5G architecture, namely, Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and operate in a cloud computing environment.

[0041] Accordingly, in the present disclosure, in operation, to establish a PDU session including a radio bearer between a gNodeB and a UE according to QoS requirements, a request including QoS requirements for at least one of URLLC services, eMMB services, and mMTC services is transmitted to at least one of the functions of the 5GC (e.g., NEF, AMF, SMF, PCF, UPF, etc.), and a control circuit that provides services using the established PDU session in operation. An application server (e.g., AF of the 5G architecture) is provided.

[0042] [V2X] V2X assumes communication, for example, between vehicles (V2V: Vehicle to Vehicle), between a vehicle and infrastructure (V2I: Vehicle to Infrastructure), between a pedestrian and a vehicle (V2P: Vehicle to Pedestrian), or between a vehicle and a network (V2N: Vehicle to Network).

[0043] In V2V, V2I, or V2P, for example, without going through a network with a base station (e.g., also called a base station (BS), gNB in NR, or eNB in LTE), terminals (or also called user equipment (UE)) can directly transmit and receive with each other using a link called "Sidelink (SL)" or "PC5". Also, in V2N, for example, communication via a link between a base station and a terminal (e.g., also called "Uu") is assumed.

[0044] The resources used for the sidelink are set, for example, by an SL Band width part (BWP) and a resource pool.

[0045] The SL BWP is, for example, the frequency band that a terminal can use for the sidelink. The SL BWP may be set separately from the Down link (DL) BWP and Uplink (UL) BWP set for a link between a base station and a terminal (e.g., the Uu link). Note that there may also be an overlap in the frequency band between the SL BWP and the UL BWP.

[0046] The resource pool includes, for example, resources in the frequency domain (e.g., also called the frequency direction or frequency axis) and time domain (e.g., also called the time direction or time axis) specified within the SL BWP. For example, multiple resource pools may be set for one terminal.

[0047] [Sidelink in NR] In NR V2X, in transmission and reception on the sidelink, for example, support for unicast, groupcast, and broadcast is being considered.

[0048] In unicast, for example, one-to-one transmission from a transmitting terminal (also referred to as a transmitter UE or Tx UE) to a receiving terminal (also referred to as a receiver UE or Rx UE) is assumed. Also, in groupcast, for example, transmission from a transmitting terminal to a plurality of receiving terminals included in a certain group is assumed. Also, in broadcast, for example, transmission from a transmitting terminal without specifying a receiving terminal is assumed.

[0049] Also, in the sidelink of NR, for example, the following channel settings are being considered.

[0050] <PSCCH: physical SL control channel> In PSCCH, for example, a control signal called sidelink control information (SCI) is transmitted and received. SCI includes, for example, information related to the transmission and reception of PSSCH, such as resource allocation information for a data signal (for example, PSSCH: physical SL shared channel).

[0051] Also, for example, SCI may include information about the transmitting terminal (in other words, the source terminal) (for example, Layer 1 source ID), and information about the receiving terminal (in other words, the destination terminal) (for example, Layer 1 destination ID). Based on this information, the transmitting terminal and the receiving terminal are identified.

[0052] <pssch> In PSSCH, for example, data signals are transmitted and received.

[0053] <PSFCH:physical SL feedback channel> In PSFCH, for example, feedback signals (e.g., hybrid automatic repeat request (HARQ) feedback) for PSSCH (e.g., data signals) are transmitted and received. The feedback signal may include, for example, a response signal (e.g., ACK / NACK information, also referred to as HARQ-ACK) indicating ACK or NACK. The feedback signal is considered to be applicable, for example, when PSSCH is transmitted and received in unicast and groupcast. ACK and NACK may be referred to as HARQ-ACK and HARQ-NACK, respectively.

[0054] <PSBCH:physical SL broadcast channel> In PSBCH, broadcast signals are transmitted and received.

[0055] [Sidelink communication mode] For sidelink communication, there are, for example, two modes (e.g., Mode 1 and Mode 2).

[0056] In Mode 1, the base station determines (in other words, schedules) the resources (e.g., called SL resources) used by the terminal in the sidelink.

[0057] In Mode 2, the terminal determines the SL resources from the resources within a preset resource pool. In other words, in Mode 2, the base station does not schedule the SL resources.

[0058] Mode 1 is assumed to be used, for example, in an environment where the connection between the base station and the terminal is established and the terminal can receive instructions from the base station for sidelink communication. In Mode 2, for example, the terminal can transmit even without an instruction from the base station, so sidelink communication can be performed including terminals under different operators or terminals outside the coverage area.

[0059] The above has been described with respect to sidelink.

[0060] For example, in LTE V2X, periodic signal transmission in the time domain is assumed. Based on this assumption, for example, in addition to the time resources (e.g., slots) for the signals notified by SCI, time resources behind the said time resources can be reserved for the terminal. The SCI that notifies the resources reserved for the terminal (in other words, the allocated resources) can be received by other terminals in addition to the terminal to which allocation is targeted (in other words, the destination terminal of the SCI transmission). In other words, the resources reserved by the SCI can be detected by other terminals different from the terminal to which allocation is targeted. When each terminal selects the resources to be used, for example, by avoiding the use of resources reserved for other terminals, the resource collision probability can be reduced.

[0061] For example, the format of SCI (e.g., "SCI format 1"), which is a control signal transmitted in PSCCH, includes the following information.

[0062] "Priority" (e.g., 3 bits): "Priority" is information that notifies the priority of the transport block (TB) transmitted in PSSCH.

[0063] "Resource reservation" (e.g., 4 bits): "Resource reservation" is information that notifies the time interval between the TB included in the PSCCH transmitted in the same slot where the SCI is located and the PSSCH including the next TB. For example, "Resource reservation" is information that notifies the interval between the resources corresponding to the current TB and the next TB (in other words, the interval between TBs).

[0064] "Frequency resource location of initial transmission and retransmission": "Frequency resource location of initial transmission and retransmission" is information that allocates resources in the frequency domain in sub-channel units. For example, the terminal may assume the use of the frequency resources indicated in this information in both the slot where the SCI is located and the reserved slots behind that slot. In the frequency domain, consecutive sub-channels may be allocated. The number of bits of "Frequency resource location of initial transmission and retransmission" is represented, for example, as follows.

Number

[0065] Here, N subchannel SL indicates, for example, the total number of sub-channels in the resource pool.

[0066] "Time gap between initial transmission and retransmission" (for example, 4 bits): "Time gap between initial transmission and retransmission" is information that notifies the time interval (e.g., also called a gap) between the initial transmission and retransmission of the same transport block (TB).

[0067] "Modulation and coding scheme" (e.g., 5 bits): "Modulation and coding scheme" is information that notifies the modulation and coding scheme (MCS).

[0068] "Retransmission index" (e.g., 1 bit): "Retransmission index" is information that notifies whether it is the initial transmission or a retransmission.

[0069] In LTE, for example, based on the above-mentioned SCI information, resources for multiple transport blocks (TBs) are allocated (in other words, reserved). For example, in LTE, resources for 4 slots can be reserved for the transmission of a TB (e.g., initial transmission), the retransmission of the TB, the transmission of the next TB different from the TB (e.g., initial transmission), and the retransmission of the next TB in the slot where the SCI is located.

[0070] The information included in SCI format 1 has been described above.

[0071] Figure 6 shows an example of resource allocation using SCI.

[0072] In Figure 6, as an example, the time resource corresponding to 1 ms is denoted as "slot", but the unit of the time resource corresponding to 1 ms is not limited to slot. For example, in LTE, the time resource corresponding to 1 ms is called "subframe".

[0073] In FIG. 6, as an example, sub-channels #1 and #2 are allocated to the terminal in the frequency domain. The sub-channel may be notified to the terminal, for example, by "Frequency resource location of initial transmission and retransmission". Also, for the terminal, the first transmission of TB#1 is allocated to slot #0 in the time domain.

[0074] Also, in FIG. 6, as an example, the interval between TBs notified by "Resource reservation" in the SCI that notifies Slot #0 allocated to the first transmission of TB#1 is set to 100 ms (for example, the time interval for 100 slots). Also, in FIG. 6, as an example, the time interval (or gap) between the first transmission and retransmission notified by "Time gap between initial transmission and retransmission" in the SCI that notifies Slot #0 allocated to the first transmission of TB#1 is set to 2 ms (for example, the time interval for 2 slots).

[0075] In the resource allocation in the time domain shown in FIG. 6, for example, based on the information included in the SCI transmitted in slot #0, for the terminal, slots at 100-ms intervals from slot #0 (for example, Slot #0, slot #100, slot #200,...) and slots at 100-ms intervals from slot #2 (for example, Slot #2, slot #102, slot #202,...) are reserved. Also, in the resource allocation in the frequency domain shown in FIG. 6, for example, based on the information included in the above SCI, sub-channels #1 and #2 in each of the reserved slots are reserved for the terminal.

[0076] Also, in FIG. 6, for example, it is possible that the terminal fails to receive the SCI transmitted in slot #0 and succeeds in receiving the SCI transmitted in slot #2. In this case, for the terminal, for example, it is notified that the TB transmitted in Slot #2 is a retransmission by the "Retransmission index" included in the SCI transmitted in slot #2, and the time interval between the initial transmission and the retransmission (for example, a time interval of 2 ms or two slots) is notified by the "Time gap between initial transmission and retransmission". For example, based on these notifications, the terminal can identify (in other words, recognize or determine) the time resource assigned to the initial transmission of the TB with the slot #0 in which the reception of the SCI has failed. Therefore, even when the terminal fails to receive the SCI, for the terminal, the slots with a period of 100 ms from slot #0 and the slots with a period of 100 ms from slot #2, and sub-channels #1 and #2 in each of these slots are reserved.

[0077] The above has described LTE V2X.

[0078] However, the resource reservation method (or allocation method) in the sidelink of NR V2X has not been sufficiently studied. Therefore, in one embodiment of the present disclosure, a method for improving the efficiency of resource allocation (or resource reservation) in sidelink communication, such as time resources (for example, intervals or gaps) or frequency resources (for example, sub-channels), will be described.

[0079] (Embodiment 1) In this embodiment, a method for setting time resources in sidelink communication will be described.

[0080] In LTE, when "Resource reservation" is notified to a terminal (e.g., a receiving terminal) by SCI, the terminal determines the interval between transport blocks (TBs) by referring to an association (e.g., which may be represented by a table) between the "Resource reservation" shown in FIG. 7 and a value "X" regarding the interval between TBs. For example, the value "X" shown in FIG. 7 is the value obtained by dividing the interval between TBs by 100. The association between the "Resource reservation" and "X" shown in FIG. 7 may be notified (or set) from the base station to each terminal by a higher layer.

[0081] For example, the terminal can set 20 ms, 50 ms, or 100X ms (100 times X, where X is an integer from 1 to 10) at an interval of X×100 ms by referring to the association shown in FIG. 7. In LTE (e.g., FIG. 7), among the intervals set for the terminal, 20 ms (X = 0.2) is the shortest interval, and 1000 ms (X = 10) is the longest interval.

[0082] However, in NR, it is required to support more diverse traffic types than LTE. Therefore, in NR, it can be assumed that, for example, it may not be possible to support intervals similar to those that can be set in LTE (e.g., FIG. 7). For example, in NR, an interval shorter than the shortest interval that can be set in LTE (e.g., FIG. 7) = 20 ms may be set. Or, in NR, an interval longer than the longest interval that can be set in LTE (e.g., FIG. 7) = 1000 ms may be set.

[0083] Therefore, in one embodiment of the present disclosure, a method for more flexibly setting time resources (e.g., intervals) in sidelink communication will be described.

[0084] [Overview of the communication system] The communication system according to this embodiment includes a base station 100 and a terminal 200.

[0085] FIG. 8 is a block diagram showing a configuration example of a part of the terminal 200 according to the present embodiment. In the terminal 200 shown in FIG. 8, a control unit (for example, corresponding to a control circuit) determines first information including a second value (X) obtained by dividing an interval of time resources to be reserved by a first value (W), and second information indicating one of at least one of the candidates when there are a plurality of candidates for at least one of the association between the second value and the first information (for example, a table described later) and the first value. A communication unit (for example, corresponding to a communication circuit) transmits the first information and the second information (for example, SCI).

[0086] Alternatively, in the terminal 200 shown in FIG. 8, a communication unit (for example, corresponding to a reception circuit) receives first information including a second value (X) obtained by dividing an interval of time resources to be reserved by a first value (W), and second information (for example, SCI) indicating one of at least one of the candidates when there are a plurality of candidates for at least one of the association between the second value and the first information (for example, a table described later) and the first value (W). A control unit (for example, corresponding to a control circuit) determines an interval (for example, X×W) based on the first information and the second information.

[0087] [Configuration of Base Station] FIG. 9 is a block diagram showing a configuration example of the base station 100 according to the present embodiment. In FIG. 9, the base station 100 includes an interval setting unit 101, a resource pool setting unit 102, an error correction encoding unit 103, a modulation unit 104, a signal allocation unit 105, a transmission unit 106, a reception unit 107, a signal separation unit 108, a demodulation unit 109, and an error correction decoding unit 110.

[0088] The interval setting unit 101 sets candidates for intervals (in other words, time intervals) between different TBs (for example, new TBs). The interval setting unit 101 may set interval candidates for each resource pool allocated to the terminal 200, for example. The interval setting unit 101 outputs information regarding the set interval candidates (hereinafter referred to as "interval candidate information") to the resource pool setting unit 102. Further, the interval setting unit 101 outputs upper layer signaling including the interval candidate information to the error correction encoding unit 103.

[0089] The resource pool setting unit 102 sets a resource pool to be used for sidelink for each terminal 200. For example, the resource pool setting unit 102 may generate information regarding the time resources and frequency resources of the resource pool (hereinafter referred to as resource pool setting information) based on the interval candidate information input from the interval setting unit 101. The resource pool setting unit 102 outputs upper layer signaling including the resource pool setting information to the error correction encoding unit 103. Further, the resource pool setting unit 102 outputs the resource pool setting information to the signal allocation unit 105 and the signal separation unit 108.

[0090] The error correction encoding unit 103 takes as input the transmission data signal (DL data signal) and the upper layer signaling input from the interval setting unit 101 and the resource pool setting unit 102, error correction encodes the input signal, and outputs the encoded signal to the modulation unit 104.

[0091] The modulation unit 104 performs modulation processing on the signal input from the error correction encoding unit 103 and outputs the modulated data signal to the signal allocation unit 105.

[0092] The signal allocation unit 105 allocates the data signal (for example, DL data signal or upper layer signaling) input from the modulation unit 104 to resources available in the link (for example, Uu link) between the base station 100 and the terminal 200. The formed transmission signal is output to the transmission unit 106.

[0093] For example, based on the information input from the resource pool setting unit 102, the signal allocation unit 105 identifies (in other words, recognizes) the slots available for sidelink communication. Then, for example, when the link used for DL data (e.g., Uu link) and the terminal 200 cannot transmit and receive simultaneously in the sidelink, the signal allocation unit 105 may allocate data signals to the resources not used in the sidelink.

[0094] Note that the setting of the resource pool may be different for each terminal 200. In this case, the available slots in the Uu link are different for each terminal 200.

[0095] The transmission unit 106 performs wireless transmission processing such as up-conversion on the signal input from the signal allocation unit 105, and transmits it to the terminal 200 via an antenna.

[0096] The reception unit 107 receives the signal transmitted from the terminal 200 via an antenna, performs wireless reception processing such as down-conversion, and outputs it to the signal separation unit 108.

[0097] Based on the information input from the resource pool setting unit 102, for example, the signal separation unit 108 identifies the slots available in the Uu link and the slots available for sidelink communication. Then, the signal separation unit 108 separates the signals allocated to the resources available in the Uu link, which are input from the reception unit 107. The signal separation unit 108 outputs the separated signals (e.g., UL data signals) to the demodulation unit 109.

[0098] The demodulation unit 109 performs demodulation processing on the signal input from the signal separation unit 108, and outputs the obtained signal to the error correction decoding unit 110.

[0099] The error correction decoding unit 110 decodes the signal input from the demodulation unit 109 to obtain the received data signal (UL data signal) from the terminal 200.

[0100] In the example shown in FIG. 9, the base station 100 includes an interval setting unit 101 and a resource pool setting unit 102, and the case of generating upper layer signaling including interval candidate information and resource pool setting information has been described, but it is not limited thereto. For example, at least one of the interval candidate information and the resource pool setting information may be set in an application layer called, for example, Pre-configured, or may be preset in a subscriber identity module (SIM). In this case, the base station 100 may use the preset information without generating the interval candidate information or the resource pool setting information. For example, based on the preset resource pool setting information, the base station 100 may recognize available slots between the base station 100 and the terminal 200, and output information indicating the available slots between the base station 100 and the terminal 200 to the signal allocation unit 105 and the signal separation unit 108.

[0101] Also, here, the case where the setting regarding the time resource in the sidelink communication (for example, information regarding the interval) is set (or notified) from the base station 100 to the terminal 200 by, for example, upper layer signaling (for example, RRC) or MAC is described, but it is not limited thereto. For example, when the setting regarding the time resource in the sidelink communication (for example, information regarding the interval) is defined in the specification (or standard), or is set in the SIM or the application layer, the terminal 200 can operate without the setting from the base station 100.

[0102] Also, for example, when the mode of sidelink communication is "Mode 1", it is assumed that the information included in the SCI transmitted by the terminal in the sidelink is generated by the base station 100. Therefore, in the case of Mode 1, the base station 100 may generate an SCI based on, for example, interval candidate information and resource pool setting information (the same process as the SCI generation unit 210 of the terminal 200 described later) and transmit it to the terminal 200. Note that the SCI may be included in, for example, signaling of a higher layer or a signal of a physical layer (e.g., PDCCH).

[0103] [Configuration of Terminal] FIG. 10 is a block diagram showing a configuration example of the terminal 200 according to the present embodiment. In FIG. 10, the terminal 200 includes a receiving unit 201, a signal separating unit 202, an SCI receiving unit 203, a Uu demodulating unit 204, a Uu error correcting and decoding unit 205, an SL demodulating unit 206, an SL error correcting and decoding unit 207, an interval setting unit 208, a resource pool setting unit 209, an SCI generating unit 210, a Uu error correcting encoding unit 211, a Uu modulating unit 212, an SL error correcting encoding unit 213, an SL modulating unit 214, a signal allocating unit 215, and a transmitting unit 216.

[0104] The control circuit shown in FIG. 8 may include, for example, an SCI receiving unit 203, an interval setting unit 208, a resource pool setting unit 209, and an SCI generating unit 210. Also, the communication circuit shown in FIG. 8 may include, for example, a receiving unit 201 and a transmitting unit 216.

[0105] The receiving unit 201 receives a received signal via an antenna, performs receiving processing such as down-conversion, and then outputs it to the signal separating unit 202.

[0106] Also, the receiving unit 201 identifies a time resource for receiving a sidelink signal transmitted from a certain terminal 200 (in other words, a transmitting terminal) based on, for example, interval information (described later) input from the SCI receiving unit 203. The receiving unit 201 may set the state of the terminal 200 to a receiving state at the identified time resource, for example.

[0107] Based on the resource pool setting information input from the resource pool setting unit 209, the signal separation unit 202 separates the signal component corresponding to the link (for example, Uu link) between the base station 100 and the terminal 200 from the signals input from the reception unit 201, and outputs it to the Uu demodulation unit 204.

[0108] Also, the signal separation unit 202 separates the sidelink signal component from the signals input from the reception unit 201 based on the resource pool setting information. Then, the signal separation unit 202 outputs, for example, the signal of the PSCCH among the sidelink signal components to the SCI reception unit 203. Further, based on the resource allocation information input from the SCI reception unit 203, the signal separation unit 202 separates the signal of the PSSCH addressed to the terminal 200 from the sidelink signal components input from the reception unit 201, and outputs it to the SL demodulation unit 206.

[0109] The SCI reception unit 203 demodulates and decodes the PSCCH signal component input from the signal separation unit 202. For example, the SCI reception unit 203 attempts to demodulate and decode the PSCCH signal, and when the decoding is successful (in other words, when the SCI included in the PSCCH is detected), the SCI reception unit 203 outputs the resource allocation information of the PSSCH addressed to the terminal 200 included in the SCI to the signal separation unit 202. Note that the SCI reception unit 203 may determine whether the information included in the SCI is information addressed to the terminal 200 based on, for example, the destination information included in the SCI.

[0110] Also, the SCI reception unit 203 specifies, for example, the interval of the time resource to which the PSSCH addressed to the terminal 200 is allocated. For example, the SCI reception unit 203 may determine the interval based on information such as the interval candidate information input from the interval setting unit 208, "Resource reservation" included in the SCI addressed to the terminal 200, or information related to the determination of the interval (described later). The SCI reception unit 203 outputs information (for example, interval information) indicating the determined interval to the reception unit 201.

[0111] The Uu demodulation unit 204 performs demodulation processing on the signal input from the signal separation unit 202, and outputs the obtained demodulated signal to the Uu error correction decoding unit 205.

[0112] The Uu error correction decoding unit 205 decodes the demodulated signal input from the Uu demodulation unit 204, outputs the obtained upper layer signaling to the interval setting unit 208 and the resource pool setting unit 209, and outputs the obtained received data signal (or, referred to as the Uu received data signal).

[0113] The SL demodulation unit 206 performs demodulation processing on the signal input from the signal separation unit 202, and outputs the obtained demodulated signal to the SL error correction decoding unit 207.

[0114] The SL error correction decoding unit 207 decodes the demodulated signal input from the SL demodulation unit 206, and performs error determination on the decoded signal, such as cyclic redundancy check (CRC). When there is no error in the decoded signal, the SL error correction decoding unit 207 outputs the obtained received data signal (or, referred to as the sidelink received data signal).

[0115] The interval setting unit 208 sets an interval candidate for the sidelink signal (for example, TB) transmitted by the terminal 200 based on, for example, the interval candidate information included in the upper layer signaling input from the Uu error correction decoding unit 205. The interval setting unit 208 outputs interval candidate information indicating the set interval candidate to the SCI reception unit 203 and the SCI generation unit 210.

[0116] The resource pool setting unit 209 sets a resource pool (for example, a time resource and a frequency resource) that the terminal 200 uses for sidelink communication based on, for example, resource pool setting information included in upper layer signaling input from the Uu error correction decoding unit 205. The resource pool to be set may include, for example, either or both of the resources used by the terminal 200 for transmission and the resources used by the terminal 200 for reception. The resource pool setting unit 209 outputs the resource pool setting information to the SCI generation unit 210, the signal separation unit 202, and the signal allocation unit 215.

[0117] The SCI generation unit 210 generates an SCI including information about the set resources based on, for example, information input from the resource pool setting unit 209 (for example, information indicating resources available for sidelink communication) and information input from the interval setting unit 208. The SCI generation unit 210 may determine, for example, information about an interval (for example, the value of "Resource reservation") or a frequency resource. The SCI may include, for example, information about the determined resources, information for identifying the transmitting terminal 200 (for example, a transmitter ID), and information for identifying the receiving terminal 200 (for example, a receiver ID). The SCI generation unit 210 outputs the generated SCI to the signal allocation unit 215.

[0118] For example, when the mode of sidelink communication is "Mode 2", the terminal 200 generates an SCI in the SCI generation unit 210. Also, for example, when the base station 100 generates an SCI and transmits the SCI to the terminal 200 when the mode of sidelink communication is "Mode 1", the terminal 200 may generate an SCI based on the SCI transmitted from the base station 100.

[0119] The Uu error correction encoding unit 211 takes the transmission data signal (UL data signal) of the Uu link as an input, error correction encodes the transmission data signal, and outputs the encoded signal to the Uu modulation unit 212.

[0120] The Uu modulation unit 212 modulates the signal input from the Uu error correction encoding unit 211 and outputs the modulated signal to the signal allocation unit 215.

[0121] The SL error correction encoding unit 213 takes the side link transmission data signal (side link data signal) as input, error correction encodes the transmission data signal, and outputs the encoded signal to the SL modulation unit 214.

[0122] The SL modulation unit 214 modulates the signal input from the SL error correction encoding unit 213 and outputs the modulated signal to the signal allocation unit 215.

[0123] The signal allocation unit 215 allocates, for example, the signal of the PSCCH including the SCI and the signal of the PSSCH including the side link data signal input from the SL modulation unit 214 to the side link resources based on the information input from the resource pool setting unit 209 and the information input from the SCI generation unit 210. Also, the signal allocation unit 215 allocates, for example, the signal input from the Uu modulation unit 212 to the resources of the Uu link (for example, the resources of the uplink data channel (PUSCH: Physical Uplink Shared Channel)). The signal allocation unit 215 outputs the signal allocated to the resources to the transmission unit 216.

[0124] The transmission unit 216 performs radio transmission processing such as up-conversion on the signal input from the signal allocation unit 215 and transmits it.

[0125] Note that in the example shown in FIG. 10, the case where the terminal 200 receives upper layer signaling including interval candidate information and resource pool setting information has been described, but it is not limited thereto. For example, at least one of the interval candidate information and the resource pool setting information may be set in an application layer called, for example, Pre-configured, or may be preset in the SIM. In this case, the terminal 200 may use the preset information without receiving the interval candidate information or the resource pool setting information. For example, based on the preset resource pool setting information, the terminal 200 recognizes the resources available between the base station 100 and the terminal 200, and the resources available for the sidelink, and may use the information regarding these resources in the signal separation unit 202 and the signal allocation unit 215.

[0126] Also, in FIG. 10, as an example, the case where different components are provided for the Uu link and the sidelink with respect to the demodulation unit, the error correction decoding unit, the error correction encoding unit, and the modulation unit has been described, but it is not limited thereto, and common components may be provided for the Uu link and the sidelink.

[0127] [Operation of Terminal 200] Next, an example of the operation of the terminal 200 (see FIG. 10) will be described.

[0128] FIG. 11 is a flowchart showing an example of the processing of the terminal 200.

[0129] The terminal 200 (for example, a transmitting terminal and a receiving terminal) that transmits and receives in the sidelink sets parameters related to the sidelink (S101). The parameters related to the sidelink may include, for example, time resources (for example, intervals between TBs), frequency resources, SL BWP, resource pools, and settings of channels arranged in each slot.

[0130] Parameters related to sidelink may be notified from a transmitting terminal to a receiving terminal by, for example, SCI. Alternatively, parameters related to sidelink may be defined for terminal 200 in, for example, a specification (or standard), may be set in an application layer called Pre-configured, may be pre-set in the SIM, or may be set by a higher layer such as a SIB called configured or other RRC or by MAC.

[0131] Based on the set parameters, terminal 200 performs sidelink communication (for example, data transmission and reception) (S102).

[0132] Next, an example of a method for setting time resources (for example, the interval between TBs) will be described.

[0133] [Operation Example 1-1] In Operation Example 1-1, for example, the value "X" that notifies the interval between TBs is set to the value obtained by dividing the value of the interval between TBs by W.

[0134] Also, in Operation Example 1-1, for example, W may be selected from a plurality of candidates.

[0135] Terminal 200 determines the interval between TBs as, for example, the multiplication value (for example, X × W) of X notified by "Resource reservation" and the selected W.

[0136] Note that the value of the interval between TBs may be notified (or set) to terminal 200 by a higher layer. Also, the value of W (for example, candidates for W) may be defined in a specification (or standard), may be set in an application layer called Pre-configured, may be set in the SIM included in terminal 200, may be set by a higher layer such as a SIB called configured or other RRC, or may be set by MAC.

[0137] Also, when multiple candidates for W are set, for example, among the multiple candidates for W, information indicating the value of W that the terminal 200 uses (in other words, selects) may be included in the SCI.

[0138] Alternatively, multiple candidates for W may be preset for the terminal 200, for example. In this case, options for W may be notified to the terminal 200 by signaling of a higher layer such as RRC or MAC. For example, the terminal 200 may select a candidate notified by the SCI from among the candidates for W included in the options. Also, for example, when there is one option for W notified by signaling of a higher layer, information for selecting W may not be notified by the SCI.

[0139] In operation example 1-1, by combining X and W, for example, the number of interval candidates can be increased without increasing the number of candidates for X as compared with LTE. Therefore, according to operation example 1-1, for example, interval candidates can be dynamically set according to the value of W, so that data transmission of various traffic types can be supported.

[0140] For example, when the value of W has two patterns, the terminal 200 may notify other terminals 200 of an SCI including 1-bit information indicating any one of the two patterns. Also, for example, when the value of W has three or four patterns, the terminal 200 may notify other terminals 200 of an SCI including 2-bit information indicating any one of the three or four patterns. Note that the number of information bits for notifying candidates for W may be 3 bits or more. Also, the number of bits of information notified by the SCI may be determined according to the number of candidates for W (in other words, the number of patterns).

[0141] FIG. 12 shows an example when the value of W is notified by 1-bit information (for example, 0 or 1) included in the SCI.

[0142] In FIG. 12, candidates for W are set to W = 100, which is the same as LTE, and W = 20, which is shorter than LTE. For example, as shown in FIG. 12, W = 100 is notified by bit 0, and W = 20 is notified by bit 1. Note that the candidates for W are not limited to the example shown in FIG. 12 (W = 100 or 20), and other values may also be used.

[0143] In FIG. 12, for example, in the case of bit 0, 20 ms, 50 ms, or 100X ms (X times 100, where X is an integer from 1 to 10) is set for the interval between TBs. Also, in FIG. 12, for example, in the case of bit 1, 4 ms, 10 ms, or 20X ms (X times 20, where X is an integer from 1 to 10) is set for the interval between TBs. Therefore, in FIG. 12, for example, more and a wider range of intervals can be set compared to FIG. 7.

[0144] FIG. 13 shows an example case where the value of W is notified by 2-bit information (for example, any of 00, 01, 10, and 11) included in the SCI.

[0145] In FIG. 13, candidates for W are set to W = 100, which is the same as LTE, and W = 5, W = 25, and W = 40, which are shorter than LTE. For example, as shown in FIG. 13, W = 100 is notified by bit 00, W = 5 is notified by bit 01, W = 25 is notified by bit 10, and W = 40 is notified by bit 11. Note that the candidates for W are not limited to the example shown in FIG. 13 (W = 100, 5, 25, or 40), and other values may also be used.

[0146] In FIG. 13, for example, in the case of bit 00, an interval between TBs is set to 20 ms, 50 ms, or 100X ms (X times 100, where X is an integer from 1 to 10). Also, in FIG. 13, for example, in the case of bit 01, an interval between TBs is set to 1 ms, 2.5 ms, or 5X ms (X times 5, where X is an integer from 1 to 10). Also, in FIG. 13, for example, in the case of bit 10, an interval between TBs is set to 5 ms, 12.5 ms, or 25X ms (X times 25, where X is an integer from 1 to 10). Also, in FIG. 13, for example, in the case of bit 11, an interval between TBs is set to 8 ms, 20 ms, or 40X ms (X times 40, where X is an integer from 1 to 10).

[0147] Note that, for example, in the sidelink, when a period of 2.5 ms is not assumed, in bit 01 (W = 5) shown in FIG. 13, the interval between TBs = 2.5 ms may be read as 2 ms or 3 ms. Similarly, for example, in the sidelink, when a period of 12.5 ms is not assumed, in bit 10 (W = 25) shown in FIG. 13, the interval between TBs = 12.5 ms may be read as 12 ms or 13 ms.

[0148] In FIG. 13, for example, compared with FIG. 7 or FIG. 12, more and a wider range of intervals can be set.

[0149] As described above, in operation example 1-1, by making the value of W variable, the interval between TBs can be set flexibly, and it is possible to cope with various traffic periods.

[0150] Note that, as an example, the case where the interval between TBs is calculated by the tables shown in FIGS. 12 and 13 has been described, but the present invention is not limited thereto. For example, the interval may be calculated based on the bits notified by SCI (e.g., Resource reservation), the value of W, and the table shown in FIG. 7. For example, when using the table shown in FIG. 7, the value of W may be set to a value different from 100. For example, when the value of W is set to a multiple of 5, the interval (in other words, the transmission period) can be set to a multiple of 1 ms.

[0151] Also, as shown in FIGS. 12 and 13, by setting the value of W to a value of 100 or less (e.g., a value similar to LTE), the interval can be set to a value smaller than 20 ms (e.g., the minimum value in LTE). Note that, in FIGS. 12 and 13, the case where the value of W is set to 100 or less (e.g., a value similar to LTE) has been described, but the value of W may be larger than 100. By this setting of W, for example, the interval can be set to be longer than 1000 ms (e.g., the maximum value in LTE).

[0152] [Operation Example 1-2] In Operation Example 1-2, for example, a plurality of candidates for the association (the pattern of X. For example, represented by a table) between the value “X) notifying the interval between TBs and the information indicating X (e.g., Resource reservation) are set.

[0153] For example, the pattern of X notified by SCI may be selected from one or a plurality of candidates (e.g., a plurality of tables).

[0154] The terminal 200 determines, for example, the multiplication value (e.g., X×W) of X notified by “Resource reservation” and W set in the terminal 200 as the interval between TBs with reference to the selected pattern of X. The value of W may be, for example, a fixed value or a variable value as in Operation Example 1-1.

[0155] Note that multiple candidates for the pattern of X (e.g., a table) may be defined in a specification (or standard), may be set in an application layer called Pre-configured, may be set in the SIM included in the terminal 200, may be set in a higher layer such as an SIB called configured or other RRC, or may be set in the MAC.

[0156] Also, when multiple candidates for the pattern of X are set, for example, information indicating the candidate that the terminal 200 uses (in other words, selects) among the multiple candidates may be included in the SCI.

[0157] Alternatively, the pattern of X may be pre-set for the terminal 200, for example. In this case, options for the pattern of X may be notified to the terminal 200 by signaling of a higher layer such as RRC or MAC. For example, the terminal 200 may select the combination notified by the SCI from among the combinations included in the options. Also, for example, when there is only one option for the combination notified by the signaling of the higher layer, information for selecting the combination does not have to be notified by the SCI.

[0158] In Operation Example 1-2, by setting multiple types of patterns of X, for example, the number of interval candidates can be increased compared to LTE. Therefore, according to Operation Example 1-2, for example, interval candidates can be dynamically set according to the pattern of X, so that data transmission of various traffic types can be supported.

[0159] For example, when the pattern of X is two patterns, the terminal 200 may notify other terminals 200 of an SCI including 1-bit information indicating either of the two patterns. Also, for example, when the pattern of X is three or four patterns, the terminal 200 may notify other terminals 200 of an SCI including 2-bit information indicating either of the three or four patterns. Note that the number of bits of the information for notifying the pattern of X may be three bits or more. Also, the number of bits of the information notified by the SCI may be determined according to the number of patterns of X.

[0160] An example in the case where there are two patterns of X (in other words, when the pattern of X is notified by 1-bit information) will be described below.

[0161] The two patterns of X are, for example, the pattern shown in FIG. 7 and the pattern shown in FIG. 14. In FIGS. 7 and 14, "W", which is a value for calculating X by dividing the value of the interval or a value for calculating the value of the interval by multiplying X, may be set to 100, for example, in the same manner as LTE.

[0162] For example, the pattern of X shown in FIG. 7 (for example, combinations of X = 0, 0.2, 0.5, and 1 to 10) may be notified by bit 0 included in the SCI, and the pattern of X shown in FIG. 14 (for example, combinations of X = 0, 0.05, 0.1, 0.2, 0.25, 0.4, 0.5, and 1 to 5) may be notified by bit 1 included in the SCI.

[0163] For example, in the case of bit 0 (FIG. 7), 20 ms, 40 ms, or 100X ms (100 times X, where X is any integer from 1 to 10) is set for the interval between TBs. Also, in the case of bit 1 (FIG. 14), 5 ms, 10 ms, 20 ms, 25 ms, 40 ms, 50 ms, or 100X ms (100 times X, where X is any integer from 1 to 5) is set for the interval between TBs. Therefore, in operation examples 1-2, for example, compared with the interval setting of LTE (FIG. 7), more and a wider range of intervals can be set.

[0164] In the above example, the case where the value of W is set to 100 has been described, but the value of W may be a value different from 100 or may be selected from a plurality of candidates.

[0165] For example, the value of W may vary for each pattern of X. For example, when W = 20 is set in FIG. 14, the intervals between TBs are set to 1 ms, 2 ms, 4 ms, 5 ms, 8 ms, 10 ms, and 20X ms (20 times X. X is an integer from 1 to 5). The combination of the pattern of X and the value of W may be defined in advance, for example, or may be notified to the terminal 200 by another bit (for example, information included in the SCI) as in Operation Example 1-1.

[0166] Also, for example, in at least one of the patterns of X, as shown in FIG. 14, values smaller than the value of X shown in FIG. 7 (for example, X = 0.2), such as X = 0.1 or 0.05, may be included. With this setting of X, shorter intervals can be set compared to the case of FIG. 7 (for example, the LTE case).

[0167] Also, in at least one of the patterns of X, for example, as shown in FIG. 14, the granularity of X may be set to be finer compared to FIG. 7. For example, in FIG. 7, three values in the range of X = 0 to 0.5 are set, whereas in FIG. 14, seven values are set in the range of X = 0 to 0.5. With this setting, for example, the number of supported values in the range where the interval is set can be increased compared to the case of FIG. 7 (for example, the LTE case).

[0168] As described above, in Operation Example 1-1 and Operation Example 1-2, the transmitting terminal determines information (for example, Resource reservation included in the SCI) indicating the value “X” obtained by dividing the time interval between TBs by W. Further, when there are a plurality of candidates for at least one of the value of W (for example, Operation Example 1-1) and the association between X and Resource reservation (for example, Operation Example 1-2), the transmitting terminal determines information (for example, a bit included in the SCI) indicating one of the at least one of the candidates. Based on this, the time interval between TBs is determined. Then, the transmitting terminal transmits the determined information to the receiving terminal.

[0169] The receiving terminal receives information including, for example, X (e.g., Resource reservation included in SCI). Further, when there are multiple candidates for at least one of the value of W (e.g., Operation Example 1-1) and the association between X and Resource reservation (e.g., Operation Example 1-2), the receiving terminal receives information (e.g., bits included in SCI) indicating one of the at least one candidate. Then, based on the received information, the receiving terminal determines the interval between TBs (e.g., X×W).

[0170] For example, since the pattern of W or X can be dynamically set by the information indicating at least one candidate of the value of W and the pattern of X, the terminal 200 can dynamically set the interval candidate and support data transmission of various traffic types.

[0171] Note that in Operation Example 1-1 and Operation Example 1-2, the notification method of "Resource reservation" for notifying the interval between TBs has been described, but Operation Example 1-1 and Operation Example 1-2 can also be applied to the notification method of "Time gap between initial transmission and retransmission".

[0172] [Operation Example 1-3] In Operation Example 1-3, the interval between TBs is set based on either the time interval (in other words, the interval) notified by "Resource reservation" or the time interval (in other words, the gap) notified by "Time gap between initial transmission and retransmission".

[0173] For example, the terminal 200 may notify other terminals 200 of an SCI including information indicating which time interval of "Resource reservation" and "Time gap between initial transmission and retransmission" is used for the setting (in other words, notification) of the interval between TBs.

[0174] According to Operation Examples 1-3, similar to Operation Examples 1-1 and 1-2, the candidate intervals can be dynamically changed, and data transmission of various traffic types can be supported.

[0175] For example, the time interval (e.g., interval or gap) used for the setting of the interval between TBs may be notified by 1-bit information (bit 0 or bit 1; e.g., additional bit) included in the SCI. For example, when bit 0 is notified, the terminal 200 may set the interval between TBs based on the time interval (e.g., interval) notified by "Resource reservation". Also, for example, when bit 1 is notified, the terminal 200 may set the interval between TBs based on the time interval (e.g., gap) notified by "Time gap between initial transmission and retransmission".

[0176] In Operation Example 1-3, for example, the set interval may be applied to the interval between TBs of the initial transmission and may be applied to the interval between the TB of the initial transmission and the TB of the retransmission. The terminal 200 can distinguish either the initial transmission or the retransmission based on, for example, the "Retransmission index".

[0177] For example, when the time period of traffic is long (e.g., when it is equal to or greater than a threshold value), the terminal 200 may set the time interval (e.g., the interval) notified by "Resource reservation" as the interval between TBs. Also, when the time period of traffic is short (e.g., when it is less than the threshold value), the terminal 200 may set the time interval (e.g., the gap) notified by "Time gap between initial transmission and retransmission", which is shorter than the time interval notified by "Resource reservation", as the interval between TBs.

[0178] In Operation Examples 1-3, for example, since a plurality of candidates for W such as in Operation Example 1-1 or patterns of X such as in Operation Example 1-2 are not set, signaling regarding the setting of time resources can be reduced.

[0179] Also, as a modification of Operation Example 1-3, when bit 0 is notified, the terminal 200 may, for example, as shown in FIG. 6, set the interval between TBs of the initial transmission as the time interval notified by "Resource reservation", and set the gap between the initial transmission and the retransmission as the interval, which is the time interval notified by "Resource reservation".

[0180] [Operation Example 1-4] In Operation Example 1-4, the interval between TBs is set based on the time interval (in other words, the interval) notified by "Resource reservation".

[0181] For example, the terminal 200 may notify other terminals 200 of an SCI including information indicating whether the time interval notified by "Resource reservation" for setting the interval between TBs (in other words, the notification) is determined according to the determination method of either the "Resource reservation" or the "Time gap between initial transmission and retransmission" specified in LTE-V2X.

[0182] According to Operation Examples 1-4, similar to Operation Examples 1-1, 1-2, and 2-3, the candidate intervals can be dynamically changed, and data transmissions of various traffic types can be supported. Also, the LTE-V2X specifications can be utilized to the maximum extent.

[0183] For example, the time interval (e.g., interval or gap) used for setting the interval between TBs may be notified by 1-bit information (bit 0 or bit 1; e.g., additional bit) included in the SCI. For example, when bit 0 is notified, the terminal 200 may set the time interval (e.g., interval) notified by "Resource reservation" in the same procedure as "Resource reservation" in the LTE-V2X specifications. Also, for example, when bit 1 is notified, the terminal 200 may set the time interval (e.g., interval) notified by "Resource reservation" in the same procedure as "Time gap between initial transmission and retransmission" in the LTE-V2X specifications.

[0184] In Operation Example 1-4, for example, the set interval may be applied to the interval between TBs of the initial transmission and may be applied to the interval between the TB of the initial transmission and the TB of the retransmission. The terminal 200 can distinguish either the initial transmission or the retransmission, for example, based on the "Retransmission index".

[0185] For example, when the time period of traffic is long (e.g., when it is equal to or greater than a threshold value), the terminal 200 may set the time interval (e.g., interval) notified by "Resource reservation" in the same procedure as "Resource reservation" in the LTE-V2X specification. Also, when the time period of traffic is short (e.g., when it is less than the threshold value), the terminal 200 may set the time interval (e.g., interval) notified by "Resource reservation" in the same procedure as "Time gap between initial transmission and retransmission" in the LTE-V2X specification.

[0186] In Operation Examples 1-4, for example, since a plurality of candidates for W such as in Operation Example 1-1 or patterns for X such as in Operation Example 1-2 are not set, signaling related to the setting of time resources can be reduced.

[0187] Note that the information indicating the method for determining the time interval used for setting the interval between TBs is not limited to being explicitly notified by the information included in the SCI (e.g., 1-bit information), and may be implicitly notified by information defined for other uses, for example.

[0188] As described above, each of Operation Examples 1-1 to 1-4 has been explained.

[0189] According to this embodiment, even when there are more diverse traffic types than LTE, such as NR, the terminal 200 can dynamically set the interval between TBs from among a plurality of time interval candidates. Therefore, according to this embodiment, the efficiency of resource allocation (e.g., time resource allocation or reservation) in wireless communication (e.g., sidelink communication) can be improved.

[0190] (Embodiment 2) In Embodiment 1 (for example, Operation Examples 1-1 and 1-2), a method of explicitly notifying the value of W or the pattern of X (for example, the table shown in FIG. 7 or FIG. 14) by the bits included in the SCI was described. In contrast, in this embodiment, a method of implicitly notifying the value of W or the pattern of X will be described.

[0191] According to this embodiment, the number of configurable intervals can be increased without increasing the number of bits of the SCI.

[0192] The base station and the terminal according to this embodiment have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1.

[0193] Hereinafter, an example of a method for setting a time resource (for example, an interval between TBs) according to this embodiment will be described.

[0194] [Operation Example 2-1] In Operation Example 2-1, "priority indication" or "QoS indication" included in the SCI is used for notifying the interval between TBs. Note that in LTE, it is called priority indication, but in the SCI of NR, it may be called a different name (for example, "QoS indication").

[0195] It is considered that Priority indication or QoS indication includes information such as priority, latency, or reliability. Based on Priority indication or QoS indication, controls such as resource allocation, congestion control between terminals, resolution of in-device coexistence issues when multiple data occurs within a terminal, or power control are being considered.

[0196] In Operation Example 2-1, the terminal 200 may determine the value of W or the pattern of X based on, for example, Priority indication or QoS indication. In other words, the information included in Priority indication or QoS indication is associated with the candidate of the value of W or the pattern of X.

[0197] For example, the terminal 200 specifies the amount of delay required for the terminal 200 (in other words, the desired amount of delay) based on Priority indication or QoS indication.

[0198] When the specified amount of delay is short (for example, less than the threshold value), the terminal 200 may set the interval between TBs based on, for example, W = 20 in Operation Example 1-1 or FIG. 14 in Operation Example 1-2. Also, when the specified amount of delay is long (for example, equal to or greater than the threshold value), the terminal 200 may set the interval between TBs based on W = 100 in Operation Example 1-1 or FIG. 7 in Operation Example 1-2.

[0199] For example, by applying W = 20 or the pattern of X shown in FIG. 14, compared with W = 100 or the pattern of X shown in FIG. 7, the interval between TBs can be set shorter, so that it becomes easier to satisfy the amount of delay required for the terminal 200.

[0200] The mapping between Priority indication or QoS indication and the value of W (for example, W = 20 or 100) or the pattern of X (for example, the table shown in FIG. 7 or FIG. 14) may be defined in the specification (or standard), set in the SIM, set in the application layer called Pre-configured, or set in the upper layer such as SIB called configured or other RRC or MAC.

[0201] According to Operation Example 2-1, the terminal 200 can notify the interval between TBs without using a new bit. Also, for example, the terminal 200 can set an interval suitable for a parameter (e.g., the required delay amount) corresponding to the value set in LTE.

[0202] [Operation Example 2-2] In Operation Example 2-2, the Redundancy Version (RV) included in the SCI is used to notify the interval between TBs.

[0203] In LTE, there is no notification of RV by the SCI. On the other hand, in NR, for example, similar to the downlink control indication (DCI), retransmission control by notification of RV and New Data Indicator (NDI) is also being considered in the SCI.

[0204] For example, as shown in FIG. 15, a bit sequence with parity bits added to the systematic bits of the transport block size (TBS: TB size) determined by the MCS instruction is stored in the circular buffer. In the example shown in FIG. 15, parity bits approximately twice as long as the systematic bits are added. Also, in the example shown in FIG. 15, the circular buffer is divided into four parts.

[0205] "RV" is a signal that notifies the bit position (e.g., any of RV0, RV1, RV2, and RV3) at which data transmission starts in the circular buffer. For example, as shown in FIG. 15, it is common for RV0 to start transmitting bits from a bit position near the beginning of the systematic bits (e.g., a bit position shifted several bits from the beginning). Also, the number of bits that can be transmitted in one transmission determines the bits that can be transmitted from the start position of the circular buffer.

[0206] For example, when RV0 is notified, since more systematic bits are included in the transmission bits compared to other RVs, RV0 is likely to be set (in other words, selected) at the first transmission.

[0207] Also, in retransmission, for example, in a situation where the terminal 200 can receive the signal of the first transmission, when bits that do not overlap with the first transmission are transmitted, it becomes a retransmission method called "incremental redundancy", and the reception quality can be improved. Therefore, in retransmission, RV1, RV2, or RV3 that does not overlap with the first transmission (for example, RV0) is likely to be selected. Also, for example, as shown in FIG. 15, RV2 has less overlap in the bit sequence with RV0 compared to RV1 and RV3 adjacent to RV0. Also, for example, the more bits that can be transmitted in one transmission (in other words, the longer the bit sequence), the more systematic bits RV3 can also include.

[0208] Considering such characteristics of RVs, for example, the longer the bit sequence that can be transmitted in one transmission, the more likely the bit sequence corresponding to RV3 or RV1 shown in FIG. 15 is to be included in the bit sequence corresponding to RV0 or RV2. In other words, for example, in FIG. 15, the terminal 200 (for example, the receiving terminal) can receive the bits included in the bit sequence corresponding to RV3 or RV1 by receiving the bit sequence corresponding to RV0 or RV2.

[0209] Therefore, it is assumed that even if a part (for example, one) of the plurality of RVs is used for the notification of W in operation example 1-1 or the notification of the pattern (for example, table) of X in operation example 1-2, the reception characteristics at the terminal 200 are less likely to deteriorate.

[0210] Therefore, in operation example 2-2, the terminal 200 may determine the value of W or the pattern of X based on, for example, RV. In other words, RV is associated with the value of W or the pattern of X.

[0211] As an example of Operation Example 2-2, the terminal 200 may notify the interval between TBs using the bits used for the notification of RV3. In the following, as an example, RV0 is notified by bit 00, RV1 is notified by bit 01, RV2 is notified by bit 10, and RV3 is notified by bit 11.

[0212] In Example 1, bit 11 may notify an interval with a value different from that in the case of other bits (for example, bit 00, bit 01, and bit 10) instead of RV3, and RV0. For example, as follows, a short interval (for example, W = 20 or the X pattern in FIG. 14) may be associated with bit 11 as compared with bits 00, 01, and 10 (for example, W = 100 or the X pattern in FIG. 7). 00: RV0 and W=100 (or, FIG. 7) 01: RV1 and W=100 (or, FIG. 7) 10: RV2 and W=100 (or, FIG. 7) 11: RV0 and W=20 (or, FIG. 14)

[0213] For example, when the interval is long (for example, when W = 100 or the X pattern in FIG. 7 is applied), any one of RV0, RV1, and RV2 can be set, whereas when the interval is short (for example, when W = 20 or the X pattern in FIG. 14 is applied), only one of RV0 can be set. However, it is assumed that the shorter the interval, the shorter the desired delay for the packet, for example. Therefore, it is assumed that the shorter the interval, the more likely the receiving terminal can receive the signal (in other words, succeed in reception) at the first transmission by transmitting the signal at the first transmission more redundantly. For this reason, as described above, even if only one of RV0 can be set when the interval is short, the retransmission efficiency is less likely to deteriorate.

[0214] In Example 1, the case where bit 11 corresponding to RV3 is used for notification of an interval different from the bits corresponding to other RVs was described. However, for notification of an interval different from the bits corresponding to other RVs (e.g., RV1), bits corresponding to other RVs different from RV3 may be used. Also, in Example 1, the case where an interval different from others is shorter than other intervals was described, but it may be longer than other intervals.

[0215] Also, as Example 2 of Operation Example 2-2, two of the plurality of RVs (e.g., RV1 and RV3) may be used for notification of W in Operation Example 1-1 or notification of the pattern of X (e.g., a table) in Operation Example 1-2. In the case of Example 2, as follows, RV1 and RV3 may not be set, and instead RV0 or RV2 may be set. 00: RV0 and W = 100 (or, Figure 7) 01: RV0 and W = 20 (or, Figure 14) 10: RV2 and W = 100 (or, Figure 7) 11: RV2 and W = 20 (or, Figure 14)

[0216] Thus, even when different intervals are notified instead of notification of two states of RV (e.g., RV1 and RV3), the RV can be changed at the time of retransmission in each of the different intervals (e.g., each of W = 20 and W = 100).

[0217] [Operation Example 2-3] In Operation Example 2-3, "RV" and "Retransmission index" included in the SCI are used for notification of the interval between TBs.

[0218] The Retransmission index is information for notifying either the first transmission or retransmission.

[0219] In Operation Example 2-3, the terminal 200 may determine the value of W or the pattern of X based on, for example, RV and Retransmission index (information indicating retransmission of data). In other words, the combination of RV and Retransmission index (transmission type) is associated with candidates for the value of W or the pattern of X.

[0220] For example, by restricting the types of available RVs according to the initial transmission and retransmission, instead, the value of W in Operation Example 1-1 or the pattern of X in Operation Example 1-2 is notified.

[0221] For example, out of a 3-bit bit string combining a 2-bit RV and a 1-bit Retransmission index, the first 2 bits are for RV and the last 1 bit is for Retransmission index. Also, for example, Retransmission index (for example, the 3rd bit out of 3 bits) indicates an initial transmission when it is 0 and a retransmission when it is 1. Also, for example, for RV, either RV0 or RV3 is set at the initial transmission, and either RV2 or RV1 is set at the retransmission.

[0222] In this case, as follows, RV, interval, and transmission type (initial transmission or retransmission) may be set for a 3-bit bit string (for example, 000 to 111). 000: RV0, W = 100 (or, Figure 7) and initial transmission 001: RV2, W = 100 (or, Figure 7) and retransmission 010: RV0, W = 20 (or, Figure 14) and initial transmission 011: RV2, W = 20 (or, Figure 14) and retransmission 100: RV3, W = 100 (or, Figure 7) and initial transmission 101: RV1, W = 100 (or, Figure 7) and retransmission 110: RV3, W = 20 (or, Figure 14) and initial transmission 111: RV1, W = 20 (or, Figure 14) and retransmission

[0223] For example, at the time of initial transmission, RV0 or RV3, which may contain more systematic bits compared to RV1 and RV2, is selected, and at the time of retransmission, RV1 or RV2, which may contain more parity bits not included in the initial transmission, is selected.

[0224] According to Operation Example 2-3, the number of selectable RVs in each of the initial transmission and retransmission is reduced, but since RVs suitable for each of the initial and retransmission are included in the options, deterioration of the reception quality at the terminal 200 can be suppressed.

[0225] [Operation Example 2-4] In Operation Example 2-4, the HARQ process number (also referred to as the HARQ process ID) included in the SCI is used for notification of the interval between TBs.

[0226] In NR, support for multiple processes is being considered, and the HARQ process ID can be notified by the SCI.

[0227] In Operation Example 2-4, the terminal 200 may determine the value of W or the pattern of X, for example, based on the HARQ process ID. In other words, the HARQ process ID is associated with candidates for the value of W or the pattern of X.

[0228] For example, for each HARQ process, the value of W in Operation Example 1-1 or the pattern of X in Operation Example 1-2 (for example, a table) may be set.

[0229] Note that the setting method for each HARQ process may be defined in the specification (or standard), may be pre-set in the SIM, may be set in the application layer called Pre-configured, or may be set in a higher layer such as an SIB called configured or other RRC or in the MAC.

[0230] For example, the longer the interval, the fewer the number of HARQ processes that can be allocated to the interval. In other words, the shorter the interval, the more the number of HARQ processes that can be allocated to the interval.

[0231] Therefore, for example, for HARQ process #0, the combination of W = 100 in operation example 1-1 or the candidates of X shown in FIG. 7 in operation example 1-2 may be set, and for other HARQ process IDs, the combination of W = 20 in operation example 1-1 or the candidates of X shown in FIG. 14 in operation example 1-2 may be set.

[0232] Note that the association between the HARQ process ID and the candidates of the W or X pattern described above is an example and is not limited. For example, the number of HARQ process IDs associated with W = 100 in operation example 1-1 or the X pattern shown in FIG. 7 in operation example 1-2 may be plural.

[0233] The terminal 200 can obtain, for example, parameters for setting the interval between TBs based on the HARQ process ID included in the SCI.

[0234] The above has described operation examples 2-1 to 2-4.

[0235] Note that any two or more of operation examples 2-1 and 2-4 may be combined.

[0236] In this embodiment, the interval between transmission blocks (TBs) is implicitly notified by information defined for other purposes. Therefore, according to this embodiment, for example, in sidelink, in order to notify the interval between TBs, it is not necessary to add new information to the parameters defined in LTE, for example, so that the signaling overhead can be reduced.

[0237] (Embodiment 3) In the SCI of LTE, for example, as shown in FIG. 6, the transmission timing is specified based on two time intervals: the interval between TBs (for example, corresponding to "Resource reservation") and the gap between the initial transmission and the retransmission (for example, "time gap between initial transmission and retransmission").

[0238] Also, in LTE, for example, for the TB of the next initial transmission (for example, Initial transmission TB#2 in FIG. 6), a transmission opportunity is given after the interval indicated by "Resource reservation" from the current initial transmission TB (for example, Initial transmission TB#1 in FIG. 6). Therefore, for example, the retransmission timing for the current TB (for example, TB#1 in FIG. 6) can be set by the time until the transmission opportunity of the next TB (for example, TB#2 in FIG. 6).

[0239] However, for example, the shorter the interval between TBs notified by "Resource reservation", the higher the possibility that the transmission timing of the next TB (for example, the initial transmission timing) overlaps with the transmission timing of the current TB (for example, the retransmission timing).

[0240] Also, in NR, the new data indicator (NDI) is notified by the SCI, and depending on whether the NDI is toggled, multiple retransmissions and the transmission of a new TB (for example, the next TB) may be notified.

[0241] In NR, HARQ feedback using the PSFCH is also being considered. When ACK (in other words, no error) is confirmed by feedback using the PSFCH, for example, the transmitting terminal does not have to secure resources for retransmission. Therefore, in feedback using the PSFCH, for example, when retransmission occurs, an operation of using resources for initial transmission is possible.

[0242] The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to Embodiment 1.

[0243] Hereinafter, an operation example of the terminal 200 according to this embodiment will be described.

[0244] [Operation Example 3-1] In Operation Example 3-1, for example, the interval (in other words, time interval) between TBs set for the terminal 200 is set to the time interval between adjacent TBs in the time domain among the TBs with which the terminal 200 communicates.

[0245] For example, the value of W in Operation Example 1-1 or the pattern of X (for example, a table) in Operation Example 1-2 is set for the terminal 200. The terminal 200 may determine the interval between TBs based on the set value, for example.

[0246] Note that the combination of the value of W or candidates of X may be defined in a specification (or standard), for example, set in the SIM, set in an application layer called Pre-configured, or set in a higher layer such as a SIB called configured or other RRC or MAC.

[0247] In Operation Example 3-1, for example, when the interval set in the terminal 200 is shorter than the threshold value (for example, the interval defined in LTE), "time gap between initial transmission and retransmission" and "Retransmission index" may not be included in the SCI.

[0248] For example, when the interval set in the terminal 200 is shorter than the threshold value, retransmission may be performed based on the transmission timing based on the interval between TBs (for example, the time interval corresponding to Resource reservation). In other words, the retransmission timing may be set based on, for example, the interval between TBs set based on the notification of "Resource reservation" and the value of W in Operation Example 1-1 (or the pattern of X in Operation Example 1-2).

[0249] FIG. 16 shows an example of resource allocation in Operation Example 3-1.

[0250] In FIG. 16, for example, the interval between TBs (time interval) is set to 4 slots by the SCI transmitted in Slot #0. Therefore, as shown in FIG. 16, for example, regardless of the type of TB (for example, HARQ process) and the type of transmission (for example, initial transmission and retransmission), the interval, which is the time interval between adjacent TBs for the transmission timing, is the same (for example, 4 slots).

[0251] For example, in FIG. 16, in Slot #0, the initial transmission data of HARQ process #0 (for example, represented as HARQ#0) is allocated, and in Slot #4, the initial transmission data of HARQ process #1 (for example, represented as HARQ#1) is allocated.

[0252] Also, in Slot #8 shown in FIG. 16, the data of HARQ process #0 is assigned with the same NDI = 0 as the first transmission (Slot #0). Therefore, the terminal 200 (e.g., the receiving terminal) determines that the data transmission of HARQ process #0 in Slot #8 is a retransmission. Also, in Slot #12 shown in FIG. 16, the data of HARQ process #1 is assigned with a different NDI = 1 from the first transmission (Slot #4). Therefore, the terminal 200 (e.g., the receiving terminal) determines that the data transmission of HARQ process #1 in Slot #12 is the first transmission. Similarly, in Slot #16 shown in FIG. 16, the data of HARQ process #0 is assigned with a different NDI = 1 from the retransmission (Slot #8). Therefore, the terminal 200 (e.g., the receiving terminal) determines that the data transmission of HARQ process #0 in Slot #16 is the first transmission.

[0253] Note that FIG. 16 shows an example in which different TBs are alternately assigned every interval (e.g., 4 slots), but it is not limited to this, and the first transmission and retransmission of the same TB may be assigned to adjacent time resources for each interval.

[0254] According to Operation Example 3-1, regardless of the first transmission and retransmission, for example, data is assigned to the time resources (in other words, intervals) set based on "Resource reservation", so that resources for retransmission do not need to be separately secured.

[0255] Also, according to Operation Example 3-1, for example, "time gap between initial transmission and retransmission" and "Retransmission index" may not be included in the SCI. Therefore, for example, bits for "time gap between initial transmission and retransmission" and "Retransmission index" can be deleted from the SCI to shorten the SCI length. Or, some or all of the bits not used for "time gap between initial transmission and retransmission" and "Retransmission index" may be set to fixed values used for error detection. With these SCI settings, the reception quality of the SCI can be improved.

[0256] Also, some of the bits not used for "time gap between initial transmission and retransmission" and "Retransmission index" may be set to bits that notify the value of W in Operation Example 1-1 or the pattern of X in Operation Example 1-2, for example. For example, in Operation Example 1-1, 2 bits (4 patterns) may be used to notify W, and the terminal 200 may select any of W = 5, 10, 15, and 20.

[0257] Also, the bits not used for "time gap between initial transmission and retransmission" and "Retransmission index" may be used for the area for notifying the NDI or HARQ ID.

[0258] Also, in Operation Example 3-1, for example, as shown in FIG. 16, the time interval between TBs is set regardless of the type of TB and the transmission type. Therefore, according to Operation Example 3-1, for example, even when the interval between TBs is short (for example, when it is less than the threshold value), it is possible to prevent the transmission timings from overlapping between the current TB and the next TB.

[0259] [Operation Example 3-2] In Operation Example 3-2, the interval (time interval) between TBs indicated by Resource reservation is set to the time interval between the retransmission timing of TB#N and the first transmission timing of TB#N+1, for example, as shown in FIG. 17.

[0260] For example, in FIG. 17, the time interval (for example, corresponding to 98 slots) between Slot#2, which is the retransmission timing of TB#1, and Slot#100, which is the first transmission timing of TB#2, is indicated to the terminal 200 by Resource reservation. Similarly, in FIG. 17, the time interval (for example, corresponding to 98 slots) between Slot#102, which is the retransmission timing of TB#2, and Slot#200, which is the first transmission timing of TB#3, is indicated to the terminal 200 by Resource reservation.

[0261] In operation example 3-2, the time interval between the timing of the first transmission of TB#N and the timing of the first transmission of TB#N+1 may be set to a value obtained by adding, for example, the interval indicated by Resource reservation and the time interval (in other words, the gap) indicated by "time gap between initial transmission and retransmission". For example, in FIG. 17, the time interval between the timing of the first transmission of TB#N and the timing of the first transmission of TB#N+1 is set to 100 slots, which is the added value of the interval (for example, 98 slots) indicated by Resource reservation and the gap (for example, 2 slots) maintained by "time gap between initial transmission and retransmission".

[0262] According to operation example 3-2, for example, depending on the setting of the interval indicated by "Resource reservation" and the time interval indicated by "time gap between initial transmission and retransmission", it becomes possible to notify various interval intervals, and the flexibility of resource allocation can be improved.

[0263] For example, the terminal 200 may set the interval indicated by "Resource reservation" to be longer than "time gap between initial transmission and retransmission" to notify various interval intervals.

[0264] Also, in Operation Example 3-2, for example, as shown in FIG. 17, after the first transmission and retransmission of TB#N, the next transmission of TB#N+1 is allocated. In other words, in Operation Example 3-2, the next transmission of TB#N+1 is not allocated between the first transmission and retransmission of TB#N. Therefore, according to Operation Example 3-2, for example, even when the interval between TBs is short (e.g., less than the threshold value), it is possible to prevent the transmission timings from overlapping between the current TB and the next TB.

[0265] Also, in Operation Example 3-2, for example, as shown in FIG. 17, by Resource reservation, an interval is set between the retransmission timing of TB#N and the first transmission timing of TB#N+1 transmitted after TB#N. Therefore, for example, in Operation Example 3-2, compared with LTE (FIG. 6), the interval notified by Resource reservation can be shorter. Thus, in Operation Example 3-2, compared with LTE, the information (e.g., interval pattern) notified by Resource reservation can be reduced.

[0266] The above has described Operation Example 3-1 and Operation Example 3-2.

[0267] The above has described Embodiments 1 to 3 respectively.

[0268] In Embodiments 1 to 3, the method of setting time resources has been described. In contrast, in the following Embodiments 4 to 7, the method of setting frequency resources will be described.

[0269] (Embodiment 4) In V2X, for example, the resources reserved by a transmitting terminal (e.g., Tx UE) are notified to a receiving terminal (Rx UE) by SCI. In LTE, for example, frequency resources (e.g., sub-channel) are allocated by "Frequency resource location of initial transmission and retransmission".

[0270] A sub-channel is a resource that includes, for example, a plurality of resource blocks (e.g., PRB: Physical Resource Block). The allocation of sub-channels may be, for example, consecutive sub-channels. Since sidelink communication is, for example, communication based on discrete fourier transform-spread-orthogonal frequency division multiplexing (DFT-Spread OFDM) called single carrier communication, the increase in peak-to-average power ratio (PAPR) can be suppressed by allocating consecutive resources (e.g., sub-channels) in the frequency domain.

[0271] In LTE V2X, for example, as shown in FIG. 6, a plurality of time resources (e.g., slots) can be reserved. At this time, in the frequency domain of the plurality of reserved time resources, for example, the same frequency resources in a certain section (e.g., sub-channels #1 and #2 in FIG. 6) can be reserved.

[0272] As described above, the notification of the reserved resources is received not only by the receiving terminal but also by other terminals different from the receiving terminal. Therefore, the reserved resources can be grasped not only by the receiving terminal to which the resources are allocated but also by other terminals. Other terminals can reduce the resource collision probability, for example, by avoiding the resources reserved by the transmitting terminal through scheduling that monitors (or senses) other SCIs different from the SCI addressed to the other terminal. Therefore, each terminal can easily avoid resource collisions, for example, in the allocation of time resources subsequent to the time resource when the SCI is received, if the first SCI can be correctly received.

[0273] Also, in LTE V2X, for example, an SCI (or PSCCH) which is a control signal and a PSSCH which is a data signal are allocated to the same slot.

[0274] On the other hand, in NR V2X, for example, a method called "Standalone PSCCH" is being considered to avoid collisions of SCI in the first transmission. In Standalone PSCCH, for example, at the first transmission, the PSCCH that transmits the SCI is transmitted (in other words, the PSSCH is not transmitted), and after the next reserved time resource after the first transmission, the PSSCH that transmits data is transmitted.

[0275] Also, in NR V2X, for example, a method called "Single sub-channel of PSCCH+PSSCH" is being considered. In Single sub-channel of PSCCH+PSSCH, for example, at the first transmission, the PSCCH that transmits the SCI and the PSSCH of one sub-channel are transmitted.

[0276] FIG. 18(a) shows an example of Standalone PSCCH, and FIG. 18(b) shows an example of Single sub-channel of PSCCH+PSSCH.

[0277] In FIG. 18(a), for example, at slot#0 where resource reservation starts, the PSCCH is transmitted and the PSSCH is not transmitted. In the example shown in FIG. 18(a), each of the two transmitting terminals transmits the PSCCH in sub-channel#0 and sub-channel#2 of slot#0. For example, the sub-channels#0, #1, and #2 of slot#2 are reserved by the PSCCH transmitted in sub-channel#0 of slot#0, and the sub-channels#1 and #2 of slot#3 are reserved by the PSCCH transmitted in sub-channel#2 of slot#0. According to Standalone PSCCH, for example, other terminals that receive (or monitor) the PSCCH of slot#0 can recognize that the resources of sub-channels#0, #1, #2 of slot#2 and sub-channels#1, #2 of slot#3 are reserved resources.

[0278] In Fig. 18(b), for example, similar to Fig. 18(a), at slot#0 where resource reservation starts, PSCCH is transmitted, and resources of subsequent slots (e.g., Slot#2 or Slot#3) are reserved. Also, in Fig. 18(b), at Slot#0, together with the transmission of PSCCH, PSSCH is also transmitted in 1 sub-channel.

[0279] By applying Standalone PSCCH or Single sub-channel of PSCCH+PSSCH, since the first PSCCH is transmitted in, for example, 1 sub-channel, the possibility that each terminal can receive PSCCH without collision is increased. For example, even when the frequency resources of PSSCH overlap, if the frequency resources of PSCCH do not overlap, each terminal can receive PSCCH without collision, and other terminals can grasp the resources reserved by the transmitting terminal.

[0280] Also, compared with Standalone PSCCH, Single sub-channel of PSCCH+PSSCH can improve the resource utilization efficiency because PSSCH is also transmitted at slot#0.

[0281] Note that in Fig. 18, the reserved resources are exemplified by the time resources of the time interval (e.g., gap) specified by, for example, "Time gap between initial transmission and retransmission". However, the reserved resources may be the time resources of a longer interval (e.g., the time resources of the interval specified by "Resource reservation") compared with the time interval specified by, for example, "Time gap between initial transmission and retransmission".

[0282] However, the study on the method of notifying frequency resources when implementing Standalone PSCCH or Single sub-channel of PSSCH+PSSCH is not sufficient.

[0283] For example, when 0 (in other words, not allocating frequency resources) or the allocation of 1 sub-channel is notified to notify the frequency resources based on Standalone PSCCH or Single sub-channel of PSSCH+PSSCH, the terminal may not be able to reserve the frequency resources to be used in subsequent slots.

[0284] Also, in V2X, for example, there is a concern (also called "Half duplex issue") that a terminal cannot receive signals transmitted from other terminals during the period when it is transmitting a signal. Therefore, depending on the situation of the terminal, there may be a terminal that cannot receive the PSCCH including the first SCI. Therefore, for example, even when a terminal cannot receive the first or multiple PSCCHs, there is room for study on the method of identifying the reserved resources by the successfully received PSCCH.

[0285] Therefore, in one embodiment of the present disclosure, a method for more flexibly setting frequency resources (for example, Sub-channel) in sidelink communication will be described.

[0286] [Overview of Communication System] The communication system according to the present embodiment includes a base station 300 and a terminal 400.

[0287] FIG. 19 is a block diagram showing a partial configuration example of the terminal 400 according to the present embodiment. In the terminal 400 shown in FIG. 19, a control unit (for example, corresponding to a control circuit) determines first information indicating the frequency resources to be reserved and second information indicating the arrangement method of a channel (for example, PSSCH) for the frequency resources. Further, a communication unit (for example, corresponding to a communication circuit) transmits the first information and the second information.

[0288] Also, in the terminal 400 shown in FIG. 19, the communication unit (for example, corresponding to a communication circuit) receives first information indicating a frequency resource to be reserved and second information indicating a method of arranging a channel (for example, PSSCH) for the frequency resource. The control unit (for example, corresponding to a control circuit) determines the arrangement of the channel based on the first information and the second information.

[0289] [Configuration of Base Station] FIG. 20 is a block diagram showing a configuration example of the base station 300 according to the present embodiment. In FIG. 20, the base station 300 includes a frequency resource size setting unit 301, a resource pool setting unit 302, an error correction encoding unit 303, a modulation unit 304, a signal allocation unit 305, a transmission unit 306, a reception unit 307, a signal separation unit 308, a demodulation unit 309, and an error correction decoding unit 310.

[0290] The frequency resource size setting unit 301 determines candidates for the size of the frequency resource when transmitting a signal using a part of the frequency resources among the frequency resources allocated to the terminal 400, for example. For example, the frequency resource size setting unit 301 may determine candidates for the frequency resource size for each resource pool allocated to the terminal 400. The frequency resource size setting unit 301 outputs upper layer signaling including frequency resource size setting information indicating the determined size candidates to the error correction encoding unit 303.

[0291] The frequency resource size may be, for example, the number of sub-channels, or information indicating a ratio with respect to the entire frequency resource allocated to the terminal 400 (an example will be described later).

[0292] The resource pool setting unit 302 sets a resource pool to be used for sidelink for each terminal 400. For example, the resource pool setting unit 302 may generate information regarding the time resource and frequency resource of the resource pool (hereinafter referred to as resource pool setting information). The resource pool setting unit 302 outputs upper layer signaling including the resource pool setting information to the error correction coding unit 303. Also, the resource pool setting unit 302 outputs the resource pool setting information to the signal allocation unit 305 and the signal separation unit 308.

[0293] The error correction coding unit 303 takes as input the upper layer signaling input from the transmission data signal (DL data signal), the frequency resource size setting unit 301, and the resource pool setting unit 302, error correction codes the input signal, and outputs the coded signal to the modulation unit 304.

[0294] The modulation unit 304 performs modulation processing on the signal input from the error correction coding unit 303, and outputs the modulated data signal to the signal allocation unit 305.

[0295] The signal allocation unit 305 allocates the data signal (for example, DL data signal or upper layer signaling) input from the modulation unit 304 to resources that can be used in a link (for example, Uu link) between the base station 300 and the terminal 400. The formed transmission signal is output to the transmission unit 306.

[0296] For example, the signal allocation unit 305 identifies (in other words, recognizes) the slots and sub-channels available for sidelink communication based on the information input from the resource pool setting unit 302. And when the terminal 400 cannot simultaneously transmit and receive in, for example, the link (for example, Uu link) used for DL data and the sidelink, the signal allocation unit 305 may allocate the data signal to resources not used for the sidelink.

[0297] Note that the resource pool settings may vary for each terminal 400. In this case, the available slots in the Uu link vary for each terminal 400.

[0298] The transmission unit 306 performs wireless transmission processing such as up-conversion on the signal input from the signal allocation unit 305, and transmits it to the terminal 400 via the antenna.

[0299] The reception unit 307 receives the signal transmitted from the terminal 400 via the antenna, performs wireless reception processing such as down-conversion, and outputs it to the signal separation unit 308.

[0300] The signal separation unit 308 identifies, for example, the available slots in the Uu link, and the available slots and sub-channels for sidelink communication, based on the information input from the resource pool setting unit 302. Then, the signal separation unit 308 separates the signal assigned to the available resources in the Uu link, which is input from the reception unit 307. The signal separation unit 308 outputs the separated signal (for example, the UL data signal) to the demodulation unit 309.

[0301] The demodulation unit 309 performs demodulation processing on the signal input from the signal separation unit 308, and outputs the obtained signal to the error correction decoding unit 310.

[0302] The error correction decoding unit 310 decodes the signal input from the demodulation unit 309 to obtain the received data signal (UL data signal) from the terminal 400.

[0303] Note that in the example shown in FIG. 20, the base station 300 includes a frequency resource size setting unit 301 and a resource pool setting unit 302, and the case where the base station 300 generates upper layer signaling including frequency resource size setting information and resource pool setting information has been described, but the present invention is not limited thereto. For example, at least one of the frequency resource size setting information and the resource pool setting information may be set in an application layer called, for example, Pre-configured, or may be preset in a subscriber identity module (SIM). In this case, the base station 300 may use the preset information without generating the frequency resource size setting information or the resource pool setting information. For example, based on the preset resource pool setting information, the base station 300 may recognize available slots between the base station 300 and the terminal 400, and output information indicating the available slots between the base station 300 and the terminal 400 to the signal allocation unit 305 and the signal separation unit 308.

[0304] Also, here, the case where settings related to frequency resources in sidelink communication (for example, information related to the frequency resource size) are set (or notified) from the base station 300 to the terminal 400 by, for example, upper layer signaling (for example, RRC) or MAC is described, but the present invention is not limited thereto. For example, when the settings related to frequency resources in sidelink communication are defined in a specification (or standard), or are set in the SIM or the application layer, the terminal 400 can operate without the settings from the base station 300.

[0305] Also, for example, when the mode of sidelink communication is "Mode 1", it is assumed that the information included in the SCI transmitted by the terminal in sidelink is generated by the base station 300. Therefore, in the case of Mode 1, the base station 300 may generate an SCI (the same processing as the SCI generation unit 410 of the terminal 400 described later) based on, for example, frequency resource size setting information and resource pool setting information, and transmit it to the terminal 400. Note that the SCI may be included in, for example, upper layer signaling or in a physical layer signal (e.g., PDCCH).

[0306] [Configuration of Terminal] FIG. 21 is a block diagram showing a configuration example of the terminal 400 according to the present embodiment. In FIG. 21, the terminal 400 includes a receiving unit 401, a signal separation unit 402, an SCI receiving unit 403, a Uu demodulation unit 404, a Uu error correction decoding unit 405, an SL demodulation unit 406, an SL error correction decoding unit 407, a frequency resource size setting unit 408, a resource pool setting unit 409, an SCI generation unit 410, a Uu error correction encoding unit 411, a Uu modulation unit 412, an SL error correction encoding unit 413, an SL modulation unit 414, a signal allocation unit 415, and a transmitting unit 416.

[0307] The control circuit shown in FIG. 19 may include, for example, an SCI receiving unit 403, a frequency resource size setting unit 408, a resource pool setting unit 409, and an SCI generation unit 410. Also, the communication circuit shown in FIG. 19 may include, for example, a receiving unit 401 and a transmitting unit 416.

[0308] The receiving unit 401 receives a received signal via an antenna, performs receiving processing such as down-conversion, and outputs it to the signal separation unit 402.

[0309] The signal separation unit 402 separates a signal component corresponding to the link between the base station 300 and the terminal 400 (e.g., Uu link) from the signals input from the receiving unit 401 based on the resource pool setting information input from the resource pool setting unit 409, and outputs it to the Uu demodulation unit 404.

[0310] Further, based on the resource pool setting information, the signal separation unit 402 separates the sidelink signal component from the signals input from the reception unit 401. Then, for example, among the sidelink signal components, the signal separation unit 402 outputs the PSCCH signal to the SCI reception unit 403. Also, based on the PSSCH resource allocation information input from the SCI reception unit 403, the signal separation unit 402 separates the PSSCH signal addressed to the terminal 400 from the sidelink signal components input from the reception unit 401 and outputs it to the SL demodulation unit 406.

[0311] The SCI reception unit 403 demodulates and decodes the SCI input from the signal separation unit 402. For example, the SCI reception unit 403 attempts to demodulate and decode the SCI. If the decoding is successful (in other words, if the SCI is detected), based on the PSSCH resource allocation information addressed to the terminal 400 included in the SCI and the frequency resource size setting information input from the frequency resource size setting unit 408, it identifies the candidate for the frequency resource size where the PSSCH is arranged among the frequency resources reserved for the terminal 400. Then, for example, based on the bits included in the SCI and the candidate for the frequency resource size, the frequency resource size setting unit 301 determines the frequency resource where the PSSCH is arranged (for example, the entire reserved frequency resource, a part of it, or any unused part), and outputs the PSSCH resource allocation information indicating the frequency resource and time resource to which the PSSCH is allocated to the signal separation unit 402. Note that the SCI reception unit 403 may determine whether the information included in the SCI is addressed to the terminal 400 based on the destination information included in the SCI, for example.

[0312] The Uu demodulation unit 404 performs demodulation processing on the signal input from the signal separation unit 402 and outputs the obtained demodulated signal to the Uu error correction decoding unit 405.

[0313] The Uu error correction decoding unit 405 decodes the demodulated signal input from the Uu demodulation unit 404, outputs the obtained upper layer signaling to the frequency resource size setting unit 408 and the resource pool setting unit 409, and outputs the obtained received data signal (or, referred to as the Uu received data signal).

[0314] The SL demodulation unit 406 performs demodulation processing on the signal input from the signal separation unit 402, and outputs the obtained demodulated signal to the SL error correction decoding unit 407.

[0315] The SL error correction decoding unit 407 decodes the demodulated signal input from the SL demodulation unit 406, and performs error determination on the decoded signal, for example, cyclic redundancy check (CRC). When there is no error in the decoded signal, the SL error correction decoding unit 407 outputs the obtained received data signal (or, referred to as the sidelink received data signal).

[0316] The frequency resource size setting unit 408 sets candidates for the frequency resource size to which the PSCCH addressed to the terminal 400 is allocated based on, for example, the frequency resource size setting information included in the upper layer signaling input from the Uu error correction decoding unit 405. The frequency resource size setting unit 408 outputs frequency resource size setting information indicating the set frequency resource size candidates to the SCI reception unit 403 and the SCI generation unit 410.

[0317] The resource pool setting unit 409 sets a resource pool (for example, time resources and frequency resources) used by the terminal 400 for sidelink based on, for example, the resource pool setting information included in the upper layer signaling input from the Uu error correction decoding unit 405. The set resource pool may include, for example, either or both of the resources used by the terminal 400 for transmission and the resources used by the terminal 400 for reception. The resource pool setting unit 409 outputs the resource pool setting information to the SCI generation unit 410, the signal separation unit 402, and the signal allocation unit 415.

[0318] The SCI generation unit 410 generates an SCI including information regarding the frequency resource for arranging the PSSCH. For example, the SCI generation unit 410 may generate an SCI based on the information input from the resource pool setting unit 409 (e.g., information indicating the resources available for sidelink), the information input from the frequency resource size setting unit 408, and the resource amount of the data included in the transmission buffer (not shown). Further, the SCI generation unit 410 may generate an SCI including information indicating which size of the frequency resource candidates of the reserved frequency resources the PSSCH is allocated to (in other words, information indicating any one of the frequency resource size candidates) in the slot for transmitting the SCI. Further, the SCI may include, for example, information regarding the determined resources, information for identifying the transmitting terminal 400 (e.g., transmitter ID), and information for identifying the receiving terminal 400 (e.g., receiver ID). The SCI generation unit 410 outputs the generated SCI to the signal allocation unit 415.

[0319] For example, when the mode of sidelink communication is "Mode 2", the terminal 400 generates an SCI in the SCI generation unit 410. Further, for example, when the base station 300 generates an SCI and transmits the SCI to the terminal 400 when the mode of sidelink communication is "Mode 1", the terminal 400 may generate an SCI based on the SCI transmitted from the base station 300.

[0320] The Uu error correction encoding unit 411 takes as input the transmission data signal (UL data signal) of the Uu link, error correction encodes the transmission data signal, and outputs the encoded signal to the Uu modulation unit 412.

[0321] The Uu modulation unit 412 modulates the signal input from the Uu error correction encoding unit 411 and outputs the modulated signal to the signal allocation unit 415.

[0322] The SL error correction encoding unit 413 takes as input the transmission data signal (sidelink data signal) of the sidelink, error correction encodes the transmission data signal, and outputs the encoded signal to the SL modulation unit 414.

[0323] The SL modulation unit 414 modulates the signal input from the SL error correction encoding unit 413 and outputs the modulated signal to the signal allocation unit 415.

[0324] The signal allocation unit 415 allocates, for example, the signal of the PSCCH including the SCI and the signal of the PSSCH including the sidelink data signal input from the SL modulation unit 414 to the sidelink resources based on the information input from the resource pool setting unit 409 and the information input from the SCI generation unit 410. Also, the signal allocation unit 415 allocates, for example, the signal input from the Uu modulation unit 412 to the resources of the Uu link (for example, the resources of the uplink data channel (PUSCH: Physical Uplink Shared Channel)). The signal allocation unit 415 outputs the signal allocated to the resources to the transmission unit 416.

[0325] The transmission unit 416 performs radio transmission processing such as up-conversion on the signal input from the signal allocation unit 415 and transmits it.

[0326] In the example shown in FIG. 21, the case where the terminal 400 receives the signaling of the upper layer including the frequency resource size setting information and the resource pool setting information has been described, but it is not limited thereto. For example, at least one of the frequency resource size setting information and the resource pool setting information may be set in an application layer called, for example, Pre-configured, or may be preset in the SIM. In this case, the terminal 400 may use the preset information without receiving the frequency resource size setting information or the resource pool setting information. For example, the terminal 400 recognizes the resources available between the base station 300 and the terminal 400 and the resources available for the sidelink based on the preset resource pool setting information, and may use the information regarding these resources in the signal separation unit 402 and the signal allocation unit 415.

[0327] In FIG. 21, as an example, the case where different components are provided for the demodulation unit, error correction decoding unit, error correction encoding unit, and modulation unit between the Uu link and the sidelink has been described. However, the present invention is not limited to this, and common components may be provided between the Uu link and the sidelink.

[0328] [Operation of Terminal 400] Next, an example of the operation of terminal 400 (refer to FIG. 21) will be described.

[0329] FIG. 22 is a flowchart showing an example of the processing of terminal 400.

[0330] Terminals 200 (for example, a transmitting terminal and a receiving terminal) that perform transmission and reception in the sidelink set parameters related to the sidelink (S201). The parameters related to the sidelink may include, for example, time resources, frequency resources (for example, sub-channels), SL BWP, resource pools, and settings of channels arranged in each slot.

[0331] The parameters related to the sidelink may be notified from the transmitting terminal to the receiving terminal by, for example, SCI. Alternatively, the parameters related to the sidelink may be defined for terminal 200 by, for example, specifications (or standards), set in an application layer called Pre-configured, preset in the SIM, or set by a higher layer such as a SIB called configured or other RRC or MAC.

[0332] Based on the set parameters, terminal 200 performs sidelink communication (for example, data transmission and reception) (S202).

[0333] Next, an example of a method for setting frequency resources (for example, sub-channels) will be described.

[0334] In this embodiment, for example, the transmitting terminal transmits to the receiving terminal an SCI including information indicating a method of arranging the PSSCH for a frequency resource reserved for sidelink communication. The information indicating the method of arranging the PSSCH for the reserved frequency resource may include, for example, information regarding the arrangement of the PSSCH for all the frequency resources, the arrangement of the PSSCH for some of the frequency resources, or whether the PSSCH is not allocated (in other words, the unused reserved frequency resource) among the reserved frequency resources.

[0335] Based on this notification, the terminal 400 (for example, the transmitting terminal and the receiving terminal) may determine, for example, the frequency resources in which the PSSCH is arranged in each of the reserved time resources (for example, slots).

[0336] Here, the information notifying the reserved frequency resource and the information indicating the method of arranging the PSSCH among the reserved frequency resources are different information. Therefore, the terminal 400 can identify the reserved frequency resources in other slots following the slot even when, for example, the PSSCH is allocated to some of the reserved frequency resources or the PSSCH is not allocated in a certain slot.

[0337] Therefore, according to this embodiment, for example, even when Standalone PSCCH or Single sub-channel of PSCCH+PSSCH is applied, the terminal 400 can dynamically set the allocation in the reserved frequency resource, and the PSCCH in which the SCI is transmitted can reduce the probability of collision with the PSSCH of other UEs.

[0338] Note that the frequency resource size candidates may be defined in the specification (or standard), may be preset in the SIM, may be set in the application layer called Pre-configured, or may be set in a higher layer such as an SIB called configured or other RRC or in the MAC.

[0339] Also, one or more frequency resource size candidates may be set. Also, among all the frequency resource size candidates, the frequency resource size candidate may be selected (in other words, notified) by the SCI. Also, the frequency resource size candidate may be selected from a plurality of predetermined candidates, and the options may be notified to the terminal 400, and the terminal 400 may select by the SCI from among the options. Note that the options for the frequency resource size may be notified, for example, in a higher layer such as RRC or in the MAC.

[0340] Hereinafter, an operation example of the terminal 400 will be described.

[0341] [Operation Example 4-1 (Standalone PSCCH)] In operation example 4-1, an example in which Standalone PSCCH is applied will be described.

[0342] In operation example 4-1, for example, 1-bit information (for example, either bit 0 or bit 1) is set (in other words, added) in the SCI.

[0343] Among the 1-bit information, bit 0 may indicate the placement (in other words, allocation or use) of the PSSCH to the frequency resource (in other words, the reserved frequency resource) allocated by, for example, "Frequency resource location of initial transmission and retransmission".

[0344] Also, among the 1-bit information, bit 1 may indicate that the PSSCH is not placed (in other words, not allocated or not used) to the frequency resource allocated by "Frequency resource location of initial transmission and retransmission" in the slot in which the SCI including the 1-bit information is transmitted and received.

[0345] For example, by setting the 1-bit information included in the SCI to bit 1, the transmitting terminal can notify the receiving terminal that the PSSCH is not arranged in the slot in which the SCI is received (for example, slot#0 in Fig. 18(a)).

[0346] Also, the transmitting terminal can reserve the frequency resources of the PSSCH in the slot following the slot in which the SCI is received (for example, slot#2 or #3 in Fig. 18(a)) for the receiving terminal according to resource allocation information (for example, "Frequency resource location of initial transmission and retransmission") different from the above 1-bit information included in the SCI.

[0347] [Operation Example 4-2 (Single sub-channel of PSCCH+PSSCH)] In Operation Example 4-2, an example where Single sub-channel of PSSCH+PSSCH is applied will be described.

[0348] In Operation Example 4-2, for example, 1-bit information (for example, either bit 0 or bit 1) is set (in other words, added) in the SCI.

[0349] Of the 1-bit information, bit 0 may indicate the arrangement (in other words, allocation or use) of the PSSCH to the frequency resources allocated (in other words, reserved frequency resources) by, for example, "Frequency resource location of initial transmission and retransmission".

[0350] Also, among the 1-bit information, bit 1 may indicate the placement of PSSCH on a part of the frequency resources (e.g., 1 sub-channel) of the frequency resources assigned by "Frequency resource location of initial transmission and retransmission" in the slot where the SCI containing the 1-bit information is transmitted and received.

[0351] For example, by setting the 1-bit information included in the SCI to bit 1, the transmitting terminal can notify the receiving terminal that the PSSCH is arranged in 1-sub-channel in the slot (e.g., slot#0 in Fig. 18(b)) where the SCI is received.

[0352] Also, the transmitting terminal can reserve the frequency resources of PSSCH in the slots (e.g., slot#2 or #3 in Fig. 18(b)) following the slot (e.g., slot#0 in Fig. 18(b)) where the SCI is received for the receiving terminal according to the resource allocation information (e.g., "Frequency resource location of initial transmission and retransmission") different from the above 1-bit information included in the SCI.

[0353] In the operation example 4-2, although 1-sub channel is described as an example of a part of the frequency resources notified by the 1-bit information, it is not limited thereto. For example, the part of the frequency resources notified by the 1-bit information may be a plurality of sub-channels or a plurality of PRBs among the frequency resources assigned by "Frequency resource location of initial transmission and retransmission".

[0354] In addition, Operation Example 4-2 may be applied not only to the first transmission of the TB but also to the retransmission of the TB. FIG. 23 shows an example in which Operation Example 4-2 is applied during the retransmission of the TB. For example, in FIG. 23, in Slot #0, bit 0 is notified, and the frequency resource for the first transmission of TB#1 is set to a part of the frequency resources (e.g., 1 sub-channel). Also, for example, in FIG. 23, in slot #2, bit 1 is notified, and the frequency resource for the retransmission of TB#1 is set to the frequency resources reserved for terminal 400 (e.g., 3 sub-channels). Also, for example, in FIG. 23, in Slot #20, bit 1 is notified, and the frequency resource for the first transmission of TB#2 is set to the frequency resources reserved for terminal 400 (e.g., 3 sub-channels). Also, for example, in FIG. 23, in Slot #22, bit 0 is notified, and the frequency resource for the retransmission of TB#2 is limited to a part of the frequency resources (e.g., 1 sub-channel).

[0355] In FIG. 23, terminal 200 can allocate the TB to a part of the reserved frequency resources in both the first transmission and the retransmission. By this resource allocation, for example, in the retransmission, when it is not necessary to allocate all of the reserved frequency resources, the amount of resources used can be reduced, so interference can be reduced, and the probability of collision with the resources transmitted by other UEs can be reduced.

[0356] [Operation Example 4-3] In Operation Example 4-3, an example of setting a plurality of frequency resource sizes will be described.

[0357] For example, bits (e.g., bits included in the SCI) for notifying the placement of the PSSCH to some or all of the frequency resources (e.g., sub-channels) of the frequency resources (e.g., sub-channels) allocated by "Frequency resource location of initial transmission and retransmission" are set (in other words, added).

[0358] For example, the case where 2-bit information is set will be described.

[0359] The 2-bit information may indicate, for example, the ratio of the resources for arranging the PSSCH (in other words, the frequency resource size) with respect to the entire frequency resources allocated by "Frequency resource location of initial transmission and retransmission" as follows. Bit 00: All resources Bit 01: 1 / 2 of the resources Bit 10: 1 / 4 of the resources Bit 11: 1 sub-channel

[0360] For example, in the case of bit 01 or bit 10, that is, 1 / 2 of the resources or 1 / 4 of the resources, the terminal 400 may divide the number of sub-channels allocated by "Frequency resource location of initial transmission and retransmission" into two or four parts to determine the number of sub-channels for arranging the PSSCH. At this time, if the result of the division is not an integer, the terminal 400 may calculate the number of sub-channels by truncating the decimal part such as Floor (number of sub-channels), or may calculate the number of sub-channels by rounding up the decimal part such as Ceil (number of sub-channels).

[0361] Also, for example, in the case of bit 01, that is, 1 / 2 of the resources, the terminal 400 may divide the number of sub-channels assigned by "Frequency resource location of initial transmission and retransmission" into two, and generate two sub-channel groups. Similarly, for example, in the case of bit 10, that is, 1 / 4 of the resources, the terminal 400 may divide the number of sub-channels assigned by "Frequency resource location of initial transmission and retransmission" into four, and generate four sub-channel groups. Then, the terminal 400 may select any one of the sub-channel groups.

[0362] Note that the candidates for the frequency resource size (for example, all resources, 1 / 2 of the resources, 1 / 4 of the resources, or 1 sub-channel) are just examples, and other values may also be used. Also, the candidates for the frequency resource size may include cases where PSSCH is not allocated as in Operation Example 4-1 (unused PSSCH).

[0363] Also, the number of bits of the information indicating the frequency resource size is not limited to 2 bits, and other numbers of bits may also be used. For example, the more types of frequency resource sizes there are, the more the number of bits of the SCI may be increased.

[0364] In this way, even when the PSSCH is arranged in some of the sub-channels of the reserved frequency resources in a certain slot (for example, the first slot) among the reserved time resources (for example, slots) of the terminal 400, the terminal 400 can reserve the frequency resources of the PSSCH in a slot different from the slot in which the SCI is received (for example, a subsequent slot).

[0365] The above has described each of Operation Examples 4-1 to 4-3.

[0366] According to this embodiment, the terminal 200 determines, for each of a plurality of reserved slots, a sub-channel in which the PSSCH is arranged based on notification information regarding the use (e.g., all uses, some uses, or no use) of a plurality of reserved sub-channels.

[0367] By this determination of the sub-channel, for example, even when Standalone PSCCH or Single sub-channel of PSSCH+PSSCH is applied, the terminal 400 can allocate the PSSCH based on different frequency resource sizes in each of the plurality of reserved slots.

[0368] Therefore, according to this embodiment, for example, even when there are more diverse traffic types than LTE, such as NR, the frequency resource size can be dynamically set, so that the efficiency of resource allocation (e.g., frequency resource allocation or reservation) in wireless communication (e.g., sidelink communication) can be improved.

[0369] [Method for selecting sub-channel] An example of a method for selecting a sub-channel set for some of the frequency resources in which the PSSCH is arranged among the reserved frequency resources will be described.

[0370] For example, in Operation Example 4-2 and Operation Example 4-3, the selected sub-channel may be a sub-channel that includes an SCI. In V2X, for example, including a PSCCH region in the PSSCH region has been considered. At this time, when the sub-channel for transmitting the PSCCH and the sub-channel for transmitting the PSSCH are the same, the number of sub-channels occupied by the PSSCH and the PSCCH can be reduced. For example, when the PSSCH is arranged in 1 sub-channel, the selected sub-channel may be set to 1 sub-channel that includes the PSCCH. Also, when multiple sub-channels can be selected as in Operation Example 4-3, for example, among the sub-channel groups obtained by dividing the "Frequency resource location of initial transmission and retransmission", a sub-channel group that includes the sub-channel containing the PSCCH may be selected.

[0371] Also, for example, in Operation Example 4-2 and Operation Example 4-3, the selected sub-channel may include the sub-channel with the lowest sub-channel number or the highest sub-channel number among the frequency resources assigned by the "Frequency resource location of initial transmission and retransmission". For example, when multiple sub-channels can be selected as in Operation Example 4-3, among the sub-channel groups obtained by dividing the "Frequency resource location of initial transmission and retransmission", a sub-channel group that includes the sub-channel with the lowest sub-channel number or the highest sub-channel number may be selected.

[0372] Also, in Operation Example 4-2 and Operation Example 4-3, among the frequency resources allocated by "Frequency resource location of initial transmission and retransmission" to the selected sub-channel, there may be included a sub-channel determined based on a value identifying the UE, such as a UE ID, RNTI, Layer-1 source ID, or Layer-1 destination ID. For example, the terminal 400 may select a sub-channel with a number obtained by adding the remainder obtained by dividing the value identifying the UE by the number of sub-channels allocated to the terminal 400 to the lowest sub-channel number among the sub-channels allocated to the terminal 400. Also, for example, when multiple sub-channels can be selected as in Operation Example 4-3, the terminal 400 may select a sub-channel group with a number obtained by adding the remainder obtained by dividing the value identifying the UE by the number of sub-channel groups obtained by dividing "Frequency resource location of initial transmission and retransmission" to the lowest sub-channel group number.

[0373] [Transport block size (TB size)] Also, for example, when PSSCH is arranged on some sub-channels as in Operation Example 4-2 and Operation Example 4-3, the amount of resources where PSSCH is arranged is less than the amount of resources when arranged over all of the reserved multiple sub-channels. Also, in NR, for example, the TB size is calculated based on the amount of resources in the allocated time domain and frequency domain and the MCS notified by a control signal (e.g., DCI).

[0374] Therefore, for example, when a TB arranged in a part of the frequency resources allocated to the terminal 400 is first transmitted and the TBS is calculated based on the amount of resources at the first transmission, even if the amount of resources for retransmission is larger than the amount of resources at the first transmission, the number of systematic bits that can be transmitted at the time of retransmission may decrease. In this case, the PSSCH arranged in the resources for retransmission will have excessive quality, and the utilization efficiency of the resources will decrease.

[0375] Therefore, in the present embodiment, for example, when the arrangement method notified by the SCI is the arrangement of the PSSCH in a part of the sub-channels, as in Operation Examples 4-2 and 4-3, the TBS may be calculated based on the size of the entire sub-channel specified by "Frequency resource location of initial transmission and retransmission". In other words, regardless of the frequency resources (for example, sub-channels) in which the PSSCH is arranged, the TBS may be calculated based on the size of the entire reserved frequency resources.

[0376] By this determination of the TBS, it is possible to suppress the PSSCH arranged in the resources for retransmission from having excessive quality. Also, for example, the transmitting terminal can determine the number of systematic bits to be transmitted and set the MCS in consideration of the amount of resources for retransmission at the first transmission.

[0377] (Embodiment 5) In Embodiment 4, a method of explicitly notifying the size of the frequency resources in which the PSSCH is arranged by the bits included in the SCI has been described. In contrast, in the present embodiment, a method of implicitly notifying the size of the frequency resources in which the PSSCH is arranged will be described.

[0378] According to the present embodiment, the terminal 400 can notify the sizes of a plurality of frequency resources in which the PSSCH is arranged without increasing the number of bits of the SCI.

[0379] The base station and terminal according to this embodiment have the same basic configuration as the base station 300 and terminal 400 according to Embodiment 4.

[0380] Hereinafter, an example of a method for setting frequency resources (for example, sub-channels) according to this embodiment will be described.

[0381] [Operation Example 5-1] In Operation Example 5-1, "priority indication" or "QoS indication" included in the SCI is used for notifying the frequency resource size (in other words, the arrangement method of the PSSCH). Note that in LTE, it is called priority indication, but in the SCI of NR, it may be called by a different name (for example, "QoS indication").

[0382] It is considered that Priority indication or QoS indication includes information such as priority, latency, or reliability. Based on Priority indication or QoS indication, controls such as resource allocation, congestion control between terminals, the transmission method when multiple data occurs within a terminal (resolution of in-device coexistence issues), or power control are considered.

[0383] In Operation Example 5-1, the terminal 400 may determine the frequency resource size of the PSSCH based on, for example, Priority indication or QoS indication. In other words, the information included in Priority indication or QoS indication is associated with the frequency resource size (in other words, the arrangement method of the PSSCH).

[0384] For example, based on the Priority indication or QoS indication, the terminal 400 identifies the delay amount required for the terminal 400 (in other words, the desired delay amount) or the required reliability.

[0385] Then, when the identified delay amount is short or the reliability is high (for example, when it is less than the threshold value), the terminal 400 may allocate the PSSCH to all of the reserved frequency resources, for example. Also, when the identified delay amount is long or the reliability is low (for example, when it is greater than or equal to the threshold value), the terminal 400 may not allocate the reserved frequency resources to the PSSCH, or may allocate them to some of the frequency resources. Note that some of the frequency resources may be set based on any one of Operation Examples 4-1 to 4-3, for example.

[0386] Note that the size of the frequency resource where the PSSCH is arranged when the delay amount is short or the reliability is high is not limited to all of the reserved frequency resources, and may be set to a size larger than the size of the frequency resource where the PSSCH is arranged when the delay amount is long or the reliability is low, for example.

[0387] For example, by arranging the PSSCH in all of the reserved frequency resources, the reception quality of the PSSCH can be improved compared to the case where the PSSCH is arranged in a part of the reserved frequency resources, so it becomes easier to satisfy the delay amount or reliability required for the terminal 400.

[0388] The mapping between the Priority indication or QoS indication and the frequency resource size may be defined in the specification (or standard), may be set in the SIM, may be set in the application layer called Pre-configured, or may be set in a higher layer such as the SIB called configured or other RRC or in the MAC.

[0389] Further, the terminal 400 may determine whether the TB included in the received PSSCH is the TB of the first transmission or the retransmission TB based on, for example, the Retransmission index included in the SCI.

[0390] According to Operation Example 5-1, the terminal 400 can notify the frequency resource size without using new bits. Further, for example, the terminal 400 can arrange the PSSCH in the frequency resource based on the frequency resource size suitable for the parameter (for example, the required delay amount or reliability) corresponding to the value set in LTE.

[0391] [Operation Example 5-2] In Operation Example 5-2, the Redundancy Version (RV) included in the SCI is used to notify the frequency resource size (the arrangement method of the PSSCH).

[0392] As described in Embodiment 2 (Operation Example 2-2), in NR, for example, similar to the downlink control information (DCI), retransmission control by notifying the RV and the New Data Indicator (NDI) is also considered in the SCI.

[0393] As described in Embodiment 2, for example, in the circular buffer shown in FIG. 15, the larger the number of bits that can be transmitted in one transmission, the more likely the bit sequence corresponding to RV3 or RV1 is included in the bit sequence corresponding to RV0 or RV2. In other words, for example, in FIG. 15, the terminal 400 (for example, the receiving terminal) can receive the bits included in the bit sequence corresponding to RV3 or RV1 by receiving the bit sequence corresponding to RV0 or RV2.

[0394] Therefore, even if a part (for example, one) of the plurality of RVs is such that the PSSCH is not arranged as in Operation Example 4-1 (in other words, the reserved frequency resource is not used), or is used for notifying the arrangement of the PSSCH to a part of the reserved frequency resource as in Operation Example 4-2, it is assumed that the reception characteristics in the terminal 400 are less likely to deteriorate.

[0395] Therefore, in Operation Example 5-2, the terminal 400 may determine the frequency resource size of the PSSCH based on, for example, the RV. In other words, the RV is associated with the frequency resource size (in other words, the arrangement method of the PSSCH).

[0396] As an example of Operation Example 5-2, the terminal 400 may notify the frequency resource size as follows using the bits used for the notification of RV3. Hereinafter, as an example, RV0 is notified by bit 00, RV1 is notified by bit 01, RV2 is notified by bit 10, and RV3 is notified by bit 11.

[0397] In Example 1, bit 11 may notify, instead of RV3, the arrangement of the PSSCH in a part of the reserved frequency resource, or no arrangement of the PSSCH (unused reserved frequency resource), and RV0. 00: RV0 and arrange PSSCH in all of the reserved frequency resources 01: RV1 and arrange PSSCH in all of the reserved frequency resources 10: RV2 and arrange PSSCH in all of the reserved frequency resources 11: RV0 and arrange PSSCH in a part of the reserved frequency resources or no arrangement of PSSCH

[0398] Note that, for example, a smaller frequency resource size may be associated with bit 11 as compared with bits 00, 01, and 10. In other words, for example, a larger frequency resource size (for example, all or a part of the reserved frequency resources) may be associated with bits 00, 01, and 10 as compared with bit 11.

[0399] For example, when PSSCH is arranged in all of the reserved frequency resources, any one of RV0, RV1, and RV2 can be set, while when PSSCH is arranged in a part of the reserved frequency resources, one of RV0 can be set. However, when PSSCH is arranged in a part of the reserved frequency resources, it is assumed to be the first transmission of the TB. Therefore, even if the RV that can be set when PSSCH is arranged in a part of the reserved frequency resources is one of the RVs that are likely to be used at the first transmission, the retransmission efficiency is less likely to deteriorate.

[0400] In addition, in Example 1, the case where the bit 11 corresponding to RV3 is used for notifying the frequency resource size different from the bits corresponding to other RVs has been described. However, for notifying an interval different from the bits corresponding to other RVs, bits corresponding to other RVs different from RV3 (for example, RV1) may be used.

[0401] Also, as Example 2 of Operation Example 5-2, two of the plurality of RVs (for example, RV1 and RV3) may be used for notifying the arrangement of PSSCH in a part of the reserved frequency resources as in Operation Example 4-2. In the case of Example 2, as follows, RV1 and RV3 may not be set, and instead RV0 or RV2 may be set. 00: RV0 and arrange PSSCH in all of the reserved frequency resources 01: RV0 and arrange PSSCH in a part of the reserved frequency resources 10: RV2 and arrange PSSCH in all of the reserved frequency resources 11: RV2 and arrange PSSCH in a part of the reserved frequency resources

[0402] In this way, when the arrangement of PSSCH in a part of the reserved frequency resources is notified instead of notifying the two states of RV (for example, RV1 and RV3), the terminal 400 can support the operation of arranging PSSCH in a part of the reserved frequency resources not only at the first transmission (for example, in the case of RV0) but also at the retransmission (for example, in the case of RV2).

[0403] Also, in the case where, for example, in retransmission, it is not necessary to allocate all of the reserved frequency resources, the terminal 400 can reduce the amount of resources used by selecting the placement of the PSSCH on a part of the reserved frequency resources, so that interference can be reduced and the probability of collision with the resources transmitted by other UEs can be reduced.

[0404] Note that in Operation Example 5-2, instead of (or additionally) notifying the placement of the PSSCH on a part of the reserved frequency resources by the RV, it may be notified that there is no placement of the PSSCH.

[0405] [Operation Example 5-3] In Operation Example 5-3, "RV" and "Retransmission index" included in the SCI are used for notifying the frequency resource size (in other words, the placement method of the PSSCH).

[0406] The Retransmission index is information for notifying either the first transmission or the retransmission.

[0407] In Operation Example 5-3, the terminal 400 may determine the frequency resource size of the PSSCH based on, for example, the RV and the Retransmission index (for example, information indicating retransmission of data). In other words, the combination of the RV and the Retransmission index (transmission type) is associated with the frequency resource size (in other words, the placement method of the PSSCH).

[0408] For example, by restricting the types of available RVs according to the first transmission and the retransmission, instead, the placement of the PSSCH on a part of the reserved frequency resources is notified.

[0409] For example, among the 3-bit bit sequences combining 2-bit RV and 1-bit Retransmission index, the first 2 bits are for RV and the last 1 bit is for Retransmission index. Also, for example, Retransmission index (e.g., the 3rd bit out of 3 bits) indicates initial transmission when it is 0 and retransmission when it is 1. Also, for example, RV is set to either RV0 or RV3 at initial transmission and to either RV2 or RV1 at retransmission.

[0410] In this case, as follows, for the 3-bit bit sequence (e.g., 000~111), RV, interval, and transmission type (initial transmission or retransmission) may be set. 000: RV0, Place PSSCH on all reserved frequency resources and initial transmission 001: RV2, Place PSSCH on all reserved frequency resources and retransmission 010: RV0, Place PSSCH on a part of the reserved frequency resources and initial transmission 011: RV2, Place PSSCH on a part of the reserved frequency resources and retransmission 100: RV3, Place PSSCH on all reserved frequency resources and initial transmission 101: RV1, Place PSSCH on all reserved frequency resources and retransmission 110: RV3, Place PSSCH on a part of the reserved frequency resources and initial transmission 111: RV1, Place PSSCH on a part of the reserved frequency resources and retransmission

[0411] For example, at initial transmission, RV0 or RV3 that may contain more systematic bits compared to RV1 and RV2 is selected, and at retransmission, RV1 or RV2 that may contain more parity bits not included in the initial transmission is selected.

[0412] According to Operation Example 5-3, the number of selectable RVs in each of the first transmission and retransmission is reduced. However, since RVs suitable for each of the first transmission and retransmission are included in the options, deterioration of reception quality at the terminal 400 can be suppressed.

[0413] Note that in Operation Example 5-3, instead of (or in addition to) notifying the placement of the PSSCH in a part of the reserved frequency resources by the RV and the Retransmission index, it may be notified that there is no placement of the PSSCH.

[0414] [Operation Example 5-4] In Operation Example 5-4, the HARQ process number (or HARQ process ID) included in the SCI is used for notifying the frequency resource size (in other words, the placement method of the PSSCH).

[0415] In NR, support for multiple processes is being considered, and the HARQ process ID can be notified by the SCI.

[0416] In Operation Example 5-4, the terminal 400 may determine the frequency resource size of the PSSCH, for example, based on the HARQ process ID. In other words, the HARQ process ID is associated with the frequency resource size (in other words, the placement method of the PSSCH).

[0417] For example, for each HARQ process, placement of the PSSCH in all of the reserved frequency resources or placement of the PSSCH in a part of the reserved frequency resources may be set.

[0418] Note that the setting method for each HARQ process may be defined, for example, in a specification (or standard), may be preset in the SIM, may be set in an application layer called Pre-configured, or may be set in a higher layer such as a SIB or other RRC or MAC called configured.

[0419] The operation examples 5-1 to 5-4 have been described above.

[0420] Note that any two or more of the operation examples 5-1 and 5-4 may be combined.

[0421] In the present embodiment, the frequency resource size of the PSSCH is implicitly notified by information defined for other purposes. Therefore, according to the present embodiment, for example, in the sidelink, in order to notify the frequency resource size of the PSSCH, it is not necessary to add new information to the parameters defined in LTE, for example. Thus, the signaling overhead can be reduced.

[0422] (Embodiment 6) In NR V2X, for example, it is considered that the SCI is transmitted in two stages.

[0423] For example, the first-stage SCI (also referred to as the 1st SCI, for example) is arranged on the PSCCH, and the second-stage SCI (also referred to as the 2nd SCI, for example) is arranged in a part of the PSSCH region.

[0424] The first-stage SCI can be received not only by the receiving terminal (in other words, the terminal to which the SCI is transmitted), but also by other terminals. For example, based on the first-stage SCI, other terminals can perform sensing to grasp the resource reservation status.

[0425] On the other hand, regarding the second-stage SCI, for example, the resource amount or resource region is notified by the first-stage SCI. Also, it is considered that the second-stage SCI is received at the receiving terminal and not received by other terminals.

[0426] Therefore, for example, in the first-stage SCI, by excluding information not used for sensing and including information that can be used for sensing at other terminals different from the transmission destination terminal of the SCI, the number of bits of the first-stage SCI can be further reduced. With this setting of the first-stage SCI, for example, the coding rate of the first-stage SCI can be lowered (in other words, made redundant) for transmission, making it easier to be received at other terminals.

[0427] Also, for example, since the second-stage SCI only needs to be received at the receiving terminal which is the transmission destination terminal of the SCI, it may be transmitted at a coding rate that can be received at the receiving terminal.

[0428] In this embodiment, a method for notifying frequency resources by two-stage SCI will be described.

[0429] The base station and terminal according to this embodiment have the same basic configuration as the base station 300 and terminal 400 according to Embodiment 4.

[0430] Hereinafter, an operation example of the terminal 400 according to this embodiment will be described.

[0431] [Operation Example 6-1] In Operation Example 6-1, for example, the terminal 400 transmits a first-stage SCI including information regarding the frequency resources in Embodiment 4 to the receiving terminal.

[0432] According to Operation Example 6-1, for example, other terminals different from the receiving terminal can also receive the first-stage SCI. Other terminals different from the receiving terminal can recognize, for example, the frequency resources where the PSSCH is arranged.

[0433] For example, other terminals may use information regarding the frequency resources where the PSSCH is arranged for interference measurement. For example, in Operation Example 4-1 of Embodiment 4, since the PSSCH is not arranged in the frequency resources, Operation Example 6-1 is effective.

[0434] Also, since the terminal 400 can identify the frequency resource where the PSSCH is arranged in the first-stage SCI, for example, when the PSSCH is arranged in some frequency resources in Operation Example 4-2 or Operation Example 4-3 of Embodiment 4, the area where the second-stage SCI is allocated can be changed according to the area where the PSSCH is actually allocated.

[0435] [Operation Example 6-2] In Operation Example 6-2, for example, the terminal 400 transmits the second-stage SCI including information on the frequency resources in Operation Example 4-2 or Operation Example 4-3 of Embodiment 4 to the receiving terminal.

[0436] According to Operation Example 6-2, for example, the number of bits transmitted in the first-stage SCI can be reduced, and the coding rate of the first-stage SCI can be reduced, so the probability that other terminals can receive the SCI can be improved.

[0437] Also, in Operation Example 6-2, the receiving terminal cannot identify the frequency resource where the PSSCH is arranged from the first-stage SCI. Therefore, the receiving terminal may assume, for example, the case where the PSSCH is arranged in some frequency resources in Operation Example 4-2 or Operation Example 4-3 of Embodiment 4, and set the area where the second-stage SCI is allocated to the same sub-channel as the PSCCH.

[0438] Alternatively, the terminal 400 may set the area where the second-stage SCI is allocated to the frequency area with the fewest number of sub-channels in Operation Example 4-2 or Operation Example 4-3 of Embodiment 4.

[0439] (Embodiment 7) In Embodiment 4, a method of notifying, by bits included in the SCI, the frequency resource in which the PSSCH is arranged (in other words, the frequency resource size) among the frequency resources allocated, for example, by "Frequency resource location of initial transmission and retransmission" was described.

[0440] In this embodiment, for example, a method will be described in which information regarding the allocation of frequency resources in each of a plurality of reserved time resources (for example, slots) is included in one SCI, enabling different frequency resources to be allocated in a plurality of slots.

[0441] According to this embodiment, for example, the flexibility of frequency resource allocation can be improved as compared with Embodiment 4.

[0442] The base station and the terminal according to this embodiment have the same basic configuration as the base station 300 and the terminal 400 according to Embodiment 4.

[0443] Hereinafter, an operation example of the terminal 400 according to this embodiment will be described.

[0444] [Operation Example 7-1] In Operation Example 7-1, the SCI includes information regarding the allocation of frequency resources in a plurality of slots.

[0445] As an example, a case where one SCI includes information regarding the allocation of frequency resources for four slots will be described. In this example, the terminal 400 may notify, by the SCI, information regarding the allocation of frequency resources for four slots among the reserved time resources, for example.

[0446] FIG. 24 shows an example of resource allocation in Operation Example 7-1.

[0447] In FIG. 24, for example, the interval notified by "Resource reservation" included in the SCI is 20 ms, and the first allocated resource in the time domain is slot #0.

[0448] As shown in FIG. 24, the terminal 400 may include the following information in the information regarding the allocation of frequency resources (e.g., resource indication value (RIV)) in the SCI of slot #0. Sub-channel#1 Sub-channel#0,#1,#2 Sub-channel#1,#2 Sub-channel#0,#1

[0449] The frequency resources for the above four slots notified in slot #0 correspond to slot #0, slot #20, slot #40, and slot #60, respectively.

[0450] The terminal 400 that has received the SCI in slot #0 can recognize the frequency resource allocation for four slots from slot #0. In other words, the terminal 400 can reserve, for example, the frequency resources for four slots from slot #0 based on one SCI. Also, as in the above example, the frequency resources for four slots can be set for each slot, for example.

[0451] Also, as shown in FIG. 24, the terminal 400 may include the following information in the information regarding the allocation of frequency resources (e.g., RIV) in the SCI of slot #20. Sub-channel#0,#1,#2 Sub-channel#1,#2 Sub-channel#0,#1 Sub-channel#0,#1,#2

[0452] The frequency resources for the above four slots notified in slot#20 correspond to slot#20, slot#40, slot#60, and slot#80 respectively.

[0453] The terminal 400 that received the SCI in slot#20 can recognize the frequency resource allocation for four slots starting from slot#20. In other words, based on one SCI, the terminal 400 can reserve, for example, the frequency resources for four slots starting from slot#20. Also, as in the above example, the frequency resources for four slots can be set for each slot, for example.

[0454] According to Operation Example 7-1, multiple slots' frequency resources can be flexibly reserved by one SCI.

[0455] Note that the allocation of the above frequency resources for four slots (e.g., sub-channel) is just an example, and other sub-channel allocations may also be possible. Also, the number of slots for which frequency resources can be notified by one SCI is not limited to four slots, and other numbers of slots may also be possible.

[0456] [Operation Example 7-2] In Operation Example 7-2, the SCI contains information regarding the allocation of frequency resources in multiple slots.

[0457] As an example, the case where one SCI contains information regarding the allocation of frequency resources for four slots will be described. In this example, the terminal 400 may notify, by SCI, information regarding the allocation of frequency resources for four slots among the reserved time resources, for example.

[0458] Figure 25 shows an example of resource allocation in Operation Example 7-2.

[0459] In FIG. 25, for example, the interval notified by "Resource reservation" included in the SCI is 20 ms, the time interval between the initial transmission and the retransmission notified by "Time gap between initial transmission and retransmission" is 2 slots, and the first allocated resource in the time domain is slot#0.

[0460] As shown in FIG. 25, the terminal 400 may include the following information in the information (e.g., RIV) regarding the allocation of frequency resources in the SCI of slot#0. Sub-channel#1 Sub-channel#0,1,2 Sub-channel#1,2 Sub-channel#0,1

[0461] The frequency resources for the above 4 slots notified in slot#0 correspond to slot#0, slot#2, slot#20, and slot#22 respectively. In FIG. 25, slot#2 and slot#22 are resources for retransmitting the data (e.g., PSSCH) transmitted in slot#0 and slot#20.

[0462] The terminal 400 that receives the SCI in slot#0 can recognize the frequency resource allocation for 4 slots from slot#0. In other words, the terminal 400 can reserve the frequency resources for, for example, 4 slots from slot#0 based on one SCI. Also, as in the above example, the frequency resources for 4 slots can be set for each slot.

[0463] Also, in Operation Example 7-2, the terminal 400 may also notify the frequency resources for initial transmission in, for example, slot#2 and slot#22 which are the resources for retransmission shown in FIG. 25. This is for the terminal 400 to calculate the TBS based on the amount of frequency resources at the time of initial transmission.

[0464] For example, as shown in FIG. 25, the terminal 400 may include the following information in the SCI of slot #2 in the information regarding the allocation of frequency resources (e.g., RIV). Sub-channel#1 Sub-channel#0,#1, #2 Sub-channel#1,#2 Sub-channel#0,#1

[0465] The frequency resources for the above four slots notified in slot #2 correspond to slot #0, slot #2, slot #20, and slot #22 respectively. The frequency resources for the above four slots notified in slot #2 (at retransmission) are, for example, the same as the frequency resources for the four slots notified in slot #0 (at first transmission).

[0466] Similarly, in slot #22 which is a resource for retransmission, for example, the same frequency resources as the four slots notified in slot #20 which is a resource for first transmission may be notified. Similarly, in slot #42 which is a resource for retransmission, for example, the same frequency resources as the four slots notified in slot #40 which is a resource for first transmission may be notified.

[0467] According to Operation Example 7-2, for example, in FIG. 25, even when the SCI of slot #0 cannot be received due to a Half duplex issue or other factors, the terminal 400 (receiving terminal) can calculate the TBS of the PSSCH of slot #2 from the frequency resources of slot #0 based on the SCI of slot #2 and can receive the PSSCH of slot #2.

[0468] Also, according to Operation Example 7-2, the frequency resources in multiple slots can be flexibly reserved by one SCI.

[0469] Note that the allocation of frequency resources (e.g., sub-channel) for the above-mentioned four slots is just an example, and the allocation of other sub-channels may also be used. Also, the number of slots for which frequency resources can be notified by one SCI is not limited to four slots, and other numbers of slots may also be used.

[0470] [Operation Example 7-3] In Operation Example 7-3, the SCI includes information regarding the allocation of frequency resources in a plurality of slots. Also, in Operation Example 7-3, the allocation of frequency resources included in the SCI is periodically repeated at certain time intervals (e.g., intervals).

[0471] As an example, the case where one SCI includes information regarding the allocation of frequency resources for two slots will be described. In this example, the terminal 400 may notify, by SCI, information regarding the allocation of frequency resources for two slots among the reserved time resources, for example.

[0472] For example, assume that the interval notified by "Resource reservation" included in the SCI is 20 ms and the first allocated resource in the time domain is slot#0. In this case, the terminal 400 may include the following information in the information regarding the allocation of frequency resources (e.g., RIV) in the SCI of slot#0, for example. Sub-channel#1 Sub-channel#0,#1,#2

[0473] For example, among the frequency resources for the above two slots notified in slot#0, sub-channel#1 corresponds to slot#0, slot#40, slot#80, … which have a 40 ms period at intervals twice that of the 20 ms interval from the first slot (e.g., slot#0). Also, among the frequency resources for the above two slots notified in slot#0, sub-channel#0, #1, and #2 correspond to slot#20, slot#60, slot#100, … which have a 40 ms period at intervals twice that of the 20 ms interval from the second slot (e.g., slot#20).

[0474] Also, the terminal 400 may include the following information in the information (e.g., RIV) regarding the allocation of frequency resources in the SCI of slot#20. Sub-channel#0,#1,#2 Sub-channel#1

[0475] Similarly, for example, among the frequency resources for the above two slots notified in slot#20, sub-channel#0, #1, and #2 correspond to slot#20, slot#60, slot#100, … which have a 40 ms period from the first slot (e.g., slot#20). Also, among the frequency resources for the above two slots notified in slot#20, sub-channel#1 corresponds to slot#40, slot#80, slot#120, … which have a 40 ms period from the second slot (e.g., slot#40).

[0476] Also, as a modification of Operation Example 7-3, as shown in FIG. 26, the frequency resources may be made different between the resources for the first transmission and the resources for the retransmission.

[0477] For example, in FIG. 26, the terminal 400 may notify, by means of the SCI, information regarding the allocation of frequency resources for two slots out of the reserved time resources.

[0478] In FIG. 26, for example, the interval notified by "Resource reservation" included in the SCI is 20 ms, and the first allocated resource in the time domain is slot #0.

[0479] As shown in FIG. 26, the terminal 400 may include the following information in the information (e.g., RIV) regarding the allocation of frequency resources in the SCI of slot #0. Sub-channel#1 Sub-channel#0,#1,#2

[0480] For example, among the frequency resources for the above two slots notified in slot #0, sub-channel #1 corresponds to slot #0, slot #20, slot #40,... which are resources for the first transmission at intervals of 20 ms from the first slot (e.g., slot #0). Also, among the frequency resources for the above two slots notified in slot #0, sub-channels #0, #1, and #2 correspond to slot #2, slot #22, slot #42,... which are resources for retransmission at intervals of 20 ms from the second slot (e.g., slot #2).

[0481] Also, as shown in FIG. 26, the terminal 400 may include the following information in the information (e.g., RIV) regarding the allocation of frequency resources in the SCI of slot #2. Sub-channel#1 Sub-channel#0,#1,#2

[0482] For example, among the frequency resources for the above two slots notified in slot #2, sub-channel #1 corresponds to the resources for the first transmission corresponding to the retransmission resources of slot #2, i.e., slots (e.g., slot #0) such as slot #0, slot #20, slot #40,... which are the resources for the first transmission at intervals of 20 ms. Also, among the frequency resources for the above two slots notified in slot #2, sub-channels #0, #1, and #2 correspond to slots such as slot #2, slot #22, slot #42,... which are the resources for retransmission at intervals of 20 ms starting from slot #2.

[0483] In other words, in FIG. 26, the frequency resources for the above two slots notified in slot #2 (at retransmission) are, for example, the same as the frequency resources for the two slots notified in slot #0 (at first transmission).

[0484] Also, in operation example 7-3, the TBS may be calculated, for example, according to the resource amount of the first transmission, or according to the resource amount of the retransmission, or may be predefined. Or, the TBS may be calculated, for example, according to the larger resource amount among the resources for the first transmission and the resources for retransmission.

[0485] Note that the allocation of the frequency resources (e.g., sub-channel) for the above two slots is just an example, and other sub-channel allocations may also be used. Also, the number of slots for which the frequency resources can be notified by one SCI is not limited to two slots, and other numbers of slots may also be used.

[0486] [Operation Example 7-4] In operation example 7-4, one setting is selected (in other words, notified) by SCI from among the settings of frequency resource allocation (e.g., the pattern of frequency resources) in a plurality of time resources.

[0487] Note that multiple settings of frequency resource allocation (in other words, multiple patterns) may be defined in the specification (or standard), may be set in the SIM, may be set in an application layer called Pre-configured, may be set in a higher layer such as SIB or other RRC called configured, or may be set in the MAC.

[0488] FIG. 27 shows an example of four patterns (Pattern A, B, C, and D) of frequency resource allocation. Each of the four patterns shown in FIG. 27 includes, for example, allocation of frequency resources for four slots.

[0489] The terminal 400 may notify the receiving terminal of the selected pattern among the four patterns by SCI (for example, 2-bit information), for example.

[0490] According to Operation Example 7-4, since the setting of frequency resource allocation for a plurality of slots can be notified by pattern, the number of notification bits in the SCI can be reduced as compared with the case where the frequency resource allocation for each of the plurality of slots is notified individually.

[0491] Further, the terminal 400 may notify, by SCI, the correspondence between the slot in which the SCI is transmitted and the slots from the 1st slot to the 4th slot shown in FIG. 27, for example.

[0492] For example, in the slot in which the SCI is transmitted, when the current slot, slot #0, corresponds to the 3rd slot shown in FIG. 27, the interval is 20 ms, and Pattern B is notified, the following allocations are made in order from the current slot (3rd slot). slot#0:sub-channel#3,#4 (3rd slot) slot#20:sub-channel#3,#4 (4th slot) slot#40:sub-channel#1,#2 (1st slot) slot#60:sub-channel#1,#2 (2nd slot)

[0493] The receiving terminal may identify frequency resources in a plurality of slots based on, for example, information indicating a pattern and information indicating an association between a slot included in the pattern and a slot in which an SCI is transmitted.

[0494] For example, by varying the correspondence between the slot in which an SCI is transmitted and the slot shown in FIG. 27, the frequency allocation can be set cyclically.

[0495] Note that the allocation of frequency resources (e.g., sub-channels) for the above-described four slots is an example, and other sub-channel allocations may be used. Also, the number of slots for which frequency resources can be notified by one SCI is not limited to four slots, and other numbers of slots may be used. Further, the number of patterns is not limited to four patterns, and other numbers of patterns may be used.

[0496] The operation examples 7-1 to 7-4 have been described above, respectively.

[0497] The embodiments of the present disclosure have been described above.

[0498] (Other embodiments) (1) In Embodiments 1 to 3 regarding the setting of time resources, information regarding an interval may be included in, for example, a first SCI. When information regarding an interval is included in the first SCI, other terminals different from the receiving terminal can also easily receive (in other words, monitor or sense) the SCI, so it becomes easier to grasp the interval of the transmission time and resource collisions can be reduced.

[0499] Alternatively, in Embodiments 1 to 3 above, information regarding an interval may be included in, for example, a second SCI. When information regarding an interval is included in the second SCI, an increase in the number of bits of the first SCI can be suppressed, and the communication range determined by the first SCI can be increased.

[0500] (2) In Embodiments 4 to 7 regarding the setting of frequency resources, not arranging the PSSCH, or arranging the PSSCH in a part of the reserved frequency resources, for example, has a remarkable effect when applied in a transmission where resources are not reserved (for example, the first transmission). Therefore, for example, the above embodiments may be applied when the first transmission of the TB is performed, or when the SCI that reserves resources for the first time is transmitted.

[0501] (3) In V2X, for example, due to the above-mentioned Half duplex issue, in the resources reserved for a terminal, other terminals may also transmit signals. Therefore, in Embodiments 4 to 7 regarding the setting of frequency resources, not arranging the PSSCH, or arranging the PSSCH in a part of the reserved frequency resources, is effective for avoiding collisions with the transmission resources of other terminals even after the reservation of resources. Therefore, for example, the above embodiments may be applied not only at the first transmission but also at the retransmission or at the first transmission of the next TB after the resource reservation.

[0502] (4) In an embodiment of the present disclosure, the maximum value of the number of resources reserved by a terminal at one time may be limited to a specific number, for example, 2, 4, 8, etc. Further, a fixed value may be defined for the maximum value in the specification (or standard), may be pre-configured at the application layer, and may also be configured at a higher layer (for example, MAC).

[0503] (5) The terminals that transmit and receive in the sidelink may include, for example, terminals that perform transmission processing but not reception processing, terminals that perform reception processing but not transmission processing, or terminals that perform both transmission and reception.

[0504] (6) When the settings related to sidelink are pre-configured in terminals 200 and 400, the settings related to sidelink may be set in, for example, specifications (e.g., standards), may be set in an application layer called Pre-configured, may be set in the SIMs provided in terminals 200 and 400, may be set in a higher layer such as an SIB or other RRC called configured, or may be set in MAC.

[0505] (7) In each operation example, consecutive slots have been described, but the slots do not have to be temporally consecutive. For example, an interval may be set using the slots included in the sidelink resource pool.

[0506] (8) One embodiment of the present disclosure is not limited to sidelink communication (in other words, direct communication between a plurality of terminals), and may also be applied to Uu link communication (in other words, communication between base stations 100 and 300 and terminals 200 and 400). In this case, for example, the channel arrangement in the sidelink described in each of the above embodiments may be replaced with the channel arrangement in the Uu link. For example, PSCCH may be replaced with a downlink data channel (PDCCH: Physical Downlink Control Channel), PSSCH may be replaced with a downlink data channel (PDSCH: Physical Downlink Shared Channel) or an uplink data channel (PUSCH: Physical Uplink Shared Channel), PSFCH may be replaced with an uplink control channel (PUCCH: Physical Uplink Control Channel), and PSBCH may be replaced with a notification channel (PBCH: Physical Broadcast Channel).

[0507] (9) In the above embodiment, the mode of sidelink communication may be, for example, Mode 2 is set, and Mode 1 does not have to be set. In the case of Mode 2, the terminals 200 and 400 can receive the SCI transmitted by other terminals and avoid transmitting using the same resources as those indicated by the SCI. For example, the terminals 200 and 400 can share the resource reservation information with other terminals by notifying other terminals of an interval.

[0508] (10) The operation examples of the above embodiments may be used in combination. For example, at least one of Embodiments 1 to 3 regarding the method for determining time resources and at least one of Embodiments 4 to 7 regarding the method for determining frequency resources may be combined to determine time resources and frequency resources.

[0509] (11) The unit of time resource is not limited to a slot, and may be, for example, a time resource unit such as a frame, a sub-frame, a slot, a sub-slot, or a symbol, or other time resource units. Also, the unit of frequency resource is not limited to a sub-channel, and may be, for example, a frequency resource unit such as a bandwidth part (BWP), a resource block (e.g., PRB), a resource block group (RBG), a sub-carrier, or a resource element group (REG), or other frequency resource units.

[0510] The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiment is realized as an LSI which is an integrated circuit, partially or entirely, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip so as to include part or all of the functional blocks. The LSI may be provided with input and output of data. Depending on the degree of integration, the LSI may also be referred to as an IC, a system LSI, a super LSI, or an ultra LSI.

[0511] The method of integrating circuits is not limited to LSI, and it may be implemented by an application-specific circuit, a general-purpose processor, or a dedicated processor. Further, after manufacturing the LSI, an FPGA (Field Programmable Gate Array) that can be programmed, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used. The present disclosure may be implemented as digital processing or analog processing.

[0512] Furthermore, if a technology for integrating circuits that replaces LSI appears due to the progress of semiconductor technology or another derived technology, naturally, the integration of functional blocks may be performed using that technology. The application of biotechnology or the like is possible as an example.

[0513] The present disclosure can be implemented in any type of device, apparatus, and system having a communication function (collectively referred to as a communication device). The communication device may include a wireless transceiver (transceiver) and a processing / control circuit. The wireless transceiver may include a receiving unit and a transmitting unit, or may include them as functions. The wireless transceiver (transmitting unit, receiving unit) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of the communication device include a telephone (mobile phone, smartphone, etc.), a tablet, a personal computer (PC) (laptop, desktop, notebook, etc.), a camera (digital still / video camera, etc.), a digital player (digital audio / video player, etc.), a wearable device (wearable camera, smartwatch, tracking device, etc.), a game console, a digital book reader, a telehealth / telemedicine (remote healthcare / medical prescription) device, a vehicle or mobile transportation means with a communication function (automobile, airplane, ship, etc.), and combinations of the above various devices.

[0514] The communication device is not limited to being portable or movable, and includes all kinds of devices, apparatuses, systems that are not portable or are fixed, such as smart home devices (home appliances, lighting devices, smart meters or measuring devices, control panels, etc.), vending machines, and any other "Things" that can exist on the IoT (Internet of Things) network.

[0515] Communication includes data communication by a cellular system, a wireless LAN system, a communication satellite system, etc., and also includes data communication by combinations of these.

[0516] In addition, the communication device also includes devices such as a controller and a sensor that are connected or coupled to a communication device that executes the communication function described in the present disclosure. For example, it includes a controller and a sensor that generate a control signal or a data signal used by the communication device that executes the communication function of the communication device.

[0517] In addition, the communication device includes infrastructure facilities, such as a base station, an access point, and any other devices, apparatuses, systems that communicate with or control the above-mentioned various non-limited devices.

[0518] A terminal according to an embodiment of the present disclosure includes a control circuit that determines first information including a second value obtained by dividing an interval of reserved time resources by a first value, and second information indicating an association between the second value and the first information and one of at least one of the candidates when there are a plurality of candidates for at least one of the first value, and a transmission circuit that transmits the first information and the second information.

[0519] In an embodiment of the present disclosure, the second information indicates any one of a plurality of candidates for the first value.

[0520] In an embodiment of the present disclosure, the second information indicates any one of a plurality of candidates for the association.

[0521] In one embodiment of the present disclosure, the second information is information indicating the priority of data, and the priority is associated with the at least one candidate.

[0522] In one embodiment of the present disclosure, the second information is information indicating a redundancy version, and the redundancy version is associated with the at least one candidate.

[0523] In one embodiment of the present disclosure, the second information includes information indicating a redundancy version and information indicating a transmission type of either the first transmission or the retransmission of data, and a combination of the redundancy version and the transmission type is associated with the at least one candidate.

[0524] In one embodiment of the present disclosure, the second information is information indicating a retransmission process number, and the retransmission process number is associated with the at least one candidate.

[0525] In one embodiment of the present disclosure, the interval is a time interval between adjacent data in the time domain among the data communicated by the terminal.

[0526] In one embodiment of the present disclosure, the interval is a time interval between the retransmission timing of the first data and the first transmission timing of the second data transmitted after the first data.

[0527] A terminal according to one embodiment of the present disclosure includes a receiving circuit that receives first information including a second value obtained by dividing an interval of reserved time resources by a first value, and second information indicating an association between the second value and the first information and one of the at least one candidate when there are a plurality of candidates for at least one of the first value, and a control circuit that determines the interval based on the first information and the second information.

[0528] In a communication method according to an embodiment of the present disclosure, a terminal determines first information including a second value obtained by dividing an interval of time resources to be reserved by a first value, and second information indicating one of at least one candidate when there are a plurality of candidates for at least one of the association between the second value and the first information and the first value, and transmits the first information and the second information.

[0529] In a communication method according to an embodiment of the present disclosure, a terminal receives first information including a second value obtained by dividing an interval of time resources to be reserved by a first value, and second information indicating one of at least one candidate when there are a plurality of candidates for at least one of the association between the second value and the first information and the first value, and determines the interval based on the first information and the second information.

[0530] The disclosures of the specification, drawings, and abstract included in Japanese Patent Application No. 2019-184039 filed on October 4, 2019 are all incorporated herein by reference.

Industrial Applicability

[0531] An embodiment of the present disclosure is useful in a mobile communication system.

Description of Signs

[0532] 100, 300 Base station 101, 208 Interval setting unit 102, 209, 302, 409 Resource pool setting unit 103, 303 Error correction coding unit 104, 304 Modulation unit 105, 215, 305, 415 Signal allocation unit 106, 216, 306, 416 Transmission unit 107, 201, 307, 401 Reception unit 108, 202, 308, 402 Signal separation unit 109, 309 Demodulation unit 110, 310 Error correction decoding unit 200,400 terminals 203,403 SCI receiving section 204,404 Uu demodulation section 205,405 Uu error correction decoding section 206,406 SL demodulation section 207,407 SL error correction decoding section 210,410 SCI generation section 211,411 Uu error correction encoding section 212,412 Uu modulation section 213,413 SL error correction encoding section 214,414 SL modulation section 301,408 Frequency resource size setting section< / pssch>

Claims

1. A control circuit that sets a time resource interval to be reserved from a plurality of time resource interval candidate values; a transmitting circuit for transmitting sidelink control information (SCI) including first information for notifying the time resource interval to be reserved, The plurality of time resource interval candidate values ​​include a multiplication value of a first value, which is an integer value, and a second value, which is variable in two patterns; the first information includes the second value; The second information indicating the plurality of time resource interval candidate values ​​is notified by a higher layer. Terminal.

2. the plurality of time resource interval candidates include a first group of time resource interval candidates specified by a multiplication value of the first value, which is an integer value, and the second value set in a first pattern, and a second group of time resource interval candidates specified by a multiplication value of the first value, which is an integer value, and the second value set in a second pattern; The terminal according to claim 1.

3. The first value, which is an integer value, is set within a range defined by a standard. The terminal according to claim 1.

4. setting a time resource interval to be reserved from a plurality of time resource interval candidate values; transmitting sidelink control information (SCI) including first information for indicating the reserved time resource interval; The plurality of time resource interval candidate values ​​include a multiplication value of a first value, which is an integer value, and a second value, which is variable in two patterns; the first information includes the second value; The second information indicating the plurality of time resource interval candidate values ​​is notified by a higher layer. Communication methods.

5. A process of setting a time resource interval to be reserved from a plurality of time resource interval candidate values; transmitting sidelink control information (SCI) including first information for indicating the reserved time resource interval; The plurality of time resource interval candidate values ​​include a multiplication value of a first value, which is an integer value, and a second value, which is variable in two patterns; the first information includes the second value; The second information indicating the plurality of time resource interval candidate values ​​is notified by a higher layer. Integrated circuits.

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