Base station, communication method and integrated circuit

Abstract

To improve the allocation efficiency of a signal in radio communication.SOLUTION: A base station includes a control circuit for controlling reference of a position for arranging data in a time resource, and a transmission circuit for transmitting the control information on the basis of a certain condition in allocation control of data for the time resource based on control information of a downlink, where the reference is a symbol position corresponding to a head symbol of a slot in the case that the control information instructs the transmission of a PUSCH (Physical Uplink Shared Channel), and the reference is a symbol position receiving control information of the slot in the case that the control information instructs the reception of a PDSCH (Physical Downlink Shared Channel).SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present disclosure relates to a terminal and a communication method. [Background technology]

[0002] In recent years, the expansion and diversification of wireless services has led to expectations for the dramatic development of the Internet of Things (IoT). Mobile communications are now being used in a wide range of applications, from smartphones and other information terminals to automobiles, homes, home appliances, and industrial equipment. To support this diversification, significant improvements in the performance and functionality of mobile communication systems are required, addressing various requirements, such as increased system capacity, an increased number of connected devices, and low latency. Against this backdrop, research, development, and standardization of 5G (5th Generation mobile communication systems) are underway. By leveraging enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC), 5G promises to provide flexible wireless communications tailored to diverse needs.

[0003] The 3rd Generation Partnership Project (3GPP), an international standardization organization, is considering New Radio (NR) as one of the 5G wireless interfaces and has completed the formulation of the Release 15 specifications that will realize eMBB and basic URLLC (see, for example, Non-Patent Documents 1-4).

[0004] In URLLC in Release 15, for example, the requirements are a wireless section latency of 1 ms or less and a reliability of 99.999% when transmitting a 32-byte packet. On the other hand, in Release 16, in order to extend URLLC to a variety of use cases such as remote driving or industrial IoT, functional extensions are being considered to achieve higher requirements compared to Release 15, such as an increase in packet size, further reduction in latency, and improvement in reliability (see, for example, Non-Patent Documents 5 and 6). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TS 38.211 V15.7.0, "NR; Physical channels and modulation (Release 15)," September 2019. [Non-patent document 2] 3GPP TS 38.212 V15.7.0, "NR; Multiplexing and channel coding (Release 15)," September 2019. [Non-patent document 3] 3GPP TS 38.213 V15.7.0, "NR; Physical layer procedure for control (Release 15)," September 2019. [Non-patent document 4] 3GPP TS 38.214 V15.7.0, "NR; Physical layer procedures for data (Release 15)," September 2019. [Non-Patent Document 5] RP-191584, “Revised WID: Physical layer enhancements for NR ultra-reliable and low latency communication (URLLC),” Huawei, HiSilicon, June 2019. [Non-patent document 6] RP-191561, “Revised WID: Support of NR industrial Internet of Things (IoT),” Nokia, Nokia Shanghai Bell, June 2019. [Non-Patent Document 7] R1-1908798, “PDCCH enhancements for NR URLLC,” Panasonic, August 2019. Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is room for further consideration regarding the method of allocating signals in wireless communication.

[0007] Non-limiting embodiments of the present disclosure contribute to providing a terminal and a communication method that can improve the efficiency of signal allocation in wireless communication. [Means for solving the problem]

[0008] A terminal according to one embodiment of the present disclosure includes a receiving circuit that receives downlink control information, and a control circuit that controls, based on certain conditions, a criterion for the position at which data is placed in a time resource in order to control the placement of data in the time resource based on the control information.

[0009] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. [Effects of the Invention]

[0010] According to an embodiment of the present disclosure, it is possible to improve frequency utilization efficiency in wireless communication.

[0011] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0012] [Figure 1] Diagram of an example architecture of a 3GPP NR system [Figure 2] Schematic diagram showing functional separation between NG-RAN and 5GC [Figure 3] Sequence diagram of RRC connection setup / reconfiguration procedure [Figure 4] Schematic diagram showing usage scenarios for enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Figure 5] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario [Figure 6] FIG. 1 shows an example of allocation of time resources to downlink data. [Figure 7] FIG. 1 is a diagram showing an example of allocation of time resources to uplink data. [Figure 8] FIG. 1 shows an example of allocation of time resources to downlink data. [Figure 9] FIG. 1 is a diagram showing an example of allocation of time resources to uplink data. [Figure 10]FIG. 1 shows an example of allocation of time resources to downlink data. [Figure 11] FIG. 1 is a diagram showing an example of allocation of time resources to uplink data. [Figure 12] FIG. 10 shows an example of time resource allocation for downlink data to which repetition is applied. [Figure 13] FIG. 1 shows an example of time resource allocation for uplink data to which repetition is applied. [Figure 14] Block diagram showing an example of the configuration of a part of a terminal [Figure 15] Block diagram showing an example of the configuration of a base station [Figure 16] Block diagram showing an example of a terminal configuration [Figure 17] Flowchart showing an example of terminal operation [Figure 18] FIG. 10 is a diagram showing an example of time resource allocation according to operation example 1-1. [Figure 19] FIG. 10 is a diagram showing an example of time resource allocation according to operation example 1-2. [Figure 20] FIG. 10 is a diagram showing an example of time resource allocation according to a modification of the first embodiment. [Figure 21] A diagram showing an example of time resource allocation [Figure 22] FIG. 10 is a diagram showing an example of time resource allocation according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0014] <5G NR system architecture and protocol stack> 3GPP is working on the next release of fifth-generation cellular technology (also known as 5G), which includes 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, allowing for the prototyping and commercial deployment of 5G NR compliant devices (e.g., smartphones).

[0015] For example, the system architecture assumes a Next Generation Radio Access Network (NG-RAN) with gNBs. The gNBs provide UE-side termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other via an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) via a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity that performs AMF) via an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity that performs UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 1 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0016] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the Packet Data Convergence Protocol (PDCP) sublayer (see, for example, TS 38.300, section 6.4), the Radio Link Control (RLC) sublayer (see, for example, TS 38.300, section 6.3), and the Medium Access Control (MAC) sublayer (see, for example, TS 38.300, section 6.2), which are terminated on the network side at the gNB. A new Access Stratum (AS) sublayer (Service Data Adaptation Protocol (SDAP)) has also been introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack has also been defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is given in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in clauses 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0017] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0018] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), the Physical Uplink Shared Channel (PUSCH), and the Physical Uplink Control Channel (PUCCH) as uplink physical channels, and the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Broadcast Channel (PBCH) as downlink physical channels.

[0019] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC), which have 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 approximately three times higher than those offered by IMT-Advanced. Meanwhile, URLLC imposes stricter requirements for ultra-low latency (0.5 ms user-plane latency for both UL and DL) and high reliability (1-10-5 within 1 ms). Finally, mMTC may require preferably high connection density (1,000,000 devices / km2 in urban environments), wide coverage in adverse environments, and extremely long battery life (15 years) for low-cost devices.

[0020] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. Subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. Similar to LTE systems, the term "resource element" can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0021] In the new radio system 5G-NR, a resource grid of subcarriers and OFDM symbols is defined for each numerology and each carrier in the uplink and downlink. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0022] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 2 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0023] For example, the gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, encryption, and integrity protection of data; - AMF selection at UE attach time if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data towards UPF; - Routing of control plane information towards AMF; - Setting up and tearing down connections; - scheduling and sending of paging messages; - Scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, Maintenance (OAM) Function); - Configuring measurements and measurement reporting for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Network slicing support; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Sharing of radio access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0024] The Access and Mobility Management Function (AMF) hosts the following main functions: - Ability to terminate Non-Access Stratum (NAS) signaling; - NAS signaling security; - Access Stratum (AS) security control; - 3GPP Core Network (CN) inter-node signaling for mobility between access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Managing the registration area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization, including checking roaming privileges; - Mobility management control (subscription and policy); - Network slicing support; - Selection of Session Management Function (SMF).

[0025] Additionally, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and policy rule enforcement for the user plane part; - Traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - Branching Point for supporting multi-homed PDU sessions; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping to the QoS flow of the SDF); - Downlink packet buffering and triggering function for downlink data notification.

[0026] 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; - Enforcement of control plane policies and QoS; - Notification of downlink data.

[0027] <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 transitions from RRC_IDLE to RRC_CONNECTED in the NAS part (see TS 38.300 v15.6.0).

[0028] RRC is a higher layer signaling protocol used to configure the UE and the gNB. With this transition, the AMF prepares UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message. The gNB then sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures the UE to set up a Signaling Radio Bearer 2 (SRB2) and a Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration steps are omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0029] Therefore, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes: control circuitry that, in operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that, in operation, transmits an initial context setup message to the gNodeB via the NG connection 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 that includes a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. Then, the UE performs uplink transmission or downlink reception based on the resource allocation configuration.

[0030] <IMT usage scenarios from 2020 onwards> Figure 4 illustrates some use cases for 5G NR. The 3rd Generation Partnership Project New Radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 4 illustrates some example use scenarios envisioned for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0031] URLLC use cases have stringent performance requirements, such as throughput, latency, and availability. URLLC use cases are envisioned as one of the enabling technologies for future applications, such as wireless control of industrial production or manufacturing processes, remote medical surgery, automated power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the uplink (UL) and 0.5 ms on the downlink (DL). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size at a user plane latency of 1 ms.

[0032] From a physical layer perspective, reliability can be improved in many possible ways. Current reliability improvement room includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and developed. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0033] Additionally, technology enhancements targeted by NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means that a transmission with previously allocated resources is stopped and the allocated resources are used for another transmission with a later requested lower latency / higher priority requirement. Thus, a previously allowed transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0034] The use case for massive machine-type communication (mMTC) is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to latency. These devices are required to be low cost and have very long battery life. From an NR perspective, using very narrow bandwidth portions is one solution that saves power and allows for long battery life from the UE perspective.

[0035] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, for example for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0036] For NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution: high reliability (up to 10-6 level), high availability, packet sizes up to 256 bytes, and time synchronization down to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the 0.5 ms to 1 ms range (e.g., 0.5 ms latency on the targeted user plane)).

[0037] Furthermore, for NR URLLC, several technical enhancements are possible from a physical layer perspective. 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).

[0038] <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 granularity QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header via the NG-U interface.

[0039] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for each PDU session, e.g., as shown above with reference to Figure 3. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and the 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and the NG-RAN associate UL and DL QoS flows with DRBs.

[0040] Figure 5 shows the 5G NR non-roaming reference architecture (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services, as illustrated in Figure 4) interacts with the 3GPP core network to provide services. For example, it accesses a Network Exposure Function (NEF) to support applications that affect traffic routing, or interacts with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on the operator's deployment, Application Functions that are considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions that are not authorized by the operator to directly access Network Functions interact with the relevant Network Functions using the external exposure framework via the NEF.

[0041] Figure 5 further illustrates further 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-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0042] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0043] [Time resource allocation] In NR, for example, a base station (also referred to as, for example, gNB) schedules a downlink data channel (e.g., PDSCH: Physical Downlink Shared Channel) or an uplink data channel (e.g., PUSCH: Physical Uplink Shared Channel) for a terminal (also referred to as, for example, UE: User Equipment) based on downlink control information (e.g., DCI: Downlink Control Information).

[0044] The DCI is transmitted from a base station to a terminal, for example, on a downlink control channel (e.g., a Physical Downlink Control Channel (PDCCH)). For example, time-domain radio resources (hereinafter referred to as "time resources") allocated to data channels are controlled by the DCI.

[0045] Furthermore, in NR, time resources can be allocated more flexibly, for example, to achieve low latency. For example, in NR, in addition to allocation (i.e., basic allocation) in units of one slot (e.g., 14 symbols per slot), allocation in units shorter than a slot (e.g., one to several symbols), also known as "minislots," is possible.

[0046] For example, the time resources allocated to the data channel may be controlled by a time resource assignment (eg, a Time Domain Resource Assignment (TDRA)) field of the DCI.

[0047] For example, multiple time resource allocation patterns (hereinafter referred to as "allocation patterns") are configured in a terminal by signaling from a higher layer (e.g., radio resource control (RRC)). The base station indicates one of the multiple allocation patterns configured in the terminal in DCI (e.g., TDRA field) and allocates time resources to the terminal (e.g., see Non-Patent Documents 2-4).

[0048] Here, the time resource allocation pattern set for the terminal may include parameters such as a "slot offset" indicating the position of the slot relative to the slot in which the terminal received the DCI, the position of the first symbol within the slot at which data transmission or reception begins (e.g., "start symbol"), and the number of symbols (e.g., "symbol length").

[0049] For example, the first symbol position at which data transmission or reception in a slot starts is set relative to the first symbol of the slot (in other words, the slot boundary). Figures 6 and 7 show examples of time resource allocation using the TRDA field of DCI. Figure 6 shows an example of time resource allocation for downlink data (e.g., PDSCH), and Figure 7 shows an example of time resource allocation for uplink data (e.g., PUSCH).

[0050] In the following description, the first symbol in a slot will be referred to as symbol 0. In other words, in Figures 6 and 7, one slot includes 14 symbols, from symbol 0 to symbol 13.

[0051] In URLLC, for example, low latency can be achieved by enabling multiple allocations of data channels (e.g., PDSCH or PUSCH) with a smaller number of allocated symbols to a slot. Also, in URLLC, the frequency at which a terminal receives DCI is, for example, not at one-slot intervals as in eMBB (e.g., receiving PDCCH in the first few symbols of each slot), but multiple times within one slot, thereby reducing the time from packet generation to scheduling.

[0052] 8 and 9 show examples of time resource allocation when a terminal can receive a PDCCH (including, for example, DCI) multiple times within one slot. Fig. 8 shows an example of time resource allocation for a PDSCH, and Fig. 9 shows an example of time resource allocation for a PUSCH.

[0053] In Release 15, for example, if the first symbol position at which data transmission or reception within a slot starts is different, multiple different allocation patterns (e.g., multiple allocation patterns with different start symbols and the same length) are configured even for time resource allocation with the same number of symbols (e.g., length). For example, in Figures 8 and 9, when a data channel with a length of 4 symbols (length = 4) can be allocated, three allocation patterns are configured with different first symbol positions at which data transmission or reception within a slot starts. In this way, the number of allocation patterns can increase as the number of candidates for the first symbol position at which data transmission or reception within a slot starts increases. An increase in the number of allocation patterns leads to an increase in the number of bits in the TDRA field in DCI. Configuring multiple different allocation patterns for data allocation with the same symbol length is inefficient.

[0054] Therefore, in Release 16, among the parameters included in the time resource allocation pattern, consideration is being given to setting the reference (e.g., also called the reference point) for the symbol position allocated to data in a slot (e.g., the first symbol position at which data transmission or reception starts) to the symbol position in the slot at which the terminal receives a PDCCH containing DCI, instead of the first symbol of the slot in Release 15 (see, for example, Non-Patent Document 7).

[0055] 10 and 11 show examples of time resource allocation based on the symbol position of PDCCH reception. Fig. 10 shows an example of time resource allocation for PDSCH, and Fig. 11 shows an example of time resource allocation for PUSCH.

[0056] For example, in the example shown in Fig. 10 (when Index = 0 is notified), the terminal determines the symbol position in the same slot (e.g., Slot offset = 0) as the slot in which the PDCCH (including DCI) is received, which corresponds to the symbol position (e.g., the 0th symbol, the 4th symbol, or the 8th symbol) in which the PDCCH (including DCI) is received in a certain slot, as a reference.The terminal then sets the symbol position (e.g., the 2nd symbol, the 6th symbol, or the 10th symbol) that is two symbols from the reference (e.g., Start symbol = 2) as the first symbol position of the PDSCH.

[0057] Also, for example, in the example shown in FIG. 11 (when Index=0 is notified), the terminal determines the symbol position in the slot next to the slot in which the PDCCH (including DCI) is received (for example, the 0th symbol, the 4th symbol, or the 8th symbol) based on the reference symbol position. The terminal then sets the symbol position (for example, the 2nd symbol, the 6th symbol, or the 10th symbol) that is 2 symbols from the reference symbol (for example, Start symbol=2) as the first symbol position of the PUSCH.

[0058] As shown in Figures 10 and 11, even when one allocation pattern is notified, the time resources (for example, symbol positions) allocated to the PDSCH or PUSCH differ depending on the symbol position within the slot in which the terminal receives the PDCCH.

[0059] For example, when a terminal can receive DCI multiple times within one slot, by configuring time resource allocation for PDSCH or PUSCH according to a criterion based on the symbol position of PDCCH reception within the slot, allocation of the same symbol length (for example, 4 symbols in FIGS. 10 and 11) can be configured using one allocation pattern. By configuring this allocation pattern, the number of bits in the TDRA field in DCI can be reduced. Furthermore, for example, when the number of TDRA field bits is fixed, a different time resource allocation pattern can be configured, thereby improving the flexibility of time resource allocation.

[0060] In Release 16 URLLC, a technology that enables flexible configuration of PUSCH processing, such as repeated transmission in minislot units (also called "repetition") or resource allocation across multiple slots, "e.g., PUSCH transmission enhancement" is being considered (see, for example, Non-Patent Document 5). Enhanced PUSCH transmission can realize, for example, low-latency and highly reliable transmission of uplink data (e.g., PUSCH).

[0061] In the enhancement of PUSCH transmission, for example, control of the number of repeated transmissions (also called the number of repetitions) or time resource allocation for each repeated transmission (for example, at least one of the first symbol position and the symbol length) by DCI has been considered. However, time resource allocation based on the symbol position of PDCCH reception in the enhancement of PUSCH transmission has not been sufficiently considered.

[0062] For example, in order to enhance PUSCH transmission, a common DCI that controls the allocation of time resources for each repeated transmission is being considered. For example, a method is being considered in which the base station notifies the terminal of the allocation pattern of time resources for each repeated transmission in a common TDRA field. This method can reduce the overhead of control information.

[0063] Fig. 12 shows an example of allocation of time resources to repeated transmission. In Fig. 12, as an example, the number of repeated transmissions is set to two (first PUSCH transmission (1st repetition) and second PUSCH transmission (2nd repetition). Note that the number of repeated transmissions is not limited to two, and may be three or more.

[0064] For example, a plurality of time resource allocation patterns for each repeated transmission shown in Fig. 12 may be configured from a base station to a terminal by signaling of a higher layer (for example, RRC). The base station instructs the terminal to select one allocation pattern from the plurality of allocation patterns configured for the terminal, for example, in the TDRA field of DCI, and allocates time resources to the terminal. At this time, as shown in Fig. 12, the position of the first symbol of the time resource allocation for each repeated transmission may be determined, for example, according to a criterion based on the symbol position of PDCCH reception, as described above. By setting this criterion, for example, when a terminal can receive DCI multiple times within one slot, the allocation of time resources in which the number of repetitions and the symbol length of each repeated transmission are the same can be configured using a single allocation pattern.

[0065] However, for example, when repeated transmission is set across multiple slots as shown in Figure 13, it may not be possible to set the allocation of time resources with the same number of repetitions and the same symbol length for each repeated transmission using a single allocation pattern.

[0066] The time resource allocation examples shown in Figures 13(a), (b), and (c) are allocations in which the number of repetitions and the symbol length of each repeated transmission are the same (number of repetitions: 2, symbol length: 4 symbols). For example, in the examples shown in Figures 13(a) and (b), data to be repeatedly transmitted is allocated within one slot. Therefore, each of the time resource allocations shown in Figures 13(a) and (b) can be set using one allocation pattern (e.g., Index=0).

[0067] In contrast, for example, in the example shown in Figure 13(c), data to be repeatedly transmitted is allocated across two slots. Therefore, the time resource allocation shown in Figure 13(c) can be set using an allocation pattern (e.g., Index = 1) different from the allocation pattern (e.g., Index = 0) for Figures 13(a) and (b). In other words, the examples shown in Figures 13(a), (b), and (c) have the same allocation of the number of repetitions and the symbol length of each repeated transmission, but can be set using multiple allocation patterns.

[0068] Furthermore, when the criterion based on the PDCCH reception symbol position is followed, if repeatedly transmitted data is allocated across multiple slots (for example, in the case of FIG. 13(c)), a symbol position earlier than the criterion is also set in the multiple slots, so the setting range of the first symbol position at which data transmission or reception starts is, for example, -13 to 13. For example, when the criterion based on the slot head is followed in Release 15, the setting range of the first symbol position at which data transmission or reception starts is, for example, 0 to 13, so when the criterion based on the PDCCH reception symbol position is followed (in the range of -13 to 13), the overhead of higher layer signals increases.

[0069] Furthermore, for example, when the setting range of the first symbol position at which transmission or reception of data in a slot starts (e.g., the range of Start symbol) is set to 0 to 13, the terminal performs a process of determining whether the first symbol position of data identified in accordance with a criterion based on the PDCCH reception symbol position is the same as the slot indicated by the slot offset (Slot offset) of the time resource pattern, which may complicate the process of identifying the time resource in the terminal. For example, the terminal determines whether the value indicated by the PDCCH reception symbol position (e.g., any of the 0th to 13th symbols) and the first symbol position of the time resource pattern (e.g., any of the 0th to 13th symbols) exceeds the number of symbols in the slot (e.g., 14).

[0070] Furthermore, in the enhancement of PUSCH transmission, a terminal cannot transmit a signal using a symbol set as a downlink (DL) symbol (or a flexible symbol). Therefore, for example, when a symbol set as a DL symbol (or a flexible symbol) is included in a time resource (or a time resource pattern) of a PUSCH allocated by DCI, dropping (in other words, not transmitting) the PUSCH transmission allocated to that symbol or postponing the transmission until the next transmission opportunity (for example, an uplink symbol) is under consideration. Note that a terminal can identify the position of a DL symbol within a slot, for example, by notification of control information (for example, SFI: Slot Format Indicator).

[0071] In this case, for example, if the first symbol position (e.g., Start symbol) of the time resource allocation for each repeated transmission is determined according to the criteria based on the symbol position of the PDCCH reception described above, the terminal performs a process to determine whether the notified time resource matches the DL symbol (or Flexible symbol), which may complicate the process of identifying the time resource in the terminal.

[0072] Therefore, in one embodiment of the present disclosure, a method for improving the efficiency of time resource allocation in URLLC, for example, is described. According to one embodiment of the present disclosure, for example, it is possible to improve the efficiency of time resource allocation in URLLC and to suppress the complication of the time resource identification process in a terminal.

[0073] For example, in one embodiment of the present disclosure, a terminal switches between determining the first symbol position at which to start transmitting or receiving data notified by DCI based on a criterion based on the first symbol position of a slot or a criterion based on the PDCCH received symbol position, based on certain conditions (an example of which will be described later).

[0074] [Communication System Overview] A communication system according to each embodiment of the present disclosure includes a base station 100 and a terminal 200.

[0075] 14 is a block diagram illustrating a configuration example of a portion of terminal 200 according to an embodiment of the present disclosure. In terminal 200 illustrated in FIG. 14, receiver 201 (e.g., corresponding to a receiver circuit) receives downlink control information (e.g., DCI). Controller 205 (e.g., corresponding to a control circuit) controls the criterion for the position (e.g., symbol position) at which data is allocated in the time resource based on a certain condition in controlling the allocation of data (e.g., PDSCH or PUSCH) in the time resource based on the control information.

[0076] [Base station configuration] Fig. 15 is a block diagram showing an example configuration of a base station 100 according to embodiment 1. In Fig. 15, the base station 100 includes a control unit 101, a higher control signal generation unit 102, a downlink control information generation unit 103, an encoding unit 104, a modulation unit 105, a signal allocation unit 106, a transmission unit 107, a reception unit 108, an extraction unit 109, a demodulation unit 110, and a decoding unit 111.

[0077] Control section 101, for example, determines information related to DCI reception in terminal 200 and outputs the determined information to higher control signal generation section 102. The information related to DCI reception may include, for example, information such as a control resource set (CORESET) setting, a search space setting, or a symbol setting within one slot in which the terminal receives a PDCCH.

[0078] Furthermore, control section 101 determines, for example, configuration information including higher layer parameters for terminal 200 (for example, referred to as Radio Resource Control (RRC) configuration information), and outputs the determined RRC configuration information to higher control signal generation section 102. The RRC configuration information may include, for example, information regarding an allocation pattern of time resources notified in the TDRA field of DCI.

[0079] Furthermore, the control unit 101 determines information related to a downlink signal for transmitting a downlink data signal (e.g., PDSCH), an upper control signal, or downlink control information (e.g., DCI). The information related to the downlink signal may include, for example, information such as a modulation and coding scheme (MCS) and radio resource allocation. The information related to the downlink signal may also include, for example, information related to TDRA or information related to repeated transmission (e.g., repetition). The control unit 101 outputs the determined information to, for example, the coding unit 104, the modulation unit 105, and the signal allocation unit 106. The control unit 101 also outputs the information related to the downlink signal to the downlink control information generation unit 103.

[0080] Furthermore, the control unit 101 determines information for the terminal 200 to transmit an uplink data signal (for example, a PUSCH), and outputs the determined information to the downlink control information generation unit 103, the extraction unit 109, the demodulation unit 110, and the decoding unit 111. The information for transmitting the uplink data signal may include, for example, a coding and modulation scheme and radio resource allocation. The information for transmitting the uplink data signal may also include, for example, information on TDRA or information on repeated transmission (for example, repetition).

[0081] The higher control signal generating unit 102 generates a higher layer control signal bit sequence based on information input from the control unit 101 (for example, information related to DCI reception or RRC setting information), and outputs the higher layer control signal bit sequence to the encoding unit 104.

[0082] The downlink control information generating unit 103 generates a downlink control information (for example, DCI) bit string based on information input from the control unit 101, and outputs the generated DCI bit string to the encoding unit 104. Note that control information may be transmitted to multiple terminals. For this reason, the downlink control information generating unit 103 may scramble the PDCCH that transmits the DCI using identification information specific to the terminal. The identification information specific to the terminal may be, for example, any of information such as a C-RNTI (Cell Radio Network Temporary Identifier) ​​and an MCS-C-RNTI (Modulation and Coding Scheme C-RNTI), or may be other information (for example, another RNTI). The other RNTI may be, for example, an RNTI introduced for URLLC.

[0083] The encoding unit 104 encodes the downlink data, the bit string input from the higher control signal generation unit 102, or the DCI bit string input from the downlink control information generation unit 103, based on, for example, information input from the control unit 101 (for example, information related to the coding rate). The encoding unit 104 outputs the encoded bit string to the modulation unit 105.

[0084] The modulation unit 105 modulates the coded bit sequence input from the coding unit 104, for example, based on information input from the control unit 101 (for example, information regarding the modulation method), and outputs the modulated signal (for example, a symbol sequence) to the signal allocation unit 106.

[0085] The signal allocation unit 106 maps the symbol sequence (including, for example, downlink data or a control signal) input from the modulation unit 105 to the radio resource based on the information indicating the radio resource input from the control unit 101. The signal allocation unit 106 outputs the downlink signal onto which the signal has been mapped to the transmission unit 107.

[0086] Transmitting unit 107 performs a transmission waveform generation process such as Orthogonal Frequency Division Multiplexing (OFDM) on the signal input from signal allocating unit 106. In addition, in the case of OFDM transmission that adds a cyclic prefix (CP), transmitting unit 107 performs an Inverse Fast Fourier Transform (IFFT) process on the signal and adds a CP to the signal after IFFT. Transmitting unit 107 also performs RF processing such as D / A conversion and up-conversion on the signal, and transmits the radio signal to terminal 200 via an antenna.

[0087] The receiving unit 108 performs RF processing such as downconvert or A / D conversion on the uplink signal received from the terminal 200 via the antenna. In addition, in the case of OFDM transmission, the receiving unit 108 performs fast Fourier transform (FFT) processing on the received signal and outputs the resulting frequency domain signal to the extracting unit 109.

[0088] Based on the information input from the control unit 101, the extraction unit 109 extracts the radio resource portion from which the uplink signal transmitted by the terminal 200 is transmitted, and outputs the extracted radio resource portion to the demodulation unit 110.

[0089] The demodulation unit 110 demodulates the signal (for example, uplink data) input from the extraction unit 109 based on the information input from the control unit 101. The demodulation unit 110 outputs the demodulation result to the decoding unit 111, for example.

[0090] The decoding unit 111 performs error correction decoding on the uplink data based on the information input from the control unit 101 and the demodulation result input from the demodulation unit 110, and obtains a decoded received bit sequence.

[0091] [Device configuration] 16 is a block diagram showing an example configuration of a terminal 200 according to an embodiment of the present disclosure. For example, in FIG. 16, the terminal 200 includes a receiving unit 201, an extracting unit 202, a demodulating unit 203, a decoding unit 204, a control unit 205, an encoding unit 206, a modulating unit 207, a signal allocating unit 208, and a transmitting unit 209.

[0092] The receiver 201 receives a downlink signal (for example, downlink data or downlink control information) from the base station 100 via an antenna, and performs RF processing such as downconvert or A / D conversion on the radio received signal to obtain a received signal (baseband signal). When receiving an OFDM signal, the receiver 201 performs FFT processing on the received signal to convert the received signal into the frequency domain. The receiver 201 outputs the received signal to the extractor 202.

[0093] Based on the information on the radio resource of the downlink control information input from the control unit 205, the extraction unit 202 extracts a radio resource portion that may include downlink control information from the received signal input from the receiving unit 201, and outputs the extracted radio resource portion to the demodulation unit 203. Furthermore, based on the information on the radio resource of the data signal input from the control unit 205, the extraction unit 202 extracts a radio resource portion that includes downlink data, and outputs the extracted radio resource portion to the demodulation unit 203.

[0094] Demodulation section 203 demodulates the signal input from extraction section 202 and outputs the demodulation result to decoding section 204 .

[0095] The decoding unit 204 performs error correction decoding on the demodulation result input from the demodulation unit 203, and obtains, for example, downlink reception data, an upper layer control signal, or downlink control information. The decoding unit 204 outputs the upper layer control signal and the downlink control information to the control unit 205, and outputs the downlink reception data. The decoding unit 204 may also generate a response signal (also referred to as, for example, ACK / NACK or HARQ-ACK) based on the decoding result of the downlink reception data.

[0096] The control unit 205 determines at least one radio resource for the downlink data signal and the uplink data signal, for example, based on information on DCI reception included in the higher layer control signal information input from the decoding unit 204, RRC setting information, and information on radio resource allocation included in the downlink control information. The control unit 205, for example, outputs information indicating the determined radio resource for the downlink data signal to the extraction unit 202, and outputs information indicating the determined radio resource for the uplink data signal to the signal allocation unit 208. Furthermore, the control unit 205 may determine information on transmission of the uplink signal based on the downlink control information, for example, and output the determined information to the encoding unit 206.

[0097] The encoding unit 206 encodes the uplink data signal based on the information input from the control unit 205 and outputs the encoded bit string to the modulation unit 207 .

[0098] Modulation section 207 modulates the coded bit sequence input from coding section 206 and outputs the modulated signal (symbol sequence) to signal allocation section 208 .

[0099] The signal allocation unit 208 maps the signal input from the modulation unit 207 to radio resources based on information input from the control unit 205, and outputs the uplink signal onto which the signal has been mapped to the transmission unit 209.

[0100] Transmitting unit 209 generates a transmission signal waveform, such as OFDM, for the signal input from signal allocating unit 208. Furthermore, in the case of OFDM transmission using a CP, transmitting unit 209 performs IFFT processing on the signal and adds a CP to the signal after IFFT. Alternatively, in the case of generating a single-carrier waveform, transmitting unit 209 may have a DFT (Discrete Fourier Transform) unit added after modulating unit 207 or before signal allocating unit 208 (not shown). Furthermore, transmitting unit 209 performs RF processing, such as D / A conversion and up-conversion, on the transmission signal, and transmits the radio signal to base station 100 via an antenna.

[0101] [Example of Operation of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 having the above configuration will be described.

[0102] FIG. 17 is a flowchart showing an example of the operation of terminal 200 according to this embodiment.

[0103] 17, terminal 200 acquires, for example, information on a time resource allocation pattern (ST101). The information on the time resource allocation pattern may be configured (in other words, notified or instructed) to terminal 200 from base station 100 by, for example, a higher layer parameter (for example, an RRC parameter) or a control signal such as DCI, or may be configured in advance in terminal 200 in accordance with a standard.

[0104] Terminal 200 receives, for example, a PDCCH including DCI (ST102). Terminal 200 acquires, for example, time resource allocation information (for example, an index indicating one of the allocation patterns) included in the DCI (for example, a TDRA field) (ST103).

[0105] Terminal 200 determines whether a condition for identifying the symbol position at which to start transmitting or receiving data is satisfied (ST104). For example, terminal 200 may determine whether "condition A" or "condition B" is satisfied. Examples of condition A and condition B will be described later.

[0106] If condition A is satisfied, terminal 200 identifies the symbol position at which to start transmitting or receiving data, according to a criterion based on the symbol position at which the PDCCH was received (ST105).

[0107] If condition B is met, terminal 200 identifies the symbol position at which to start transmitting or receiving data, according to a criterion based on the position of the first symbol of the slot (ST106).

[0108] Terminal 200 transmits or receives data based on the identified symbol position (ST107).

[0109] [Time resource allocation example] Next, an example of time resource allocation will be described.

[0110] In the present embodiment, for example, terminal 200 supports repetition. For example, terminal 200 supports at least one of repeated transmission of a PUSCH and reception of a PDSCH repeatedly transmitted from base station 100.

[0111] Furthermore, the time resources of the PUSCH transmitted by terminal 200 (e.g., also referred to as "PUSCH resources") or the time resources of the PDSCH received by terminal 200 (e.g., also referred to as "PDSCH resources") may be controlled by, for example, a TDRA field included in DCI.

[0112] For example, multiple time resource allocation patterns may be configured from base station 100 to terminal 200 by signaling of an upper layer (for example, RRC). For example, information identifying each time resource allocation pattern (for example, an index) may be associated with the time resource allocation pattern. Base station 100 indicates to terminal 200, in the TDRA field of DCI, one allocation pattern (for example, an index) of the multiple allocation patterns configured for terminal 200, and allocates time resources to terminal 200.

[0113] The allocation pattern of time resources set in terminal 200 may include parameters such as a slot offset (e.g., slot offset), a first symbol position in a slot at which data transmission or reception starts (e.g., start symbol), and the number of symbols (e.g., length). The parameters included in the allocation pattern are not limited to these, and may be other parameters related to time resources. For example, in the case of repeated transmission of a PUSCH or repeated reception of a PDSCH, the allocation pattern may include a parameter related to the number of repeated transmissions or allocation of time resources for each repeated transmission.

[0114] In this embodiment, terminal 200 may identify time resources (e.g., symbol positions within a slot) to be allocated to data based on, for example, operation example 1-1, operation example 1-2, or operation example 1-3 described below.

[0115] <Example of operation 1-1> In operation example 1-1, terminal 200 controls a criterion (for example, a reference point) for the position at which PUSCH or PDSCH is allocated in time resources based on whether repetition is applied in PUSCH transmission or PDSCH reception in controlling allocation of PUSCH or PDSCH in time resources based on DCI. In other words, terminal 200 switches the criterion for the position at which PUSCH or PDSCH is allocated in time resources based on whether repetition is applied to data.

[0116] For example, when terminal 200 does not repeatedly transmit a PUSCH or does not repeatedly receive a PDSCH, it identifies the first symbol position at which to start transmitting or receiving data in a slot according to a criterion based on the symbol position in the slot at which a PDCCH containing DCI is received.

[0117] On the other hand, for example, when repeatedly transmitting a PUSCH or repeatedly receiving a PDSCH, terminal 200 identifies the first symbol position at which to start transmitting or receiving data in a slot, according to a criterion based on the first symbol of the slot.

[0118] In other words, in the operational example 1-1, the condition A in FIG. 17 is that repetition is not applied to the terminal 200, and the condition B is that repetition is applied to the terminal 200.

[0119] Base station 100 may notify terminal 200 of different allocation patterns depending on whether repetition is not applied or applied.

[0120] Fig. 18 shows an example of allocation of time resources for PUSCH according to operation example 1-1. For example, the upper part of Fig. 18 shows an allocation pattern of time resources (e.g., TDRA table) and an example of allocation of time resources corresponding to the case where repetition is not applied to terminal 200. Moreover, the lower part of Fig. 18 shows an allocation pattern of time resources (e.g., TDRA table) and an example of allocation of time resources corresponding to the case where repetition is applied to terminal 200.

[0121] As shown in FIG. 18, the parameters (for example, the value or number of parameters) included in the same allocation pattern (for example, Index=0) may differ between when repetition is not applied to terminal 200 and when repetition is applied.

[0122] For example, as shown in the upper part of FIG. 18, when repetition is not applied to terminal 200, terminal 200 identifies the symbol position at which to place data within a slot included in an allocation pattern for PUSCH resources, according to a criterion based on received symbols of a PDCCH including DCI.

[0123] For example, in the upper part of FIG. 18, terminal 200 receives a PDCCH at the eighth symbol in a certain slot. Also, in the upper part of FIG. 18, terminal 200 is instructed that index=0 in the TDRA field of DCI included in the received PDCCH. Therefore, in the upper part of FIG. 18, terminal 200 determines the eighth symbol (in other words, the symbol position corresponding to the symbol position at which a PDCCH is received in another slot) in the slot next to the slot in which the PDCCH is received (for example, Slot offset=1) as the reference for the position at which to arrange a PUSCH. Then, terminal 200 specifies, for example, the tenth symbol, which is the symbol position two symbols from the reference (for example, Start symbol=2) in the slot next to the slot in which the PDCCH is received, as the first symbol position at which to start transmitting a PUSCH. For example, in the upper part of FIG. 18, the symbol length is four symbols (Length=4), so terminal 200 transmits a PUSCH at four symbols, from the tenth symbol to the thirteenth symbol in the slot.

[0124] Also, for example, as shown in the lower part of FIG. 18, when repetition is applied to terminal 200, terminal 200 identifies the symbol position at which to allocate data in a slot included in an allocation pattern for PUSCH resources, according to a criterion based on the first symbol of the slot.

[0125] For example, in the lower part of FIG. 18, terminal 200 receives a PDCCH at the eighth symbol in a certain slot. Also, in the lower part of FIG. 18, terminal 200 is instructed that index=0 in the TDRA field of DCI included in the received PDCCH. Therefore, in the lower part of FIG. 18, terminal 200 determines the 0th symbol (first symbol) in the slot next to the slot in which the PDCCH is received (for example, Slot offset=1) as the reference for the position at which to arrange a PUSCH. Then, for example, terminal 200 specifies the 10th symbol, which is the symbol position 10 symbols from the reference (for example, Start symbol=10) in the slot next to the slot in which the PDCCH is received, as the first symbol position at which to start transmission of a PUSCH in the first repeated transmission. Similarly, in the lower part of FIG. 18, terminal 200 determines the 0th symbol (first symbol) in the slot two slots after the slot in which the PDCCH is received (for example, Slot offset=2) as the reference for the position at which to arrange a PUSCH. Then, terminal 200 specifies, for example, the 0th symbol, which is the 0th symbol from the reference (for example, Start symbol=0) in the slot two slots after the slot in which the PDCCH was received, as the leading symbol position at which to start transmitting the PUSCH in the second repeated transmission. For example, in the lower part of FIG. 18, the symbol length in each repeated transmission is 4 symbols (Length=4), so terminal 200 transmits the PUSCH in the four symbols from the 10th symbol to the 13th symbol in the slot one slot after the slot in which the PDCCH was received, and in the four symbols from the 0th symbol to the 3rd symbol in the slot two slots after.

[0126] Although an example of allocation of PUSCH resources has been described with reference to FIG. 18, allocation of PDSCH resources may be performed in a similar manner depending on whether or not repetition is applied.

[0127] According to operation example 1-1, when repetition is applied, time resources are determined based on the first symbol of a slot, so terminal 200 does not need to determine, for example, whether the position of the first symbol of identified data is the same as the slot indicated by the slot offset of the time resource pattern. Thus, even when repetition applied to a PUSCH is set across multiple slots (for example, the lower part of FIG. 18), terminal 200 can easily identify time resources available for transmitting the PUSCH.

[0128] Furthermore, for example, the symbol set as the DL symbol (or Flexible symbol) in a slot is reported from base station 100 to terminal 200 by, for example, an SFI, which is slot-based information. Thus, when repetition is applied to the PUSCH, terminal 200 can compare the slot-based DL symbol (or Flexible symbol) setting with the slot-based PUSCH resource setting to determine whether each symbol included in the PUSCH resource is usable. By this determination, terminal 200 can easily identify time resources usable for transmitting the PUSCH, even when, for example, a time resource pattern of the PUSCH assigned by DCI includes a symbol set as a DL symbol (or Flexible symbol) (not shown).

[0129] Therefore, according to the operation example 1-1, the processing relating to the identification of time resources in the terminal 200 can be prevented from becoming complicated.

[0130] Furthermore, when repetition is applied, time resources are determined based on the first symbol of the slot. For example, the setting range of the first symbol position of data is 0 to 13, which can suppress an increase in overhead of higher layer signals, such as the example shown in FIG. 13.

[0131] Furthermore, according to operation example 1-1, when repetition is not applied, terminal 200 determines the time resource of the PDSCH or PUSCH according to a criterion based on the symbol position of the PDCCH reception. This allocation makes it possible to set allocation of the same symbol length using one allocation pattern, for example. Therefore, according to operation example 1-1, for example, the number of bits of the TDRA field in DCI can be reduced. Alternatively, according to operation example 1-1, for example, when the number of bits of the TDRA field is fixed, a different time resource allocation pattern can be set, thereby improving the flexibility of time resource allocation.

[0132] <Example of operation 1-2> In operation example 1-2, in controlling the allocation of PUSCH or PDSCH to time resources based on DCI, terminal 200 controls a criterion (for example, a reference point) for the position at which PUSCH or PDSCH is allocated to time resources based on whether a repeatedly transmitted PUSCH or a repeatedly received PDSCH is allocated to one slot. In other words, terminal 200 switches the criterion for the position at which PUSCH or PDSCH is allocated to time resources based on the number of slots to which repetition data is allocated.

[0133] For example, when the time resource of the PUSCH to be repeatedly transmitted or the time resource of the PDSCH to be repeatedly received is included in one slot, terminal 200 identifies the first symbol position at which to start transmitting or receiving data in the slot according to a criterion based on the symbol position in the slot at which the PDCCH containing DCI was received.

[0134] On the other hand, for example, when the time resource of the PUSCH to be repeatedly transmitted or the time resource of the PDSCH to be repeatedly received is set across multiple slots, terminal 200 identifies the first symbol position at which to start transmitting or receiving data within the slot in accordance with a criterion based on the first symbol of the slot.

[0135] In other words, in the operational example 1-2, condition A in FIG. 17 is that the repeated data is assigned to one slot, and condition B is that the repeated data is assigned to multiple slots.

[0136] Base station 100 may notify different allocation patterns depending on whether repeated data is allocated to one slot or multiple slots.

[0137] Fig. 19 shows an example of allocation of PUSCH resources according to operation example 1-2. For example, the upper part of Fig. 19 shows a time resource allocation pattern (for example, a TDRA table) and an example of allocation of time resources corresponding to a case where the time resource of a PUSCH to be repeated is included in one slot. Furthermore, the lower part of Fig. 19 shows a time resource allocation pattern (for example, a TDRA table) and an example of allocation of time resources corresponding to a case where the time resource of a PUSCH to be repeated is set across multiple slots.

[0138] As shown in FIG. 19, the parameters (e.g., parameter values) included in the same allocation pattern (e.g., Index=0) may be different when the time resource of the repeated PUSCH is included in one slot and when the time resource of the repeated PUSCH is set across multiple slots.

[0139] For example, in the top part of FIG. 19, terminal 200 identifies symbol positions at which to place data within slots included in an allocation pattern for PUSCH resources, according to criteria based on received symbols of a PDCCH including DCI.

[0140] For example, in the upper part of Fig. 19, terminal 200 receives a PDCCH at the fourth symbol in a certain slot. Also, in the upper part of Fig. 19, terminal 200 is instructed that index = 0 in the TDRA field of DCI included in the received PDCCH. Therefore, in the upper part of Fig. 19, terminal 200 determines the fourth symbol in the slot (for example, Slot offset = 1) next to the slot in which the PDCCH is received (in other words, the symbol position corresponding to the symbol position in which the PDCCH is received in another slot) as the reference for the position at which to arrange the PUSCH. Then, terminal 200 specifies, for example, the sixth symbol, which is the symbol position two symbols from the reference (for example, Start symbol = 2) in the slot next to the slot in which the PDCCH is received, as the start symbol position at which to start transmission of the PUSCH in the first repeated transmission. Similarly, in the upper part of Fig. 19, terminal 200 specifies the 10th symbol, which is the sixth symbol from the reference (e.g., Start symbol = 6) in the slot next to the slot in which the PDCCH was received (e.g., Slot offset = 1), as the leading symbol position at which to start transmitting the PUSCH in the second repeated transmission. For example, in the upper part of Fig. 19, the symbol length in each repeated transmission is four symbols (length = 4), so terminal 200 transmits the PUSCH in the eight symbols from the sixth symbol to the thirteenth symbol in the slot one slot after the slot in which the PDCCH was received.

[0141] Also, for example, in the lower part of FIG. 19, terminal 200 identifies the symbol position at which to place data in a slot included in an allocation pattern for PUSCH resources, according to a criterion based on the first symbol of the slot.

[0142] For example, in the lower part of FIG. 19, terminal 200 receives a PDCCH at the eighth symbol in a certain slot. Also, in the lower part of FIG. 19, terminal 200 is instructed that index=0 in the TDRA field of DCI. Therefore, in the lower part of FIG. 19, terminal 200 determines the 0th symbol (first symbol) in the slot next to the slot in which the PDCCH is received (for example, Slot offset=1) as the reference for the position at which to arrange a PUSCH. Then, for example, terminal 200 specifies the 10th symbol, which is the symbol position 10 symbols from the reference (for example, Start symbol=10) in the slot next to the slot in which the PDCCH is received, as the first symbol position at which to start transmission of a PUSCH in the first repeated transmission. Similarly, in the lower part of FIG. 19, terminal 200 determines the 0th symbol (first symbol) in the slot two slots after the slot in which the PDCCH is received (for example, Slot offset=2) as the reference for the position at which to arrange a PUSCH. Then, terminal 200 specifies, for example, the 0th symbol, which is the 0th symbol from the reference (for example, start symbol=0), in the slot two slots after the slot in which the PDCCH was received, as the start symbol position at which to start transmitting the PUSCH in the second repeated transmission. For example, in the lower part of FIG. 19, the symbol length in each repeated transmission is 4 symbols (length=4), so terminal 200 transmits the PUSCH in the four symbols from the 10th symbol to the 13th symbol in the slot one slot after the slot in which the PDCCH was received, and in the four symbols from the 0th symbol to the 3rd symbol in the slot two slots after.

[0143] Although an example of allocation of PUSCH resources has been described with reference to FIG. 19, allocation of PDSCH resources may be performed in a similar manner according to the slot to which the repetition data is allocated.

[0144] According to operation example 1-2, when repetition data is allocated across multiple slots, time resources are determined based on the first symbol of the slot, and therefore terminal 200 does not need to determine, for example, whether the position of the first symbol of the identified data is the same as the slot indicated by the slot offset of the time resource pattern. Thus, even when repetition applied to a PUSCH is set across multiple slots (for example, the lower part of FIG. 19 ), terminal 200 can easily identify time resources available for transmitting the PUSCH.

[0145] Furthermore, for example, the symbol set as the DL symbol (or Flexible symbol) in a slot is reported from base station 100 to terminal 200 by, for example, an SFI, which is slot-based information. Thus, when a repeated PUSCH is allocated to multiple slots, terminal 200 can compare the slot-based DL symbol (or Flexible symbol) setting with the slot-based PUSCH resource setting to determine whether each symbol included in the PUSCH resource is usable. By this determination, terminal 200 can easily identify time resources usable for transmitting the PUSCH, even when, for example, a time resource pattern of the PUSCH allocated by DCI includes a symbol set as a DL symbol (or Flexible symbol) (not shown).

[0146] Therefore, according to the operation example 1-2, the processing relating to the identification of time resources in the terminal 200 can be prevented from becoming complicated.

[0147] Furthermore, when repeated data is allocated across multiple slots, the time resource is determined based on the first symbol of the slot. For example, the setting range of the first symbol position of the data is 0 to 13, which can suppress an increase in overhead of the upper layer signal, for example, as shown in the example of FIG. 13.

[0148] Furthermore, according to operation example 1-2, when repeated data is allocated to one slot, terminal 200 determines the time resource of the PDSCH or PUSCH according to a criterion based on the symbol position of the PDCCH reception. This allocation makes it possible to set allocation of the same symbol length using one allocation pattern, for example. Therefore, according to operation example 1-2, for example, the number of bits of the TDRA field in DCI can be reduced. Alternatively, according to operation example 1-2, for example, when the number of bits of the TDRA field is fixed, a different time resource allocation pattern can be set, thereby improving the flexibility of time resource allocation.

[0149] <Example of operation 1-3> In operation example 1-3, terminal 200 identifies the position of the first symbol in a slot in parameters included in the allocation pattern of time resources, according to a criterion based on the symbol position in the slot in which a PDCCH including DCI is received.

[0150] Furthermore, in operation example 1-3, terminal 200 applies repetition (for example, repeated transmission of PUSCH or repeated reception of PDSCH) when receiving PDCCH at a specific symbol in a slot.

[0151] For example, when terminal 200 meets the condition of receiving a PDCCH (e.g., DCI) at a specific symbol within a slot, it determines the symbol position within the slot allocated to the PUSCH or PDSCH, which corresponds to the position of the symbol at which the DCI is received within the slot, as the reference for the PUSCH or PDSCH to be repeated.

[0152] On the other hand, when terminal 200 receives the PDCCH at a symbol other than the specific symbol in the slot, it does not apply repetition.

[0153] The "specific symbol" may be, for example, at least one symbol including the first symbol of each slot, or at least one symbol near the first symbol of each slot.

[0154] According to Operation Example 1-3, Repetition is applied when terminal 200 receives PDCCH at a specific symbol. For example, if the specific symbol is a symbol including the first symbol of each slot, the received symbol of PDCCH may include the first symbol of the slot. Therefore, in this case, the criterion based on the symbol position in the slot where PDCCH is received is equal to the criterion based on the first symbol of the slot, so that during Repetition, for example, the same effect as in Operation Example 1-1 can be obtained.

[0155] In addition, in operation example 1-3, terminal 200 may apply repeated transmission of PUSCH or repeated reception of PDSCH set across multiple slots when, for example, PDCCH is received at a specific symbol. For example, when a condition for receiving PDCCH (e.g., DCI) at a specific symbol in a slot is met, terminal 200 determines, as a reference for PUSCH or PDSCH repeated across multiple slots, a symbol position in a slot allocated to PUSCH or PDSCH that corresponds to the position of the symbol at which DCI is received within the slot. This operation can provide, for example, the same effect as in operation example 1-2 when data is repeated across multiple slots.

[0156] Operation examples 1 to 3 have been described above.

[0157] As described above, in the present embodiment, terminal 200 controls the criterion for the position at which data is allocated to time resources based on certain conditions, for example, in controlling the allocation of data to time resources based on received DCI. Through this control, terminal 200 can, for example, suppress the complication of processing related to identifying time resources in terminal 200 by switching the criterion for the position at which data is allocated depending on, for example, the time resource to which data is allocated or the application of Repetition. Therefore, according to the present embodiment, it is possible to improve the efficiency of signal allocation in wireless communication such as URLLC.

[0158] [Modification of the first embodiment] In the first embodiment, for example, when repetition is applied, terminal 200 specifies the first symbol position within a slot at which to start transmitting or receiving data, based on the first symbol of the slot.

[0159] In this case, if terminal 200 can receive DCI multiple times within one slot, depending on the timing of receiving the PDCCH, one or more of the allocation patterns of time resources set in terminal 200 may not be valid patterns for allocating PUSCH or PDSCH.

[0160] As an example, assume that a PDSCH resource allocation pattern as shown in Fig. 8 is set, and terminal 200 can receive a PDCCH at any of the 0th, 4th, and 8th symbols in a slot. In this case, for DCI included in a PDCCH received at the 4th symbol in a slot, PDSCH allocation with Index = 1 (e.g., Start symbol = 6) or Index = 2 (e.g., Start symbol = 10), which corresponds to a reception timing after the reception timing of the PDCCH, is valid. On the other hand, PDSCH allocation with Index = 0 (e.g., Start symbol = 2), which corresponds to a reception timing before the reception timing of the PDCCH, is not valid.

[0161] Furthermore, in PUSCH transmission, a period (for example, "N2 symbols") equivalent to the processing time from when terminal 200 receives DCI to when it generates a PUSCH can be set. As an example, assume that N2=16 symbols, a PUSCH resource allocation pattern as shown in FIG. 9 is set, and terminal 200 can receive a PDCCH at any of the 0th symbol, 4th symbol, and 8th symbol in a slot. In this case, for DCI included in a PDCCH received at the 4th symbol in a slot, PUSCH allocation with Index=1 (for example, Start symbol=6) or Index=2 (for example, Start symbol=10), which corresponds to a PUSCH transmission timing N2 (=16) symbols or later from the PDCCH reception timing, is valid. On the other hand, PUSCH allocation with Index=0 (for example, Start symbol=2), which corresponds to a PUSCH transmission timing N2 (=16) symbols earlier from the PDCCH reception timing, is not valid.

[0162] Incidentally, in PUSCH repetition, as described above, terminal 200 cannot transmit a PUSCH in a symbol set as a DL symbol (or a Flexible symbol). Therefore, when a time resource pattern of a PUSCH assigned by DCI includes a symbol set as a DL symbol (or a Flexible symbol), terminal 200 can, for example, decide to drop (in other words, not transmit) the transmission of a PUSCH assigned to that symbol, or postpone transmission until the next transmission opportunity (for example, an uplink symbol).

[0163] These symbols for which PUSCH transmission is not possible are sometimes called "invalid symbols," for example.

[0164] In a modification of the first embodiment, for example, when PUSCH repetition is applied, it is permitted to allocate a PUSCH resource that is more than N2 (for example, N2=16) symbols after terminal 200 receives the PDCCH. Furthermore, terminal 200 may determine, for example, a symbol corresponding to a PUSCH resource that is more than N2 symbols after terminal 200 receives the PDCCH (or a unit of PUSCH resources including this symbol) as an invalid symbol.

[0165] For example, terminal 200 may drop the transmission of the PUSCH assigned to a symbol determined to be an invalid symbol, or may postpone the transmission of the PUSCH until the next transmission opportunity (for example, an uplink symbol).

[0166] Fig. 20 shows an example of time resource allocation in a modification of Embodiment 1. In Fig. 20, N2 = 16 symbols, and terminal 200 can transmit PUSCH N2 = 16 symbols after receiving PDCCH. Also, as an example, Index = 0 is indicated in all of the DCIs in Fig. 20(a), (b), and (c). Note that N2 is not limited to 16 symbols and may be another number of symbols.

[0167] 20, for example, in PUSCH repetition, the TDRA field notifies allocation of time resources for the first PUSCH repetition, and allocation of time resources for second and subsequent repetitions is allocated to transmit consecutive PUSCH symbols with the same number of symbols as in the first PUSCH repetition. Note that in the example shown in FIG. 20, the number of repetitions is two, but the number of repetitions may be three or more.

[0168] For example, as shown in Figure 20(a), when terminal 200 receives a PDCCH at the 0th symbol of a certain slot, the second symbol (e.g., Start symbol = 2) of the next slot (e.g., Slot offset = 1) is N2 = 16 symbols after the reception of the PDCCH. Therefore, in Figure 20(a), terminal 200 starts PUSCH transmission using the time resource of the PUSCH notified by the TDRA field.

[0169] On the other hand, for example, as shown in FIG. 20(b), when terminal 200 receives a PDCCH in the fourth symbol of a certain slot, the second symbol (e.g., Start symbol=2) of the next slot (e.g., Slot offset=1) is N2=16 symbols before the reception of the PDCCH and is an invalid symbol. Therefore, in FIG. 20(b), terminal 200 may, for example, determine to postpone transmission of the PUSCH and transmit the PUSCH in a valid symbol (e.g., the sixth symbol or later) after N2=16 symbols. Note that in FIG. 20(b), terminal 200 may also determine to drop the PUSCH in the invalid symbols.

[0170] Similarly, for example, as shown in FIG. 20(c), when terminal 200 receives a PDCCH in the eighth symbol of a certain slot, the second symbol (e.g., Start symbol=2) of the next slot (e.g., Slot offset=1) is N2=16 symbols before the reception of the PDCCH and is an invalid symbol. Therefore, in FIG. 20(c), terminal 200 may, for example, determine to postpone transmission of the PUSCH and transmit the PUSCH in a valid symbol (e.g., the 10th symbol or later) after N2=16 symbols. Note that in FIG. 20(c), terminal 200 may also determine to drop the PUSCH in the invalid symbols.

[0171] In a modification of the first embodiment, the invalid symbol may be, for example, a symbol that precedes N2 symbols after terminal 200 receives the PDCCH.

[0172] Furthermore, the invalid symbol may be, for example, an allocation unit of PUSCH resources including symbols N2 symbols before the time when terminal 200 receives the PDCCH (for example, a unit of PUSCH resources notified in a TDRA field).

[0173] Alternatively, the invalid symbols may be, for example, a pair of a DMRS and a PUSCH including symbols occurring more than N2 (=16) symbols after terminal 200 receives the PDCCH. In other words, if no DMRS is included in symbols excluding symbols occurring more than N2 symbols after terminal 200 receives the PDCCH, the entire PUSCH resource allocation unit may be set as invalid symbols.

[0174] According to a modification of the first embodiment, terminal 200 determines to drop data or postpone transmission of data when a symbol to which data is allocated in time resources is included within a period (for example, N2) corresponding to the data processing time in terminal 200. This processing enables terminal 200 to use a time resource allocation pattern configured for terminal 200, for example, regardless of the timing at which terminal 200 receives a PDCCH. This makes it possible to reduce the number of bits in the TDRA field in DCI. Alternatively, time resources can be allocated more flexibly.

[0175] Note that the modification of the first embodiment is not limited to PUSCH repetition, and may be applied to PDSCH repetition. In the case of PDSCH repetition, for example, time resources before PDCCH reception may be set as invalid symbols.

[0176] (Embodiment 2) In the enhancement of PUSCH transmission, as described above, the terminal cannot transmit the PUSCH in a symbol set as a DL symbol (or a Flexible symbol). Therefore, for example, when a time resource pattern of the PUSCH allocated by DCI includes a symbol set as a DL symbol (or a Flexible symbol), the terminal may decide to drop the PUSCH transmission of the symbol or postpone the PUSCH transmission until the next transmission opportunity (for example, an uplink symbol). Furthermore, the terminal may identify the position of the DL symbol in the slot, for example, by notification of the SFI.

[0177] Furthermore, in uplink (UL) symbols, a terminal cannot transmit a PUSCH in a symbol in which the terminal or another terminal transmits an uplink control channel (e.g., a physical uplink control channel (PUCCH)) or a reference signal (e.g., a sounding reference signal (SRS)).

[0178] However, the terminal cannot identify the position of a symbol where PUSCH cannot be transmitted (in other words, a symbol where uplink data transmission is not permitted; hereinafter, referred to as an "invalid UL symbol") using, for example, the SFI.

[0179] Therefore, in this embodiment, a method for a terminal to identify an invalid UL symbol position will be described.

[0180] The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0181] In this embodiment, for example, terminal 200 supports repeated transmission of PUSCH (in other words, repetition).

[0182] Furthermore, time resources (e.g., PUSCH resources) of PUSCHs transmitted by terminal 200 are controlled by, for example, the TDRA field of DCI. For example, multiple time resource allocation patterns are configured in terminal 200 by higher layer signaling. Furthermore, base station 100 indicates to terminal 200 one of the multiple allocation patterns configured in terminal 200 by the TDRA field of DCI, thereby allocating PUSCH resources to terminal 200.

[0183] The allocation pattern of time resources set in terminal 200 may include parameters such as a slot offset, a start symbol position in a slot at which data transmission or reception starts, and the number of symbols (Length). Furthermore, when repeated transmission of a PUSCH or repeated reception of a PDSCH is applied, the allocation pattern may include the number of repeated transmissions or time resource allocation for each repeated transmission.

[0184] Furthermore, in this embodiment, base station 100 notifies terminal 200, for example, of information regarding invalid UL symbol positions. The information regarding invalid UL symbol positions may be indicated to terminal 200 by, for example, DCI (for example, DCI including one allocation pattern). Furthermore, the information regarding invalid UL symbol positions may be notified in a field different from the TDRA field, or may be included in the allocation pattern of time resources notified in the TDRA field.

[0185] Furthermore, in this embodiment, the standard for identifying the symbol position is different between the first symbol position where data transmission starts in a slot and the invalid UL symbol position in a slot.

[0186] For example, terminal 200 identifies the position of the first symbol in a slot in the parameters included in the time resource allocation pattern, for example, according to a criterion based on the position of a symbol in the slot in which a PDCCH including DCI is received. On the other hand, terminal 200 identifies the position of an invalid UL symbol, for example, according to a criterion based on the first symbol of the slot.

[0187] FIG. 21 shows an example of time resource allocation in the case where terminal 200 identifies invalid UL symbol positions according to a criterion based on the symbol position in a slot in which PDCCH is received.

[0188] On the other hand, Fig. 22 shows an example of time resource allocation according to this embodiment. In other words, Fig. 22 shows an example of time resource allocation when specifying invalid UL symbol positions based on the first symbol of a slot.

[0189] 21 and 22, for example, a criterion for the position where the PUSCH is arranged is determined for the PUSCH resource based on the symbol position in the slot where the PDCCH is received. For example, when terminal 200 identifies the time resource of the PUSCH based on DCI, it determines the symbol position in the slot to which the PUSCH is allocated (for example, the next slot corresponding to Slot offset=1) that corresponds to the symbol position where DCI is received in a certain slot (for example, the 0th symbol or the 4th symbol), as a criterion for the position where the PUSCH is arranged.

[0190] 21 and 22 also show examples in which PUSCH transmissions of invalid UL symbols (eg, invalid UL symbols) are dropped.

[0191] For example, as shown in Fig. 21, when the reference for the invalid UL symbol position is based on the symbol position at which the PDCCH is received, for example, if the Start symbol included in the allocation pattern is the same, the identified invalid UL symbol position will be different if the PDCCH reception timing (the 0th symbol and the 4th symbol in Fig. 21) is different. Therefore, as shown in Fig. 21, an allocation pattern for notifying one invalid UL symbol position (for example, the 6th symbol in Fig. 21) can be set for each PDCCH reception timing. In other words, in Fig. 21, multiple allocation patterns are set for invalid UL symbol positions at the same position, which can increase the overhead of higher layer signals for setting allocation patterns.

[0192] In contrast, in Fig. 22, when terminal 200 identifies an invalid UL symbol position, it determines the position of the first symbol of a slot to which a PUSCH is allocated as a reference for the position where an invalid UL symbol is arranged. For example, as shown in Fig. 22, even if the reception timing of a PDCCH (the 0th symbol and the 4th symbol in Fig. 22) is different, terminal 200 can identify an invalid UL symbol position (for example, the 6th symbol) using one allocation pattern (for example, Index = 0 in Fig. 22). In other words, in Fig. 22, one allocation pattern is set to notify one invalid UL symbol position regardless of the reception timing of a PDCCH.

[0193] As described above, in this embodiment, when the information regarding the position where the PUSCH is placed is based on the PDCCH (e.g., DCI) notified from base station 100 (e.g., the first condition), terminal 200 identifies the PUSCH resource according to a criterion based on the PDCCH reception symbol position, and when the information regarding the invalid UL symbol position is based on the information (e.g., the second condition), terminal 200 identifies the invalid UL symbol position according to a criterion based on the first symbol position of the slot.

[0194] According to the present embodiment, this processing allows base station 100 to notify terminal 200 of invalid UL symbol positions regardless of PDCCH reception timing, thereby reducing the number of patterns for notifying invalid UL symbol positions.

[0195] (Embodiment 3) In Release 16 URLLC, enhancements to PUSCH transmission, such as repeat transmission in minislot units or flexible resource allocation between slots, are being considered, while the application of Release 15 operations is being considered for the downlink.

[0196] For this reason, there is a possibility that the method of repeating transmission in minislot units or flexibly setting resource allocation between slots may not be applied to the downlink.

[0197] Therefore, in this embodiment, a method of allocating time resources for each of the downlink and the uplink will be described.

[0198] The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0199] For example, in controlling the allocation of PUSCH or PDSCH to time resources based on DCI, terminal 200 controls the criterion for the position at which PUSCH or PDSCH is allocated in time resources based on whether the data to be allocated is a PUSCH or a PDSCH. In other words, terminal 200 switches the criterion for the position at which PUSCH or PDSCH is allocated in time resources based on whether the data is a PUSCH or a PDSCH.

[0200] For example, when a time resource for a PDSCH is allocated, terminal 200 identifies the leading symbol position at which to start receiving the PDSCH in a slot, according to a criterion based on the symbol position in the slot at which a PDCCH including DCI is received.

[0201] On the other hand, when a time resource for a PUSCH is allocated, terminal 200 identifies the first symbol position within the slot at which to start transmitting the PUSCH, according to a criterion based on the first symbol of the slot.

[0202] In other words, in this embodiment, condition A in FIG. 17 is that time resources for PDSCH are allocated (for example, in the case of downlink), and condition B is that time resources for PUSCH are allocated (for example, in the case of uplink).

[0203] Base station 100 may notify different allocation patterns for PDSCH time resource allocation and PUSCH time resource allocation.

[0204] According to the present embodiment, in the case of PUSCH transmission, time resources are determined based on the first symbol of a slot, and therefore terminal 200 does not need to determine, for example, whether the position of the first symbol of identified data is the same as the slot indicated by the slot offset of the time resource pattern. Thus, even when Repetition applied to PUSCH is set across multiple slots, terminal 200 can easily identify time resources available for PUSCH transmission.

[0205] Furthermore, for example, the symbol set as the DL symbol (or Flexible symbol) in a slot is reported from base station 100 to terminal 200 by, for example, an SFI, which is slot-based information. Thus, in the case of PUSCH transmission to which Repetition can be applied, terminal 200 can compare the slot-based DL symbol (or Flexible symbol) setting with the slot-based PUSCH resource setting, and determine whether each symbol included in the PUSCH resource is usable. By this determination, terminal 200 can easily identify time resources usable for PUSCH transmission, even when, for example, a time resource pattern of the PUSCH assigned by DCI includes a symbol set as a DL symbol (or Flexible symbol) (not shown).

[0206] Therefore, according to this embodiment, it is possible to prevent the processing relating to identifying time resources in terminal 200 from becoming complicated.

[0207] Furthermore, when transmitting a PUSCH to which repetition may be applied, time resources are determined based on the first symbol of the slot. Therefore, for example, the setting range of the first symbol position of data is 0 to 13, which can suppress an increase in overhead of higher layer signals, such as the example shown in FIG. 13.

[0208] Furthermore, according to the present embodiment, in the case of PDSCH transmission in which repetition cannot be applied, terminal 200 determines the time resources of the PDSCH according to a criterion based on the symbol position of PDCCH reception. This allocation makes it possible to set allocations of the same symbol length using one allocation pattern, for example. Therefore, according to the present embodiment, it is possible to reduce the number of bits of the TDRA field in DCI, for example. Alternatively, according to the present embodiment, it is possible to set a different time resource allocation pattern when the number of TDRA field bits is fixed, for example, and therefore improve the flexibility of time resource allocation.

[0209] The above describes the embodiments according to the example of the present disclosure.

[0210] (Other embodiments) Note that the above embodiment has described a method for reducing the complexity of processing related to identifying time resources in terminal 200 when time resources are controlled by DCI, by switching, depending on conditions, whether to identify the position at which to start transmitting or receiving data within a slot based on the slot start or based on the symbol position of PDCCH reception. However, the conditions for switching the criteria for the position at which data is arranged are not limited to the conditions described in the above-described embodiments, and other conditions may also be used.

[0211] For example, for PDSCH time resource allocation, the transmission method (in other words, HARQ codebook) of a response signal (also called ACK / NACK or HARQ-ACK) may be set as a condition. For example, in a Type-1 (semi-static) codebook, the slot head may be used as a reference, and in a Type-2 (dynamic) codebook, the symbol position of the PDCCH reception may be used as a reference.

[0212] Furthermore, for example, differences in scheduling methods may be set as conditions for allocating time resources for the PDSCH. For example, in Semi-Persistent Scheduling (SPS), the slot start may be used as a reference, and in Dynamic scheduling, the symbol position of the PDCCH reception may be used as a reference.

[0213] Furthermore, the conditions for switching the criteria for the location of data placement are not limited to these, and other conditions may be used.

[0214] Furthermore, in one embodiment of the present disclosure, when terminal 200 receives a PDCCH at the nth symbol in a slot, the symbol position in the slot at which PUSCH transmission or PDSCH reception starts may be expressed as n+S. Here, S corresponds to a value (e.g., start symbol) notified in the TDRA field of the DCI described above. For example, when the slot start is used as a reference, n=0 regardless of the timing of PDCCH reception.

[0215] Furthermore, in the above-described embodiment, a method for allocating time resources to data (e.g., downlink data or uplink data) has been described, but the target of time resource allocation is not limited to data. For example, an embodiment of the present disclosure may be applied to allocation of time resources to reference signals (e.g., demodulation reference signals (DMRS: Demodulation Reference Signals), channel state information reference signals (CSI-RS: Channel State Information RSs), and SRSs).

[0216] Furthermore, in the above embodiment, the case where the terminal receives the PDCCH including DCI at one symbol has been described, but the present invention is not limited to this, and the terminal may receive the PDCCH including DCI at multiple symbols. When the terminal receives the PDCCH including DCI at multiple symbols, terminal 200 may determine a criterion for allocating data based on the position of any one symbol (for example, the first (or start) symbol) among the multiple symbols.

[0217] In addition, the above-described embodiment assumes uplink communication in which a signal is transmitted from a terminal to a base station, or downlink communication in which a signal is transmitted from a base station to a terminal. However, an embodiment of the present disclosure is not limited to this and may be applied to communication between terminals (e.g., sidelink communication).

[0218] Furthermore, the downlink control channel, the downlink data channel, the uplink control channel, and the uplink data channel are not limited to PDCCH, PDSCH, PUCCH, and PUSCH, respectively, and may be control channels with other names.

[0219] Furthermore, the unit of time resource is not limited to the time resource (for example, slot or sub-slot) described in each of the above embodiments, but may be another time resource unit (for example, sub-frame or frame, etc.).

[0220] In the above-described embodiments, the number of constituent symbols of a slot (in other words, a unit time interval) has been described as 14, but the number of constituent symbols of a slot is not limited to 14 and may be another number of symbols (for example, 12 symbols). Furthermore, the arrangement positions of signals (for example, PDCCH, PDSCH, or PUSCH) or invalid symbols (or invalid UL symbols) shown in the above-described embodiments are merely examples, and they may be arranged in other positions.

[0221] Furthermore, at least two of embodiment 1 (for example, operation example 1-1, operation example 1-2, operation example 1-3, and modified examples), embodiment 2, and embodiment 3 described in one example of the present disclosure may be combined.

[0222] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0223] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0224] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0225] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a wireless transceiver and processing / control circuitry. The wireless transceiver may include a receiver and a transmitter, or both functions. The wireless transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0226] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0227] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0228] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0229] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0230] A terminal according to one embodiment of the present disclosure includes a receiving circuit that receives downlink control information, and a control circuit that controls, based on certain conditions, a criterion for the position at which data is placed in a time resource in order to control the placement of data in the time resource based on the control information.

[0231] In one embodiment of the present disclosure, if a first condition is satisfied, the control circuit determines, as the criterion, a symbol position in a second unit interval that corresponds to the position of the symbol at which the control information is received within a first unit interval of the time resource, and if a second condition is satisfied, determines, as the criterion, the position of the first symbol in the second unit interval.

[0232] In one embodiment of the present disclosure, the first condition is that repetition is not applied to the data, and the second condition is that repetition is applied to the data.

[0233] In one embodiment of the present disclosure, the first condition is that the data to be repeated is allocated to one of the second unit intervals, and the second condition is that the data to be repeated is allocated across the second unit interval and a third unit interval following the second unit interval.

[0234] In one embodiment of the present disclosure, the first condition is that the data is downlink data, and the second condition is that the data is uplink data.

[0235] In one embodiment of the present disclosure, the condition is that the control information is received at a certain symbol within a first unit interval in the time resource, and if the condition is satisfied, the control circuit determines a symbol position within a second unit interval in the time resource corresponding to the position of the symbol at which the control information was received within the first unit interval as the reference for the data to be repeated within the second unit interval.

[0236] In one embodiment of the present disclosure, the condition is that the control information is received at a certain symbol within a first unit interval in the time resource, and when the condition is satisfied, the control circuit determines a symbol position within a second unit interval in the time resource corresponding to the position of the symbol at which the control information was received within the first unit interval as the reference for the data to be repeated across the second unit interval and a third unit interval following the second unit interval.

[0237] In one embodiment of the present disclosure, the control circuit determines not to transmit the data or to postpone transmission of the data if a symbol to which the data is assigned is included in the time resource within a period corresponding to the processing time of the data.

[0238] In one embodiment of the present disclosure, the control information includes first information regarding a first position where the data is placed in the time resource and second information regarding a second position where transmission of the data is not permitted, the conditions include a first condition based on the first information and a second condition based on the second information, and when the first condition is satisfied, the control circuit determines a symbol position in a second unit interval in the time resource corresponding to a position of a symbol at which the control information is received in a first unit interval in the time resource as the reference for the first position, and when the second condition is satisfied, determines a first symbol position of the second unit interval as the reference for the second position.

[0239] In a communication method according to one embodiment of the present disclosure, a terminal receives downlink control information, and in controlling the placement of data in time resources based on the control information, controls a criterion for the position at which the data is placed in the time resources based on certain conditions.

[0240] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2019-187624, filed on October 11, 2019, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0241] One embodiment of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0242] 100 base stations 101,205 Control section 102 Upper control signal generation unit 103 Downlink control information generation unit 104,206 Encoding section 105,207 Modulation section 106,208 Signal allocation section 107,209 Transmitter 108,201 Receiver 109,202 Extraction part 110,203 Demodulation section 111,204 Decoding section 200 devices

Claims

1. a control circuit for controlling a criterion for a position at which data is allocated to a time resource based on downlink control information, the control circuit controlling the criterion for a position at which data is allocated to the time resource based on a certain condition; a transmission circuit for transmitting the control information; Equipped with When the control information indicates transmission of a PUSCH (Physical Uplink Shared Channel), the reference is a symbol position corresponding to the first symbol of a slot, When the control information indicates reception of a PDSCH (Physical Downlink Shared Channel), the reference is a symbol position corresponding to the symbol in the slot where the control information is received. Base station.

2. The symbol used to transmit the control information is different for each transmission of the control information. The base station of claim 1 .

3. the control information includes time resource allocation information; a location for placing the data is identified using the time resource allocation information and the criteria; The base station of claim 1 .

4. The base station is In a data allocation control for a time resource based on downlink control information, a criterion for a position at which the data is allocated in the time resource is controlled based on a certain condition; transmitting the control information; When the control information indicates transmission of a PUSCH (Physical Uplink Shared Channel), the reference is a symbol position corresponding to the first symbol of a slot, When the control information indicates reception of a PDSCH (Physical Downlink Shared Channel), the reference is a symbol position corresponding to the symbol in the slot where the control information is received. Communication method.

5. The symbol used to transmit the control information is different for each transmission of the control information. The communication method according to claim 4.

6. the control information includes time resource allocation information; a location for placing the data is identified using the time resource allocation information and the criteria; The communication method according to claim 4.

7. a process of controlling a criterion for a position at which the data is allocated to the time resource based on a certain condition in a data allocation control for the time resource based on downlink control information; and a process of transmitting the control information. When the control information indicates transmission of a PUSCH (Physical Uplink Shared Channel), the reference is a symbol position corresponding to the first symbol of a slot, When the control information indicates reception of a PDSCH (Physical Downlink Shared Channel), the reference is a symbol position corresponding to the symbol in the slot where the control information is received. Integrated circuit.

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