Terminal and wireless communication method

Abstract

This terminal receives downlink control information and, in data delivery to a plurality of terminals, the terminal enables and / or disables feedback about an automatic repeat request in a downlink channel on the basis of a priority-related field included in the downlink control information.

Description

[Technical field]

[0001] The present disclosure relates to a terminal and a wireless communication method compatible with multicast / broadcast services. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP) has developed specifications for the 5th generation mobile communication system (5G, also known as New Radio (NR) or Next Generation (NG)), and is also developing specifications for the next generation, known as Beyond 5G, 5G Evolution, or 6G.

[0003] 3GPP Release 17 targets simultaneous data transmission (also called distribution) services (provisional name: MBS: Multicast and Broadcast Services) in NR to multiple specific or unspecified terminals (User Equipment, UE) (Non-Patent Document 1).

[0004] In the MBS, for example, studies are being conducted on scheduling of UE groups that are the subject of services, and improving reliability (for example, feedback of hybrid automatic repeat request (HARQ) to radio base stations (gNBs)). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] "New Work Item on NR support of Multicast and Broadcast Services", RP-193248, 3GPP TSG RAN Meeting #86, 3GPP, December 2019 Summary of the Invention

[0006] In MBS, HARQ positive acknowledgements (ACKs) and negative acknowledgements (NACKs) can be fed back to the gNB.

[0007] However, it is difficult for the UE to quickly and reliably recognize the timing at which such HARQ (Automatic Repeat Request) feedback is enabled / disabled.

[0008] Therefore, the following disclosure has been made in consideration of the above circumstances, and aims to provide a terminal and a wireless communication method that can quickly and reliably recognize whether automatic repeat request feedback is enabled or disabled in a simultaneous data transmission service to multiple specific or unspecified terminals.

[0009] One aspect of the present disclosure is a terminal (UE 200) including a receiving unit (control signal / reference signal processing unit 240) that receives downlink control information, and a control unit (control unit 270) that, in data distribution to multiple terminals, at least one of enabling and disabling feedback of an automatic repeat request in a downlink channel based on a priority field included in the downlink control information.

[0010] One aspect of the present disclosure is a terminal (UE200) including a receiver (radio signal transceiver 210) for receiving a downlink data channel in data distribution to multiple terminals, and a control unit (control unit 270) for assuming that, when semi-fixed scheduling is applied to the downlink data channel, an instruction to enable or disable feedback of an automatic repeat request by downlink control information via a downlink control channel common to a terminal group is applied to reception of the downlink data channel immediately after the downlink control information and to reception of the subsequent downlink data channel.

[0011] One aspect of the present disclosure is a terminal (UE200) including a receiver (radio signal transceiver 210) for receiving a downlink data channel in data distribution to multiple terminals, and a control unit (control unit 270) for assuming that, when semi-fixed scheduling is applied to the downlink data channel, an instruction to enable or disable feedback of an automatic repeat request by downlink control information via a downlink control channel common to a terminal group is applied to reception of the subsequent downlink data channel, excluding the downlink data channel immediately following the downlink control information, when semi-fixed scheduling is applied to the downlink data channel.

[0012] One aspect of the present disclosure is a terminal (UE200) that includes a receiving unit (radio signal transceiver unit 210) that receives a downlink data channel in data distribution to multiple terminals, and a control unit (control unit 270) that, when releasing the downlink data channel to which semi-fixed scheduling is applied, determines whether feedback of an automatic repeat request applied when releasing the downlink data channel is enabled or disabled based on the enabling or disabling of the feedback of the automatic repeat request applied when receiving the downlink data channel.

[0013] One aspect of the present disclosure is a wireless communication method including the steps of receiving downlink control information and, in data distribution to multiple terminals, at least one of enabling and disabling feedback of an automatic repeat request in a downlink channel based on a priority field included in the downlink control information.

[0014] One aspect of the present disclosure is a wireless communication method for data distribution to a plurality of terminals, the method including: receiving a downlink data channel; and assuming that, when semi-fixed scheduling is applied to the downlink data channel, an instruction to enable or disable feedback of an automatic repeat request by downlink control information via a downlink control channel common to a terminal group is applied to reception of the downlink data channel immediately after the downlink control information and to reception of the subsequent downlink data channel. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing an overall schematic configuration of a wireless communication system 10. As shown in FIG. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a radio frame, a subframe, and a slot used in the radio communication system 10. As shown in FIG. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of the PTM transmission method 1 and the PTM transmission method 2. As shown in FIG. [Figure 4] Figure 4 is a functional block configuration diagram of gNB100 and UE200. [Diagram 5] FIG. 5 is a diagram showing an example of a sequence of PDCCH (including DCI), PDSCH, and HARQ feedback in MBS. [Figure 6] FIG. 6 is a diagram showing an example of correspondence between PRI and PUCCH resource set according to operation example 1-2. [Figure 7] FIG. 7 is an explanatory diagram of a PUCCH resource set switching operation according to operation example 1-3. [Figure 8] FIG. 8 is a diagram showing an example of correspondence between priority indicators and HARQ feedback according to operation example 3-1 and operation example 3-2. [Figure 9] FIG. 9 is a diagram illustrating an example of a correspondence relationship between DCI and PDSCH according to the fourth operation example. [Figure 10] FIG. 10 is a diagram illustrating an example of a correspondence relationship between DCI and PDSCH according to the fifth operation example. [Figure 11] FIG. 11 is a diagram showing an example of the hardware configuration of gNB100 and UE200. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and the description thereof will be omitted as appropriate.

[0017] (1) Overall configuration of wireless communication system (1.1) System configuration example 1 is a schematic diagram of an overall configuration of a wireless communication system 10 according to the present embodiment. The wireless communication system 10 is a wireless communication system conforming to 5G New Radio (NR), and includes a Next Generation-Radio Access Network 20 (hereinafter, NG-RAN 20) and a plurality of terminals 200 (User Equipment 200, hereinafter, UE 200).

[0018] The wireless communication system 10 may be a wireless communication system conforming to a standard called Beyond 5G, 5G Evolution, or 6G.

[0019] The NG-RAN 20 includes a radio base station 100 (hereinafter, gNB 100). Note that the specific configuration of the radio communication system 10, including the number of gNBs and UEs, is not limited to the example shown in FIG.

[0020] The NG-RAN 20 actually includes a plurality of NG-RAN nodes, specifically, gNBs (or ng-eNBs), and is connected to a 5G-compliant core network (5GC, not shown). The NG-RAN 20 and the 5GC may be simply referred to as a "network."

[0021] The gNB 100 is a radio base station conforming to NR, and performs radio communication conforming to NR with the UE 200. The gNB 100 and the UE 200 can support Massive MIMO, which generates a more directional beam BM by controlling radio signals transmitted from multiple antenna elements, Carrier Aggregation (CA), which uses a bundle of multiple component carriers (CCs), and Dual Connectivity (DC), which simultaneously communicates between the UE and each of multiple NG-RAN Nodes.

[0022] The wireless communication system 10 supports FR1 and FR2. The frequency bands of each FR (Frequency Range) are as follows.

[0023] FR1: 410MHz~7.125GHz FR2: 24.25GHz~52.6GHz FR1 may use a Sub-Carrier Spacing (SCS) of 15, 30 or 60 kHz and a bandwidth (BW) of 5 to 100 MHz. FR2 is a higher frequency than FR1, and may use an SCS of 60 or 120 kHz (240 kHz may be included) and a bandwidth (BW) of 50 to 400 MHz.

[0024] Furthermore, the wireless communication system 10 may also support a frequency band higher than the FR2 frequency band. Specifically, the wireless communication system 10 may support a frequency band exceeding 52.6 GHz up to 114.25 GHz. The wireless communication system 10 may also support a frequency band between FR1 and FR2.

[0025] Also, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM) with a larger Sub-Carrier Spacing (SCS) may be applied. Furthermore, DFT-S-OFDM may be applied not only to the uplink (UL) but also to the downlink (DL).

[0026] FIG. 2 shows an example of the configuration of radio frames, subframes, and slots used in the radio communication system 10. In FIG.

[0027] As shown in Figure 2, one slot is composed of 14 symbols, and the larger (wider) the SCS, the shorter the symbol period (and slot period). The number of symbols constituting one slot does not necessarily have to be 14 symbols (e.g., 28, 56 symbols). The number of slots per subframe may differ depending on the SCS. Furthermore, the SCS may be wider than 240 kHz (e.g., 480 kHz, 960 kHz as shown in Figure 2).

[0028] The time direction (t) shown in Fig. 2 may be called a time domain, a symbol period, a symbol time, etc. The frequency direction may be called a frequency domain, a resource block, a resource block group, a subcarrier, a BWP (Bandwidth part), a subchannel, a common frequency resource, etc.

[0029] (1.2) Provision of MBS In the wireless communication system 10, Multicast and Broadcast Services (MBS) may be provided.

[0030] For example, in a stadium or a hall, a large number of UEs 200 are located within a certain geographical area, and a large number of UEs 200 may simultaneously receive the same data. In such a case, it is effective to use MBS instead of unicast.

[0031] Note that unicast may be interpreted as one-to-one communication with the network, with a specific UE 200 being designated (identification information unique to the UE 200 may be designated).

[0032] Multicast may be interpreted as one-to-many (specific many) communication with a network by specifying a specific number of UEs 200 (identification information for multicast may be specified). Note that the number of UEs 200 receiving the received multicast data may ultimately be one.

[0033] Broadcasting may be interpreted as one-to-one communication with the network for all UEs 200. Data to be multicast / broadcast may be identical copied content, but some content such as the header may be different. Data to be multicast / broadcast may be transmitted (distributed) simultaneously, but strict simultaneity is not necessarily required, and propagation delay and / or processing delay within the RAN node may be included.

[0034] The target UE 200 may have a radio resource control layer (RRC) state of an idle state (RRC idle), a connected state (RRC connected), or another state (e.g., an inactive state). The inactive state may be interpreted as a state in which some RRC settings are maintained.

[0035] In MBS, the following three types of methods are assumed for scheduling of multicast / broadcast PDSCH (Physical Downlink Shared Channel), specifically, scheduling of MBS packets (which may be read as data). Note that RRC connected UE may be read as RRC idle UE or RRC inactive UE.

[0036] ·PTM transmission method 1 (PTM-1): For the MBS group of RRC connected UE, the group-common PDSCH is scheduled using the group-common PDCCH (Physical Downlink Control Channel).

[0037] The CRC of the PDCCH and the PDSCH are scrambled by a group-common RNTI (which may also be called the Radio Network Temporary Identifier, G-RNTI).

[0038] ·PTM transmission method 2 (PTM-2): · For the MBS group of an RRC connected UE, a group-common PDSCH is scheduled using a UE-specific PDCCH.

[0039] The PDCCH CRC is scrambled by the UE-specific RNTI.

[0040] The PDSCH is scrambled by the group-common RNTI.

[0041] ·PTP transmission method: For RRC connected UEs, schedule UE-specific PDSCH using UE-specific PDCCH.

[0042] The CRC of the PDCCH and the PDSCH are scrambled by a UE-specific RNTI, which may mean that the MBS packet is transmitted by unicast.

[0043] Fig. 3 shows configuration examples of PTM transmission method 1 and PTM transmission method 2. Note that the UE-specific PDCCH / PDSCH can be identified by the target UE, but does not need to be identified by other UEs in the same MBS group. The group-common PDCCH / PDSCH is transmitted in the same time / frequency resource and can be identified by all UEs in the same MBS group. The names of PTM transmission methods 1 and 2 are tentative names, and may be called by other names as long as the above-mentioned operations are performed.

[0044] Note that in point-to-point (PTP) distribution, the RAN node may distribute individual copies of the MBS data packets over the air to individual UEs, whereas in point-to-multipoint (PTM) distribution, the RAN node may distribute a single copy of the MBS data packets over the air to a set of UEs.

[0045] Also, in order to improve the reliability of MBS, the following two feedback methods are envisaged for HARQ (Hybrid Automatic repeat request) feedback, specifically, HARQ feedback for multicast / broadcast PDSCH.

[0046] Option 1: Both ACK and NACK feedback (ACK / NACK feedback) · UE that successfully receives and decodes PDSCH sends ACK · UEs that fail to receive and decode PDSCH send NACK PUCCH (Physical Uplink Control Channel) resource setting: PUCCH-Config can be set for multicast PUCCH resources: shared / orthogonal between UEs, depending on network configuration HARQ-ACK CB (codebook): Supports type-1 and type-2 (CB decision algorithm (specified in 3GPP TS38.213)) Multiplexing: Unicast or Multicast available Option 2: NACK-only feedback · UE that successfully receives and decodes PDSCH does not send ACK (does not send a response) · UEs that fail to receive and decode PDSCH send NACK For a given UE, PUCCH resource configuration can be configured separately via unicast or groupcast (multicast) In addition, ACK may be called a positive acknowledgement, and NACK may be called a negative acknowledgement. HARQ may be called an automatic repeat request.

[0047] Enabling and disabling of option 1 or option 2 may be applied as follows:

[0048] RRC and Downlink Control Information (DCI) RRC only In addition, the following is assumed for SPS (Semi-persistent Scheduling) of multicast / broadcast PDSCH.

[0049] ·SPS group-common PDSCH adopted Multiple SPS group-common PDSCHs can be configured as UE capabilities. -HARQ feedback for SPS group-common PDSCH possible - Activation / deactivation possible via at least the group-common PDCCH (downlink control channel) Note that deactivation may be replaced with other synonymous terms such as release. For example, activation may be replaced with start, initiation, trigger, etc., and deactivation may be replaced with end, stop, etc.

[0050] SPS is a scheduling used in contrast to dynamic scheduling, and may be called semi-fixed, semi-persistent or semi-persistent scheduling, and may be interpreted as Configured Scheduling (CS).

[0051] Scheduling may be interpreted as a process of allocating resources for transmitting data. Dynamic scheduling may be interpreted as a mechanism where all PDSCHs are scheduled by DCI (e.g., DCI 1_0, DCI 1_1, or DCI 1_2). SPS may be interpreted as a mechanism where PDSCH transmissions are scheduled by higher layer signaling such as RRC messages.

[0052] Also, for the physical layer, there may be scheduling categories of time domain scheduling and frequency domain scheduling.

[0053] Furthermore, multicast, groupcast, broadcast, and MBS may be interchangeable. A multicast PDSCH and a PDSCH scrambled by a group-common RNTI may be interchangeable.

[0054] Furthermore, the terms data and packet may be used interchangeably and may be interpreted as synonymous with terms such as signal, data unit, etc. Additionally, the terms send, receive, transmit, and distribute may be used interchangeably.

[0055] (2) Functional block configuration of wireless communication system Next, a functional block configuration of the wireless communication system 10 will be described. Specifically, the functional block configurations of the gNB 100 and the UE 200 will be described.

[0056] Fig. 4 is a functional block diagram of the gNB 100 and the UE 200. The following describes the UE 200. As shown in Fig. 4, the UE 200 includes a radio signal transmitting / receiving unit 210, an amplifier unit 220, a modulation / demodulation unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transmitting / receiving unit 260, and a control unit 270.

[0057] Note that Fig. 4 shows only main functional blocks related to the description of the embodiment, and the UE 200 has other functional blocks (e.g., a power supply unit, etc.). Fig. 4 shows the functional block configuration of the UE 200 (gNB 100), and for the hardware configuration, please refer to Fig. 8.

[0058] The radio signal transmission / reception unit 210 transmits and receives radio signals conforming to NR. The radio signal transmission / reception unit 210 supports Massive MIMO, CA that uses a bundle of multiple CCs, and DC that simultaneously communicates between a UE and each of two NG-RAN nodes.

[0059] Moreover, the radio signal transmitting / receiving unit 210 supports MBS and can receive a downlink channel that is common to a terminal group (group common) in data distribution to a plurality of UEs 200. In this embodiment, the radio signal transmitting / receiving unit 210 may constitute a receiving unit.

[0060] Specifically, the radio signal transmitting / receiving unit 210 can receive a downlink data channel (PDSCH) in MBS, that is, data distribution to multiple terminals.

[0061] The radio signal transmitting / receiving unit 210 can also receive a downlink data channel (PDSCH) common to a terminal group, specifically, a group-common PDSCH (which may include an SPS group-common PDSCH). The radio signal transmitting / receiving unit 210 can also receive a downlink control channel common to a terminal group, specifically, a group-common PDCCH.

[0062] The amplifier unit 220 is configured by a PA (Power Amplifier) / LNA (Low Noise Amplifier) ​​etc. The amplifier unit 220 amplifies the signal output from the modem unit 230 to a predetermined power level. The amplifier unit 220 also amplifies the RF signal output from the wireless signal transmitting / receiving unit 210.

[0063] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, and the like for each predetermined communication destination (such as the gNB 100). The modem unit 230 may apply Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM). Furthermore, DFT-S-OFDM may be used not only for the uplink (UL) but also for the downlink (DL).

[0064] The control signal / reference signal processor 240 executes processing related to various control signals transmitted and received by the UE 200, and processing related to various reference signals transmitted and received by the UE 200.

[0065] Specifically, the control signal / reference signal processor 240 receives various control signals, such as control signals (messages) of a radio resource control layer (RRC), transmitted from the gNB 100 via a predetermined control channel. In addition, the control signal / reference signal processor 240 transmits various control signals to the gNB 100 via a predetermined control channel.

[0066] The control signal / reference signal processor 240 executes processing using reference signals (RS) such as a Demodulation Reference Signal (DMRS) and a Phase Tracking Reference Signal (PTRS).

[0067] DMRS is a known reference signal (pilot signal) between a base station and a terminal for estimating a fading channel used for data demodulation. PTRS is a terminal-specific reference signal for estimating phase noise, which is an issue in high frequency bands.

[0068] In addition to the DMRS and PTRS, the reference signals may include a Channel State Information-Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), and a Positioning Reference Signal (PRS) for position information.

[0069] The channels include a control channel and a data channel. The control channels may include a PDCCH, a Physical Uplink Control Channel (PUCCH), a Random Access Channel (RACH, Downlink Control Information (DCI) including a Random Access Radio Network Temporary Identifier (RA-RNTI)), a Physical Broadcast Channel (PBCH), and the like.

[0070] Moreover, the data channel includes a PDSCH, a PUSCH (Physical Uplink Shared Channel), etc. Data may mean data transmitted via a data channel.

[0071] In this embodiment, the control signal and reference signal processor 240 may configure a receiver that receives downlink control information (DCI). In addition, the control signal and reference signal processor 240 may receive a message in RRC indicating the enabling or disabling of a function instructed by DCI to enable or disable HARQ feedback.

[0072] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding, etc. for each predetermined communication destination (gNB100 or another gNB).

[0073] Specifically, the encoding / decoding unit 250 divides the data output from the data transmitting / receiving unit 260 into pieces of a predetermined size, performs channel coding on the divided data, and decodes the data output from the modem unit 230 and concatenates the decoded data.

[0074] The data transmission / reception unit 260 transmits and receives Protocol Data Units (PDUs) and Service Data Units (SDUs). Specifically, the data transmission / reception unit 260 performs assembly / disassembly of PDUs / SDUs in multiple layers (such as a Medium Access Control layer (MAC), a Radio Link Control layer (RLC), and a Packet Data Convergence Protocol layer (PDCP)). In addition, the data transmission / reception unit 260 performs data error correction and retransmission control based on a hybrid automatic repeat request (Hybrid ARQ).

[0075] The control unit 270 controls each functional block constituting the UE 200. In particular, in this embodiment, the control unit 270 executes control related to scheduling of a downlink channel for MBS and HARQ feedback of the channel.

[0076] The control unit 270 executes control corresponding to the scheduling of a downlink data channel that is common to a terminal group (group common) in data delivery to the MBS, that is, to a plurality of UEs 200. Specifically, the control unit 270 can execute control corresponding to the scheduling of a group-common PDCCH and a group-common PDSCH.

[0077] The control unit 270 may at least one of enable and disable HARQ (Automatic Repeat Request) feedback in the downlink channel based on a specific field included in DCI (Downlink Control Information) in the MBS, i.e., data distribution to multiple UEs 200.

[0078] Specifically, among the fields defined in the DCI format (see 3GPP TS38.212, etc.), a field related to HARQ feedback may be used to specify enable / disable of HARQ feedback.

[0079] At least one of the following fields may be used:

[0080] ·TPC command for scheduled PUCCH ·PUCCH resource indicator (PRI) ·PDSCH-to-HARQ_feedback timing indicator This field may be defined in DCI format 1_0, 1_1, 1_2, etc.

[0081] The control unit 270 may enable / disable HARQ feedback based on a resource indication field for PUCCH (uplink control channel) included in DCI, specifically, a PUCCH resource indicator (PRI) field.

[0082] For example, a specific value of PRI (e.g., 000) may be associated with no HARQ feedback. Also, a PUCCH resource set not including a PRI associated with no HARQ feedback and a PUCCH resource set including a PRI associated with no HARQ feedback may be switched.

[0083] The control unit 270 may recognize that enable / disable of HARQ feedback by DCI is specified by signaling of a higher layer (for example, RRC). When the control unit 270 receives such signaling, it may switch to a PUCCH resource set including a PRI associated with no HARQ feedback. Also, when the control unit 270 receives signaling to cancel the specification of enable / disable of HARQ feedback by DCI, it may switch (return) to a PUCCH resource set not including a PRI associated with no HARQ feedback.

[0084] When the DCI instructs that there is no HARQ feedback, the control unit 270 does not transmit the PUCCH resource and does not need to perform HARQ feedback. Note that a more specific operation regarding the switching of the PUCCH resource set will be described later.

[0085] The control unit 270 may determine whether or not to apply enable / disable of HARQ feedback based on a specific field included in the above-mentioned DCI, based on a message (which may also be read as signaling) of the RRC layer.

[0086] Specifically, the control unit 270 may assume that, if the message is for enabling a function indicated by the DCI, the control unit 270 receives an instruction to enable or disable HARQ feedback in the DCI. Also, if the message is for disabling a function indicated by the DCI, the control unit 270 may disable the feedback without receiving an instruction to enable or disable HARQ feedback in the DCI.

[0087] For example, the control unit 270 may apply any of the following operations depending on the configuration of the RRC signaling.

[0088] When HARQ feedback is disabled: It is assumed that the enable / disable of HARQ feedback by DCI is never indicated.

[0089] · HARQ feedback enable: It is assumed that enable / disable of HARQ feedback by DCI is always indicated.

[0090] Note that enable / disable of HARQ feedback may be set for each RNTI (C (Cell)-RNTI / G (Group)-RNTI), or a method of instructing enable / disable of HARQ feedback by DCI may be switched by RRC signaling. For example, RRC signaling may be used to switch between a method of instructing by a specific field included in the above-mentioned DCI and a method of instructing by combining a plurality of such fields.

[0091] Furthermore, the control unit 270 may at least one of enable / disable HARQ feedback in the downlink channel based on at least one of a format, identification information, resource, and search space associated with DCI.

[0092] For example, enabling / disabling of HARQ feedback may be performed based on at least one of the DCI format (e.g., DCI format 1_0, 1_1, 1_2, etc. including the specific fields described above), the RNTI (identification information) used for scrambling the CRC of the DCI, the CORESET (control resource sets), the search space, and the PDSCH resources (time / frequency / code / space).

[0093] The control unit 270 may at least one of enabling and disabling HARQ feedback in a downlink channel based on a field related to priority included in DCI in data delivery to a plurality of UEs 200. Here, the downlink channel is assumed to be a downlink data channel (PDSCH), but may be a downlink control channel (PDCCH).

[0094] The DCI may be a DCI (or a DCI format) for scaling a PDSCH for MBS, and may be a field that indicates a priority related to HARQ among the fields included in the DCI. For example, the field may be called a priority indicator field, or may be another field related to an indication of priority.

[0095] The control unit 270 may enable HARQ feedback when the priority is high, and may disable HARQ feedback when the priority is low. Alternatively, the control unit 270 may assume that HARQ feedback is enabled or disabled for each value of the Priority indicator field. Note that, when the Priority indicator field is not included in the DCI, the control unit 270 may assume that the RRC specifies whether to enable or disable HARQ feedback.

[0096] In addition, the control unit 270 may assume that when semi-static scheduling (SPS) is applied to the downlink data channel (PDSCH), an instruction to enable or disable HARQ feedback by DCI via a downlink control channel common to a terminal group (group-common PDCCH) applies to the reception of the PDSCH immediately after the DCI and the reception of the subsequent PDSCH.

[0097] Specifically, in the case of Multicast SPS PDSCH reception, control unit 270 may assume that an enable / disable instruction for HARQ feedback in an activation DCI of a group-common PDCCH is applied to the PDSCH reception immediately after the activation DCI of the group-common PDCCH and to the subsequent SPS PDSCH reception.

[0098] Note that the Multicast SPS PDSCH reception may mean group-common SPS PDSCH reception, may be an SPS PDSCH received by multiple terminals, or may be an SPS PDSCH reception associated with a G-RNTI or G-CS-RNTI (i.e., an RNTI associated with multiple terminals). Also, Multicast may be read as Broadcast.

[0099] Alternatively, the control unit 270 may assume that when semi-static scheduling (SPS) is applied to the downlink data channel (PDSCH), an instruction to enable or disable HARQ feedback by DCI via a downlink control channel common to a terminal group (group-common PDCCH) is applied to reception of subsequent PDSCHs, except for the PDSCH immediately following the DCI.

[0100] Specifically, in the case of Multicast SPS PDSCH reception, control unit 270 may assume that the HARQ feedback enable / disable instruction in the activation DCI of the group-common PDCCH is applied only to the subsequent SPS PDSCH reception, and a predetermined value (e.g., enable) is applied to the HARQ feedback for the PDSCH reception immediately after the activation DCI of the group-common PDCCH.

[0101] In addition, when releasing a downlink data channel (PDSCH) to which semi-static scheduling (SPS) is applied, the control unit 270 may determine whether the HARQ feedback applied when releasing the PDSCH is enabled or disabled, based on the enabling or disabling of the HARQ feedback applied when receiving the PDSCH.

[0102] Note that PDSCH release may be read as deactivation. The control unit 270 may assume that the HARQ feedback for Multicast SPS PDSCH release (deactivation) is set or instructed to be either enable or disable by any of the above-mentioned methods. Alternatively, the control unit 270 may assume that the release of Multicast SPS PDSCH is the same as the HARQ feedback (enable or disable) applied at the time of receiving or activating the corresponding SPS PDSCH, or may assume that the release is always a predetermined value (e.g., enable).

[0103] In addition, gNB100 can perform the above-mentioned downlink channel scheduling and control related to HARQ.

[0104] (3) Operation of wireless communication system Next, a description will be given of the operation of the wireless communication system 10. Specifically, a description will be given of the operation related to the scheduling of the downlink channel for the MBS and the HARQ feedback of the channel.

[0105] Fig. 5 shows an example of a sequence of PDCCH (including DCI), PDSCH, and HARQ feedback in MBS. As shown in Fig. 5, HARQ feedback such as group-common PDSCH may be enabled / disabled. Note that enable / disable may be interpreted as another term such as on / off, start / end (stop), etc.

[0106] For example, enabling / disabling of HARQ feedback can be realized by a combination of RRC signaling and instructions by DCI fields, but a specific example of operation regarding enabling / disabling of HARQ feedback will be described below.

[0107] Note that adding a new field for indicating enable / disable of HARQ feedback is undesirable from the viewpoint of increasing DCI overhead. Also, when using DCI format 1_0 for MBS (multicast / broadcast) scheduling, the payload size must be the same as that for unicast, and care must be taken to avoid increasing the number of dedicated fields as much as possible.

[0108] (3.1) Example 1 In this operation example, among the fields in the DCI format, a field related to HARQ feedback may be used to specify enable / disable of HARQ feedback. The field related to HARQ feedback may be interpreted as a field that has some effect on or is related to the HARQ feedback.

[0109] The enable / disable of the HARQ feedback may be specified for reception of a specific transport block (TB) (e.g., a TB assigned by a DCI including a HARQ feedback enable / disable notification), or may not be specified for a specific TB and may be applied to TBs other than the specific TB (e.g., a TB via an SPS group-common PDSCH). In other words, after receiving a notification of the enable / disable of the HARQ feedback, the system may operate according to the notified enable / disable until a certain condition is satisfied (e.g., until another notification is received).

[0110] The DCI format used may be 1_0, 1_1, or 1_2, or may be another DCI format (for example, 1_3) defined for scheduling of the group-common PDSCH.

[0111] (Example 1-1) Specifically, enable / disable of HARQ feedback may be specified based on any of the following fields: Note that the field names and the number of bits are not limited to these.

[0112] (i) TPC command for scheduled PUCCH: 2 bits (3GPP TS38.213 Chapter 7.2.1) (ii) PUCCH resource indicator: 3 bits (3GPP TS38.213 Chapter 9.2.3) (iii) PDSCH-to-HARQ_feedback timing indicator: 3 bits (3GPP TS38.213 Chapter 9.2.3)

[0113] (Example 1-2) When using a PUCCH resource indicator (PRI), the UE 200 may operate as follows: When a higher layer (e.g., RRC signaling) configures that enable / disable of HARQ feedback is specified by DCI, the UE 200 may change the correspondence between the PRI and the PUCCH resource set.

[0114] Fig. 6 shows an example of correspondence between PRI and PUCCH resource set according to operation example 1-2. The upper part of Fig. 6 shows a conventional example of correspondence between PRI and PUCCH resource set when enable / disable of HARQ feedback is not applied. The lower part of Fig. 6 shows an example of correspondence between PRI and PUCCH resource set when enable / disable of HARQ feedback is applied (embodiment).

[0115] In the lower part of Fig. 6, PRI=000 corresponds to no HARQ feedback, but this is an example and is not limited to this. Which PRI value means no HARQ feedback may be specified in the 3GPP specifications or may be set by a higher layer. In this operation example, the PRI field is used, but the same applies when the other fields described above are used (same below).

[0116] Also, PUCCH resource #0 in the upper part of Fig. 6 may be the same as or different from PUCCH resource #0 in the lower part of Fig. 6. For example, except for PRI=000, the same PUCCH resource may be indicated in the upper part and the lower part of Fig. 6. In this case, for example, PUCCH resource #1 in the upper part of Fig. 6 may be the same as PUCCH resource #0 in the lower part of Fig. 6.

[0117] When no HARQ feedback is instructed by the PRI, the UE 200 may stop transmitting HARQ feedback (ACK / NACK) by the PUCCH resource. Or, the UE 200 may not start the operation related to the HARQ feedback transmission. The UE 200 may not transmit HARQ-ACK including that of the unicast PDSCH to be placed on the same PUCCH resource. Or, the UE 200 may not transmit HARQ-ACK of the multicast PDSCH to be placed on the same PUCCH resource. Or, the UE 200 may not transmit HARQ-ACK only for the MBS PDSCH (which may include the group-common PDSCH and the SPS group-common PDSCH) scheduled by the DCI instructed to not have HARQ feedback.

[0118] (Example 1-3) UE200 may dynamically switch between the conventional correspondence between PRI and PUCCH resource set shown in the upper part of Figure 6 and the example of correspondence between PRI and PUCCH resource set when enable / disable of HARQ feedback is not applied shown in the lower part of Figure 6.

[0119] 7 is an explanatory diagram of a switching operation of a PUCCH resource set according to an operation example 1-3. The PUCCH resource set may be dynamically switched between HARQ feedback when receiving an MBS PDSCH and HARQ feedback when receiving a unicast PDSCH.

[0120] As shown in FIG. 7, the UE 200 may switch between a PUCCH resource set including no HARQ feedback (disabled) (embodiment) and a PUCCH resource set not including no HARQ feedback (conventional) based on the RNTI associated with the PDSCH.

[0121] (Example of operation 1-3-1) When a PUCCH-Config (PUCCH resource / resource set, etc.) is configured for HARQ feedback of MBS PDSCH separately from that for unicast HARQ feedback, UE 200 may operate as follows.

[0122] The PUCCH resource set for HARQ feedback for MBS PDSCH is set as shown in the example at the bottom of Figure 6.

[0123] For HARQ-ACK transmission for the MBS PDSCH (HARQ-ACK transmission of the PDSCH scheduled by DCI with CRC scrambled by G-RNTI), the PUCCH resource may be determined according to the PUCCH resource set in the lower part of FIG.

[0124] ·Whether the PUCCH resource set for HARQ feedback for MBS PDSCH is the conventional or embodiment is determined based on whether the enable / disable of HARQ feedback is specified by DCI by a higher layer.

[0125] When the enable / disable of HARQ feedback is specified by DCI by a higher layer, the PUCCH resource set (lower part of FIG. 6) of the embodiment may be set. In this case, for HARQ-ACK transmission for MBS PDSCH (HARQ-ACK transmission of PDSCH scheduled by DCI with CRC scrambled by G-RNTI), PUCCH resources may be determined according to the PUCCH resource set in the lower part of FIG.

[0126] When the enable / disable of HARQ feedback is not specified by the DCI by the higher layer, the conventional PUCCH resource set (upper part of FIG. 6) may be set. In this case, for HARQ-ACK transmission for MBS PDSCH (HARQ-ACK transmission of PDSCH scheduled by DCI with CRC scrambled by G-RNTI), PUCCH resources may be determined according to the PUCCH resource set in the upper part of FIG. 6.

[0127] The PUCCH resource set for HARQ-ACK for unicast PDSCH may be configured according to the conventional correspondence between PRI and PUCCH resource sets that does not include no HARQ feedback (the upper side of Figure 6, which may be an example of a correspondence between PRI and PUCCH resource sets different from those for MBS).

[0128] For HARQ-ACK transmission for a unicast PDSCH (HARQ-ACK transmission of a PDSCH scheduled by DCI with CRC scrambled by other than G-RNTI), the PUCCH resource may be determined according to the PUCCH resource set in the upper part of FIG.

[0129] (Example of operation 1-3-2) If a separate PUCCH-Config (PUCCH resource / resource set, etc.) is not configured for HARQ feedback of MBS PDSCH from that for unicast HARQ feedback, UE 200 may operate as follows.

[0130] HARQ-ACK transmission for MBS PDSCH (HARQ-ACK transmission for PDSCH scheduled by DCI with CRC scrambled by G-RNTI) may be as follows:

[0131] When the enable / disable of HARQ feedback is specified by DCI by a higher layer, the configured PUCCH resource set is treated as the embodiment (lower part of Figure 6), and the PUCCH resource is determined using the PUCCH resource set of the embodiment.

[0132] If the enable / disable of HARQ feedback is specified by DCI but not configured by higher layers, the configured PUCCH resource set is treated as the conventional one (upper part of Figure 6), and the PUCCH resource is determined using the conventional PUCCH resource set.

[0133] For HARQ-ACK transmission for unicast PDSCH (HARQ-ACK transmission for PDSCH scheduled by DCI with CRC scrambled by other than G-RNTI), the PUCCH resource is determined using the conventional PUCCH resource set (upper part of Figure 6).

[0134] (Example 1-4) The enable / disable of the HARQ feedback may be specified by combining at least two of the following fields shown in the operation example 1-1. Note that the field names and the number of bits are not limited to these.

[0135] (i) TPC command for scheduled PUCCH: 2 bits (3GPP TS38.213 Chapter 7.2.1) (ii) PUCCH resource indicator: 3 bits (3GPP TS38.213 Chapter 9.2.3) (iii) PDSCH-to-HARQ_feedback timing indicator: 3 bits (3GPP TS38.213 Chapter 9.2.3) For example, when (ii) and (iii) are predetermined values ​​(e.g., both are 0 (zero)), or when (i), (ii), and (iii) are predetermined values ​​(e.g., all are 0 (zero)), it may be interpreted that disabling of HARQ feedback is specified.

[0136] By combining multiple fields in this manner, it is possible to increase the flexibility (certainty) of instructions regarding HARQ feedback compared to operation example 1-1.

[0137] (Example 1-5) For example, in a case where the above-mentioned (ii) and (iii) are predetermined values ​​(for example, both are 0 (zero)), and the enable / disable of HARQ feedback is specified by DCI, a higher layer may configure that the enable / disable of HARQ feedback is specified by DCI, and when "0" is indicated by the PDSCH-to-HARQ_feedback timing indicator (iii), a PUCCH resource set including no HARQ feedback (disabled) (embodiment, lower side of FIG. 6) may be applied. And when "0" is indicated by the PUCCH resource indicator (ii), the UE 200 may determine that the disable of HARQ feedback has been specified.

[0138] When no HARQ feedback is instructed by the PRI, the UE 200 may stop transmitting HARQ feedback (ACK / NACK) by the PUCCH resource. Or, the operation related to the HARQ feedback transmission may not be started. As in the operation example 1-2, the UE 200 may not transmit HARQ-ACK including that of the unicast PDSCH to be placed on the same PUCCH resource. Or, the UE 200 may not transmit HARQ-ACK of the multicast PDSCH to be placed on the same PUCCH resource. Or, the UE 200 may not transmit HARQ-ACK only for the MBS PDSCH (which may include the group-common PDSCH and the SPS group-common PDSCH) scheduled by the DCI instructed to not have HARQ feedback.

[0139] (Example 1-6) When switching between a PUCCH resource set including no HARQ feedback (disabled) shown in FIG. 7 (embodiment) and a PUCCH resource set including no HARQ feedback (conventional) is performed dynamically, UE 200 may dynamically switch between a PUCCH resource set including no HARQ feedback and a PUCCH resource set including no HARQ feedback based on an RNTI associated with a PDSCH and (iii) a PDSCH-to-HARQ_feedback timing indicator field.

[0140] (Example of operation 1-6-1) When a PUCCH-Config (PUCCH resource / resource set, etc.) is configured for HARQ feedback of MBS PDSCH separately from that for unicast HARQ feedback, UE 200 may operate as follows.

[0141] ·Whether the PUCCH resource set for HARQ feedback for MBS PDSCH is the conventional or embodiment is determined based on whether the enable / disable of HARQ feedback is specified by DCI by a higher layer.

[0142] When the enable / disable of HARQ feedback is specified by DCI by a higher layer, if the PDSCH-to-HARQ_feedback timing indicator field is a predetermined value (e.g., all 0 (zero)), the PUCCH resource set of the embodiment may be configured. Otherwise, the conventional PUCCH resource set may be configured.

[0143] When the enable / disable of HARQ feedback is not specified by the DCI by the higher layer, the conventional PUCCH resource set (upper part of FIG. 6) may be set. In this case, for HARQ-ACK transmission for MBS PDSCH (HARQ-ACK transmission of PDSCH scheduled by DCI with CRC scrambled by G-RNTI), PUCCH resources may be determined according to the conventional PUCCH resource set (upper part of FIG. 6).

[0144] The PUCCH resource set for HARQ-ACK for unicast PDSCH may be set according to the conventional PUCCH resource set (the upper side of FIG. 6, which may be an example of a correspondence between a PRI and a PUCCH resource set different from that for MBS).

[0145] For HARQ-ACK transmission for a unicast PDSCH (HARQ-ACK transmission of a PDSCH scheduled by DCI with CRC scrambled by other than G-RNTI), the PUCCH resource may be determined according to a conventional PUCCH resource set.

[0146] (Example of operation 1-6-2) If a separate PUCCH-Config (PUCCH resource / resource set, etc.) is not configured for HARQ feedback of MBS PDSCH from that for unicast HARQ feedback, UE 200 may operate as follows.

[0147] HARQ-ACK transmission for MBS PDSCH (HARQ-ACK transmission for PDSCH scheduled by DCI with CRC scrambled by G-RNTI) may be as follows:

[0148] When the enable / disable of HARQ feedback is specified by DCI by a higher layer, if the PDSCH-to-HARQ_feedback timing indicator field is a predetermined value (e.g., all 0 (zero)), the configured PUCCH resource set is treated as the embodiment (lower part of FIG. 6) and the PUCCH resource is determined using the PUCCH resource set of the embodiment. Otherwise, the configured PUCCH resource set is treated as the conventional one and the PUCCH resource is determined using the conventional PUCCH resource set.

[0149] · If the enable / disable of HARQ feedback is specified by DCI but is not configured by higher layers, the configured PUCCH resource set is treated as the conventional one, and the PUCCH resource is determined using the conventional PUCCH resource set.

[0150] For HARQ-ACK transmission for unicast PDSCH (HARQ-ACK transmission for PDSCH scheduled by DCI with CRC scrambled by other than G-RNTI), the PUCCH resource is determined using the configured conventional PUCCH resource set.

[0151] (Example 1-7) The following setting may be performed using RRC signaling. For example, when the HARQ feedback is set to be disabled by the RRC signaling, the UE 200 may assume that the enable / disable of the HARQ feedback by the DCI is not always instructed.

[0152] On the other hand, if HARQ feedback is set to be enabled, UE 200 may assume that enable / disable of HARQ feedback is always instructed by DCI.

[0153] In addition, when HARQ feedback is set to enable, the method of indicating enable / disable of HARQ feedback by DCI is not particularly limited, and may be the method of designation by the above-mentioned DCI field, or may be different. In addition, the size of the DCI format or the field in the DCI may be the same or different between the case where HARQ feedback is disabled and the case where HARQ feedback is enabled.

[0154] (Example 1-8) The enable / disable of the HARQ feedback may be set for each RNTI. For example, a plurality of G-RNTIs may be set, and the enable / disable of the HARQ feedback may be set for each of them. For example, when two G-RNTIs are set, which are G-RNTI-1 and G-RNTI-2, respectively, the HARQ feedback may be set as enable for the G-RNTI-1, and the HARQ feedback may be set as disable for the G-RNTI-2. The UE 200 may determine whether to execute the HARQ feedback based on whether the RNTI associated with the received PDSCH is G-RNTI-1 or G-RNTI-2. The RNTI is not particularly limited, and may be a C-RNTI or a G-RNTI.

[0155] (Example 1-9) The method of indicating enable / disable of HARQ feedback by DCI may be switched by RRC signaling.

[0156] For example, the indication method between operation example 1-1 and operation example 1-4 may be switched by RRC signaling.

[0157] (3.2) Example 2 In this operation example, enable / disable of HARQ feedback may be specified based on at least any of the following signals and / or information related to DCI reception. Such specification may be an implicit instruction, not an explicit one.

[0158] (Example 2-1) The UE 200 may assume enable / disable of the HARQ feedback based on the DCI format. For example, the UE 200 may operate as follows.

[0159] HARQ feedback enable / disable is a separate DCI format UE 200 may perform HARQ feedback for an MBS PDSCH scheduled by a predetermined DCI format, and may not perform HARQ feedback for an MBS PDSCH scheduled by a DCI format other than the predetermined DCI format.

[0160] The format for enabling HARQ feedback may include at least any one of the fields (i) to (iii) shown in Operation Example 1-1 and the like.

[0161] The format for disabling HARQ feedback does not have to include fields (i) to (iii) shown in Operation Example 1-1.

[0162] The above-mentioned DCI formats may be distinguished by payload size or format indicator.

[0163] (Example 2-2) The UE 200 may assume enable / disable of the HARQ feedback based on the RNTI that scrambles the CRC of the DCI. For example, the UE 200 may operate as follows.

[0164] G1-RNTI (one of the G-RNTIs, tentative name) is defined and is used for scheduling the group-common PDSCH (group-common PDSCH with HARQ) where HARQ feedback is performed.

[0165] G2-RNTI (one of the G-RNTIs, tentative name) is defined and is used for scheduling group-common PDSCH (group-common PDSCH without HARQ) where HARQ feedback is not performed.

[0166] (Example 2-3) UE 200 may consider enabling / disabling HARQ feedback based on the CORESET and / or search space used to transmit DCI.

[0167] (Example 2-4) UE 200 may consider enabling / disabling HARQ feedback based on the PDSCH resource (time / frequency / code / space) indicated by the DCI.

[0168] (3.3) Example 3 In this operation example, in data distribution (MBS) for multiple UEs 200, enabling or disabling of HARQ feedback in a downlink channel may be specified based on a field related to priority included in DCI.

[0169] Specifically, HARQ feedback = {enable / disable} corresponding to MBS PDSCH reception may be specified based on a field related to priority among fields in DCI (or a DCI format) that schedules MBS PDSCH.

[0170] (Operation example 3-0): The field related to priority may be a priority indicator field (may be a tentative name) or may be another field related to an instruction of priority. The priority indicator field may indicate the level of priority related to HARQ by using one bit, or may indicate the priority in more detail by using multiple bits. The priority related to HARQ may indicate, for example, the priority of HARQ itself or the priority of HARQ feedback.

[0171] The priority indicated by the Priority indicator field or another field related to the Priority indication may be the priority of the PDCCH or HARQ feedback corresponding to a scaled PDSCH (scheduled PDSCH).

[0172] Based on such priority, HARQ feedback = {enable / disable} corresponding to MBS PDSCH reception may be specified by at least one of the methods in operation examples 3-1 to 3-4.

[0173] (Example 3-1) If the priority is high (for example, priority indicator = 1), HARQ feedback is enabled.

[0174] (Example 3-2) If the priority is low (for example, priority indicator = 0), HARQ feedback is disabled.

[0175] Fig. 8 shows an example of the correspondence between priority indicators and HARQ feedback according to operation example 3-1 and operation example 3-2. As shown in Fig. 8, when priority indicator = 1, HARQ feedback may be enabled, and when priority indicator = 0, HARQ feedback may be disabled.

[0176] (Example 3-3) For each priority indicator value (which may be three or more values), whether HARQ feedback is enabled or disabled is set.

[0177] (Example 3-4) For each priority indicator value (at least for either 0 or 1), it is set whether or not a HARQ feedback enable / disable instruction is to be issued by DCI.

[0178] In this case, the instruction may be given according to either the first or second operation example.

[0179] Furthermore, when the Priority indicator field is not included in the DCI / DCI format, HARQ feedback = {enable / disable} corresponding to MBS PDSCH reception may be specified by at least one of the methods in operation example 3-5 or 3-6.

[0180] (Example 3-5) The enable / disable of HARQ feedback set by the RRC parameter is applied. If the enable / disable is not set by the RRC parameter, a predetermined value (for example, enable or disable) may be assumed.

[0181] (Example 3-6) Enable / disable is applied based on the priority of HARQ feedback / PUCCH set by an RRC parameter. If the priority is not set by an RRC parameter, a predetermined value (for example, enable or disable) may be assumed.

[0182] According to this operation example, the UE 200 can determine whether or not to provide appropriate HARQ feedback depending on the priority.

[0183] In addition, enable / disable may be applied based on the priority of HARQ feedback / PUCCH set by an RRC parameter, not only when the Priority indicator field is not included in the DCI / DCI format. Even in this case, if enable / disable is not set by the RRC parameter, a predetermined value (e.g., enable or disable) may be assumed.

[0184] (3.4) Example 4 In this operation example, when semi-static scheduling (SPS) is applied to the downlink data channel (PDSCH), it may be assumed that an instruction to enable or disable HARQ feedback by DCI via a downlink control channel (group-common PDCCH) that is common to a terminal group is applied to the reception of the PDSCH immediately after the DCI and the reception of the subsequent PDSCH.

[0185] 9 illustrates an example of a correspondence relationship between DCI and PDSCH according to operation example 4. In the case of multicast SPS PDSCH reception, a HARQ feedback enable / disable instruction in an activation DCI of a group-common PDCCH may be applied to a PDSCH reception immediately after the activation DCI of a group-common PDCCH and a subsequent SPS PDSCH reception.

[0186] (Example 4-1) The instruction by the activation DCI of the group-common PDCCH may be performed according to any one of the operation examples 1 to 3.

[0187] (Example 4-2) This indication by the activation DCI of the group-common PDCCH may be made using a field of the DCI that is not used for the special fields of activation.

[0188] (Example 4-3) When activation of the multicast SPS PDSCH is performed by DCI of a UE-specific PDCCH, enable / disable of HARQ feedback for the subsequent SPS PDSCH reception may be indicated in the activation DCI of the UE-specific PDCCH.

[0189] This instruction may be performed according to any one of operation examples 1 to 3. Furthermore, the PDSCH reception immediately after the activation DCI of the UE-specific PDCCH may be HARQ feedback enable, or may follow the enable / disable instruction of HARQ feedback for the SPS PDSCH reception.

[0190] Note that the instruction to enable / disable HARQ for the multicast SPS PDSCH may be performed only by the activation DCI of the group-common PDCCH, or may be performed by any one of the activation DCIs of the group-common / UE-specific PDCCH.

[0191] Moreover, "reception of a PDSCH immediately after" may mean reception of an SPS PDSCH with a corresponding PDCCH, and "reception of a subsequent SPS PDSCH" may mean reception of an SPS PDSCH without a corresponding PDCCH.

[0192] According to this operation example, it is possible to easily set a configuration in which HARQ feedback is requested for highly reliable periodic transmission and HARQ feedback is not requested for unreliable transmission. In addition, a common setting can be set for all SPS receptions, which can simplify the implementation of UE 200.

[0193] (3.5) Example 5 In this operation example, when semi-static scheduling (SPS) is applied to the downlink data channel (PDSCH), it may be assumed that an instruction to enable or disable HARQ feedback by DCI via a downlink control channel (group-common PDCCH) that is common to a terminal group is applied to the reception of subsequent PDSCHs, except for the PDSCH immediately following the DCI.

[0194] 10 shows an example of the correspondence relationship between DCI and PDSCH according to operation example 5. In the case of multicast SPS PDSCH reception, the HARQ feedback enable / disable instruction in the activation DCI of the group-common PDCCH is applied only to the subsequent SPS PDSCH reception, and for the PDSCH reception immediately following the activation DCI of the group-common PDCCH, the HARQ feedback may be set to a predetermined value (e.g., enable).

[0195] (Example 5-1) The instruction by the activation DCI of the group-common PDCCH may be performed according to any one of the operation examples 1 to 3.

[0196] (Example 5-2) This indication by the activation DCI of the group-common PDCCH may be made using a field of the DCI that is not used for the special fields of activation.

[0197] (Example 5-3) When multicast SPS PDSCH activation is performed by DCI of a UE-specific PDCCH, enable / disable of HARQ feedback for the subsequent SPS PDSCH reception may be indicated in the activation DCI of the UE-specific PDCCH.

[0198] This instruction may be performed according to any one of operation examples 1 to 3. Furthermore, the PDSCH reception immediately after the activation DCI of the UE-specific PDCCH may be HARQ feedback enable, or may follow the enable / disable instruction of HARQ feedback for the SPS PDSCH reception.

[0199] Note that the instruction to enable / disable HARQ for the multicast SPS PDSCH may be performed only by the activation DCI of the group-common PDCCH, or may be performed by any one of the activation DCI of the group-common / UE-specific PDCCH.

[0200] Moreover, "reception of a PDSCH immediately after" may mean reception of an SPS PDSCH with a corresponding PDCCH, and "reception of a subsequent SPS PDSCH" may mean reception of an SPS PDSCH without a corresponding PDCCH.

[0201] According to this operation example, gNB100 can always determine whether PDSCH activation has succeeded or failed, thereby improving communication quality.

[0202] (3.6) Example 6 In this operation example, when releasing a downlink data channel (PDSCH) to which semi-static scheduling (SPS) is applied, it may be determined whether the HARQ feedback applied when releasing the PDSCH is enabled or disabled based on whether the HARQ feedback applied when receiving the PDSCH is enabled or disabled.

[0203] Specifically, whether HARQ feedback for release (deactivation) of the Multicast SPS PDSCH is enabled or disabled may be determined by any of the following operation examples.

[0204] (Example 6-1) Enabling / disabling of HARQ feedback for deactivation is performed according to any one of the operation examples 1 to 5.

[0205] (Example 6-2) Release (deactivation) of the Multicast SPS PDSCH is the same as enable / disable of HARQ feedback related to the corresponding SPS PDSCH reception.

[0206] (Example 6-3) It must be set to a predetermined value (for example, enable).

[0207] (Example 6-4) The release (deactivation) of the Multicast SPS PDSCH is the same as the enable / disable of HARQ feedback related to the corresponding SPS PDSCH activation.

[0208] In addition, the DCI may be a Group-common release (deactivation) DCI or a UE-specific release (deactivation) DCI.

[0209] According to this operation example, it is possible to clearly instruct the UE 200 to perform HARQ feedback operation for release (deactivation) of the Multicast SPS PDSCH. In addition, when the enable is always set, the gNB 100 can always know whether the PDSCH activation is successful or not, and therefore, communication quality can be improved. On the other hand, when the enable / disable is determined according to conditions, it is possible to realize appropriate feedback according to the situation.

[0210] (3.7) Example 7 In this operation example, ACK / NACK feedback or NACK-only feedback may be specified in addition to specifying HARQ feedback enable / disable.

[0211] Specifically, the designation may be performed according to any one of the operation examples 1 to 6.

[0212] (3.8) Example of changes The above-described operation examples may be combined and applied in a composite manner as long as no contradiction occurs. Also, as described above, a term indicating a time domain such as a slot may be replaced with a term indicating another time domain such as a subslot.

[0213] The above-described operational example relates to an MBS targeted for simultaneous transmission (distribution) to multiple UEs, however, the UEs targeted by the MBS do not necessarily always have to be multiple, and as long as operation in accordance with the MBS is performed, such as using a group-common PDSCH, multiple specific or unspecified UEs may include cases where there is essentially one UE, and do not have to be multiple UEs.

[0214] (4) Actions and Effects According to the above-described embodiment, the following advantageous effects can be obtained. Specifically, according to the UE 200 according to the operation examples 1 to 7, it is possible to efficiently enable / disable HARQ feedback for a downlink channel related to an MBS, specifically, for a group-common PDSCH or the like.

[0215] This allows UE 200 to quickly and reliably know when to enable and / or disable HARQ feedback.

[0216] In this embodiment, the UE 200 may at least enable / disable the HARQ feedback in the downlink channel based on a specific field included in the DCI, for example, a PUCCH resource indicator (PRI) field. Therefore, it is possible to reliably realize the enable / disable of the HARQ feedback while using the existing DCI.

[0217] In this embodiment, the UE 200 may recognize that enable / disable of the HARQ feedback by DCI is specified by signaling of a higher layer (for example, RRC), etc. Therefore, it is possible to flexibly and reliably realize enable / disable of the HARQ feedback.

[0218] In this embodiment, the UE 200 may at least enable / disable the HARQ feedback in the downlink channel based on at least one of the format, the identification information, the resource, and the search space related to the DCI. Therefore, it is possible to realize the enable / disable of the HARQ feedback more flexibly and reliably.

[0219] In this embodiment, in data distribution (MBS) for multiple UEs 200, the enablement or disablement of HARQ feedback in the downlink channel may be specified based on a field related to priority included in DCI. Therefore, the UE 200 can determine the presence or absence of appropriate HARQ feedback according to the priority.

[0220] In this embodiment, when semi-static scheduling (SPS) is applied to the downlink data channel (PDSCH), it may be assumed that an instruction to enable or disable HARQ feedback by DCI via a downlink control channel (group-common PDCCH) common to a terminal group is applied to the reception of the PDSCH immediately after the DCI and the reception of the subsequent PDSCH. Therefore, it is easy to set a configuration in which HARQ feedback is requested for highly reliable periodic transmission and HARQ feedback is not requested for unreliable transmission.

[0221] In this embodiment, when semi-static scheduling (SPS) is applied to the downlink data channel (PDSCH), it may be assumed that the instruction to enable or disable HARQ feedback by DCI via a downlink control channel (group-common PDCCH) common to a terminal group is applied to the reception of the subsequent PDSCH except for the PDSCH immediately after the DCI. Therefore, the gNB 100 can always grasp the success or failure of PDSCH activation, thereby improving communication quality.

[0222] In this embodiment, when releasing a downlink data channel (PDSCH) to which semi-static scheduling (SPS) is applied, it may be determined whether the HARQ feedback applied at the time of releasing the PDSCH is enabled or disabled based on the enablement or disablement of the HARQ feedback applied at the time of receiving the PDSCH. Therefore, it is possible to clearly instruct the UE 200 to perform the HARQ feedback operation for the release (deactivation) of the Multicast SPS PDSCH.

[0223] (5) Other embodiments Although the embodiment has been described above, it will be apparent to those skilled in the art that the present invention is not limited to the description of the embodiment and that various modifications and improvements are possible.

[0224] For example, in the above-described embodiment, the names PDCCH and PDSCH are used as downlink channels, but the downlink control channel or the downlink data channel (which may be a shared channel) may be called by another name.

[0225] Also, in the above description, configure, activate, update, indicate, enable, specify, and select may be interchanged. Similarly, link, associate, correspond, and map may be interchanged, and allocate, assign, monitor, and map may be interchanged.

[0226] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be read as interchangeable terms. Similarly, common, shared, group-common, UE-common, and UE-shared may be read as interchangeable terms.

[0227] Moreover, the block configuration diagram (FIG. 4) used in the description of the above-mentioned embodiment shows functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device that is physically or logically combined, or may be realized by using two or more devices that are physically or logically separated and directly or indirectly connected (for example, by using wires, wirelessly, etc.). The functional block may be realized by combining the one device or the multiple devices with software.

[0228] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs the function of transmission is called a transmitting unit or a transmitter. As described above, there is no particular limitation on the method of realization of any of these.

[0229] Furthermore, the above-mentioned gNB 100 and UE 200 may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 11 is a diagram showing an example of a hardware configuration of the device. As shown in Fig. 11, the device may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

[0230] In the following description, the term "apparatus" may be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the apparatus may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0231] Each functional block of the device (see FIG. 4) is realized by any hardware element of the computer device, or a combination of the hardware elements.

[0232] In addition, each function in the device is realized by loading a specific software (program) onto hardware such as the processor 1001 and memory 1002, causing the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of the reading and writing of data in the memory 1002 and storage 1003.

[0233] The processor 1001 controls the entire computer by running, for example, an operating system, and may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, a register, and the like.

[0234] Furthermore, the processor 1001 reads out programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the programs, programs that cause a computer to execute at least a part of the operations described in the above-mentioned embodiments are used. Furthermore, the above-mentioned various processes may be executed by one processor 1001, or may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0235] The memory 1002 is a computer-readable recording medium, and may be configured by at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), etc. The memory 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The memory 1002 can store a program (program code), a software module, etc., capable of executing a method according to an embodiment of the present disclosure.

[0236] Storage 1003 is a computer-readable recording medium, and may be composed of at least one of, for example, an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, and the like. Storage 1003 may be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0237] The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, or a communication module.

[0238] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0239] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0240] In addition, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0241] Furthermore, the device may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc., and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0242] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination of these. Furthermore, the RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0243] Each aspect / embodiment described in the present disclosure may be applied to at least one of a system using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), other suitable systems, and next-generation systems extended based on these. In addition, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) may be applied.

[0244] The order of the steps, sequences, flow charts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0245] In the present disclosure, a specific operation performed by a base station may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal may be performed by at least one of the base station and other network nodes other than the base station (e.g., MME or S-GW, etc., but are not limited to these). Although the above example illustrates a case in which there is one other network node other than the base station, it may also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0246] Information, signals (information, etc.) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), and may be input and output via multiple network nodes.

[0247] The input / output information may be stored in a specific location (e.g., memory) or may be managed using a management table. The input / output information may be overwritten, updated, or appended. The output information may be deleted. The input information may be transmitted to another device.

[0248] The determination may be based on a value represented by a single bit (0 or 1), a Boolean (true or false) value, or a numerical comparison (e.g., comparison with a predetermined value).

[0249] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to execution. In addition, notification of specific information (e.g., notification that "X is the case") is not limited to being done explicitly, but may be done implicitly (e.g., not notifying the specific information).

[0250] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0251] Additionally, software, instructions, information, etc. may be transmitted or received over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired and / or wireless technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave, etc.), then these wired and / or wireless technologies are included within the definition of transmission media.

[0252] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0253] In addition, the terms described in this disclosure and the terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0254] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0255] In addition, the information, parameters, etc. described in the present disclosure may be represented using absolute values, may be represented using relative values ​​from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by an index.

[0256] The names used for the above-mentioned parameters are not limiting in any way. Furthermore, the formulas using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not limiting in any way.

[0257] In this disclosure, terms such as "base station (BS)", "radio base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as a macro cell, a small cell, a femto cell, a pico cell, etc.

[0258] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0259] The term "cell" or "sector" refers to part or all of the coverage area of ​​a base station and / or a base station subsystem that provides communication services within that coverage.

[0260] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0261] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0262] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may include a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0263] Furthermore, a base station in the present disclosure may be read as a mobile station (user terminal, the same applies below). For example, each aspect / embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the mobile station may be configured to have the functions of a base station. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel (or side link).

[0264] Similarly, a mobile station in the present disclosure may be interpreted as a base station, in which case the base station may have the functions of a mobile station. A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0265] Numerology may be a communication parameter that applies to the transmission and / or reception of a signal or channel, and may indicate, for example, at least one of a SubCarrier Spacing (SCS), a bandwidth, a symbol length, a Cyclic Prefix length, a Transmission Time Interval (TTI), a number of symbols per TTI, a radio frame structure, a particular filtering operation that the transceiver performs in the frequency domain, a particular windowing operation that the transceiver performs in the time domain, etc.

[0266] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) A slot may be a numerology-based unit of time.

[0267] A slot may include multiple minislots. Each minislot may be composed of one or more symbols in the time domain. A minislot may also be called a subslot. A minislot may be composed of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0268] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. The radio frame, the subframe, the slot, the minislot, and the symbol may each be referred to by a different name.

[0269] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0270] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0271] The TTI may be a transmission time unit of a channel-coded data packet (transport block), a code block, a code word, etc., or may be a processing unit of scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) in which a transport block block, a code word, etc. are actually mapped may be shorter than the TTI.

[0272] In addition, when one slot or one minislot is called TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

[0273] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a slot, etc.

[0274] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0275] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0276] In addition, the time domain of the RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each of one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0277] One or more RBs may be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0278] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0279] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a numerology on a carrier, where the common RBs may be identified by the index of the RBs relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0280] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0281] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell", "carrier", etc. in this disclosure may be replaced with "BWP".

[0282] The above-mentioned structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0283] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0284] The reference signal may also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

[0285] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0286] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0287] Any reference to an element using a designation such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way.

[0288] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term "comprising." Further, as used in this disclosure, the term "or" is not intended to be an exclusive or.

[0289] In this disclosure, where articles have been added due to translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0290] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in a memory), and the like. In addition, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to be a "judgment" or "decision." In other words, "judgment" and "decision" can include considering some action to be a "judgment" or "decision." In addition, "judgment" can be interpreted as "assuming," "expecting," "considering," etc.

[0291] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0292] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0293] 10. Wireless communication systems 20 NG-RAN 100 gNB 200UE 210 Radio signal transmitter / receiver 220 Amplifier section 230 Modulation and demodulation section 240 Control signal / reference signal processing unit 250 Encoding / Decoding Unit 260 Data transmission and reception unit 270 Control Unit 1001 Processor 1002 Memory 1003 Storage 1004 Communication equipment 1005 Input Device 1006 Output device 1007 Bus

Claims

1. In data distribution to a plurality of terminals, a receiving unit for receiving a downlink data channel common to a terminal group that is semi-fixedly scheduled; a control unit that controls feedback for reception of the downlink data channel based on an instruction to enable or disable feedback for reception of the downlink data channel included in downlink control information of a downlink control channel; A terminal comprising:

2. The terminal described in claim 1, wherein the control unit determines whether to apply an instruction to enable or disable feedback for reception of the downlink data channel contained in the downlink control information based on signaling from an upper layer.

3. The terminal described in claim 1, wherein the control unit enables application of feedback to the release of semi-fixed scheduling of the downlink data channel.

4. In data distribution to a plurality of terminals, a step of receiving a downlink data channel common to a terminal group that is semi-fixedly scheduled; A step of controlling feedback for reception of the downlink data channel based on an instruction for enabling or disabling feedback for reception of the downlink data channel, the instruction being included in downlink control information of a downlink control channel. A communication method for a terminal including:

5. In data distribution to a plurality of terminals, a transmitter that transmits a common downlink data channel to a terminal group that is semi-fixedly scheduled; A control unit that includes an instruction for enabling or disabling feedback for reception of the downlink data channel in downlink control information of the downlink control channel. A base station comprising:

6. A communication system including a base station and a plurality of terminals, The base station, A transmitter that transmits a common downlink data channel to a terminal group that is semi-fixedly scheduled in data distribution to a plurality of terminals; A control unit that includes an instruction to enable or disable feedback for reception of the downlink data channel in downlink control information of a downlink control channel, The terminal includes: A receiving unit for receiving the downlink data channel; a control unit that controls feedback for reception of the downlink data channel based on the instruction Communication systems.

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