Terminal and wireless communication method

Abstract

A terminal according to the present invention transmits feedback for automatic repeat request. In this terminal, a bit string of the feedback and a resource of an uplink control channel are associated with each other, and if feedback is provided for only a negative response, only an index of one cyclic shift is applied to one resource.

Description

[Technical Field]

[0001] The present disclosure relates to a terminal and a wireless communication method that support 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 specified or unspecified terminals (User Equipment, UE) (Non-Patent Document 1).

[0004] In MBS, for example, studies are underway on scheduling of UE groups that are the subject of services and improving reliability (for example, feedback of HARQ (Hybrid Automatic Repeat Request) 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] Even in the HARQ of MBS, it is assumed that a method of feeding back only NACK (NACK-only feedback) will be applied.

[0007] However, in the case of MBS, the configuration (multiplexing) method of NACK-only feedback may differ for each UE, which causes a problem that the network (gNB) cannot recognize the number of feedback bits, and blind decoding (BD) is required.

[0008] The following disclosure has been made in light of the above circumstances, and aims to provide a terminal and a wireless communication method that can achieve efficient NACK-only feedback in MBS.

[0009] One aspect of the present disclosure is a terminal (UE200) including a transmitter (data transmitter / receiver 260) that transmits feedback of an automatic repeat request, and a control unit (control unit 270) that associates a bit string of the feedback with a resource of an uplink control channel and applies only one cyclic shift index to one of the resources when only a negative acknowledgement is fed back.

[0010] One aspect of the present disclosure is a terminal (UE200) including a transmitter (data transmitter / receiver 260) that transmits feedback of an automatic repeat request, and a controller (controller 270) that associates a bit string of the feedback with a resource of an uplink control channel and applies binary phase shift keying to one of the resources when only a negative acknowledgement is fed back.

[0011] One aspect of the present disclosure is a terminal (UE200) including a transmitter (data transmitter / receiver 260) that transmits feedback of an automatic repeat request, and a control unit (control unit 270) that assumes that the bit string of the feedback corresponds to a resource of an uplink control channel, and that when only a negative response is fed back, the index of the resource indicates the correspondence between the bit string of the feedback and the resource.

[0012] One aspect of the present disclosure is a terminal (UE200) having a transmitter (data transmitter / receiver 260) that transmits feedback of an automatic repeat request, and a control unit (control unit 270) that assumes that when the bit string of the feedback is bundled and only a negative acknowledgement is fed back, there is only one set of resources for the uplink control channel.

[0013] One aspect of the present disclosure is a terminal (UE200) that includes a transmitter (data transmitter / receiver 260) that transmits feedback of an automatic repeat request, and a control unit (control unit 270) that applies multiple cyclic shift indexes to a single uplink control channel resource when multiple bits are multiplexed in feedback of only a negative acknowledgement using a specific uplink control channel format.

[0014] One aspect of the present disclosure is a wireless communication method including the steps of: transmitting feedback of an automatic repeat request; and, in a case where a bit string of the feedback corresponds to a resource of an uplink control channel and only a negative acknowledgement is fed back, applying only one cyclic shift index to one of the resources. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the overall schematic configuration of a wireless communication system 10. As shown in FIG. [Figure 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. [Figure 3]FIG. 3 is a diagram showing an example of the configuration of PTM transmission method 1 and PTM transmission method 2. In FIG. [Figure 4] Figure 4 is a functional block diagram of gNB100 and UE200. [Figure 5] FIG. 5 is a diagram showing an example of a sequence of PDCCH, PDSCH and HARQ feedback in MBS. [Figure 6] FIG. 6 is a diagram illustrating an example of determining a PUCCH resource according to Scheme A. In FIG. [Figure 7] FIG. 7 is a diagram illustrating an example of transmission of sequence-based uplink control information (UCI) applicable to PUCCH format 0 (PF 0). [Figure 8] FIG. 8 is a diagram showing an example of allocation of HARQ-ACK and scheduling requests (Positive SR, Negative SR). [Figure 9] FIG. 9 is a diagram showing an example of BPSK signal points according to operation example 2-2b. [Figure 10] FIG. 10 is a diagram illustrating an example of the configuration of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 3-1. [Figure 11] FIG. 11 is a diagram showing a configuration example (part 1) of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 3-2. [Figure 12] FIG. 12 is a diagram showing a configuration example (part 2) of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 3-2. [Figure 13] FIG. 13 is a diagram illustrating an example of determining a PUCCH resource set related to NACK-only feedback and ACK / NACK feedback according to operation example 3-4. [Figure 14] FIG. 14 is a diagram illustrating an example of a PUCCH resource set according to operation example 3-6. [Figure 15]FIG. 15 is a diagram showing an example of signal points on an IQ plane according to Operation Example 5-1. [Figure 16] FIG. 16 is a diagram showing an example of the configuration of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 5-1. [Figure 17] FIG. 17 is a diagram showing an example of the hardware configuration of gNB100 and UE200. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments 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 descriptions thereof will be omitted as appropriate.

[0017] (1) Overall configuration of the wireless communication system (1.1) System configuration example 1 is a schematic diagram of the overall configuration of a wireless communication system 10 according to this 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 system 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 multiple 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 also be simply referred to as a "network."

[0021] The gNB 100 is a radio base station that complies with NR and performs NR-compliant radio communication with the UE 200. The gNB 100 and the UE 200 are capable of supporting Massive MIMO, which generates a more directional beam (BM) by controlling radio signals transmitted from multiple antenna elements, Carrier Aggregation (CA), which aggregates and uses multiple component carriers (CCs), and Dual Connectivity (DC), which simultaneously communicates between the UE and 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: 410 MHz to 7.125 GHz FR2: 24.25 GHz~52.6 GHz 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 (including 240 kHz) 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] Alternatively, 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 a radio frame, a subframe, and a slot used in the radio communication system 10. In FIG.

[0027] As shown in Figure 2, one slot consists of 14 symbols, and the larger (wider) the SCS, the shorter the symbol period (and slot period). Note that the number of symbols constituting one slot does not necessarily have to be 14 symbols (e.g., 28 or 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 or 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, or 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 The wireless communication system 10 may provide multicast and broadcast services (MBS).

[0030] For example, in a stadium or a hall, it is assumed that a large number of UEs 200 are located within a certain geographical area and receive the same data simultaneously. 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, in which a specific UE 200 is designated (identification information unique to the UE 200 may be designated).

[0032] Multicast may be interpreted as one-to-many (specified many) communication with a network, 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 between the network and all UEs 200. The multicast / broadcast data may be identical copies of the data, but some parts of the data, such as the header, may be different. The multicast / broadcast data may be transmitted (distributed) simultaneously, but strict simultaneity is not necessarily required, and propagation delays and / or processing delays within the RAN node may be included.

[0034] The target UE 200 may be in a radio resource control (RRC) layer 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 methods are assumed for scheduling multicast / broadcast PDSCH (Physical Downlink Shared Channel), specifically, scheduling MBS packets (which may be read as data). Note that RRC connected UE may also be read as RRC idle UE or RRC inactive UE.

[0036] ·PTM transmission method 1 (PTM-1): · For the MBS group of RRC connected UEs, 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 a Radio Network Temporary Identifier, G-RNTI).

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

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

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

[0041] ·PTP transmission method: For RRC connected UEs, UE-specific PDSCH is scheduled 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] Figure 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, and they may be called by different names as long as the above-mentioned operations are performed.

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

[0045] Furthermore, 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: Feedback both ACK and NACK (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 configuration: PUCCH-Config can be configured 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 can be applied 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) Note that ACK may be called a positive acknowledgement, and NACK may be called a negative acknowledgement. HARQ may be called an automatic repeat request.

[0047] To enable or disable option 1 or option 2, one of the following may be applied:

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

[0049] -SPS group-common PDSCH (also called group common SPS PDSCH) is used Multiple SPS group-common PDSCHs can be configured as UE capabilities. HARQ feedback for SPS group-common PDSCH is possible Activation / deactivation is possible via at least the group-common PDCCH (downlink control channel) Note that deactivation may be interpreted as another synonymous term such as release. For example, activation may be interpreted as start, start, trigger, etc., and deactivation may be interpreted as end, stop, etc.

[0050] SPS is a scheduling method used in contrast to dynamic scheduling, and may also be called semi-fixed, semi-persistent, or semi-persistent scheduling, and may also 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 in which 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 in which PDSCH transmissions are scheduled by higher layer signaling, such as RRC messages.

[0052] Note that multicast SPS PDSCH reception may refer to group common SPS PDSCH reception, may be an SPS PDSCH received by multiple terminals, or may be 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.

[0053] For the physical layer, there may be scheduling categories of time domain scheduling and frequency domain scheduling.

[0054] Furthermore, multicast, groupcast, broadcast, and MBS may be interchangeable. Multicast PDSCH and PDSCH scrambled with a group-common RNTI may be interchangeable.

[0055] Furthermore, the terms data and packet may be read interchangeably and may be interpreted as synonymous with terms such as signal, data unit, etc. Also, send, receive, transmit, and deliver may be read interchangeably.

[0056] (2) Functional block configuration of wireless communication system Next, a description will be given of the functional block configuration of the wireless communication system 10. Specifically, the functional block configurations of the gNB 100 and the UE 200 will be described.

[0057] 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.

[0058] It should be noted that Fig. 4 shows only the main functional blocks relevant to the description of the embodiment, and that 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. 17.

[0059] The radio signal transmitting / receiving unit 210 transmits and receives radio signals conforming to NR. The radio signal transmitting / receiving unit 210 supports Massive MIMO, CA that uses a bundle of multiple CCs, and DC that simultaneously communicates between a UE and two NG-RAN nodes.

[0060] 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 multiple UEs 200.

[0061] Furthermore, the radio signal transmitting and receiving unit 210 can receive a downlink data channel (PDSCH) in MBS, that is, data distribution to multiple terminals.

[0062] Specifically, the radio signal transmitting and receiving unit 210 can receive a group-common PDSCH (which may include an SPS group-common PDSCH), which is a downlink data channel (PDSCH) common to a terminal group.

[0063] Furthermore, the radio signal transmitting and receiving unit 210 can receive a downlink control channel common to a terminal group, specifically a group-common PDCCH, and can receive a downlink control channel specific to a terminal, specifically a UE-specific PDCCH.

[0064] 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 modulation / demodulation unit 230 to a predetermined power level. The amplifier unit 220 also amplifies the RF signal output from the radio signal transmission / reception unit 210.

[0065] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication destination (e.g., 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 uplink (UL) but also for downlink (DL).

[0066] The control signal / reference signal processor 240 performs 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 .

[0067] Specifically, the control signal / reference signal processor 240 receives various control signals, such as control signals (messages) of the radio resource control layer (RRC), transmitted from the gNB 100 via a predetermined control channel. The control signal / reference signal processor 240 also transmits various control signals to the gNB 100 via a predetermined control channel.

[0068] The control signal / reference signal processor 240 performs processing using reference signals (RS) such as a Demodulation Reference Signal (DMRS) and a Phase Tracking Reference Signal (PTRS).

[0069] DMRS is a reference signal (pilot signal) known between the base station and the terminal for estimating the 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.

[0070] 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.

[0071] The channels include a control channel and a data channel. The control channels may include a PDCCH, a PUCCH (Physical Uplink Control Channel), a RACH (Random Access Channel, Downlink Control Information (DCI) including a Random Access Radio Network Temporary Identifier (RA-RNTI)), a Physical Broadcast Channel (PBCH), etc.

[0072] Furthermore, the data channel includes a PDSCH, a PUSCH (Physical Uplink Shared Channel), etc. Data may refer to data transmitted via a data channel.

[0073] In this embodiment, the control signal and reference signal processor 240 may configure a receiver that receives downlink control information (DCI). Also, the control signal and reference signal processor 240 may receive, in RRC, a message indicating the enabling or disabling of a function instructed by DCI to enable or disable HARQ feedback.

[0074] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding for each predetermined communication destination (gNB100 or another gNB).

[0075] 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, decodes the data output from the modem unit 230, and concatenates the decoded data.

[0076] The data transceiver 260 transmits and receives Protocol Data Units (PDUs) and Service Data Units (SDUs). Specifically, the data transceiver 260 assembles and disassembles PDUs and SDUs at multiple layers (such as a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer).

[0077] Furthermore, the data transmitter / receiver 260 performs data error correction and retransmission control based on Hybrid Automatic Repeat Request (HARQ). Specifically, the data transmitter / receiver 260 can transmit HARQ (Automatic Repeat Request) feedback. In this embodiment, the data transmitter / receiver 260 may constitute a transmitter.

[0078] As described above, HARQ feedback may include ACK (acknowledgement) and NACK (negative acknowledgement), and a scheme in which only NACK is fed back (returned) and ACK is not fed back (NACK-only feedback) may be applied.

[0079] 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 downlink channels for MBSs and HARQ feedback of the channels.

[0080] 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 the MBS, that is, data delivery 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.

[0081] Control unit 270 may assume that, for the SPS group-common PDSCH, activation / deactivation of SPS, that is, semi-static scheduling, of the downlink data channel (PDSCH) for the terminal group is applied on a terminal group basis.

[0082] In addition, when applying NACK-only feedback, that is, when feeding back only HARQ NACK (Negative Acknowledgement), the control unit 270 may apply only one cyclic shift (CS) index to one resource of the PUCCH (Uplink Control Channel).

[0083] Note that application of such a cyclic shift index may be limited to a case where a bit string of HARQ feedback (which may be called a codebook) and a PUCCH resource are associated (referred to as Scheme A). Alternatively, this may be expressed as a case where NACK-only feedback is performed using PUCCH format (PF) 0 in Scheme A. Note that the bit string of HARQ feedback may be a bit string including ACK, or may be replaced with a bit string corresponding to PDSCH reception.

[0084] PF 0 is called a short format, and the number of symbols may be 1 or 2. Furthermore, application of such a cyclic shift index may be applied to both the case where 1-bit feedback is transmitted and the case where multiple bits are multiplexed and transmitted.

[0085] Furthermore, as described above, when the feedback bit string and the PUCCH resource are associated and only NACK is fed back, the control unit 270 may apply binary phase shift keying (BPSK) to one PUCCH resource. Note that in this case, only BPSK is used, and other phase shift keying, specifically, quadrature phase shift keying (QPSK), may not be used.

[0086] Alternatively, as described above, the control unit 270 may assume that the feedback bit string and the PUCCH resource are associated, and when only NACK is fed back, the PUCCH resource index indicates the correspondence between the HARQ feedback bit string and the PUCCH resource.

[0087] Specifically, control unit 270 may assume that the value of the PUCCH resource index is associated with a specific table, and that the table associates HARQ-ACK bit values ​​with PUCCH resources. An example of the configuration of the table will be described later.

[0088] Furthermore, when the HARQ feedback bit string is bundled and only NACK is fed back, the control unit 270 may assume that there is only one set of PUCCH resources. When the HARQ feedback bit string is bundled, this may be called Scheme C for convenience. In Scheme C, the HARQ feedback bit string may be bundled (aggregated) and aggregated into one bit. Specifically, in Scheme C, if there is at least one NACK in one or more HARQ feedback bit strings, the one bit representing the NACK may be transmitted. Note that Scheme B may refer to HARQ feedback that is not subjected to any particular processing such as multiplexing (Schemes A to C will be described further below).

[0089] Furthermore, when multiplexing multiple bits in feedback of only NACK using a specific PUCCH format, control section 270 may apply multiple cyclic shift indexes to one PUCCH resource.

[0090] Specifically, when multiplexing multiple bits for NACK-only feedback using PUCCH format 0 (PF 0), control unit 270 may use multiple cyclic shift indexes for one PUCCH resource.

[0091] For example, a plurality of cyclic shift indexes may be associated with a specific PUCCH resource, and which cyclic shift index to use may be determined depending on whether PDSCH decoding is successful. Alternatively, some of the plurality of bits may be represented by selecting a cyclic shift index, and the remaining may be represented by the PUCCH resource. Specific examples of such operations will be described later.

[0092] In addition, gNB100 can perform the above-mentioned downlink channel scheduling and control related to HARQ.

[0093] (3) Operation of the 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 relating to scheduling of a downlink channel for MBS and HARQ feedback of that channel.

[0094] 5 shows an example of a sequence of PDCCH, PDSCH, and HARQ feedback in MBS. As shown in FIG. 5, PDCCH (which may include DCI) and PDSCH may be transmitted by unicast or multicast (broadcast). UE 200 may also transmit HARQ feedback (ACK / NACK) for the channel (transport block (TB) received via the channel).

[0095] 5, it appears that both a unicast PDSCH and a multicast PDSCH are transmitted after one PDCCH / DCI, but either a unicast PDSCH or a multicast PDSCH may be transmitted after one PDCCH / DCI. In other words, one PDCCH / DCI may schedule either a unicast PDSCH or a multicast PDSCH.

[0096] Furthermore, as shown in FIG. 5, in HARQ feedback, NACK-only feedback may be applied as described above, and feedback information (which may be a bit string) may be multiplexed in the NACK-only feedback.

[0097] In the case of MBS, if the NACK-only feedback function is applied as is, there is a problem that the gNB100 cannot recognize the number of bits related to the NACK-only feedback, and blind decoding is required.

[0098] Therefore, the following multiplexing method may be considered for NACK-only feedback.

[0099] (Scheme A): The value of the HARQ-ACK codebook (bit string) is associated with the PUCCH resource.

[0100] (Scheme B): No duplication (Scheme C): Apply bundling and make it 1 bit.

[0101] The multiplexing method is not necessarily limited to Schemes A to C. Fig. 6 shows an example of determining PUCCH resources according to Scheme A. As shown in Fig. 6, values ​​of an HARQ codebook (bit string) are associated with PUCCH resources (which may be a combination of time and frequency directions).

[0102] For example, if the HARQ feedback for three PDSCH receptions is NACK, -, NACK(010), Resource 2 is used. Also, in Scheme C, as described above, feedback may be sent if there is a NACK. Note that '-' may mean that the corresponding PDSCH was successfully decoded.

[0103] FIG. 7 shows an example of transmission of sequence-based uplink control information (UCI) applicable to PUCCH format 0 (PF 0). As shown in FIG. 7, a base sequence (X0, ...X n ,…, X 11 ) are subjected to a cyclic shift. The initial cyclic shift m0 may be set by RRC. FIG. 7 shows an example where m0 = 1. Note that A in FIG. 7 may include m0. FIG. 7 also shows ACK / NACK feedback, and the cyclic shift is determined based on the decoding result of the corresponding PDSCH.

[0104] 8 shows an example of allocation of HARQ-ACK and scheduling requests (Positive SR, Negative SR). As shown in FIG. 8, UCI may include scheduling requests (Positive SR, Negative SR) in addition to HARQ feedback, and PUCCH resources to be used may differ depending on whether the request is positive or negative.

[0105] (3.1) Example 1 In this operation example, when NACK-only feedback is performed using PUCCH format 0 (PF 0) in the above-mentioned Scheme A, only one cyclic shift index may be used per PUCCH resource, regardless of whether one bit is transmitted or multiple bits are multiplexed.

[0106] Specifically, the UE 200 may operate according to any one of the operation examples 1-1 to 1-3.

[0107] (Example 1-1): Always m_CS(m CS (The same applies below) = Use X a_X shown in Fig. 7 may be determined by m_0 + m_CS. X may be determined according to the 3GPP specifications, or may be X = 0. In addition, a_X may be limited to the case where it is not multiplexed with 1-bit Positive SR.

[0108] (Operation example 1-2): Assume that multiplexing with 1-bit Positive SR is not performed (there is no overlap in at least one of the time domain and frequency domain). (Example 1-3): When multiplexed with 1-bit Positive SR, use m_CS = Y. Y may be determined by the 3GPP specifications, or may be set to 1. Y may be different (orthogonal) for each user (UE 200), or may be set in advance.

[0109] According to this operation example, multiple bits of NACK-only feedback information can be transmitted using PUCCH format 0 (PF 0).

[0110] (3.2) Example 2 In this operation example, when NACK-only feedback is performed using PUCCH format 1 (PF 1) in the above-mentioned Scheme A, in both cases of transmitting one bit and multiple bits, only BPSK (the signal point corresponding to NACK) may be used per PUCCH resource.

[0111] In other words, in this operation example, QPSK does not have to be used. Note that the signal points (see FIG. 7) may be signal points on the IQ plane corresponding to NACK of BPSK, but are not limited to such signal points. For example, a π / 2-BPSK signal point may be used. Also, PF1 is called a long format, and the number of symbols may be 4 to 14.

[0112] Specifically, the UE 200 may operate according to operation example 2-1 or 2-2.

[0113] (Example 2-1): Assume that multiplexing with 1-bit Positive SR is not performed. (Example 2-2): When multiplexed with 1-bit Positive SR, NACK is sent using the SR resource. (Example 2-2a): Works as ACK / NACK feedback instead of NACK-only feedback (Operation example 2-2b): Different signal points are used for Positive SR + NACK transmission and Positive SR only transmission (i.e., successful PDSCH decoding). Fig. 9 shows an example of BPSK constellation points according to operation example 2-2b. As shown in Fig. 9, in the case of Positive SR + NACK, it may be "-1", and in the case of only Positive SR, it may be "+1".

[0114] According to this operation example, multiple bits of NACK-only feedback can be transmitted using PUCCH format 1 (PF 1).

[0115] (3.3) Example 3 In this operation example, each PUCCH resource index may be associated with a table / list (multiple resources) in which HARQ-ACK bits and PUCCH resources are linked in Scheme A. Note that the HARQ feedback method for each PUCCH resource may be operation example 1, 2, or 5.

[0116] Specifically, the UE 200 may operate according to any one of the operation examples 3-1 to 3-6.

[0117] (Operation Example 3-1): A certain PUCCH resource set (i.e., a specific PUCCH resource set) is defined as a set that can be multiplexed up to a maximum of N bits (the number of bits including ACK), and the corresponding table includes a maximum of (2^N-1) PUCCH resources. FIG. 10 shows an example of the configuration of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 3-1.

[0118] The PUCCH resource index may be specified by, for example, DCI. Fig. 10 shows an example where N = 5. As shown in Fig. 10, when PUCCH resource index = 010, Table 2 may be associated. In Table 2, 5 HARQ-ACK bits may be associated with PUCCH resources (see Fig. 6).

[0119] Furthermore, when N bits can be transmitted and M<N bits are multiplexed, the most significant or least significant (NM) bits of the HARQ-ACK bit sequence corresponding to each PUCCH resource may be "1", i.e., not a NACK (equivalent to an ACK). For example, when M=4, only a bit sequence of 1**** may be used.

[0120] (Operation example 3-2): Multiple PUCCH resource sets are configured, and N is different for each set. Fig. 11 shows a configuration example (part 1) of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 3-2. Fig. 12 shows a configuration example (part 2) of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 3-2.

[0121] For example, four PUCCH resource sets: sets 0, 1, 2, and 3 may be configured, and up to N0, N1, N2, and N3 bits may be multiplexed, respectively.

[0122] Furthermore, when transmitting M HARQ-ACK bits (bits including ACK), the set to be used may be determined based on the relationship between M and N0, N1, N2, and N3. For example, it may be determined as follows:

[0123] If M <= N0, set 0 If N0 < M <= N1, set 1 If N1 < M <= N2, set 2 If N2 < M <= N3, set 3 Furthermore, N0, N1, N2, and N3 may be different from the values ​​used for ACK / NACK feedback and may be set in advance. Figures 11 and 12 show an example where N0 = 2 and N1 = 5. Note that the method for determining the PUCCH resource in each PUCCH resource set may follow Operation Example 3-1.

[0124] (Operation example 3-3): Only a single PUCCH resource set is configured For example, regardless of the number of HARQ-ACK bits (number of bits including ACK), operation example 3-1 may be applied.

[0125] (Operation Example 3-4): UE 200 determines and transmits a PUCCH resource from among the PUCCH resources included in the table / list specified by the PUCCH resource indicator among the PUCCH resource sets to be used, based on whether PDSCH decoding is successful, or does not transmit HARQ-ACK if all PDSCH decoding is successful. 13 shows an example of determining a PUCCH resource set related to NACK-only feedback and ACK / NACK feedback according to operation example 3-4. Operation example 3-4 may be combined with other operation examples.

[0126] Note that the PUCCH resource set in this operation example may be a set for NACK-only feedback, or may be common to a set for ACK / NACK feedback. Note that Figures 10 to 13 may be interpreted as examples in which a set for NACK-only feedback is set separately from a set for ACK / NACK feedback.

[0127] (Operation example 3-5): For parts where it is possible to recognize that PDCCH / PDSCH has not been received by the Downlink Assignment Index (DAI), a bit is generated as NACK even in multiplexing of NACK-only feedback. (Operation Example 3-6): If the number of multiplexed bits (which may be replaced with the number of bits including ACK, or the number corresponding to PDSCH reception) exceeds the maximum number of bits of the PUCCH resource set set according to Operation Example 3-1 / 3-2, UE200 may operate according to one of the following:

[0128] (i): The UE 200 does not consider this case. (ii): The UE 200 drops at least some bits. For example, bits with low priority or bits corresponding to PDSCHs scheduled forward / backward in time may be dropped, or up to a maximum number of bits may be dropped.

[0129] (iii): The UE 200 bundles at least some (some) bits. For example, bits with low priority or bits corresponding to PDSCHs scheduled forward / backward in time may be bundled, or up to the maximum number of bits may be bundled.

[0130] Figure 14 shows an example of a PUCCH resource set according to operation example 3 to 6. In this operation example, a certain PUCCH resource set may be defined as one table / list as shown in Figure 14, and the PUCCH resource may be determined by the HARQ-ACK bit, regardless of the PUCCH resource indicator.

[0131] According to this operation example, a configuration based on the configuration of existing parameters related to the configuration of PUCCH resources can be achieved, and signaling can be simplified.

[0132] (3.4) Example 4 In this operation example, in Scheme C, only one PUCCH resource set for NACK-only feedback may be configured.

[0133] Specifically, the UE 200 may operate according to any one of the operation examples 4-1 to 4-4.

[0134] (Operation example 4-1): Only PUCCH format 0 (PF 0) or PUCCH format 1 (PF 1) is associated (Operation Example 4-2): Even when HARQ-ACK bits for multiple PDCCH / PDSCH receptions are bundled, the number of HARQ-ACK bits to be transmitted is 1 bit, and the corresponding PUCCH resource set is used. (Operation example 4-3): For the part where it is possible to recognize that PDCCH / PDSCH has not been received by DAI, perform bundling as a NACK (i.e., as a failure to decode PDCCH / PDSCH). (Operation Example 4-4): It is not assumed that HARQ-ACK bundling will be performed for PDCCH / PDSCH receptions exceeding a predetermined number. According to this operation example, multiple bits of NACK-only feedback can be transmitted together, which simplifies the setting of PUCCH resources.

[0135] (3.5) Example 5 In this operation example, when multiple bits are multiplexed for NACK-only feedback using PUCCH format 0 (PF 0), multiple cyclic shift indexes may be used for one PUCCH resource.

[0136] Specifically, the UE 200 may operate according to operation example 5-1 or 5-2.

[0137] (Operation example 5-1): Multiple cyclic shift indexes are associated with a certain PUCCH resource, and which cyclic shift index to use is determined based on whether PDSCH decoding is successful. Fig. 15 shows an example of signal points on an IQ plane according to operation example 5-1 Fig. 16 shows an example of the configuration of a PUCCH resource set and a table linked to the PUCCH resource set according to operation example 5-1.

[0138] For example, cyclic shift indexes 0, 4, and 8 are associated with PUCCH resource X, and for two HARQ-ACK bits (which may be replaced with the number of bits including ACK, or the number corresponding to PDSCH reception), the cyclic shift index may be used as follows:

[0139] ·HARQ-ACK bits = 00:CS index 0 ·HARQ-ACK bits = 01:CS index 4 ·HARQ-ACK bits = 10:CS index 8 HARQ-ACK bits = 11: N / A (Operation Example 5-2): Some of the bits are represented by the selection of a cyclic shift index, and the rest are represented by the PUCCH resource. For example, in FIG. 16, the underlined HARQ-ACK bits (2 bits) may be represented by selecting a cyclic shift index, and the remaining 3 bits may be represented by a PUCCH resource.

[0140] Operation example 5-2 may be combined with operation example 3.

[0141] (4) Actions and Effects According to the above-described embodiment, the following advantageous effects can be obtained: Specifically, in Scheme A, when UE 200 feeds back only HARQ NACK, UE 200 can apply only one cyclic shift index to one resource of PUCCH (uplink control channel).

[0142] Furthermore, in Scheme A, when UE 200 feeds back only NACK of HARQ, UE 200 can apply BPSK (only) to one resource of PUCCH.

[0143] Furthermore, in Scheme A, when UE 200 feeds back only HARQ NACK, it can be assumed that the index of the PUCCH resource indicates the correspondence relationship between the bit string of the HARQ feedback and the PUCCH resource.

[0144] Furthermore, in Scheme C, when UE 200 feeds back only ACK, it can be assumed that there is only one set of PUCCH resources.

[0145] Furthermore, when multiplexing multiple bits in feedback of only NACK using a specific PUCCH format (PF 0), UE 200 can apply multiple cyclic shift indexes to one PUCCH resource.

[0146] This allows the network to recognize the NACK-only feedback method of each UE 200, and can achieve efficient NACK-only feedback in MBS while avoiding blind decoding and the like.

[0147] (5) Other embodiments Although the embodiments have been described above, it will be obvious to those skilled in the art that the present invention is not limited to the description of the embodiments and that various modifications and improvements are possible.

[0148] For example, in the above-described embodiment, the names PDCCH and PDSCH are used as downlink channels, but the downlink control channel or downlink data channel (which may be a shared channel) may be called by another name.

[0149] Also, in the above description, "configure," "activate," "update," "indicate," "enable," "specify," and "select" may be interchangeable. Similarly, "link," "associate," "correspond," and "map" may be interchangeable, and "allocate," "assign," "monitor," and "map" may also be interchangeable.

[0150] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0151] Furthermore, the block diagram (FIG. 4) used in the description of the above-described 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 using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are connected directly or indirectly (for example, by wire, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or the multiple devices with software.

[0152] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how each is implemented.

[0153] Furthermore, the gNB 100 and UE 200 described above may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 17 is a diagram showing an example of the hardware configuration of the device. As shown in Figure 17, 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, a bus 1007, etc.

[0154] In the following description, the term "apparatus" can 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.

[0155] 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.

[0156] In addition, each function of the device is realized by loading specified software (programs) onto hardware such as processor 1001 and memory 1002, causing processor 1001 to perform calculations, control communication via communication device 1004, and control at least one of reading and writing data in memory 1002 and storage 1003.

[0157] The processor 1001 controls the entire computer by running, for example, an operating system, and may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, a register, and the like.

[0158] The processor 1001 also reads 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 in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-mentioned embodiments. Furthermore, the various processes described above 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.

[0159] The memory 1002 is a computer-readable recording medium and may be configured by, for example, at least one of 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., that can execute a method according to an embodiment of the present disclosure.

[0160] Storage 1003 is a computer-readable recording medium, and may be, for example, at least one of 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 disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. Storage 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, or other appropriate medium including at least one of memory 1002 and storage 1003.

[0161] The communication device 1004 is hardware (transmission / reception device) for communicating 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.

[0162] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0163] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0164] Furthermore, each device such as the processor 1001 and the memory 1002 is connected to 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.

[0165] 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), or a field programmable gate array (FPGA), 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.

[0166] 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 thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0167] 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, a 4th generation mobile communication system (4G), a 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), or other suitable system, and a next-generation system extended based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G) may also be applied.

[0168] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless it is consistent. 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.

[0169] In the present disclosure, a specific operation described as being performed by a base station may also 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 another network node other than the base station (for example, an MME or an S-GW, etc., but are not limited to these). Although the above example illustrates a case where there is one other network node other than the base station, a combination of multiple other network nodes (for example, an MME and an S-GW) may also be used.

[0170] Information, signals (information, etc.) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0171] The input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be sent to another device.

[0172] The determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0173] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0174] 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.

[0175] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0176] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, 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.

[0177] Note that terms explained in this disclosure and 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). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0178] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0179] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0180] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions 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 intended to be limiting in any way.

[0181] 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," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0182] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0183] The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage area.

[0184] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0185] 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.

[0186] 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 mobile object, or the mobile object itself. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (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 also include devices that do not necessarily move during communication operations. 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.

[0187] Furthermore, a base station in the present disclosure may be interpreted as a mobile station (user terminal, the same applies hereinafter). For example, the aspects / embodiments 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 interpreted as terms corresponding to communication between terminals (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be interpreted as a side channel (or side link).

[0188] 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.

[0189] Numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by a transceiver in the frequency domain, and specific windowing operations performed by a transceiver in the time domain.

[0190] 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 time unit.

[0191] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. A minislot may also be called a subslot. A minislot may consist 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.

[0192] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0193] 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 existing LTE, a period shorter than 1 ms (e.g., 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.

[0194] Here, TTI refers to, for example, the smallest 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. However, the definition of TTI is not limited to this.

[0195] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code word, etc. is actually mapped may be shorter than the TTI.

[0196] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0197] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0198] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 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.

[0199] A resource block (RB) is a resource allocation unit in the time domain and 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 numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0200] The time domain of an RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each TTI, subframe, etc. may be composed of one or more resource blocks.

[0201] Note that one or more RBs may also 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.

[0202] 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.

[0203] 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 given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0204] 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.

[0205] 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 read as "BWP."

[0206] The above-described structures of the radio frame, subframe, slot, minislot, and symbol 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, and other configurations can be changed in various ways.

[0207] 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 one or more wires, cables, and / or 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.

[0208] The reference signal may also be abbreviated as Reference Signal (RS), and may also be called a pilot depending on the applicable standard.

[0209] 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."

[0210] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0211] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing 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.

[0212] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0213] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0214] 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, searching, inquiring (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 memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0215] 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."

[0216] 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 herein. 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]

[0217] 10. Wireless communication systems 20 NG-RAN 100 gNB 200 UE 210 Radio signal transmitter / receiver 220 Amplifier section 230 Modulation and Demodulation Unit 240 Control signal / reference signal processing section 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. A terminal supporting a multicast service, a control unit that applies only one cyclic shift index to one resource when a first format of the uplink control channel is used, and applies a signal point indicating NACK in binary phase shift keying to one resource when a second format of the uplink control channel is used, when a bit string of feedback of an automatic repeat request for multicast data is associated with a resource of an uplink control channel and only a negative acknowledgement is fed back by multiplexing a plurality of bits; a transmitter for transmitting the feedback; Equipped with The resource is defined as a resource set that can be multiplexed up to N bits, and the corresponding table has a maximum of 2 N A terminal that includes one resource and applies to the total number of bits of said feedback.

2. The terminal according to claim 1 , wherein the control unit does not multiplex the feedback and a positive scheduling request.

3. A base station supporting a multicast service, comprising: a receiving unit for receiving feedback of an automatic repeat request for multicast data from a terminal; a control unit that determines, when the feedback bit string and the resource of the uplink control channel are associated with each other and only a negative acknowledgement is fed back by multiplexing a plurality of bits, that only one cyclic shift index is applied to one of the resources when a first format of the uplink control channel is used, and that a signal point indicating a NACK in binary phase shift keying is applied to one of the resources when a second format of the uplink control channel is used; Equipped with The resource is defined as a resource set that can be multiplexed up to N bits, and the corresponding table has a maximum of 2 N A base station including one resource and applied to the total number of bits of the feedback.

4. A communication system including a terminal and a base station that supports a multicast service, The terminal a control unit that applies only one cyclic shift index to one resource when a first format of the uplink control channel is used, and applies a signal point indicating NACK in binary phase shift keying to one resource when a second format of the uplink control channel is used, when a bit string of feedback of an automatic repeat request for multicast data is associated with a resource of an uplink control channel and only a negative acknowledgement is fed back by multiplexing a plurality of bits; a transmitter for transmitting the feedback; Equipped with The resource is defined as a resource set that can be multiplexed up to N bits, and the corresponding table has a maximum of 2 N - includes one resource and applies to the total number of bits of said feedback, The base station a receiving unit for receiving the feedback from the terminal; a control unit that determines, when only the negative acknowledgement is fed back by multiplexing a plurality of bits, that only one cyclic shift index is applied to one of the resources when a first format of the uplink control channel is used, and that a signal point indicating a NACK in binary phase shift keying is applied to one of the resources when a second format of the uplink control channel is used; Equipped with Communication system.

5. A communication method for a terminal that supports a multicast service, comprising: a step of applying only one cyclic shift index to one resource when a first format of the uplink control channel is used, and applying a signal point indicating a NACK in binary phase shift keying to one resource when a second format of the uplink control channel is used, when a bit string of feedback of an automatic repeat request for multicast data is associated with a resource of an uplink control channel and only a negative acknowledgement is fed back by multiplexing a plurality of bits; and transmitting said feedback; The resource is defined as a resource set that can be multiplexed up to N bits, and a maximum of 2 N A terminal communication method including one resource and applied to the total number of bits of the feedback.

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