TERMINAL, WIRELESS COMMUNICATION SYSTEM, AND WIRELESS COMMUNICATION METHOD

Abstract

This terminal receives downlink control information of the smallest size for a downlink data channel. The terminal executes a scheduling of the downlink data channel on the basis of antenna port information included in the downlink control information.

Description

[Technical field]

[0001] The present disclosure relates to a terminal, a wireless communication system, 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 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 the MBS, it is assumed that, among the existing downlink control information (DCI) formats, scheduling will be supported using at least DCI format 1_0 (hereinafter, abbreviated as DCI 1_0) for the downlink data channel (PDSCH: Physical Downlink Shared Channel).

[0007] However, although DCI 1_0 has the advantage of being small in size compared to other DCI formats, it has a problem in that its functionality is limited, for example, antenna ports cannot be specified.

[0008] Therefore, the following disclosure has been made in consideration of the above circumstances, and aims to provide a terminal, a wireless communication system, and a wireless communication method that can realize flexible and efficient scheduling using downlink control information 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 for a downlink data channel, and a control unit (control unit 270) that performs scheduling of downlink data channels in data distribution to multiple terminals based on specific downlink control information that is separate from the downlink control information.

[0010] One aspect of the present disclosure is a terminal (UE 200) that includes a receiving unit (control signal / reference signal processing unit 240) that receives downlink control information for a downlink data channel, and a control unit that performs scheduling of downlink data channels in data distribution to multiple terminals based on specific downlink control information having the same size as the downlink control information.

[0011] One aspect of the present disclosure is a terminal (UE 200) that includes a receiving unit (control signal / reference signal processing unit 240) that receives downlink control information for a downlink data channel, and a control unit (control unit 270) that performs scheduling of downlink data channels in data distribution to multiple terminals based on specific downlink control information in which some fields included in the downlink control information have been changed.

[0012] One aspect of the present disclosure is a wireless communication system including a wireless base station and a terminal, the wireless base station including a transmitter for transmitting downlink control information for a downlink data channel, the terminal including: The wireless communication system includes a receiving unit that receives the downlink control information, and a control unit that performs scheduling of a downlink data channel in data distribution to multiple terminals based on specific downlink control information that is separate from the downlink control information.

[0013] One aspect of the present disclosure is a wireless communication system including a wireless base station and a terminal, the wireless base station including a transmitter for transmitting downlink control information for a downlink data channel, the terminal including: A wireless communication system comprising: a receiving unit that receives the downlink control information; and a control unit that performs scheduling of downlink data channels in data distribution to multiple terminals based on specific downlink control information of the same size as the downlink control information.

[0014] One aspect of the present disclosure is a wireless communication system including a wireless base station and a terminal, the wireless base station including a transmitter for transmitting downlink control information for a downlink data channel, the terminal including: A wireless communication system comprising: a receiving unit that receives the downlink control information; and a control unit that performs scheduling of a downlink data channel in data distribution to multiple terminals based on specific downlink control information in which some fields included in the downlink control information have been changed.

[0015] One aspect of the present disclosure is a terminal (UE 200) that includes a receiver (control signal / reference signal processor 240) that receives downlink control information of a minimum size for a downlink data channel, and a controller (controller 270) that performs scheduling of the downlink data channel based on antenna port information included in the downlink control information.

[0016] One aspect of the present disclosure is a wireless communication system including a wireless base station and a terminal, the wireless base station comprising: a transmitter configured to transmit downlink control information of a minimum size for a downlink data channel; The terminal is a wireless communication system including a receiver that receives the downlink control information, and a controller that executes scheduling of the downlink data channel based on antenna port information included in the downlink control information.

[0017] One aspect of the present disclosure is a wireless communication method including a step of receiving downlink control information of a minimum size for a downlink data channel, and a step of performing scheduling of the downlink data channel based on antenna port information included in the downlink control information. [Brief description of the drawings]

[0018] [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, PDSCH and HARQ feedback in MBS. [Figure 6] FIG. 6 is a diagram showing the sizes of main DCI including DCI 1_3 (tentative name) according to the operation example 1-1. [Figure 7] FIG. 7 is a diagram showing the sizes of main DCI including DCI 1_3 (tentative name) according to a modification of operation example 1-1. [Figure 8] FIG. 8 is a diagram illustrating an example of a correspondence relationship between the RNTI and the DCI format according to the operation example 1-1. [Figure 9] FIG. 9 is a diagram illustrating an example of a correspondence relationship between RNTI and DCI format according to operation example 1-2. [Figure 10] FIG. 10 is a diagram illustrating an example of a correspondence relationship between RNTI and DCI format according to the second operation example. [Figure 11] FIG. 11 is a diagram showing a setting example of the Antenna port(s) field according to the second operation example. [Figure 12] FIG. 12 is a diagram illustrating an example of setting the PUCCH resource indicator. [Figure 13] FIG. 13 is a diagram illustrating an example of a correspondence relationship between each PUCCH resource and a PRI (variable field) according to the second operation example. [Figure 14] FIG. 14 is a diagram illustrating an example of setting a variable-size DCI field according to the second operation example. [Figure 15] FIG. 15 is a diagram showing a setting example of the Antenna port(s) field according to the third operation example. [Figure 16] FIG. 16 is a diagram illustrating an example of correspondence between the DCI format and the Antenna port(s) field according to the third operation example. [Figure 17] FIG. 17 is a diagram showing an example of the hardware configuration of gNB100 and UE200. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 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.

[0020] (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).

[0021] The wireless communication system 10 may be a wireless communication system conforming to a standard called Beyond 5G, 5G Evolution, or 6G.

[0022] 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.

[0023] 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."

[0024] 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.

[0025] The wireless communication system 10 supports FR1 and FR2. The frequency bands of each FR (Frequency Range) are as follows.

[0026] 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.

[0027] 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.

[0028] 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).

[0029] FIG. 2 shows an example of the configuration of radio frames, subframes, and slots used in the radio communication system 10. In FIG.

[0030] 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).

[0031] 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.

[0032] (1.2) Provision of MBS In the wireless communication system 10, Multicast and Broadcast Services (MBS) may be provided.

[0033] 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.

[0034] 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).

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] ·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).

[0040] The CRC (Cyclic Redundancy Checksum) of the PDCCH and the PDSCH are scrambled by the group-common RNTI (Radio Network Temporary Identifier).

[0041] ·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.

[0042] The PDCCH CRC is scrambled by the UE-specific RNTI.

[0043] The PDSCH is scrambled by the group-common RNTI.

[0044] ·PTP transmission method: For RRC connected UEs, schedule UE-specific PDSCH using UE-specific PDCCH.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Enabling / Disabling of Option 1 or Option 2 may be applied as follows:

[0051] RRC and Downlink Control Information (DCI) RRC only In addition, the following is assumed for SPS (Semi-persistent Scheduling) of multicast / broadcast PDSCH.

[0052] ·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 group-common PDCCH 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.

[0053] SPS is scheduling used in contrast to dynamic scheduling, and may also be called semi-fixed, semi-persistent, or semi-persistent scheduling, and may be interpreted as Configured Scheduling (CS).

[0054] 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.

[0055] Also, for the physical layer, there may be scheduling categories of time domain scheduling and frequency domain scheduling.

[0056] Furthermore, multicast, groupcast, broadcast, and MBS may be interchangeable. A multicast PDSCH (which may include a group-common PDSCH and an SPS group-common PDSCH), an MBS PDSCH, and a PDSCH scrambled by a group-common RNTI (which may be referred to as a G-RNTI) may be interchangeable.

[0057] 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.

[0058] (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.

[0059] 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.

[0060] 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. 17.

[0061] 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.

[0062] 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.

[0063] The radio signal transceiver 210 can 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 transceiver 210 can also receive a downlink control channel common to a terminal group, specifically, a group-common 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 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.

[0065] 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).

[0066] 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.

[0067] Specifically, the control signal / reference signal processor 240 receives various control signals, for example, radio resource control layer (RRC) control signals, 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.

[0068] 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).

[0069] 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.

[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 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.

[0072] Moreover, the data channel includes a PDSCH, a PUSCH (Physical Uplink Shared Channel), etc. Data may mean 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). Specifically, the control signal and reference signal processor 240 can receive DCI for a downlink data channel. The downlink data channel may mean a PDSCH, and the (scheduling) DCI for the PDSCH may be, for example, DCI format 1_0 (DCI 1_0). The DCI for the PDSCH may include DCI 1_1 and DCI 1_2. Furthermore, a new DCI format, DCI 1_3 (tentative name), may be included. The DCI may also include DCI format 2_x (for convenience, referred to as DCI 2_x) that notifies a plurality of UEs of DCI, such as a slot format.

[0074] DCI 1_0, 1_1, and 1_2 may all be DCIs for scheduling PDSCH in one cell, but DCI 1_0 may be specified as the DCI with the smallest size among them. In other words, DCI 1_0 may be specified as the DCI (downlink control information) with the smallest size for PDSCH (downlink data channel). DCI 1_0 may also be a DCI format for scheduling PDSCH when performing system information or random access. DCI 1_0 may also be a DCI format in which multiple UEs in a BWP / cell assume the same DCI size.

[0075] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding, etc. for each predetermined communication destination (gNB100 or another gNB).

[0076] 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.

[0077] 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).

[0078] 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.

[0079] 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.

[0080] In addition, the control unit 270 can perform scheduling of downlink channels, specifically, downlink data channels such as PDSCH (which may include group-common PDSCH and SPS group-common PDSCH, the same applies below), based on the DCI received by the control signal / reference signal processing unit 240.

[0081] In this embodiment, the control unit 270 may perform scheduling of the PDSCH in the MBS, that is, data distribution to multiple terminals, based on a specific DCI that is different from the DCI for the PDSCH (for example, DCI 1_0). Here, the specific DCI may be called DCI 1_3, which is a new DCI format as described above. DCI 1_3 may be the same size as DCI 1_0 or may be a different size. DCI 1_3 may be the same size as DCI 1_0 and may be the smallest size DCI. The size may mean the bit length (number of bits).

[0082] The control unit 270 may perform scheduling of the PDSCH in the MBS based on a specific DCI having the same size as the DCI for the PDSCH (for example, DCI 1_1, 1-2). The specific DCI having the same size may have the same name as the existing DCI, such as DCI 1_2, or the specific DCI may be called DCI 1_3.

[0083] The specific DCI may be scrambled by the G-RNTI together with the CRC (DCI format with CRC scrambled by G-RNTI). The G-RNTI is an RNTI associated with a terminal group and may be called by another name.

[0084] The control unit 270 may perform scheduling of the PDSCH in the MBS based on a specific DCI in which some fields included in the DCI for the PDSCH (for example, DCI 1_0) have been changed. For example, some of the fields (3 bits) of the PUCCH resource indicator (PRI) included in DCI 1_0 may be changed to other information.

[0085] The information to be changed may be information that is defined in DCI 1_2 and the like and is not defined in DCI 1_0, such as antenna port information.

[0086] Furthermore, the control unit 270 may perform PDSCH scheduling based on antenna port information included in the DCI. The information of the antenna port information may be represented by one bit or two bits. The (number of) antenna port may be read as (the number of) DMRS port.

[0087] The control unit 270 may determine whether or not antenna port information is included in the DCI based on at least one of control information of a higher layer (for example, RRC) or identification information used for scrambling the DCI, specifically, the RNTI. In other words, whether or not the DCI includes an antenna port field may be determined based on the control information or the RNTI.

[0088] Also, in this case, the DCI (for example, DCI 1_0) may be limited to MBS, that is, to scheduling of multicast PDSCH. Thus, in this case, the PDSCH may be interpreted as a PDSCH for MBS (multicast PDSCH), and may be a PDSCH associated (scrambled) with an RNTI, such as a G-RNTI, that is assigned to multiple UEs.

[0089] In addition, the gNB 100 can execute the above-mentioned downlink channel scheduling, control related to HARQ, etc. For example, the gNB 100 may include a transmission unit (control signal / reference signal processing unit 240) that transmits downlink control information for a downlink data channel.

[0090] (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 scheduling of downlink channels related to MBS, specifically, the operation of scheduling the MBS PDSCH more flexibly than DCI 1_0.

[0091] Fig. 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). In addition, UE 200 may transmit HARQ feedback (ACK / NACK) for the channel (transport block (TB) received via the channel).

[0092] In addition, in FIG. 5, it appears that both the unicast PDSCH and the multicast PDSCH are transmitted after one PDCCH / DCI, but either the unicast PDSCH or the multicast PDSCH may be transmitted after one PDCCH / DCI. In other words, one PDCCH / DCI may schedule either the unicast PDSCH or the multicast PDSCH. In the above-mentioned PTM-1, DCI 1_0 may be supported. Specifically, in PTM-1, DCI 1_0 may be scrambled by G-RNTI together with CRC (DCI 1_0 with CRC scrambled by G-RNTI).

[0093] The G-RNTI may be used for group-common PDCCH CRC scrambling and / or PDSCH data scrambling of the MBS. The G-RNTI may be set by control information of a higher layer (e.g., RRC). Note that the G-RNTI may be an RNTI related to the group-common PDCCH and / or group-common PDSCH (which may include the SPS group-common PDSCH) (hereinafter the same).

[0094] As described above, at least DCI 1_0 may be used for the MBS PDSCH. However, it is not desirable to use only DCI 1_0 for scheduling the MBS PDSCH, since this limits functionality.

[0095] For example, DCI 1_0 does not include antenna port information (Antenna port(s)), and therefore multiple-input multiple-output (MIMO) transmission of PDSCH is not possible (PDSCH is a one-layer transmission).

[0096] Considering the use case of MBS, as mentioned above, PDSCH transmission with relatively high data traffic is expected, such as simultaneous video streaming in stadiums, etc. For this reason, it is not desirable to limit MBS PDSCH to one MIMO layer. It is desirable to be able to use MIMO in MBS as well.

[0097] Furthermore, by using fields other than the antenna port(s), it is possible to expect improvements in the flexibility of PDSCH scheduling, the efficiency of PDSCH resource utilization, and the efficiency of frequency utilization.

[0098] For example, fields containing at least one of the following information may be used:

[0099] (i) Carrier indicator (ii) Bandwidth part indicator (iii) resource allocation type 0 is available (iv)PRB (Physical Resource Block) bundling size indicator (v) Rate matching indicator (vi)ZP (Zero Power) CSI-RS trigger (vii) Antenna port(s) (viii) Transmission configuration indication (ix) SRS request (x)DMRS sequence initialization (xi) Priority indicator The information (i) to (xi) may be information that is not included in DCI 1_0, but is included in DCI 1_2. Such DCI fields may also be applied to MBS PDSCH scheduling. In the following, an example of an operation for indicating such information in MBS PDSCH scheduling will be described.

[0100] (3.0) Example 0 In this operation example, only DCI 1_0 may be used in PTM-1. Such DCI may be called Group common DCI. Since scheduling is performed by Group common DCI, the DCI format that can schedule MBS PDSCH according to DCI CRC scrambled by G-RNTI may be limited to DCI 1_0. This can solve the problem described below.

[0101] In PTM-2, since scheduling is performed by unicast DCI (CRC scrambled by UE-specific RNTI), any of DCI 1_0, DCI 1_1, and DCI 1_2 may be used as the DCI format that can schedule MBS PDSCH. In this case, the usable DCI format may be set by a higher layer (such as RRC). This can contribute to reducing the processing load of UE 200 and can solve the problems described below.

[0102] In PTM-1, only a maximum of one layer of PDSCH can be scheduled, whereas in PTM-2, multiple layers of PDSCH may be scheduled. The UE may assume that in PTM-1, only a maximum of one layer of PDSCH is scheduled, whereas in PTM-2, multiple layers of PDSCH are scheduled.

[0103] In addition, since it is a heavy burden for the UE 200 to implement both PTM-1 and PTM-2 for scheduling the MBS PDSCH, it is assumed that some UEs implement only PTM-1. Therefore, in the following, an example of operation when PTM-1 is applied will be further described.

[0104] (3.1) Example 1 (3.1.1) Example 1-1 In this operation example, DCI 1_3 (tentative name) may be newly defined. Specifically, in PTM-1 in which the MBS PDSCH is scheduled using DCI CRC scrambled by the G-RNTI, the MBS PDSCH may be scheduled using a DCI format other than DCI 1_0.

[0105] A DCI format other than DCI 1_0 may be a new DCI, for example, DCI 1_3 (tentative name) may be specified. 6 shows the sizes of main DCI including DCI 1_3 (tentative name) according to the operation example 1-1. DCI 1_3 may have a DCI payload (or a field) size different from the existing DCI format.

[0106] DCI 1_3 may include at least any of the above-mentioned information (i) to (xi) in addition to the fields of DCI 1_0 that are used for scheduling the MBS PDSCH.

[0107] Since the number of blind detection (BD) of DCI may increase, UE 200 may perform BD of DCI 1_3 only when BD of DCI 1_3 is configured by a higher layer.

[0108] Furthermore, such a new DCI format as DCI 1_3 may be a DCI format dedicated to scheduling of MBS PDSCH. In other words, the DCI may be detected only when MBS is configured. When PTM-1 is configured, UE 200 may assume only that DCI 1_3 is scheduled by G-RNTI from the viewpoint of reducing processing load.

[0109] When a new DCI format such as DCI 1_3 is used, the gNB 100 and the UE 200 may further operate as follows: For example, in PTM-1 in which the MBS PDSCH is scheduled using DCI CRC scrambled by the G-RNTI, the MBS PDSCH may be scheduled using a DCI format other than DCI 1_0.

[0110] Fig. 7 shows the sizes of main DCIs including DCI 1_3 (tentative name) according to a modification of operation example 1-1. As shown in Fig. 7, DCI 1_3 may be equal in size to any of the other existing DCI formats. Equal in size may be interpreted as having the same bit length (number of bits). For example, DCI 1_3 may be the same size as DCI 1_0 (the reason for making DCI 1_0 and DCI 1_3 the same size will be described later).

[0111] Fig. 8 shows an example of the correspondence relationship between RNTI and DCI format according to the operation example 1-1. As shown in Fig. 8, DCI 1_0 and DCI 1_3 may be switched depending on CRC scrambled by RNTI.

[0112] Specifically, when scrambling by the C-RNTI, DCI 1_0 may be used, and when scrambling by the G-RNTI, DCI 1_3 may be used.

[0113] The operation of scrambling by the C-RNTI and using DCI 1_0 is in accordance with 3GPP Release-15 and 16 and may be applied to, for example, scheduling of a UE specific PDSCH. The operation of scrambling by the G-RNTI and using DCI 1_3 is in accordance with 3GPP Release-17 and may be applied to scheduling of an MBS PDSCH.

[0114] Alternatively, the above-mentioned switching may be performed using any field of DCI 1_0 (e.g., Identifier for DCI formats - 1 bit).

[0115] When the RNTIs are different, switching can be done based on the RNTI, but when the CRC scrambled RNTI is the same for DCI 1_0 and DCI 1_3, as in PTM-2, switching between DCI 1_0 and DCI 1_3 must be done based on the DCI field.

[0116] (3.1.2) Example 1-2 In this operation example, the MBS PDSCH may be scheduled using DCI 1_1 or DCI 1_2. Specifically, in PTM-1 in which the MBS PDSCH is scheduled using DCI CRC scrambled by the G-RNTI, the MBS PDSCH may be scheduled using a DCI format other than DCI 1_0 (any existing DCI format may be used).

[0117] The DCI format used for scheduling the MBS PDSCH may be a DCI payload equal to any of the existing DCI formats (DCI 1_1 / DCI 1_2 / DCI 2_x).

[0118] Fig. 9 shows an example of the correspondence relationship between RNTI and DCI format according to operation example 1-2. As shown in Fig. 9, the MBS PDSCH may be scheduled using a DCI format (CRC scrambled by G-RNTI) other than DCI 1_0, for example, DCI 1_2. Note that such DCI 1_2 (CRC scrambled by G-RNTI) may be called DCI 1_3 (tentative name) in order to distinguish it from existing DCI formats.

[0119] Additionally, the above information (i) to (xi) may be used in the schedule of the MBS PDSCH.

[0120] UE 200 may perform a CRC check scrambled with G-RNTI only when configured / instructed by a higher layer to measure (detect) the DCI or the DCI format.

[0121] The size of DCI 1_1 or DCI 1_2 is variable for each UE (it may be set by RRC for each UE). On the other hand, the size of DCI common to all UEs that is CRC scrambled by the G-RNTI must be constant between UEs associated with the common G-RNTI.

[0122] To apply this operation example, it is necessary to use a DCI format (DCI 1_2 in FIG. 9) of the same size as the DCI CRC scrambled by the G-RNTI between UEs associated with a common G-RNTI. Operation example 2 described below can also eliminate such a restriction.

[0123] (3.2) Example 2 In this operation example, the MBS PDSCH may be scheduled using DCI 1_0. Specifically, in PTM-1 in which the MBS PDSCH is scheduled using DCI CRC scrambled by the G-RNTI, the MBS PDSCH may be scheduled using DCI 1_0.

[0124] DCI 1_0 CRC scrambled by the G-RNTI may include at least one DCI field other than the DCI field included in the existing DCI 1_0 (hereinafter, this may particularly mean the DCI field in the case where it is CRC scrambled by the C-RNTI). In other words, DCI 1_0 CRC scrambled by the G-RNTI does not have to include at least one DCI field included in the existing DCI 1_0.

[0125] Fig. 10 illustrates an example of a correspondence relationship between RNTIs and DCI formats according to operation example 2. As illustrated in Fig. 10, the size of the DCI field included in the existing DCI 1_0 may be reduced, and a DCI field not included in the existing DCI 1_0 (e.g., any of the above-mentioned information (i) to (xi) may be specified) may be defined using unused DCI bits.

[0126] For example, three bits are allocated to the PUCCH resource indicator (PRI), but one bit may be allocated to the PRI, and two bits may be allocated to indicate the information (i) to (xi) described above.

[0127] In DCI 1_0 CRC scrambled by G-RNTI, fields that may be unnecessary or may be reduced include the following:

[0128] Identifier for DCI formats - 1 bit TPC command for scheduled PUCCH - 2 bits PUCCH resource indicator - 3 bits PDSCH-to-HARQ_feedback timing indicator - 3 bits As for the Identifier for DCI formats, since there is no DCI format 0_0 (UL grant) CRC scrambled by the G-RNTI (MBS PUSCH is not specified), there is no need to distinguish between DCI 0_0 and DCI 1_0 using this field, and this is unnecessary.

[0129] Regarding the above-mentioned unnecessary or reduceable fields, it may be interpreted that at least one of the fields does not exist (or the number of allocated bits is reduced) in DCI 1_0 CRC scrambled by the G-RNTI.

[0130] The bits / fields that have been deleted or reduced in this manner and are no longer used may be used to indicate DCI fields that do not exist in the existing DCI 1_0 (CRC scrambled by C-RNTI) (e.g., information (i) to (xi) described above).

[0131] Alternatively, it may be "Operation 1: The field names remain as described above, and some fields are used for purposes other than describing the field names (for example, "Identifier for DCI formats" is used to indicate the number of MIMO layers / DMRS port index(es)), and "Operation 2: The field names remain as described above, and some fields are not used for any purpose" (for example, "Identifier for DCI formats" exists, but is not used for any purpose (the UE ignores it)).

[0132] Moreover, operation 1 and operation 2 may be switched by a higher layer, or may be applied only when UE 200 reports that it supports the operation as UE capability information.

[0133] Alternatively, the following information may be interpreted as being transmitted by DCI 1_0 (CRC scrambled by G-RNTI):

[0134] ·Frequency domain resource assignment Time domain resource assignment - 4 bits VRB (Virtual Resource Block)-to-PRB mapping - 1 bit Modulation and coding scheme - 5bit New data indicator - 1 bit Redundancy version - 2 bits HARQ process number - 4 bits Downlink assignment index - 2 bits TPC command for scheduled PUCCH - 2 bits PUCCH resource indicator - 3 bits PDSCH-to-HARQ_feedback timing indicator - 3 bits Antenna port(s) - 1 bit Here, an example is shown in which the antenna port(s) is specified by one bit (see also operation example 3). This operation example focuses on the antenna port(s), but this is just an example and is not limited to the antenna port(s).

[0135] The number of bits of the newly added Antenna port(s) may be variable and configurable by a higher layer. However, the size of DCI 1_0 may be invariant (constant) by a higher layer (for example, the Antenna port(s) field can be variable and configured in the range of 1 to 6 bits by a higher layer, but if the Antenna port(s) field exceeds 1 bit, other fields (for example, the TPC command for scheduled PUCCH and / or PUCCH resource indicator may not exist or may be ignored).

[0136] Fig. 11 shows an example of setting the Antenna port(s) field according to the operation example 2. Fig. 11 shows an example in which the size of the Antenna port(s) field can be set to 1 to 6 bits by a higher layer. Note that the size of DCI 1_0 is invariable and constant. In other words, the total of the three fields is always 6 bits, regardless of the value of the Antenna port(s) field(x).

[0137] The reduced bit field may be used or ignored. Whether to use or ignore may be switched by a higher layer. In FIG. 11, an example is imagined in which the TPC command is reduced first and then the PUCCH resource indicator is reduced, but the reverse may also be possible. In addition, the TPC command and the PUCCH resource indicator (PRI) are only examples, and are not limited to these.

[0138] In addition, when PRI is used, a PUCCH resource is indicated by a PRI field common to multiple UEs associated with the same G-RNTI, so it is difficult to flexibly indicate a PUCCH resource.

[0139] Fig. 12 shows an example of setting the PUCCH resource indicator. As shown in Fig. 12, when multiple PUCCH resources are indicated in a common DCI field of a common DCI, it is only possible to indicate PUCCH resources in a coordinated manner between multiple UEs (select one from the eight patterns in the box). Therefore, in this operation example, an operation is proposed in which the number of PRI bits is reduced or eliminated (0 bits) without indicating a PUCCH resource using three bits of PRI.

[0140] Furthermore, when PRI is used, since the size of the PRI field is variable, a correspondence relationship between each PUCCH resource and the PRI (variable field) may be defined. Figure 13 shows an example of the correspondence relationship between each PUCCH resource and the PRI (variable field).

[0141] As shown in Fig. 13, the number of corresponding PUCCH resources may change depending on whether the PRI field is 0 to 3 bits. Even if the PRI is 0 bits, different PUCCH resources can be set between UEs by configuring a different PUCCH resource for each UE by RRC. In addition, if the feedback is NACK only for HARQ, it is possible to operate even if a common PUCCH resource is configured for each UE.

[0142] In DCI 1_2 of 3GPP Release-16, PRI is variable length and the total size of DCI is also variable length, but in this operation example, DCI is 1_0 and the total size of DCI is fixed. When PRI becomes variable length, DCI bits become vacant, so these vacant bits are used to indicate DCI other than PRI.

[0143] Furthermore, the variation of the bit length (number of bits) of the field as shown in FIG. 13 may be applied to other fields as well.

[0144] Fig. 14 shows an example of setting a variable-size DCI field according to operation example 2. As shown in Fig. 14, the field size of the PDSCH-to-HARQ_feedback timing indicator may also be variable.

[0145] Also, HARQ transmission for MBS PDSCH may be performed only if configured by higher layers. If not configured by higher layers, UE 200 may not perform HARQ transmission for MBS PDSCH. In this case, the following fields may be deleted or reduced:

[0146] Downlink assignment index - 2 bits TPC command for scheduled PUCCH - 2 bits PUCCH resource indicator - 3 bits PDSCH-to-HARQ_feedback timing indicator - 3 bits Without HARQ feedback, no downlink assignment index (DAI) is required.

[0147] (3.3) Example 3 In this operation example, the PDSCH may be transmitted by multiple ports (MIMO) using DCI 1_0. Specifically, the MBS PDSCH scheduled by the DCI format including the "Antenna port(s)" field can be transmitted by multiple ports (MIMO).

[0148] 15 shows a setting example of the Antenna port(s) field according to the operation example 3. For "Antenna port(s)" of the DCI format with CRC scrambled by G-RNTI, any of 3GPP TS38.212 (Tables 7.3.1.2.2-1 to 7.3.1.2.2-4) may be used. The DCI bit and the number of MIMO layers / DMRS port / CDM (Code Domain Sharing) group may be indicated.

[0149] The same DMRS port may use the same CDM group. Up to two DMRS ports per CDM group may be orthogonally multiplexed using an orthogonal cover code (OCC) (cyclic shift) in the frequency domain.

[0150] Which table is used may be set by a higher layer, or may be predefined as a 3GPP specification, or a new table may be defined for MBS as shown in FIG.

[0151] The contents of the table shown in Fig. 15 are merely examples and are not limited thereto. The DMRS port number corresponds to an antenna port, and switching between "0" and "1" may indicate antenna switching. The number of DMRS ports may indicate the number of MIMO layers. The number of rows and / or columns of the table may also be changed.

[0152] The number of DMRS CDM group(s) without data may be a predetermined value (set by the 3GPP specifications or higher layers). Originally, in Multi-User (MU)-MIMO, it indicates whether PDSCH scheduling to another UE is performed, but it is difficult to assume that MU-MIMO will be applied to MBS PDSCH (using bits for MU-MIMO is considered to be a waste).

[0153] Fig. 16 shows an example of correspondence between the DCI format and the Antenna port(s) field according to the operation example 3. As shown in Fig. 16, the size of the Antenna port(s) field may differ depending on the DCI format / RNTI, and the Antenna port table to be referenced may differ.

[0154] In the case of an Antenna port(s) field with a predetermined number of bits (when an Antenna port(s) table with a predetermined number of columns is configured), particularly when the table in the lower part of FIG. 15 (a table in which DMRS for up to two ports can be configured) is configured, UE200 may not report part of the CSI (e.g., Precoding Matrix Index (PMI)).

[0155] Assuming a cross-port antenna (an antenna that uses radio waves in both horizontal and vertical directions), the 1-bit Antenna port(s) field, which can only indicate on / off of two-layer MIMO, does not require a PMI report (if the gNB100 can recognize whether or not it has a sufficient SNR to enable MIMO, it can appropriately indicate the 1-bit Antenna port(s) field).

[0156] To perform normal MIMO, the UE 200 reports which precoder is appropriate from among multiple MIMO precoders to the gNB 100 as PMI. In a cross-pol antenna, the horizontal and vertical channels are generally uncorrelated, so they can be used at all times (no rank drop occurs). Therefore, when performing two-layer MIMO in a cross-pol antenna, it is not necessary to consider the channel correlation between antenna ports, so two-layer MIMO can be used in PDSCH even without PMI.

[0157] Furthermore, when MIMO is performed in a multicast PDSCH, the appropriate MIMO precoder differs for each UE, so even if a PMI is reported for each UE, the gNB 100 cannot use the PMI appropriately.

[0158] This operation example may be applied to a unicast PDSCH instead of a multicast PDSCH. Also, this operation example may be applied to D2D (Device to Device), V2X (Vehicle to X), and IAB (Integrated Access and Backhaul).

[0159] This operation example may be interpreted as scheduling a multi-port (MIMO) PDSCH using DCI 1_0.

[0160] Whether or not the antenna port(s) field is present may be determined depending on the RNTI in which higher layer control information and / or DCI 1_0 is CRC scrambled.

[0161] DCI 1_0 may be limited to DCI 1_0 that schedules a multicast PDSCH (or DCI 1_0 may be limited to DCI 1_0 that is CRC scrambled by an RNTI (eg, G-RNTI) that is assigned to multiple UEs).

[0162] Furthermore, the PDSCH may be a multicast PDSCH (such as a group-common PDSCH), or may be a PDSCH in which data / DMRS sequences are scrambled by an RNTI (for example, a G-RNTI) assigned to multiple UEs.

[0163] (4) Actions and Effects According to the above-described embodiment, the following advantageous effects can be obtained. Specifically, according to the gNB 100 and the UE 200 according to the operation examples 1 to 3, flexible and efficient scheduling using DCI can be realized in MBS, that is, in a service of transmitting data simultaneously to a plurality of specific or unspecified UEs.

[0164] In particular, it is possible to specify antenna port(s) and the like using DCI 1_0 or DCI 1_3 (tentative name), etc. Also, the bit length (number of bits) of DCI is suppressed. This allows for more flexible and efficient scheduling of MBS PDSCH and the like.

[0165] (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.

[0166] 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.

[0167] In addition, in the above-mentioned embodiment, the MBS PDSCH is described as an example, but at least one of the above-mentioned operation examples may be applied to other downlink channels such as the MBS PDCCH. Furthermore, the above-mentioned operation examples may be combined and applied in a composite manner as long as no contradiction occurs.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] Furthermore, the above-mentioned gNB100 and UE200 may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 17 is a diagram showing an example of a hardware configuration of the device. As shown in Fig. 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, and a bus 1007.

[0173] 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.

[0174] 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.

[0175] In addition, each function in the device is realized by loading a specific software (program) onto hardware such as the processor 1001, memory 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of reading and writing of data in the memory 1002 and storage 1003.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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).

[0182] 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).

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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).

[0189] 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.

[0190] 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.

[0191] 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).

[0192] 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).

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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)).

[0202] 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.

[0203] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0204] 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.

[0205] 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.

[0206] 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).

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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) in which a transport block, a code block, a code word, etc. are actually mapped may be shorter than the TTI.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] 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".

[0225] 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.

[0226] 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.

[0227] The reference signal may also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

[0228] 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."

[0229] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0230] 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.

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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."

[0235] 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]

[0236] 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. a receiving unit that receives first downlink control information scrambled by a group common RNTI for multicast; a control unit that executes scheduling of a multicast downlink data channel in data delivery to a plurality of terminals based on the first downlink control information; The first downlink control information does not include each field of (1) Identifier for DCI formats and (2) TPC Command for scheduled PUCCH among fields included in the second downlink control information scrambled by the terminal-specific RNTI, but includes (3) PUCCH resource indicator and (4) PDSCH-to-HARQ_feedback timing indicator; When the first downlink control information includes an antenna port field, a size of the antenna port field is based on a higher layer, When the first downlink control information does not include an antenna port field, the first downlink control information has the same size as the second downlink control information. A terminal characterized by:

2. The terminal according to claim 1 , wherein the group common RNTI for multicast is a G-RNTI, and the terminal specific RNTI is a C-RNTI.

3. receiving first downlink control information scrambled by a group common RNTI for multicast; and executing scheduling of a downlink data channel for multicast in data distribution to a plurality of terminals based on the first downlink control information; The first downlink control information does not include each field of (1) Identifier for DCI formats and (2) TPC Command for scheduled PUCCH among fields included in the second downlink control information scrambled by the terminal-specific RNTI, but includes (3) PUCCH resource indicator and (4) PDSCH-to-HARQ_feedback timing indicator; When the first downlink control information includes an antenna port field, a size of the antenna port field is based on a higher layer, When the first downlink control information does not include an antenna port field, the first downlink control information has the same size as the second downlink control information.

23. A wireless communication method for a terminal comprising:

4. A system including a base station and a terminal, the base station comprises a transmitter that transmits first downlink control information scrambled by a group common RNTI for multicast; The terminal includes: A receiving unit that receives the first downlink control information; a control unit that executes scheduling of a downlink data channel for multicast in data distribution to a plurality of terminals based on the first downlink control information; Equipped with The first downlink control information does not include each field of (1) Identifier for DCI formats and (2) TPC command for scheduled PUCCH among a plurality of fields included in second downlink control information scrambled by a terminal-specific RNTI, but includes (3) PUCCH resource indicator and (4) PDSCH-to-HARQ_feedback timing indicator; When the first downlink control information includes an antenna port field, a size of the antenna port field is based on a higher layer, When the first downlink control information does not include an antenna port field, the first downlink control information has the same size as the second downlink control information. A system characterized by:

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