Terminal, wireless communication system, and wireless communication method

Abstract

In the present invention, a terminal receives a downlink data channel which is common to a terminal group in data distribution to a plurality of terminals. The terminal assumes that a pseudo collocation of the downlink data channel is, when satisfying specific conditions, in a specific state common to the plurality of terminals.

Description

[Technical Field]

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

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

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

[0004] Furthermore, 3GPP Release-16 specifies that, with regard to Quasi-Colocation (QCL), if the time from reception of Downlink Control Information (DCI) to the Physical Downlink Shared Channel (PDSCH) is shorter than a specified time (timeDurationForQCL), the PDSCH is received using the QCL with the smallest control resource sets (CORESET) ID of the latest monitoring slot (Non-Patent Document 2). [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 [Non-patent document 2] 3GPP TS 38.214 V16.4.0, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Physical layer procedures for data (Release 16), 3GPP, December 2020 Summary of the Invention

[0006] The QCL of the smallest CORESET ID in the latest monitoring slot differs for each UE and may be a unicast CORESET. For this reason, even if the above-described operation is applied to an MBS as is, it is not possible to determine an appropriate QCL for the multicast PDSCH (which may also be called a group-common PDSCH).

[0007] Therefore, the following disclosure has been made in consideration of this situation, and aims to provide a terminal, a wireless communication system, and a wireless communication method that can assume appropriate pseudo-colocation in a simultaneous data transmission service to multiple specific or unspecified terminals.

[0008] One aspect of the present disclosure is a terminal (UE200) that includes a receiver (radio signal transmitter / receiver 210) that receives a downlink data channel that is common to a group of terminals in data distribution to multiple terminals, and a control unit (controller 270) that assumes that the pseudo-colocation of the downlink data channel is a specific state that is common to the multiple terminals when certain conditions are met.

[0009] One aspect of the present disclosure is a wireless communication system including a wireless base station and a terminal, wherein the wireless base station has a transmitter that transmits a downlink data channel that is common to a group of terminals in data distribution to multiple terminals, and the terminal has a receiver that receives the downlink data channel and a control unit that assumes that the pseudo-colocation of the downlink data channel is a specific state that is common to the multiple terminals when specific conditions are met.

[0010] One aspect of the present disclosure is a wireless communication method for distributing data to multiple terminals, including the steps of receiving a downlink data channel that is common to a group of terminals, and assuming that the pseudo-colocation of the downlink data channel is a specific state that is common to the multiple terminals if certain conditions are met. [Brief explanation of the drawings]

[0011] [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 setting of the TCI state field in DCI format 1_1 / 1_2. [Figure 4] FIG. 4 is a diagram showing an example (part 1) of the relationship between DCI format 1_0, timeDurationForQCL, and PDSCH. [Figure 5] FIG. 5 is a diagram showing an example of the configuration of PTM transmission method 1 and PTM transmission method 2. In FIG. [Figure 6] Figure 6 is a functional block diagram of gNB100 and UE200. [Figure 7] FIG. 7 is a diagram showing an example of a sequence of PDCCH, PDSCH and HARQ feedback in MBS. [Figure 8]FIG. 8 is a diagram illustrating a second example of the relationship between DCI format 1_0, timeDurationForQCL, and PDSCH. [Figure 9] FIG. 9 is a diagram illustrating an example of the relationship between the group-common PDCCH, timeDurationForQCL, and the group-common PDSCH. [Figure 10] FIG. 10 is a diagram illustrating an example of the relationship between CFR, group-common PDCCH, group-common PDSCH, and unicast PDCCH / PDSCH. [Figure 11] FIG. 11 is a diagram illustrating an example of the minimum DCI codepoint according to the second operation example. [Figure 12] FIG. 12 is a diagram illustrating an example of the relationship between the CFR, the group-common PDCCH, the group-common PDSCH, and the unicast PDCCH / PDSCH according to a modified example. [Figure 13] FIG. 13 is a diagram showing an example of the hardware configuration of gNB100 and UE200. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] (1) Overall configuration of wireless communication system FIG. 1 is a diagram showing the overall schematic configuration of a wireless communication system 10 according to this embodiment. (1) Overall configuration of 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).

[0014] The wireless communication system 10 may be a wireless communication system conforming to a system called Beyond 5G, 5G Evolution, or 6G.

[0015] 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.

[0016] 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."

[0017] 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.

[0018] The wireless communication system 10 supports FR1 and FR2. The frequency bands of each FR (Frequency Range) are as follows:

[0019] 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.

[0020] 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.

[0021] 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).

[0022] 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.

[0023] 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).

[0024] 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.

[0025] (1.2) QCL / TCI state Quasi-Colocation (QCL) means that two antenna ports are quasi-colocated if, for example, the characteristics of the channel over which symbols on one antenna port are carried can be inferred from the channel over which symbols on the other antenna port are carried.

[0026] Also, it can be interpreted that QCL is assumed between SSBs (Synchronization Signal / Physical Broadcast Channel blocks) with the same SSB index, and QCL should not be assumed between other SSBs (i.e., different SSB indexes). Note that QCL may also be called quasi-collocation.

[0027] In order to receive the PDSCH (Physical Downlink Shared Channel) or PDCCH (Physical Downlink Control Channel) (or its demodulation reference signal (DMRS)), in NR, the TCI (Transmission Configuration Indication) state is set (if not set, the SSB index and QCL relationship at the time of the most recent PRACH (Physical Random Access Channel) transmission can be used).

[0028] The TCI state may be explicitly set by the radio resource control layer (RRC) or the medium access control layer (MAC CE). The QCL relationship may include both the case where the TCI state is explicitly set and the case where the TCI state is not set. The QCL / TCI state / Baum may be interchangeable.

[0029] For example, when a PDCCH (Physical Downlink Control Channel) is quasi-colocated with an SSB (Quasi-Collocated), this can be interpreted as meaning that the PDCCH has passed through the same channel state as the SSB. Therefore, the channel estimation information used to detect the SSB is also useful for detecting the PDCCH.

[0030] Here, the channel condition may be defined by the following parameters:

[0031] Doppler shift Doppler spread Average delay Delayed spread Spatial Rx parameters Furthermore, the QCL type may be specified using such parameters. Specifically, the QCL type is specified as follows in Chapter 5.1.5 of 3GPP TS38.214:

[0032] ·QCL-Type A: {Doppler shift, Doppler spread, average delay, delay spread} ·QCL-Type B: {Doppler shift, Doppler spread} ·QCL-Type C: {Doppler shift, average delay} ·QCL-Type D: {Spatial Rx parameter} As the TCI state of the DMRS of the PDCCH / PDSCH, Type A is always set, and Type D may also be set (especially in the case of FR2).

[0033] Type A RS (CSI (Channel State Information)-RS) is used for long-term channel information measurement and may be used, for example, for DMRS channel estimation. Measuring DMRS only provides instantaneous measurement values, and therefore does not provide Doppler information or the like. UE 200 acquires information on QCL-Type A (Doppler shift, Doppler spread, average delay, delay spread) by measuring a periodic RS (e.g., TRS (Tracking Reference Signal)) configured as a QCL Type A RS in advance, and receives PDSCH / PDCCH using this information.

[0034] The Type D RS is used to notify the base station of a transmission spatial domain filter (i.e., an analog beam). The UE 200 selects an appropriate UE-side reception spatial domain filter by measuring an RS (e.g., a TRS) that has been set as a Type D RS in advance, and receives the PDCCH / PDSCH using the reception spatial domain filter.

[0035] The TCI state of the PDCCH may be notified by RRC and / or MAC CE. Up to eight TCI states of the PDSCH may be notified by RRC / MAC CE and may be indicated by a maximum 3-bit TCI state field of DCI format 1_1 / 1_2 (present when tciPresentInDCI of RRC is configured).

[0036] If the time from DCI to PDSCH is shorter than timeDurationForQCL (details will be described later), the TCI state of the PDSCH may be determined by a predetermined method. If the DCI format is 1_1 / 1_2 and tciPresentInDCI is not set, there is no TCI state field, so the TCI state of the PDSCH may be determined by a predetermined method.

[0037] 3 shows an example of setting the TCI state field for DCI format 1_1 / 1_2. As shown in FIG. 3, a 3-bit TCI state field may be allocated. The value of the TCI state field may be associated with the TCI state for a predetermined PDSCH.

[0038] In DCI format 1_0, since there is no TCI state field to begin with, the TCI state of the PDSCH may be determined by a predetermined method. Such a predetermined method may be called a Default TCI state.

[0039] It is particularly expected that the schedule for multicast PDSCH (MBS PDSCH) will use DCI format 1_0.

[0040] Fig. 4 shows an example (part 1) of the relationship between DCI format 1_0, timeDurationForQCL, and PDSCH. As shown in Fig. 4, PDSCH may be scheduled according to DCI format 1_0. Typically, the time from DCI to PDSCH is set to be longer than timeDurationForQCL.

[0041] When the PDSCH is scheduled according to DCI format 1_0, the TCI state field is not included as described above. In this case, the time from the DCI to the PDSCH may be set to be longer than timeDurationForQCL.

[0042] Also, the QCL of the PDCCH (DCI) that scheduled the PDSCH may be assumed to be the QCL of the PDSCH.

[0043] (1.3) Provision of MBS The wireless communication system 10 may provide multicast and broadcast services (MBS).

[0044] 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.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In MBS, the following three methods are assumed for scheduling multicast / broadcast PDSCH, 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.

[0050] ·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.

[0051] The CRC of the PDCCH and the PDSCH are scrambled using a group-common RNTI (Radio Network Temporary Identifier).

[0052] ·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.

[0053] The PDCCH CRC is scrambled by the UE-specific RNTI.

[0054] The PDSCH is scrambled using the group-common RNTI.

[0055] ·PTP transmission method: For RRC connected UEs, UE-specific PDSCH is scheduled using UE-specific PDCCH.

[0056] 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.

[0057] Fig. 5 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Enabling / Disabling of Option 1 or Option 2 may be applied in any of the following ways:

[0062] RRC and Downlink Control Information (DCI) RRC only Furthermore, the following is assumed for SPS (Semi-persistent Scheduling) of multicast / broadcast PDSCH.

[0063] ·SPS group-common PDSCH adopted 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 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.

[0064] 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).

[0065] 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.

[0066] Also, for the physical layer, there may be scheduling categories of time domain scheduling and frequency domain scheduling.

[0067] 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) and a PDSCH scrambled by a group-common RNTI (which may be referred to as a G-RNTI) may be interchangeable.

[0068] 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.

[0069] (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.

[0070] Fig. 6 is a functional block diagram of the gNB 100 and the UE 200. The following describes the UE 200. As shown in Fig. 6, 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.

[0071] It should be noted that Fig. 6 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. 13.

[0072] 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.

[0073] Furthermore, 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. In this embodiment, the radio signal transmitting / receiving unit 210 may constitute a receiving unit that receives the downlink channel.

[0074] 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.

[0075] 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.

[0076] 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).

[0077] 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 .

[0078] Specifically, the control signal / reference signal processor 240 receives various control signals, for example, control signals of a radio resource control layer (RRC), transmitted via a predetermined control channel from the gNB 100. The control signal / reference signal processor 240 also transmits various control signals to the gNB 100 via a predetermined control channel.

[0079] 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).

[0080] 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.

[0081] 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.

[0082] 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.

[0083] Furthermore, the data channel includes a PDSCH, a PUSCH (Physical Uplink Shared Channel), etc. Data may refer to data transmitted via a data channel.

[0084] The control signal and reference signal processing unit 240 may receive control information of a higher layer (for example, RRC) including the QCL of the PDSCH. In this embodiment, the control signal and reference signal processing unit 240 may constitute a receiving unit that receives control information of the higher layer.

[0085] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding for each predetermined communication destination (gNB100 or another gNB).

[0086] 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.

[0087] The data transmitter / receiver 260 transmits and receives Protocol Data Units (PDUs) and Service Data Units (SDUs). Specifically, the data transmitter / receiver 260 assembles and disassembles 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)). The data transmitter / receiver 260 also performs data error correction and retransmission control based on Hybrid Automatic Repeat Request (Hybrid ARQ).

[0088] 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.

[0089] 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.

[0090] The control unit 270 may assume that the QCL of the PDSCH (which may include the group-common PDSCH and the SPS group-common PDSCH) is in a specific state common to a plurality of UEs 200 when a specific condition is satisfied.

[0091] The specific condition may be, for example, any of the following:

[0092] The scheduling offset between DCI (PDCCH) and PDSCH is equal to or less than a predetermined time (for example, timeDurationForQCL).

[0093] Regardless of whether the scheduling offset is equal to or less than the predetermined time (less than), the QCL of the MBS PDSCH may be applied in the same manner, that is, may be a specific state common to a plurality of UEs 200.

[0094] -A specific DCI format or DCI.

[0095] For example, DCI format 1_0 does not have a TCI state field, or DCI format 1_1 or 1_2 in which tciPresentInDCI is not set.

[0096] When configured by a higher layer (e.g., RRC).

[0097] - When reporting related UE capability information (UE capability).

[0098] The specific state (which may be referred to as a predetermined QCL) common to a plurality of UEs 200 may be the QCL of the monitoring symbols of the PDCCH. That is, control unit 270 may receive the PDSCH based on the QCL of the PDCCH.

[0099] Alternatively, the QCL may be a QCL of a symbol other than the monitoring symbol of the PDCCH. In this case, the control unit 270 may receive the PDSCH based on the QCL of some received signal (channel), such as a QCL related to unicast transmission or a QCL related to multicast transmission, and the QCL based on which the PDSCH is received may be set by a higher layer.

[0100] Alternatively, the control unit 270 may assume that the QCL of the PDSCH is the same as the QCL of the control resource set (CORESET). That is, the predetermined QCL may be the QCL of the CORESET. The CORESET may be any CORESET associated with an MBS within the active BWP of the serving cell.

[0101] Alternatively, control unit 270 may assume that the QCL of a PDSCH is in the same state as the QCL of the PDSCH and another PDSCH. Specifically, control unit 270 may assume that the QCL of an MBS PDSCH is the same as the QCL of another PDSCH related to the MBS. For example, among the QCLs of the MBS PDSCH, the QCL may be the QCL of the minimum or maximum DCI codepoint (or TCI codepoint), or the QCL of the minimum or maximum TCI state.

[0102] Furthermore, the control unit 270 may determine the QCL state of the PDSCH based on control information of a higher layer. Specifically, the control unit 270 can determine the QCL state of the PDSCH based on QCL information included in control information of a higher layer (for example, RRC) received by the control signal / reference signal processing unit 240. Note that the control information is not limited to RRC, and may be notified by, for example, MAC CE or the like.

[0103] The gNB100 can also execute control related to the scheduling of the downlink channels described above. Specifically, the radio signal transmitting / receiving unit 210 of the gNB100 may transmit a PDSCH common to a terminal group to multiple UEs 200 included in the terminal group in an MBS. The radio signal transmitting / receiving unit 210 of the gNB100 may constitute a transmitting unit.

[0104] (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 regarding downlink channel scheduling for MBS, particularly regarding the assumption of QCL.

[0105] 7 shows an example of a sequence of PDCCH, PDSCH, and HARQ feedback in MBS. As shown in FIG. 7, 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).

[0106] 7, 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.

[0107] Furthermore, as for QCL, timeDurationForQCL is set as described above (see FIG. 4). When SCS=120 kHz, timeDurationForQCL is set to a minimum of 14 symbols. On the other hand, in the case of MBS PDSCH, it is considered undesirable to always set a scheduling offset between DCI and PDSCH of 14 symbols or more.

[0108] Fig. 8 shows a second example of the relationship between DCI format 1_0, timeDurationForQCL, and PDSCH. Fig. 8 shows an example in which the scheduling offset between DCI and PDSCH is shorter than timeDurationForQCL.

[0109] As described above, when the PDSCH is scheduled with a time in which the scheduling offset between the DCI and the PDSCH is shorter than timeDurationForQCL, the UE 200 receives the PDSCH using the "QCL of the smallest CORESET ID of the latest monitoring slot."

[0110] Specifically, it is specified that the UE may assume that the DM-RS ports of the PDSCH of a serving cell are quasi-colocated with the RS(s) with respect to the QCL parameter(s) used for PDCCH quasi-colocation indication of the CORESET associated with a monitored search space with the lowest controlResourceSetId in the latest slot in which one or more CORESETs within the active BWP of the serving cell are monitored by the UE (3GPP TS38.214 Chapter 5.1.5).

[0111] The "QCL of the smallest CORESET ID in the latest monitoring slot" may differ for each UE. It may also be a CORESET related to unicast transmission. Therefore, even if this behavior is applied directly to MBS PDSCH, it is highly unlikely that an appropriate QCL will be obtained.

[0112] Note that the UE cannot recognize the PDSCH schedule before completing DCI decoding. However, DCI can schedule the PDSCH without a symbol gap. After receiving the search space, the UE performs PDSCH BD and simultaneously stores (buffers) the DL received signal. After detecting DCI, if the UE determines that a PDSCH schedule exists on a certain symbol, it demodulates and decodes the PDSCH using the stored DL signal.

[0113] In 3GPP Release-15 and 16, DL signals can only be received using one receive beam at a time. Therefore, when storing DL signals, they must be received based on some QCL. For example, 3GPP Release-15 specifies that if DCI to PDSCH is scheduled for a period shorter than timeDurationForQCL, PDSCH is received using the "QCL of the smallest CORESET ID in the latest monitoring slot."

[0114] FIG. 9 shows an example of the relationship between the group-common PDCCH, timeDurationForQCL, and the group-common PDSCH.

[0115] In MBS, in a UE group (terminal group) that uses a certain G-RNTI, as described above, the "QCL of the smallest CORESET ID of the latest monitoring slot" differs for each UE, and therefore the same PDSCH cannot be received with the same QCL.

[0116] Furthermore, 3GPP is considering the setting of CFR (Common Frequency Resource, tentative name) for MBS. Fig. 10 shows an example of the relationship between CFR, group-common PDCCH, group-common PDSCH, and unicast PDCCH / PDSCH.

[0117] For example, the definition of CFR as an MBS-specific BWP (Option 2A) is being considered. With this option, unicast and multicast will have different BWPs, so the QCL of the MBS PDSCH will also be the QCL of the MBS PDCCH, even when it comes to the QCL of the "smallest CORESET ID in the latest monitoring slot" (within the active BWP of the serving cell), so there will be no problem. Note that while Figure 10 shows an example in which the CFR is different from the BWP for unicast, a configuration in which they are mutually inclusive is also acceptable.

[0118] On the other hand, the definition of an MBS frequency region within a dedicated unicast BWP (Option 2B) is also being considered. In this option, unicast and multicast are in the same BWP, so if the QCL of the smallest CORESET ID in the latest monitoring slot (within the active BWP of the serving cell) is used, the QCL of the MBS PDSCH may become the QCL of the unicast PDCCH, which is a problem.

[0119] Considering this situation, in the following operation example, the QCL of the group-common PDSCH is set to be common between UEs. The QCL of the unicast PDCCH / PDSCH may be different between UEs. The default TCI state of the group-common PDSCH (DCI to PDSCH is less than timeDurationForQCL) is specified.

[0120] (3.0) Example 0 In this operation example, conditions for applying a predetermined QCL to the MBS PDSCH are shown. The QCL of the PDSCH (DMRS) related to the MBS may be set to a predetermined QCL under predetermined conditions.

[0121] The predetermined condition may be any of the following:

[0122] The scheduling offset of DCI to PDSCH is a predetermined time (for example, equal to or less than timeDurationForQCL).

[0123] It should be noted that the QCL of the MBS PDSCH may be applied in the same manner, regardless of whether it is equal to or shorter than the predetermined time.

[0124] ·Specified DCI format or DCI For example, a DCI format or DCI that does not have a TCI state field (for example, when tciPresentInDCI is not set in DCI format 1_0 or DCI format 1_1 / 1_2) can be mentioned.

[0125] Set by upper layer For example, the UE 200 may be configured by an RRC IE (enableDefaultTCIStateForMulticast (tentative name)). The enableDefaultTCIStateForMulticast may be interpreted as an IE that enables the default TCI state for multicast.

[0126] - When reporting (signaling) the capability information (UE capability) of the relevant UE.

[0127] The PDSCH associated with an MBS may be interpreted as a PDSCH scheduled in a PDSCH-config or PDSCH resource in which the MBS is configured, or in a CORESET / Search-Space (SS) associated with the MBS, or as a PDSCH scheduled with DCI with CRC scrambled by G-RNTI.

[0128] "Related to MBS" may be interpreted as "related to MBS frequency region (which may be CFR)."

[0129] The "predetermined QCL" may be interpreted as a PDCCH monitoring symbol, in which case the UE 200 may receive the PDSCH based on the QCL of the PDCCH.

[0130] Alternatively, the predetermined QCL may be interpreted as a symbol other than the PDCCH monitoring symbol. In this case, the UE 200 may store the received signal based on some predetermined QCL. Since the UE 200 can assume only one predetermined QCL at a time, the application of either the predetermined QCL for unicast or the predetermined QCL for multicast may be switched by a higher layer.

[0131] If enableDefaultTCIStateForMulticast is not set, UE200 may perform operations in accordance with 3GPP Release-15, specifically, operations using the Type A RS or Type D RS described above, store the received signal assuming a predetermined QCL for unicast, and receive PDSCH.

[0132] When enableDefaultTCIStateForMulticast is set, UE200 operates according to one of the operation examples described below, stores the received signal assuming a predetermined QCL for multicast, and may receive PDSCH (which may be interpreted as operation in accordance with 3GPP Release-17).

[0133] As mentioned above, enableDefaultTCIStateForMulticast is a tentative name and may be called by a different name.

[0134] (3.1) Example 1 In this operation example, the "predetermined QCL" may be the QCL of the CORESET. As described above, the PDSCH (DMRS) associated with the MBS may be received using the predetermined QCL.

[0135] The predetermined QCL may be the QCL of any of the following CORESETs associated with the MBS (but within the active BWP of the serving cell):

[0136] QCL of the minimum or maximum CORESET ID among the CORESETs related to the MBS QCL of the smallest CORESET ID of the latest monitoring slot among the CORESETs related to MBS According to this operation example, the same QCL as any one of the CORESETs from the MBS CORESET can be appropriately applied to the MBS PDSCH.

[0137] Furthermore, in the 3GPP specifications related to this operation example (for example, 3GPP TS38.214, Chapter 5.1.5), this may be expressed as follows:

[0138] If a UE is configured with enableDefaultTCIStateForMulticast and the UE is configured by higher layer parameter PDCCH-Config that associates with MBS frequency region (CFR), the UE may assume that the DM-RS ports of PDSCH associated with MBS frequency region (CFR) of a serving cell are quasi-colocated with the RS(s) with respect to the QCL parameter(s) used for PDCCH quasi-colocation indication of the CORESET associated with MBS frequency region (CFR) in the latest monitoring slot of the serving cell in the active BWP. CORESET associated with a monitored search space with the lowest controlResourceSetId among CORESETs associated with MBS frequency region (CFR) in the latest monitoring slot within the active BWP of the serving cell.).

[0139] (3.2) Example 2 In this operation example, the "predetermined QCL" may be the QCL of the PDSCH. As described above, the PDSCH (DMRS) associated with the MBS may be received using the predetermined QCL.

[0140] The predetermined QCL may be any of the following QCLs of the PDSCH associated with the MBS:

[0141] QCL of minimum or maximum DCI codepoint (or TCI codepoint) QCL of minimum or maximum TCI state ID Fig. 11 shows an example of the minimum DCI codepoint according to Operation Example 2. As shown in Fig. 11, the minimum DCI codepoint (QCL corresponding to TCI state "#28" in TCI state field "000") may be selected.

[0142] According to this operation example, a QCL that is appropriately set for the MBS PDSCH can be applied to the MBS PDSCH.

[0143] Furthermore, in the 3GPP specifications related to this operation example (for example, 3GPP TS38.214, Chapter 5.1.5), this may be expressed as follows:

[0144] If a UE is configured with enableDefaultTCIStateForMulticast and the UE is configured by higher layer parameter PDCCH-Config that associates with MBS frequency region (CFR), the UE may assume that the DM-RS ports of PDSCH associated with MBS frequency region (CFR) of a serving cell are quasi-colocated with the RS(s) with respect to the QCL parameter(s) associated with the TCI states corresponding to the lowest codepoint among the TCI codepoints within PDSCH configured for MBS frequency region (CFR) in the serving cell's active BWP. (CFR) within the active BWP of the serving cell.).

[0145] (3.3) Example 3 In this operation example, the "predetermined QCL" may be set by a higher layer. As described above, the PDSCH (DMRS) associated with the MBS may be received using the predetermined QCL.

[0146] The predetermined QCL set by higher layers may be the TCI state or QCL set by the RRC or MAC CE.

[0147] In this case, the TCI state / QCL used in the Default TCI state may be set in advance by a higher layer. Note that this TCI state / QCL may be called Unified TCI, Common TCI state / QCL, etc. In particular, the TCI state / QCL set in relation to the MBS may be used.

[0148] According to this operation example, a QCL appropriately set for MBS can be applied to the MBS PDSCH.

[0149] Furthermore, in the 3GPP specifications related to this operation example (for example, 3GPP TS38.214, Chapter 5.1.5), this may be expressed as follows:

[0150] If a UE is configured with enableDefaultTCIStateForMulticast and the UE is configured by higher layer parameter PDCCH-Config that associates with an MBS frequency region (CFR), the UE may assume that the DM-RS ports of PDSCH associated with the MBS frequency region (CFR) of a serving cell are quasi-colocated with the RS(s) with respect to the QCL parameter(s) associated with the TCI states configured for the MBS frequency region (CFR) within the active BWP of the serving cell.

[0151] (3.4) Example of changes The following changes may be made to the above-described operational examples: For example, the wording (draft) of the 3GPP specifications for operational examples 1 to 3 states that when enableDefaultTCIStateForMulticast is set, the PDSCH related to the MBS is received based on a predetermined QCL for the MBS.

[0152] In this case, for the Default TCI state of the unicast PDSCH (i.e., QCL of the unicast PDSCH scheduled by unicast DCI to unicast PDSCH <timeDurationForQCL, for the DCI without a TCI state field (e.g., DCI format 1_0 without a TCI state field, or DCI formats 1_1, 1_2 where tciPresentInDCI is not set)), it is not clear.

[0153] Therefore, gNB100 and UE200 may operate according to any of the following.

[0154] · For the Default TCI state of the unicast PDSCH, perform the operation using the above-mentioned Type A RS or Type D RS, specifically, the operation of measuring the Type A RS or Type D RS described in (1.2) QCL / TCI state. For the Default TCI state of the multicast PDSCH, follow the above-mentioned operation example.

[0155] · For the Default TCI state of the unicast PDSCH as well, follow this operation example similar to the Default TCI state of the multicast PDSCH (however, it may be limited to the case where enableDefaultTCIStateForMulticast is set).

[0156] If enableDefaultTCIStateForMulticast is set, UE200 may receive the multicast / unicast PDSCH with a predetermined QCL under predetermined conditions.

[0157] Taking such operations into consideration, the above-mentioned draft 3GPP specification states that "the UE may assume that the DM-RS ports of PDSCH associated with MBS frequency region (CFR)...", but the part "associated with MBS frequency region (CFR)" may be deleted.

[0158] FIG. 12 shows an example of the relationship between the CFR, the group-common PDCCH, the group-common PDSCH, and the unicast PDCCH / PDSCH according to a modified example.

[0159] As shown in FIG. 12, if the scheduling resource of the PDSCH is associated with (included in) the MBS CFR, the Default TCI state for the MBS PDSCH may be applied.

[0160] On the other hand, when a CORESET / SS / CCE (Control channel element) is associated with (included in) an MBS CFR, the Default TCI state for the MBS PDSCH may be applied to the PDSCH scheduled by the DCI.

[0161] (4) Actions and Effects According to the above-described embodiment, the following advantageous effects can be obtained. Specifically, according to the gNB 100 and UE 200 according to operation examples 0 to 3, an appropriate quasi-colocation (QCL) can be assumed in an MBS, that is, a simultaneous data transmission service to multiple specific or unspecified UEs.

[0162] In particular, even if the PDSCH is scheduled with a scheduling offset between DCI and PDSCH that is shorter than timeDurationForQCL, a suitable quasi-co-location (QCL) in MBS can be assumed.

[0163] (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.

[0164] 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.

[0165] In addition, in the above-described embodiment, the MBS PDSCH has been described as an example, but at least one of the above-described operation examples may be applied to other downlink channels such as the MBS PDCCH. Furthermore, the above-described operation examples may be combined and applied in a composite manner as long as no contradiction occurs.

[0166] 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 be interchangeable.

[0167] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0168] Furthermore, the block diagram (FIG. 6) 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 multiple devices with software.

[0169] 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.

[0170] 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. Fig. 13 is a diagram showing an example of the hardware configuration of the device. As shown in Fig. 13, 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.

[0171] 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.

[0172] Each functional block of the device (see FIG. 6) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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).

[0180] 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).

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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).

[0190] 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).

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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)).

[0200] 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.

[0201] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0202] 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.

[0203] 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.

[0204] 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).

[0205] 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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 block, a code word, etc. is actually mapped may be shorter than the TTI.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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."

[0223] 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.

[0224] 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.

[0225] The reference signal may also be abbreviated as Reference Signal (RS), and may also be called a pilot depending on the applicable standard.

[0226] 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."

[0227] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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."

[0233] 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]

[0234] 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 receiving unit configured to receive, in a multicast / broadcast service (MBS) in which data is distributed to a plurality of terminals, higher layer parameters associated with a common frequency resource (CFR) associated with the MBS, and, when the CFR is set, receive downlink control information (DCI) without a TCI state field in the CFR, the DCI scheduling a downlink data channel (PDSCH) associated with the MBS; A control unit that, when a time offset between reception of the DCI and the PDSCH is less than a specific time, assumes that the quasi-colocation of the demodulation reference signal port of the PDSCH is the same as the quasi-colocation of a control resource set (CORESET) having a smallest controlResourceSetId among the control resource sets (CORESET) included in the CFR in the latest slot; Equipped with When the time offset between the reception of DCI scheduling a PDSCH when the CFR is not set and the PDSCH is less than the specific time, the control unit assumes that the pseudo-colocation of the demodulation reference signal port of the PDSCH is the same as the pseudo-colocation of the CORESET having the smallest controlResourceSetId among the CORESETs in the latest slot. Terminal.

2. The receiving unit receives a PDSCH associated with the MBS, which is scheduled by another DCI including the TCI state field, in the CFR using the TCI state field. The terminal according to claim 1 .

3. In a multicast / broadcast service (MBS) in which data is distributed to a plurality of terminals, receiving higher layer parameters associated with a common frequency resource (CFR) related to the MBS, and if the CFR is configured, receiving downlink control information (DCI) in the CFR without a TCI state field, the DCI scheduling a downlink data channel (PDSCH) related to the MBS; If a time offset between reception of the DCI and the PDSCH is less than a specific time, assuming that the quasi-colocation of demodulation reference signal ports of the PDSCH is the same as the quasi-colocation of a control resource set (CORESET) having a smallest controlResourceSetId among the control resource sets (CORESET) included in the CFR in the latest slot; When the time offset between the reception of DCI scheduling a PDSCH and the PDSCH when the CFR is not set is less than the specific time, assuming that the pseudo-colocation of demodulation reference signal ports of the PDSCH is the same as the pseudo-colocation of a CORESET having the smallest controlResourceSetId among CORESETs in the latest slot; A wireless communication method comprising:

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