Terminal, communication method of terminal, and communication system

Abstract

The terminal can transmit feedback of an automatic repeat request, and determine a structure of feedback of a first downlink data channel common to a terminal group and feedback of a second downlink data channel inherent to the terminal according to a terminal capability or a parameter of a radio resource control layer.

Description

Technical Field

[0001] This disclosure relates to terminals and wireless communication methods that support multicast / broadcast services. Background Technology

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

[0003] In 3GPP Release 17, the simultaneous data transmission (also known as publishing) service to a number of specific or unspecified terminals (User Equipment, UE) in NR (provisionally referred to as MBS: Multicast and Broadcast Services) became the object (Non-Patent Document 1).

[0004] In MBS, for example, the scheduling of UE groups as service objects and reliability improvements are being studied (e.g., HARQ (Hybrid Automatic Repeat Request) feedback to the radio base station (gNB).

[0005] Existing technical documents

[0006] Non-patent literature

[0007] 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

[0008] In MBS's HARQ, the feedback ACK / NACK method is also used, and the decision algorithm for the codebook (CB) supporting HARQ-ACK is envisioned (type-1 and type-2, specified in 3GPP TS38.213).

[0009] Furthermore, the PDSCH (Physical Downlink Shared Channel, MBS PDSCH) used by MBS and the PDSCH (Unicast PDSCH) inherent to a specific UE can be time-division multiplexed (TDM) or frequency-division multiplexed (FDM). In this case, the structure of HARQ-ACK CB will also be different depending on the TDM or FDM multiplexing method.

[0010] However, HARQ-ACK CB relies on the premise that multiple PDSCHs in a specific cell (within the same cell) are not repeatedly assigned to the same symbol. It functions in TDM, but sometimes does not function in FDM. Therefore, it is sometimes difficult for the UE to determine the appropriate structure of HARQ-ACK CB.

[0011] Therefore, the following disclosure is made in view of the following situation, with the aim of providing a terminal and a wireless communication method capable of constructing appropriate HARQ feedback independent of the multiplexing methods of MBSPDSCH and unicast PDSCH.

[0012] One aspect of this disclosure is a terminal (UE 200) comprising: a transmitting unit (data transceiver unit 260) that transmits feedback of an automatic retransmission request; and a control unit (control unit 270) that determines the structure of the feedback of a common first downlink data channel in a group of terminals and the feedback of a terminal-specific second downlink data channel based on terminal capabilities or parameters of a radio resource control layer.

[0013] One aspect of this disclosure is a terminal (UE 200) having: a transmitting unit (data transceiver unit 260) that transmits feedback of automatic retransmission requests; and a control unit (control unit 270) that envisions that a common first downlink data channel in the terminal group and a terminal-specific second downlink data channel are received in the same time domain only when specific conditions are met in the same cell.

[0014] One aspect of this disclosure is a wireless communication method comprising the steps of: sending feedback of an automatic retransmission request; and determining, based on terminal capabilities or parameters of a radio resource control layer, the structure of the feedback of a common first downlink data channel in a group of terminals and the structure of the feedback of a terminal-specific second downlink data channel.

[0015] One aspect of this disclosure is a wireless communication method comprising the steps of: sending feedback of an automatic retransmission request; and envisioning that a common first downlink data channel in the terminal group and a terminal-specific second downlink data channel are received in the same time domain only if certain conditions are met in the same cell. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the wireless communication system 10.

[0017] Figure 2 This is a diagram illustrating an example of the structure of wireless frames, subframes, and time slots used in the wireless communication system 10.

[0018] Figure 3 This is a diagram showing structural examples of PTM transmission mode 1 and PTM transmission mode 2.

[0019] Figure 4 This is the function block structure diagram of gNB 100 and UE 200.

[0020] Figure 5 This is a diagram illustrating the timing example of PDCCH, PDSCH, and HARQ feedback in MBS.

[0021] Figure 6 This is a diagram illustrating an example of constructing a type-1 HARQ-ACK CB by linking the PDSCTDRA table / set.

[0022] Figure 7 This is a diagram illustrating the structure of type 1 HARQ-ACK CB (the case of FDM between unicast PDSCH and MBS PDSCH) of action example 1.

[0023] Figure 8 This is a diagram illustrating the structure of type 1 HARQ-ACK CB for action example 1 (the case of TDM using unicast PDSCH and MBS PDSCH).

[0024] Figure 9 This is a diagram illustrating the structure of type 1 HARQ-ACK CB in action example 2.

[0025] Figure 10 This is a diagram illustrating an example of the hardware structure of gNB 100 and UE 200. Detailed Implementation

[0026] The embodiments are described below with reference to the accompanying drawings. Furthermore, the same or similar reference numerals are used to denote the same function and structure, and their descriptions are omitted where appropriate.

[0027] (1) Overall general structure of wireless communication system

[0028] (1.1) System Structure Example

[0029] Figure 1This is a schematic diagram of the overall structure of the wireless communication system 10 in this embodiment. The wireless communication system 10 is a wireless communication system that follows 5G New Radio (NR) and includes a Next Generation-Radio Access Network (NG-RAN 20) and multiple terminals 200 (User Equipment 200, hereinafter referred to as UE 200).

[0030] Alternatively, the wireless communication system 10 can also be a wireless communication system that follows the methods referred to as Beyond 5G, 5G Evolution, or 6G.

[0031] NG-RAN 20 includes a radio base station 100 (hereinafter referred to as gNB 100). Furthermore, the specific structure of the wireless communication system 10, including the number of gNBs and UEs, is not limited to... Figure 1 The example shown.

[0032] NG-RAN 20 actually contains multiple NG-RAN nodes, specifically gNB (or ng-eNB), connected to a 5G-compliant core network (5GC, not shown). Additionally, NG-RAN 20 and 5GC can be simply referred to as the "network".

[0033] The gNB 100 is an NR-compliant radio base station that performs NR-compliant wireless communication with the UE 200. The gNB 100 and UE 200 can support Massive MIMO, which generates a more directional beam BM by controlling the radio signals transmitted from multiple antenna elements; Carrier aggregation (CA), which uses multiple component carriers (CC); and Dual connectivity (DC), which allows simultaneous communication between the UE and multiple NG-RAN nodes.

[0034] The wireless communication system 10 supports FR1 and FR2. The frequency bands of each FR (Frequency Range) are as follows.

[0035] FR1: 410MHz~7.125GHz FR2: 24.25GHz~52.6GHz In FR1, a sub-carrier spacing (SCS) of 15, 30, or 60 kHz can be used, with a bandwidth (BW) of 5–100 MHz. FR2 operates at a higher frequency than FR1, and can use an SCS of 60 or 120 kHz (or even 240 kHz), with a bandwidth (BW) of 50–400 MHz.

[0036] Furthermore, the wireless communication system 10 can also support frequency bands higher than FR2. Specifically, the wireless communication system 10 supports frequency bands exceeding 52.6 GHz up to 114.25 GHz. Additionally, the wireless communication system 10 can also correspond to frequency bands between FR1 and FR2.

[0037] Furthermore, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform-Spread OFDM (DFT-S-OFDM) with larger sub-carrier spacing (SCS) can be applied. DFT-S-OFDM can be applied not only to the uplink (UL) but also to the downlink (DL).

[0038] Figure 2 An example of the structure of wireless frames, subframes, and time slots used in wireless communication system 10 is shown.

[0039] like Figure 2 As shown, one time slot consists of 14 symbols. The larger (wider) the SCS, the shorter the symbol period (and time slot period). Furthermore, the number of symbols constituting one time slot does not necessarily have to be 14 symbols (e.g., 28, 56 symbols). Additionally, the number of time slots per subframe can vary depending on the SCS. Moreover, the SCS can be wider than 240kHz (e.g., ...). Figure 2 As shown, 480kHz and 960kHz).

[0040] in addition, Figure 2 The time direction (t) shown can also be referred to as the time domain, symbol period, or symbol time, etc. Furthermore, the frequency direction can also be referred to as the frequency domain, resource block, resource block group, subcarrier, BWP (Bandwidth part), subchannel, common frequency resource, etc.

[0041] (1.2) Provision of MBS

[0042] In the wireless communication system 10, multicast and broadcast services (MBS) can be provided.

[0043] For example, in a stadium, hall, or similar setting, imagine a scenario where many UE 200 devices are located within a certain geographical area and simultaneously receive the same data. In this case, using MBS instead of unicast is effective.

[0044] In addition, unicast can be interpreted as communication between a specific UE 200 and the network on a one-to-one basis (or by specifying the UE 200's inherent identification information).

[0045] Multicast can be interpreted as communication between a specified number of UEs 200 (or multiple specified identification information for multicast) and the network in a one-to-many (specifically multiple) manner. Additionally, the number of UEs 200 receiving multicast data can also be a single entity.

[0046] Broadcasting can also be interpreted as communication between all UE 200 and the network in a one-to-many manner. Multicast / broadcast data can be duplicates of the same content, but the header and other parts can differ. Furthermore, multicast / broadcast data can be sent (published) simultaneously, but strict simultaneity is not required; propagation delays and / or processing delays within RAN nodes may be included.

[0047] Furthermore, the state of the Radio Resource Control (RRC) layer of the UE 200 being tested can be any of the following: idle (RRCidle), connected (RRC connected), or inactive (e.g., inactive). The inactive state can be interpreted as maintaining a portion of the RRC settings.

[0048] In MBS, regarding the scheduling of multicast / broadcast PDSCH (Physical Downlink Shared Channel), specifically regarding the scheduling of MBS packets (which can be replaced by data), the following three methods are envisioned. Additionally, RRC-connected UEs can be replaced with RRC idle UEs or RRC inactive UEs.

[0049] • PTM transmission method 1 (PTM-1): • For MBS groups of RRC-connected UEs, the group-common PDCCH (Physical Downlink Control Channel) is used to schedule the group-common PDSCH.

[0050] • The CRC and PDSCH of PDCCH are scrambled using the group common RNTI (Radio Network Temporary Identifier, also known as G-RNTI).

[0051] • PTM transmission method 2 (PTM-2): • For MBS groups of RRC-connected UEs, use the terminal-specific (UE-specific) PDCCH to schedule the common PDSCH group.

[0052] • The CRC of PDCCH is scrambled by the terminal's inherent RNTI.

[0053] • PDSCH is scrambled by the group's common RNTI.

[0054] • PTP sending method: • For RRC-connected UEs, the terminal's inherent PDCCH is used to schedule the terminal's inherent PDSCH.

[0055] • The CRC and PDSCH of PDCCH are scrambled by the terminal's inherent RNTI. That is, it can refer to sending MBS packets via unicast.

[0056] Figure 3 Examples of PTM transmission methods 1 and 2 are shown. Additionally, the UE-specific PDCCH / PDSCH can be recognized by the target UE, but not by other UEs within the same MBS group. Group-common PDCCH / PDSCH is transmitted on the same time / frequency resources and can be recognized by all UEs within the same MBS group. Furthermore, the names PTM transmission method 1 and PTM transmission method 2 are provisional; they can be used under other names as long as the above actions are performed.

[0057] Additionally, in point-to-point (PTP) deployment, the RAN node can wirelessly deploy individual copies of MBS data packets to each UE. In point-to-multipoint (PTM) deployment, the RAN node can wirelessly deploy a single copy of the MBS data packets to a group of UEs.

[0058] In addition, to improve the reliability of MBS, regarding HARQ (Hybrid Automatic Repeat Request) feedback, specifically regarding HARQ feedback for multicast / broadcast PDSCH, the following two feedback methods are envisioned.

[0059] Option 1: Feedback via both ACK and NACK (ACK / NACK feedback)

[0060] PDSCH reception The UE that successfully decoded the code sends an ACK.

[0061] PDSCH reception UEs that fail to decode send NACK

[0062] • PUCCH (Physical Uplink Control Channel) resource settings: Enables PUCCH-Config settings for multicast.

[0063] • PUCCH resources: Shared / orthogonal among UEs (based on network settings)

[0064] • HARQ-ACK CB (codebook): Supports type-1 and type-2 (CB determines the algorithm (specified in 3GPP TS38.213)).

[0065] • Reuse: Can be applied to unicast or multicast

[0066] Option 2: NACK-only feedback

[0067] PDSCH reception A UE that successfully decodes does not send an ACK (acknowledgment).

[0068] PDSCH reception UEs that fail to decode send NACK

[0069] • In the pre-defined UE, PUCCH resource settings can be configured separately via unicast or multicast.

[0070] Additionally, ACK can also be called a positive acknowledgement, and NACK can also be called a negative acknowledgement. HARQ can also be called an automatic retransmission request.

[0071] The enable / disable option for option 1 or option 2 can be applied to any of the following.

[0072] • RRC and Downlink Control Information (DCI)

[0073] ·RRC only

[0074] Furthermore, for SPS (Semi-persistent Scheduling) of multicast / broadcast PDSCH, the following is envisioned.

[0075] • Use SPS group common PDSCH (also known as group common SPS PDSCH)

[0076] • As a UE capability, it can configure a common PDSCH for multiple SPS groups.

[0077] • Capable of providing HARQ feedback on common PDSCH for SPS groups

[0078] • It should be able to perform activation / deactivation based on the group common PDCCH (downlink control channel).

[0079] In addition, deactivation can be replaced with other synonyms such as release. For example, activation can be replaced with startup, start, trigger, etc., and deactivation can be further replaced with end, stop, etc.

[0080] SPS is a scheduling mechanism used in contrast to dynamic scheduling. It can be called semi-static, semi-persistent, or semi-permanent scheduling, and can also be interpreted as configured scheduling (CS).

[0081] Scheduling can be interpreted as the process of allocating resources for sending data. In dynamic scheduling, it can be interpreted as a mechanism where all PDSCHs are scheduled by DCIs (e.g., DCI1_0, DCI1_1, or DCI1_2). SPS can be interpreted as a mechanism where PDSCH transmission is scheduled by higher-level signaling such as RRC messages.

[0082] In addition, multicast SPS PDSCH reception can refer to group common SPS PDSCH reception, SPS PDSCH reception by multiple terminals, or SPSPDSCH reception associated with G-RNTI or G-CS-RNTI (i.e., RNTI associated with multiple terminals). Furthermore, multicast can also be replaced by broadcast.

[0083] For the physical layer, there can be scheduling categories in the time domain and frequency domain.

[0084] In addition, multicast, broadcast, and MBS can be used interchangeably. Multicast PDSCH and PDSCH scrambled by the group common RNTI can also be used interchangeably.

[0085] Furthermore, the terms "data" and "data packets" are interchangeable and can be interpreted as synonyms with terms such as "signal" and "data unit." Additionally, "send," "receive," "transmit," and "publish" are also interchangeable.

[0086] (2) Functional block structure of wireless communication system

[0087] Next, the functional block structure of the wireless communication system 10 will be described. Specifically, the functional block structures of gNB 100 and UE 200 will be described.

[0088] Figure 4 This is the function block structure diagram of gNB 100 and UE 200. The following is a description of UE 200. Figure 4 As shown, the UE200 includes a wireless signal transceiver unit 210, an amplifier unit 220, a modem unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transceiver unit 260, and a control unit 270.

[0089] In addition, Figure 4 Only the main functional blocks relevant to the description of the implementation method are shown in the diagram. It should be noted that the UE 200 has other functional blocks (e.g., a power supply unit, etc.). Furthermore, Figure 4 This shows the functional block structure of UE 200 (gNB 100). For information on the hardware structure, please refer to [reference needed]. Figure 10 .

[0090] The radio transceiver unit 210 transmits and receives radio signals conforming to NR. The radio transceiver unit 210 supports Massive MIMO, CA using multiple CCs, and DC that enables simultaneous communication between the UE and two NG-RAN nodes.

[0091] The wireless transceiver unit 210 corresponds to the MBS and is able to receive downlink channels that are group common to the terminal group during data transmission to multiple UEs 200.

[0092] In addition, the wireless transceiver unit 210 is able to receive the downlink data channel (PDSCH) in MBS, i.e., data distribution to multiple terminals.

[0093] Specifically, the wireless transceiver unit 210 is able to receive a downlink data channel (PDSCH) that is common to the terminal group, namely the group common PDSCH (which may include SPS group common PDSCH).

[0094] In addition, the wireless transceiver unit 210 can receive downlink control channels that are common to the terminal group (specifically, group common PDCCH) and can also receive downlink control channels specific to the terminal (specifically, UE specific PDCCH).

[0095] The amplification unit 220 is composed of a power amplifier (PA) or a low-noise amplifier (LNA). The amplification unit 220 amplifies the signal output from the modem 230 to a predetermined power level. Furthermore, the amplification unit 220 amplifies the RF signal output from the wireless transceiver unit 210.

[0096] The modem 230 performs data modulation / demodulation, transmit power setting, and resource block allocation for each predetermined communication target (gNB 100, etc.). Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform-Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) can also be applied in the modem 230. Furthermore, DFT-S-OFDM can be used not only for the uplink (UL) but also for the downlink (DL).

[0097] The control signal and reference signal processing unit 240 performs processing related to various control signals transmitted and received by the UE 200, as well as processing related to various reference signals transmitted and received by the UE 200.

[0098] Specifically, the control signal / reference signal processing unit 240 receives various control signals transmitted from the gNB 100 via a predetermined control channel, such as control signals (messages) from the Radio Resource Control (RRC) layer. Furthermore, the control signal / reference signal processing unit 240 transmits various control signals to the gNB 100 via the predetermined control channel.

[0099] The control signal and reference signal processing unit 240 performs processing using reference signals (RS) such as demodulation reference signal (DMRS) and phase tracking reference signal (PTRS).

[0100] DMRS is a known reference signal (pilot signal) between the base station and the terminal used for estimating the fading channel used in data demodulation. PTRS is a terminal-specific reference signal used for estimating phase noise, a problem that arises in the high-frequency band.

[0101] In addition to DMRS and PTRS, the reference signal may also include Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), and Positioning Reference Signal (PRS) for location information.

[0102] In addition, the channels include control channels and data channels. The control channel may include PDCCH, PUCCH (Physical Uplink Control Channel), RACH (Downlink Control Information (DCI) containing Random Access Channel and Random Access Radio Network Temporary Identifier (RA-RNTI)), and Physical Broadcast Channel (PBCH), etc.

[0103] In addition, the data channel includes PDSCH and PUSCH (Physical Uplink Shared Channel). Data can refer to data transmitted via the data channel.

[0104] In this embodiment, the control signal / reference signal processing unit 240 may also be configured as a receiving unit for receiving downlink control information (DCI). Furthermore, the control signal / reference signal processing unit 240 may receive messages in the RRC indicating the activation or deactivation of a function that is enabled or disabled by the DCI-indicated HARQ feedback.

[0105] The encoding / decoding unit 250 performs data segmentation / linking and channel encoding / decoding for each predetermined communication target (gNB 100 or other gNB).

[0106] Specifically, the encoding / decoding unit 250 divides the data output from the data transceiver unit 260 into predetermined sizes and performs channel coding on the divided data. Furthermore, the encoding / decoding unit 250 decodes the data output from the modulation / demodulation unit 230 and concatenates the decoded data.

[0107] The data transceiver unit 260 performs the transmission and reception of Protocol Data Units (PDUs) and Service Data Units (SDUs). Specifically, the data transceiver unit 260 performs the assembly / disassembly of PDUs / SDUs in multiple layers (such as the Media Access Control (MAC) layer, Radio Link Control (RLC) layer, and Packet Data Convergence Protocol (PDCP) layer).

[0108] Furthermore, the data transceiver unit 260 performs error correction and retransmission control based on the Hybrid Automatic Repeat Request (HARQ). Specifically, the data transceiver unit 260 is capable of sending HARQ (Automatic Repeat Request) feedback. In this embodiment, the data transceiver unit 260 may be configured as a transmitting unit.

[0109] The control unit 270 controls the functional blocks that constitute the UE 200. In particular, in this embodiment, the control unit 270 performs scheduling of downlink channels related to MBS and control related to HARQ feedback of the channel.

[0110] During data transmission to MBS (i.e., multiple UEs 200), control unit 270 performs control corresponding to the scheduling of downlink data channels that are common to the terminal group (group common). Specifically, control unit 270 may perform control corresponding to the scheduling of group common PDCCH and group common PDSCH.

[0111] The control unit 270 can envision activating / deactivating the SPS, i.e., semi-static scheduling, for the downlink data channel (PDSCH) of the SPS group on a per-terminal-group basis, with regard to the common PDSCH of the SPS group.

[0112] Furthermore, the control unit 270 can set the structure of the codebook (or bit string, etc.) related to the MBS. Specifically, the control unit 270 can change or determine the structure of the Type 1 HARQ-ACK CB (codebook) based on specific conditions.

[0113] Furthermore, in the HARQ-ACK CB determination algorithm, as mentioned above, Type 1 (type-1) and Type 2 (type-2) are specified. The main difference between Type 1 and Type 2 is that Type 1 constructs the HARQ-ACK CB semi-statically, while Type 2 constructs the HARQ-ACK CB dynamically.

[0114] In the case of Type 1 HARQ-ACK CB, the control unit 270 can feed back the HARQ-ACK bit corresponding to the predetermined range (e.g., a range based on higher-level parameters) within a predetermined range, regardless of whether there is a PDSCH schedule.

[0115] This predetermined range can be determined based on at least one of the following: a specified period (e.g., a set of predetermined number of occasions for candidate PDSCH reception or a predetermined number of monitoring occasions for PDCCH), the number of component carriers set or activated for UE 200, the number of transport blocks (TBs) (layers or rank), the number of code block groups per TB, and whether or not there is application space bundling. This predetermined range may also be referred to as a HARQ-ACK bundling window, HARQ feedback window, bundling window, feedback window, etc.

[0116] For example, the control unit 270 can determine the structure of the HARQ feedback of the PDSCH (also known as MBS PDSCH) related to MBS and the HARQ feedback of the PDSCH inherent in the terminal, based on the UE capability of the UE 200.

[0117] Specifically, the control unit 270 can determine the structure of the HARQ feedback for the common PDSCH (also known as the first downlink data channel) for the UE group (terminal group) and the HARQ feedback for the terminal-specific PDSCH (second downlink data channel). The terminal-specific PDSCH can also be referred to as the unicast PDSCH.

[0118] As a structural requirement for HARQ-ACK CB, UE capabilities include, for example, the ability to simultaneously receive (Frequency Division Multiplexing (FDM)) unicast PDSCH and MBS PDSCH in the same symbol within a cell.

[0119] However, the capability is not limited to this, as long as it can explicitly or implicitly represent the simultaneous reception of unicast PDSCH and MBS PDSCH. That is, the control unit 270 can determine the structure based on whether MBS PDSCH (first downlink data channel) and unicast PDSCH (second downlink data channel) can be received in the same time domain in the same cell (i.e., whether it is set to be received in the same time domain).

[0120] Furthermore, the control unit 270 can determine the structure of HARQ feedback for MBSPDSCH and HARQ feedback for unicast PDSCH (specifically, the structure of HARQ-ACK CB) based on parameters of the Radio Resource Control (RRC) layer rather than UE capabilities.

[0121] For example, the control unit 270 can also determine the structure of the HARQ-ACK CB based on whether predetermined parameters in the RRC are set. The predetermined parameters are not limited; for example, they can be any parameters that indicate whether FDM of unicast PDSCH and MBS PDSCH is applied (or whether TDM is not applied).

[0122] Alternatively, the control unit 270 may determine the structure of the HARQ-ACK CB based on the values ​​represented by the parameters of the RRC. For example, this content only needs to represent FDM (or TDM) using unicast PDSCH and MBS PDSCH.

[0123] Furthermore, the control unit 270 may also interpret the possibility that unicast PDSCH and MBS PDSCH are received at the same time in a cell as limited to meeting predetermined conditions.

[0124] In other words, the control unit 270 can envision that MBSPDSCH and unicast PDSCH are received in the same time domain only when specific conditions are met in the same cell.

[0125] Alternatively, the control unit 270 may be limited to the following situation: the HARQ-ACK bit for a certain MBS PDSCH and the HARQ-ACK bit for a certain unicast PDSCH correspond to different HARQ-ACK bits of type 1 HARQ-ACK CB.

[0126] In addition, gNB 100 is capable of performing downlink channel scheduling and HARQ-related control as described above.

[0127] (3) Operation of wireless communication system

[0128] Next, the operation of the wireless communication system 10 will be explained. Specifically, the scheduling of the downlink channel related to MBS and the operation related to HARQ feedback of the channel will be explained.

[0129] Figure 5 This shows a timing example of PDCCH, PDSCH, and HARQ feedback in MBS. For example... Figure 5As shown, the PDCCH (which may contain DCI) and PDSCH can be transmitted via unicast or multicast (broadcast). In addition, the UE 200 can send HARQ feedback (ACK / NACK) for this channel (transport blocks (TB) received via this channel).

[0130] In addition, Figure 5 In this context, it appears that both unicast and multicast PDSCHs are sent after a PDCCH / DCI, but it can also be sent to either unicast or multicast PDSCHs after a PDCCH / DCI. That is, a PDCCH / DCI can schedule either unicast or multicast PDSCHs.

[0131] In addition, such as Figure 5 As shown, in the feedback of MBS's HARQ, HARQ-ACK CB can be constructed as described above. Regarding the structure of HARQ-ACK CB, it is envisioned that type 1 HARQ-ACK CB is generated by unioning the PDSCH Time Domain Resource Allocation (TDRA) table / set.

[0132] Type 1 HARQ-ACK CB, as described above, is semi-static and can be interpreted as HARQ-ACK bits corresponding to actual and potential PDSCH reception. Type 1 HARQ-ACK CB is a method based on the premise that multiple PDSCHs on the same symbol do not overlap within a cell.

[0133] Type 1 HARQ-ACK CB works when MBS PDSCH and unicast PDSCH are TDM, but not when MBS PDSCH and unicast PDSCH are FDM, so other methods are needed.

[0134] Figure 6 An example of constructing a type 1 HARQ-ACK CB by linking the PDSCHTDR table / set is shown. Figure 6 In the example, it is shown that the same letters of PDSCH are represented by the same HARQ-ACK bits.

[0135] As mentioned above, in Type 1 HARQ-ACK CB, the following two configuration methods can be envisioned.

[0136] • (i) The configuration method when MBS PDSCH and unicast PDSCH are multiplexed in a cell (or the same cell) via TDM.

[0137] (ii) The configuration method when MBS PDSCH and unicast PDSCH are multiplexed in a cell (or the same cell) via FDM.

[0138] (i) Alternatively, a method can be used to generate the CB based on the connection of the TDRA table / set using the same method as the separate unicast case. This method can be applied to all time slots. Furthermore, it can be limited to time slots capable of transmitting both unicast PDSCH and MBSPDSCH.

[0139] (ii) Alternatively, a method may be used to generate a CB that is not based on or based on a TDRA table / set link, but rather through a method different from the unicast case alone. In this case, the CB can be generated using any of the following methods.

[0140] • (Option 1): Generate the CB for the unicast PDSCH for all time slots and the CB for the MBS PDSCH for all time slots, and then link them together.

[0141] • (Option 2): Generate a CB for unicast PDSCH and a CB for MBS PDSCH in each time slot, and repeatedly link them for all time slots.

[0142] • (Option 3): Divide the unicast PDSCH and MBS PDSCH into SLIV (Start and Length Indicator Value) groups (e.g., Figure 6 A, B, and C are equivalent to each SLIV group. In each SLIV group, CBs for unicast PDSCH and MBS PDSCH are repeatedly generated and linked together for all SLIV groups in all time slots.

[0143] (3.1) Example of action 1

[0144] In this example, the method of constructing the Type 1 HARQ-ACK CB can be changed based on predetermined conditions. Alternatively, the method of constructing the Type 1 HARQ-ACK CB can use either (i) or (ii) described above.

[0145] Specifically, UE 200 can perform actions according to action examples 1-1 to 1-4.

[0146] • (Action Example 1-1): The predetermined UE capability is a predetermined value.

[0147] For example, it could be the following UE capability: indicating whether it supports the function of simultaneously receiving unicast PDSCH and MBS PDSCH on the same symbol (or other time domain statements) in a certain cell (or it can be interpreted as supporting FDM).

[0148] If the feature is supported, (i) can be applied; if it is not supported, (ii) can be applied.

[0149] Based on such an action example, in UEs that do not support FDM, it is possible to avoid feedback of excessive bits.

[0150] • (Action Example 1-2): Set the predetermined RRC parameters

[0151] For example, it could also be an RRC parameter indicating whether (ii) is executed. If this RRC parameter is set, (i) can be applied; if it is not set, (ii) can be applied.

[0152] Based on such action examples, the network can appropriately control UE 200 to meet the required communication quality.

[0153] • (Action Example 1-3): The predetermined RRC parameter is a predetermined value.

[0154] For example, it could be an RRC parameter that directly represents (i) or (ii). Through such an example of action, the network can also appropriately control the UE 200 to meet the required communication quality.

[0155] • (Action Examples 1-4): The settings related to PDSCH allocation are settings that may result in the simultaneous reception of (FDM) unicast PDSCH and MBS PDSCH on the same symbol in a cell.

[0156] Figure 7 The structure example of type 1 HARQ-ACK CB for action example 1 is shown (the case of TDM performed by unicast PDSCH and MBS PDSCH). Figure 8 The structure example of type 1 HARQ-ACK CB for action example 1 is shown (the case of TDM performed by unicast PDSCH and MBS PDSCH).

[0157] For example, for PDSCH candidates in the TDRA table / set, if they may be assigned the same symbol in a certain cell, the construction method of (ii), i.e., the case of FDM between unicast PDSCH and MBS PDSCH, can be applied.

[0158] On the other hand, for PDSCH candidates in the TDRA table / set, if they cannot be assigned the same symbol in a certain cell, the case of (i), i.e., TDM between unicast PDSCH and MBS PDSCH, can be applied.

[0159] Additionally, regarding the candidates for the indication in the PDSCH-to-HARQ_feedback timing indicator field of DCI, if they are likely to be scheduled to the same time slot in a cell, (i) or (ii) can be applied.

[0160] Alternatively, regarding the candidate indication in the PDSCH-to-HARQ_feedback timing indicator field, it can be applied in cases where it is impossible to be scheduled to the same time slot in a certain cell (ii).

[0161] Based on this action example, an appropriate reuse method can be selected based on whether FDM is actually possible.

[0162] (3.2) Action Example 2

[0163] The possibility of MBS PDSCH and unicast PDSCH being received on the same symbol in a cell can also be limited to situations where predetermined conditions are met.

[0164] Specifically, UE 200 can perform actions according to Action Example 2-1.

[0165] • (Action Example 2-1): This can be limited to the case where the HARQ-ACK bits for a certain MBS PDSCH and the HARQ-ACK bits for a certain unicast PDSCH correspond to different HARQ-ACK bits of type 1 HARQ-ACK CB.

[0166] For example, it can be limited to the case where the HARQ-ACK CB is constructed according to the construction method of (i) and corresponds to different HARQ-ACK bits.

[0167] Figure 9 The structure example of type 1 HARQ-ACK CB for action example 2 is shown. Figure 9 The structural example shown is similar to Figure 6 The structure shown is the same.

[0168] For example, in receiving and Figure 9In the case of a unicast PDSCH corresponding to “A” (SLIV group), it can be assumed that the MBS PDSCH corresponding to “B” can be received simultaneously, but the MBS PDSCH corresponding to “A” cannot be received simultaneously.

[0169] Based on this example, the same configuration method for HARQ-ACK CB can be applied in the case of TDM / FDM.

[0170] (4) Function / Effect

[0171] According to the above implementation method, the following effects can be obtained. Specifically, UE 200 can determine the structure of HARQ feedback for MBS PDSCH (first downlink data channel) and HARQ feedback for unicast PDSCH (second downlink data channel) based on terminal capabilities or RRC parameters.

[0172] Furthermore, UE 200 can envision MBS PDSCH and unicast PDSCH being received in the same time domain only when specific conditions are met within the same cell.

[0173] Therefore, even when the structure of the HARQ-ACK CB differs depending on the multiplexing method of TDM or FDM, the UE 200 can construct appropriate HARQ feedback regardless of the multiplexing method of MBS PDSCH and unicast PDSCH.

[0174] Furthermore, in this embodiment, UE 200 can determine the structure of the Type 1 HARQ-ACK CB based on whether the MBS PDSCH and unicast PDSCH are received in the same time domain within the same cell. Therefore, it is possible to construct an appropriate Type 1 HARQ-ACK CB corresponding to the state of the MBS PDSCH and unicast PDSCH.

[0175] (5) Other implementation methods

[0176] The above describes the implementation methods, but the present invention is not limited to the description of these implementation methods. It is obvious to those skilled in the art that various modifications and improvements can be made.

[0177] For example, in the above implementation, the names PDCCH and PDSCH are used as downlink channels, but as long as it is a downlink control channel or a downlink data channel (or a shared channel), it can also be called by other names.

[0178] Furthermore, in the above description, the terms configure, activate, update, indicate, enable, specify, and select can be interchanged. Similarly, the terms link, associate, correspond, and map can be interchanged, as can allocate, assign, monitor, and map.

[0179] Furthermore, specific, dedicated, UE specific, and UE dedicated can be used interchangeably. Similarly, common, shared, group-common, UE common, and UE shared can also be used interchangeably.

[0180] Furthermore, the block structure diagram used in the description of the above embodiments ( Figure 4 The term "functional block" represents a module based on function. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Furthermore, there are no particular limitations on the implementation method of each functional block. That is, each functional block can be implemented using a single device that is physically or logically combined, or by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. Functional blocks can also be implemented by combining software within one or more of the aforementioned devices.

[0181] The functions include judgment, decision, determination, calculation, calculation, processing, derivation, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but are not limited to these. For example, the functional block (structural part) that enables sending is called the transmitting unit or transmitter. In short, as mentioned above, there are no particular limitations on the implementation method.

[0182] Furthermore, the aforementioned gNB 100 and UE 200 can also function as computers for processing the wireless communication method disclosed herein. Figure 10This is a diagram illustrating an example of the hardware structure of the device. (As shown) Figure 10 As shown, the device can also 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.

[0183] Additionally, in the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware structure of this device can be configured as either a device comprising one or more of the illustrated components, or a device without any components.

[0184] The functional blocks of the device (refer to) Figure 4 This can be achieved through any hardware element or combination of hardware elements in the computer device.

[0185] Furthermore, the functions of the device are implemented by reading predetermined software (programs) into hardware such as processor 1001 and memory 1002, so that processor 1001 performs calculations and controls communication of communication device 1004 or controls at least one of reading and writing data in memory 1002 and storage 1003.

[0186] The processor 1001 controls the computer as a whole, for example, by instructing the operating system to operate. The processor 1001 may also be a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc.

[0187] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one direction of the memory 1002 in the memory 1003 and the communication device 1004, and performs various processes accordingly. The program is used to cause the computer to perform at least a portion of the actions described in the above embodiments. Moreover, the various processes described above can be executed by one processor 1001, or by two or more processors 1001 simultaneously or sequentially. The processor 1001 can also be implemented using more than one chip. Additionally, the program can be transmitted from a network via a telecommunications line.

[0188] Memory 1002 is a computer-readable recording medium, and may be composed of at least one of the following: Read Only Memory (ROM), Erasable Programmable Memory (EPROM), Electrically Erasable Programmable Memory (EEPROM), Random Access Memory (RAM). Memory 1002 may be referred to as a register, cache memory, main memory (main storage device), etc. Memory 1002 may store programs (program code), software modules, etc., capable of executing the methods involved in one embodiment of this disclosure.

[0189] Memory 1003 is a computer-readable recording medium, and may be composed of at least one of the following: optical discs such as CD-ROM (Compact Disc ROM), hard disks, floppy disks, magneto-optical discs (e.g., compact discs, digital multipurpose discs, Blu-ray discs), smart cards, flash memory (e.g., cards, sticks, key drives), floppy disks, magnetic stripes, etc. Memory 1003 may also be referred to as an auxiliary storage device. The aforementioned recording medium may be, for example, a database, server, or other suitable media that includes at least one of memory 1002 and memory 1003.

[0190] The communication device 1004 is hardware (transceiver) used for communication between computers via at least one of a wired network and a wireless network. For example, it may also be called a network device, network controller, network card, communication module, etc.

[0191] The communication device 1004 may also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., to realize at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0192] Input device 1005 is an input device that accepts input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, LED, etc.). Alternatively, input device 1005 and output device 1006 can also be integrated (e.g., a touch panel).

[0193] Furthermore, devices such as processor 1001 and memory 1002 are connected via bus 1007 for communicating information. Bus 1007 can be a single bus or can be composed of different buses between devices.

[0194] Furthermore, the device can 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), and a field-programmable gate array (FPGA), which can be used to implement some or all of the functional blocks. For example, the processor 1001 can also be implemented using at least one of these hardware components.

[0195] Furthermore, the notification of information is not limited to the forms / implementations described in this disclosure, and other methods may also be used. For example, the notification of information may be implemented through 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 combinations thereof. In addition, RRC signaling may also be referred to as an RRC message, for example, it may be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0196] The various forms / implementations described in this disclosure can also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), 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, UWB (Ultra-Wideband), Bluetooth (registered trademark), other suitable systems, and next-generation systems extended therefrom. Furthermore, multiple systems can be combined (e.g., a combination of at least one of LTE and LTE-A with 5G, etc.) for application.

[0197] The processing steps, timing, and processes described in this disclosure can be rearranged in order without contradiction. For example, the illustrated order is used to indicate the elements of each step in the methods described in this disclosure, but the order is not limited to the specific order indicated.

[0198] In this disclosure, certain actions performed by the base station are sometimes also performed by its upper node, depending on the circumstances. In a network consisting of one or more network nodes having a base station, it is obvious that various actions performed to communicate with a terminal can be performed by at least one of the base station and other network nodes besides the base station (e.g., considering an MME or S-GW, but not limited to these). The above illustration depicts a case where there is only one other network node besides the base station, but it can also be a combination of multiple other network nodes (e.g., an MME and an S-GW).

[0199] It can output information and signals (information, etc.) from a higher (or lower) level to a lower (or higher) level. It can also be input or output through multiple network nodes.

[0200] Input or output information can be stored in a specific location (e.g., memory) or managed using a management table. Input and output information can be overwritten, updated, or appended. Output information can be deleted. Input information can also be sent to other devices.

[0201] The determination can be made by the value represented by 1 bit (0 or 1), by a Boolean value (Boolean: true or false), or by comparing numerical values ​​(e.g., comparing with a predetermined value).

[0202] The various forms / implementations described in this disclosure can be used individually or in combination, and can be switched depending on the execution. Furthermore, the notification of predetermined information is not limited to explicit notification (e.g., a "Yes X" notification) but can also be implicit notification (e.g., not notifying the predetermined information).

[0203] Software, whether called software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted as referring to commands, command sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0204] In addition, software, commands, and information can also be sent and received via transmission media. For example, when using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL) etc.) and wireless technologies (infrared, microwave, etc.) to send software from a webpage, server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission media.

[0205] The information, signals, etc., described in this disclosure can also be represented using any of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc., that may be involved in the above description as a whole can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0206] Furthermore, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms that have the same or similar meanings. For example, at least one of the channel and symbol may also be a signal (signaling). Additionally, a signal may also be a message. Furthermore, a component carrier (CC) may also be referred to as carrier frequency, cell, frequency carrier, etc.

[0207] The terms “system” and “network” as used in this disclosure are used interchangeably.

[0208] Furthermore, the information, parameters, etc., described in this disclosure may be represented using absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may be indicated using indexes.

[0209] The names used for the above parameters are non-limiting in any respect. Furthermore, the formulas, etc., using these parameters sometimes differ from those explicitly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by appropriate names, therefore the various names assigned to these channels and information elements are non-limiting in any respect.

[0210] In this disclosure, the terms "Base Station (BS)," "wireless 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" are used interchangeably. Sometimes, terms such as macro cell, small cell, femtocell, and picocell are also used to refer to base stations.

[0211] 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 also provide communication services through the base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0212] Terms such as “cell” or “sector” refer to a portion or the entire coverage area of ​​at least one of the base stations and base station subsystems that provide communication services within that coverage area.

[0213] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0214] For mobile stations, those skilled in the art sometimes also use the following terms: 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, handheld device, user agent, mobile client, client, or some other appropriate terms.

[0215] At least one of the base station and mobile station can also be referred to as a transmitting device, receiving device, communication device, etc. Additionally, at least one of the base station and mobile station can also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body can be a vehicle (e.g., a car, an airplane, etc.), a mobile body moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Furthermore, at least one of the base station and mobile station also includes devices that do not necessarily move during communication. For example, at least one of the base station and mobile station can be an IoT (Internet of Things) device such as a sensor.

[0216] Furthermore, the base station in this disclosure can also be replaced by a mobile station (user terminal, hereinafter the same). For example, various forms / implementations of this disclosure can also be applied to structures that replace communication between the base station and the mobile station with communication between multiple mobile stations (e.g., also referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the structure can also be configured such that the mobile station has the functions of the base station. In addition, terms such as "uplink" and "downlink" can also be replaced with terms corresponding to communication between terminals (e.g., "side"). For example, uplink channel, downlink channel, etc. can also be replaced with side channel (or side link).

[0217] Similarly, the mobile station in this disclosure can be replaced by a base station. In this case, the base station can also be configured to have the functions of a mobile station.

[0218] A radio frame can consist of one or more frames in the time domain. Each frame in the time domain is called a subframe. A subframe can also consist of one or more time slots in the time domain. A subframe can have a fixed duration (e.g., 1 ms) independent of the parameter set (numerology).

[0219] A parameter set can be communication parameters applied to at least one of the transmission and reception of a signal or channel. For example, a parameter set can represent at least one of the following: Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transceiver in the frequency domain, and specific windowing processing performed by the transceiver in the time domain.

[0220] In the time domain, a time slot can be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A time slot can be a time unit based on a set of parameters.

[0221] A time slot can contain multiple mini-time slots. Each mini-time slot can consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can consist of fewer symbols than a time slot. PDSCH (or PUSCH) transmitted in time units larger than mini-time slots can be called PDSCH (or PUSCH) mapping type (type) A. PDSCH (or PUSCH) transmitted using mini-time slots can be called PDSCH (or PUSCH) mapping type (type) B.

[0222] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can each be referred to by other corresponding names.

[0223] For example, a single subframe can be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and a single time slot or a single mini-time slot can also be called a TTI. That is, at least one of a subframe or TTI can be a subframe (1ms) in existing LTE, a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. Furthermore, the unit representing TTI may not be called a subframe, but rather a time slot, mini-time slot, etc.

[0224] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules the allocation of radio resources (bandwidth, transmit power, etc., available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0225] The Time Interval (TTI) can be a unit of time for transmitting channel-coded data packets (transmission blocks), code blocks, codewords, etc., or it can be a processing unit such as scheduling or link adaptation. Furthermore, when a TTI is given, the actual time interval (e.g., the number of symbols) that the transmission block, code block, codeword, etc., are mapped to can be shorter than the TTI.

[0226] Furthermore, when one time slot or one mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can become the minimum time unit for scheduling. In addition, the number of time slots (mini-time slots) constituting the minimum time unit for scheduling can be controlled.

[0227] A TTI with a duration of 1ms is also called a normal TTI (TTI in LTE Rel.8-12), a long TTI, a normal subframe, a long subframe, or a time slot. A TTI shorter than a normal TTI can also be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini time slot, a sub-time slot, or a time slot.

[0228] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) can be understood as a TTI with a duration of more than 1ms, and a short TTI (e.g., a shortened TTI, etc.) can be understood as a TTI with a duration of less than a long TTI but more than 1ms.

[0229] A resource block (RB) is a unit of resource allocation in both the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers contained in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers contained in an RB can also be determined based on the parameter set.

[0230] Furthermore, the temporal domain of an RB can contain one or more symbols, which can be a single time slot, a single mini-time slot, a single subframe, or the length of a single TTI. A single TTI, a single subframe, etc., can each be composed of one or more resource blocks.

[0231] In addition, one or more RBs can also be called Physical Resource Block (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0232] Furthermore, a resource block can consist of one or more resource elements (REs). For example, one RE can be a radio resource area consisting of one subcarrier and one symbol.

[0233] The Bandwidth Part (BWP) (also known as partial bandwidth, etc.) represents a subset of contiguous common resource blocks (RBs) used for a specific parameter set on a given carrier. Here, common RBs can be determined by indexing RBs based on a common reference point of that carrier. PRBs can be defined and numbered within a BWP.

[0234] A BWP can include a UL BWP and a DL BWP. One or more BWPs can be set for a UE within a single carrier.

[0235] At least one of the configured BWPs can be active, and it is not assumed that the UE will transmit or receive predetermined signals / channels outside of the active BWP. In addition, the terms "cell" and "carrier" in this disclosure can be replaced by "BWP".

[0236] The structures of radio frames, subframes, time slots, mini-time slots, and symbols described above are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained within a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc., can be varied in many ways.

[0237] The terms “connected,” “coupled,” or any variations thereof are intended to indicate any direct or indirect connection or combination between two or more elements, including cases where there is one or more intermediate elements between the two elements that are “connected” or “coupled.” The combination or connection between elements can be physical, logical, or a combination of these. For example, “access” can be used instead of “connected.” In the context of this disclosure, it can be understood that two elements are “connected” or “coupled” to each other using at least one of one or more wires, cables, and printed electrical connections, and, as some non-limiting and non-inclusive examples, using electromagnetic energy with wavelengths in the wireless frequency domain, microwave region, and light (including both visible and invisible regions) to “connect” or “couple” to each other.

[0238] The reference signal can be simply called the Reference Signal (RS), or, depending on the standard applied, the pilot.

[0239] As used in this disclosure, the word "based on" does not mean "based on only" unless otherwise expressly stated. In other words, the word "based on" means both "based on only" and "based on at least" both.

[0240] Alternatively, the "unit" in the structure of the above devices can be replaced with "section", "circuit", "equipment", etc.

[0241] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not necessarily limit the number or order of these elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Therefore, reference to the first and second elements does not imply that only two elements can be used there, or that the first element must precede the second element in some form.

[0242] When the terms "include," "including," and their variations are used in this disclosure, these terms, like the term "comprising," imply inclusion. Furthermore, the term "or" as used in this disclosure does not refer to XOR.

[0243] In this disclosure, for example, in cases where articles are added through translation, such as in English (a, an, and the), this disclosure also includes cases where the noun following these articles is in a plural form.

[0244] The terms "determining" and "determining" as used in this disclosure sometimes encompass a variety of actions. For example, "determining" or "determining" may include actions such as judging, calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), and ascertaining, which are considered as actions of "determining" or "determining." Furthermore, "determining" or "determining" may include actions such as receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, and accessing (e.g., accessing data in memory), which are considered as actions of "determining" or "determining." Additionally, "determining" or "determining" may include actions such as resolving, selecting, choosing, establishing, and comparing, which are considered as actions of "determining" or "determining." That is, "judgment" and "decision" can include matters that are considered as having been "judged" or "decided". In addition, "judgment (decision)" can also be replaced by "assuming", "expecting", "considering", etc.

[0245] In this disclosure, the phrase "A and B are different" can mean "A and B are not the same." Additionally, this phrase can also mean "A and B are each different from C." Terms such as "separate" and "combined" can also be interpreted in the same way as "different."

[0246] The present disclosure has been described in detail above, but it will be 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 as modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the present disclosure is for illustrative purposes only and is not intended to be limiting.

[0247] Label Explanation

[0248] 10: Wireless Communication System

[0249] 20: NG-RAN

[0250] 100: gNB

[0251] 200:UE

[0252] 210: Wireless Signal Transceiver Unit

[0253] 220: Enlarged section

[0254] 230: Modulation and Demodulation Section

[0255] 240: Control Signal & Reference Signal Processing Unit

[0256] 250: Encoding / Decoding Section

[0257] 260: Data Transceiver Department

[0258] 270: Control Department

[0259] 1001: Processor

[0260] 1002: Memory

[0261] 1003: Memory

[0262] 1004: Communication device

[0263] 1005: Input device

[0264] 1006: Output device

[0265] 1007: Bus

Claims

1. A terminal having: The control unit, based on parameters from the radio resource control layer, determines which of the first and second methods should be used for feedback transmission. In the first method, an automatic repeat request feedback codebook is generated based on the connection between the time-domain resource allocation for the first downlink data channel in multicast and the time-domain resource allocation for the second downlink data channel in unicast. In the second method, the codebooks for the automatic repeat request feedback of the first downlink data channel and the second downlink data channel are generated separately and then combined to generate a new codebook. The transmitting unit, based on the decision, transmits automatic retransmission request feedback for the reception of the first downlink data channel and automatic retransmission request feedback for the reception of the second downlink data channel.

2. The terminal according to claim 1, wherein, Upon receiving the parameters indicating that the first downlink data channel and the second downlink data channel are frequency-division multiplexed, the control unit decides to use the second method.

3. The terminal according to claim 1, wherein, The transmitting unit transmits information indicating its ability to receive the first downlink data channel and the second downlink data channel in the same time domain.

4. A communication method for a terminal, comprising the following steps: Based on the parameters of the Radio Resource Control (RRC) layer, it is determined which of the first and second methods will be used for feedback transmission. In the first method, an automatic repeat request (ARP) feedback codebook is generated based on the connection between the time-domain resource allocation for the first downlink data channel in multicast and the time-domain resource allocation for the second downlink data channel in unicast. In the second method, the ARP feedback codebooks for the first and second downlink data channels are generated separately and then combined to generate the next codebook. Based on the decision, an automatic retransmission request feedback for the reception of the first downlink data channel and an automatic retransmission request feedback for the reception of the second downlink data channel are sent.

5. A communication system comprising a base station and a terminal, The base station has a transmitting unit that performs transmission based on the first downlink data channel in multicast and transmission based on the second downlink data channel in unicast. The terminal has: The control unit, based on parameters from the radio resource control layer, determines which of the first and second methods should be used for feedback transmission. In the first method, an automatic repeat request feedback codebook is generated based on the connection between the time-domain resource allocation for the first downlink data channel and the time-domain resource allocation for the second downlink data channel. In the second method, the codebooks for the automatic repeat request feedback of the first and second downlink data channels are combined to generate a new codebook. The transmitting unit, based on the decision, transmits automatic retransmission request feedback for reception based on the first downlink data channel and automatic retransmission request feedback for reception based on the second downlink data channel.

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