Terminal, base station, communication method and integrated circuit

Abstract

The present invention improves the efficiency of downlink retransmission control. A terminal includes: a control circuit that performs retransmission control for a plurality of transport blocks in units of a code block group including at least one code block, the code block being a code block among one or more transport blocks among the plurality of transport blocks; and a communication circuit that performs communication according to the retransmission control.

Description

Terminals, base stations, communication methods and integrated circuits

[0001] This application is a divisional application of Chinese invention patent application filed on May 20, 2021, with application number 202180058149.3, entitled "Terminal, Base Station, Communication Method and Integrated Circuit", and filed by Panasonic Corporation (USA). Technical Field

[0002] This disclosure relates to terminals, base stations, and communication methods. Background Technology

[0003] In recent years, against the backdrop of the expansion and diversification of wireless services, the rapid development of the Internet of Things (IoT) is anticipated. The application of mobile communication is expanding beyond information terminals such as smartphones to all areas, including vehicles, homes, home appliances, and industrial equipment. To support this service diversification, in addition to increasing system capacity, there are demands for significantly improved performance and functionality of mobile communication systems to meet various necessary conditions such as the increase in the number of connected devices and low latency. Fifth-generation mobile communication systems (5G) can flexibly provide wireless communication to meet diverse needs through enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC).

[0004] The 3rd Generation Partnership Project (3GPP), an international standards organization, is developing specifications for New Radio (NR), one of the wireless interfaces for 5G.

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent literature 1: RP-201386, “Revised SID on Study on support of reduced capability NR devices,” Ericsson, June 29 - July 3, 2020.

[0008] Non-patent literature 2: RP-200938, “Revised WID UE Power Saving Enhancements for NR,” MediaTek Inc., June 29 - July 3, 2020.

[0009] Non-patent document 3: 3GPP TS36.212, “Evolved Universal Terrestrial RadioAccess (E-UTRA); Multiplexing and channel coding (Release 16),” March 2020.

[0010] Non-patent literature 4: 3GPP TS36.213, “Evolved Universal Terrestrial RadioAccess (E-UTRA); Physical layer procedures (Release 17),” March 2020.

[0011] Non-patent literature 5: 3GPP TS38.212, “NR; Multiplexing and channel coding (Release 16),” March 2020.

[0012] Non-patent literature 6: 3GPP TS38.214, “NR; Physical layer procedures for data (Release 16),” March 2020. Summary of the Invention

[0013] However, there is still room for research on retransmission control for the downlink (DL).

[0014] The non-limiting embodiments of this disclosure help to provide terminals, base stations, and communication methods that can improve the efficiency of downlink retransmission control.

[0015] One embodiment of the present disclosure includes a terminal comprising: a control circuit for retransmitting multiple transmission blocks in units of a group of code blocks containing at least one code block, the code block being a code block in one or more of the multiple transmission blocks; and a communication circuit for communicating according to the retransmission control.

[0016] It should be noted that these general or specific methods can be implemented by systems, devices, methods, integrated circuits, computer programs, or recording media, or by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0017] According to one embodiment of this disclosure, the efficiency of downlink retransmission control can be improved.

[0018] Further advantages and effects of one embodiment of the present invention will be illustrated by the description and drawings. These advantages and / or effects are provided by the various embodiments and the features described in the description and drawings, but not necessarily all of them need to be provided in order to obtain one or more of the same features. Attached Figure Description

[0019] Figure 1 is a diagram illustrating an example of multiple transport block (TB) scheduling.

[0020] Figure 2 is a block diagram showing a structural example of a part of a base station.

[0021] Figure 3 is a block diagram showing a structural example of a portion of a terminal.

[0022] Figure 4 is a block diagram showing an example of the structure of a base station.

[0023] Figure 5 is a block diagram showing an example of the terminal's structure.

[0024] Figure 6 is a diagram illustrating an example of code block segmentation.

[0025] Figure 7 is a diagram showing a structural example of the Code Block Group (CBG) in Implementation Method 1.

[0026] Figure 8 is a diagram showing a structural example of the CBG in Embodiment 1.

[0027] Figure 9 is a diagram showing a structural example of the CBG in Embodiment 1.

[0028] Figure 10 is a diagram showing a structural example of the CBG in Embodiment 1.

[0029] Figure 11 is a diagram showing a structural example of the CBG in Embodiment 1.

[0030] Figure 12 is a flowchart illustrating an example of the operation of a base station in Implementation Method 1.

[0031] Figure 13 is a flowchart illustrating an example of the operation of the terminal in Implementation Method 1.

[0032] Figure 14 is a diagram showing an example of the configuration of the Physical Uplink Control Channel (PUCCH) resources in Implementation 2.

[0033] Figure 15 is a diagram showing an example of the PUCCH resource configuration in Implementation 2.

[0034] Figure 16 is a diagram showing an example of the PUCCH resource configuration in Implementation 2.

[0035] Figure 17 is a diagram showing an example of the PUCCH resource configuration in Implementation 2.

[0036] Figure 18 is a diagram showing an example of the combination of PUCCH resources in Implementation 2.

[0037] Figure 19 is a diagram showing an example of the PUCCH resource configuration in Implementation 2.

[0038] Figure 20 is a diagram illustrating an example of retransmission control in Implementation 2.

[0039] Figure 21 is a diagram illustrating an example of retransmission control in Implementation Method 2.

[0040] Figure 22 is a diagram showing a configuration example of the TB group in Implementation Method 3.

[0041] Figure 23 is a diagram of an exemplary architecture of a 3GPP NR system.

[0042] Figure 24 is a schematic diagram illustrating the functional separation between NG-RAN (Next Generation-Radio Access Network) and 5GC (5th Generation Core).

[0043] Figure 25 is a sequence diagram of the setup / reset process for an RRC (Radio Resource Control) connection.

[0044] Figure 26 is a schematic diagram illustrating the application scenarios of enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC).

[0045] Figure 27 is a block diagram illustrating an exemplary 5G system architecture for non-roaming scenarios.

[0046] Explanation of reference numerals in the attached figures

[0047] 100 Base station; 101, 205 Control unit; 102 Higher layer control signal generation unit; 103 Downlink control information generation unit; 104, 206 Encoding unit; 105, 207 Modulation unit; 106, 208 Signal distribution unit; 107, 209 Transmitting unit; 108, 201 Receiving unit; 109, 202 Extraction unit; 110, 203 Demodulation unit; 111, 204 Decoding unit; 200 Terminal. Detailed Implementation

[0048] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0049] Looking ahead, we anticipate further development of 5G or the technological advancements of 6G (6th Generation mobile communication systems). For instance, early 5G terminals corresponding to NR were mostly high-end models. Furthermore, Rel. 16, for example, explored specifications for high-performance IoT applications, such as those used in industries with stringent requirements. On the other hand, for relatively simple devices like cameras, wearables, and inexpensive smartphones used in industry, we expect lower power consumption in terminals (e.g., see Non-Patent Literature 1 or Non-Patent Literature 2).

[0050] As a technique to reduce terminal power consumption, one example is to have the terminal intermittently receive the downlink control channel (e.g., PDCCH: Physical Downlink Control Channel), thereby reducing the number of blind decoding operations for PDCCH reception and thus suppressing terminal power consumption. However, for example, the less frequent the PDCCH reception due to intermittent PDCCH reception, the fewer opportunities there are for data to be allocated by the PDCCH, and therefore, transmission efficiency may decrease.

[0051] As one method to suppress the decline in transmission efficiency and reduce the receiving frequency of PDCCH, thereby suppressing the power consumption of the terminal, one example is multi-transport block (TB) scheduling (e.g., multi-TBscheduling).

[0052] Figure 1 is a diagram illustrating an example of multi-TB scheduling. For example, downlink control signals (e.g., DCI: Downlink Control Information) containing scheduling information such as resource allocation from a base station (e.g., also referred to as a "gNB") can be transmitted via the PDCCH. A terminal (e.g., also referred to as a "User Equipment") can, for example, receive downlink data signals (e.g., PDSCH: Physical Downlink Shared Channel) or transmit uplink data signals (e.g., PUSCH: Physical Uplink Shared Channel) based on the resource allocation indicated by the DCI on the PDCCH.

[0053] In scheduling different from multi-TB scheduling, for example, a DCI may indicate a PDSCH or a PUSCH, and the number of TBs (or "data blocks") contained in a PDSCH or a PUSCH may be one, or, in the case of spatial multiplexing transmission within the same time and frequency resources, the number of TBs may be two. On the other hand, as shown in Figure 1, in multi-TB scheduling, for example, a DCI may allocate multiple PDSCHs or PUSCHs to be transmitted and received at different times or frequencies (e.g., denoted as "PDSCH / PUSCH"). Furthermore, for example, in multi-TB scheduling, as shown in Figure 1, each PDSCH or PUSCH may contain multiple different TBs. Thus, in multi-TB scheduling, for example, a DCI may schedule multiple TBs to be transmitted and received at different times or frequencies.

[0054] Multi-TB scheduling has been used, for example, for uplink transmissions in NR using unlicensed frequency bands (e.g., also known as "NR-Unlicensed (NR-U)"), and for enhanced machine-type communication (eMTC) in Long Term Evolution (LTE), as well as for uplink and downlink transmissions in Narrow Band Internet of Things (NB-IoT) (e.g., see Non-Patent Documents 3 to 6).

[0055] In NR, while multi-TB scheduling is used for uplink transmissions using unlicensed frequency bands, it is not applied to downlink transmissions. For example, when multi-TB scheduling is applied to downlink transmissions, the terminal can send a response signal for the PDSCH for retransmission control. However, in NR, there is room for research into retransmission control that includes feedback on the response signal for downlink data (e.g., PDSCH) allocated by multi-TB scheduling. Furthermore, the response signal may be referred to as "Acknowledgement / Negative Acknowledgement (ACK / NACK)" or "HARQ-ACK (Hybrid Automatic Repeat Request-ACK)".

[0056] Furthermore, in LTE eMTC or NB-IoT, multi-TB scheduling is used for uplink and downlink transmissions, and the standard specifies retransmission control including ACK / NACK feedback for data (e.g., PDSCH or PUSCH) after multi-TB scheduling. However, LTE specifies, for example, a method of retransmitting the entire TB initially transmitted (e.g., TB-based retransmission), while NR specifies a method (e.g., CBG-based retransmission), where, if a TB contains multiple code blocks (e.g., CB: Code Block), the entire TB is not retransmitted, but the erroneous CBG within a CBG (Code Block Group) containing at least one CB is retransmitted. Therefore, there is still room for research regarding CBG-based retransmission control for data allocated by multi-TB scheduling, and the ACK / NACK feedback method.

[0057] Therefore, in one non-limiting embodiment of this disclosure, for example, a CBG-based retransmission control method in multi-TB scheduling is described. According to one non-limiting embodiment of this disclosure, for example, CBG-based retransmission control can be appropriately performed in multi-TB scheduling.

[0058] (Implementation Method 1)

[0059] [Overview of Communication Systems]

[0060] The communication system of the various embodiments of this disclosure includes a base station 100 and a terminal 200.

[0061] Figure 2 is a block diagram showing a structural example of a portion of a base station 100 according to an embodiment of the present disclosure. In the base station 100 shown in Figure 2, a control unit 101 (e.g., equivalent to a control circuit) performs retransmission control for multiple TBs in units of CBGs containing at least one CB, where the CB is the CB in one or more TBs. A transmitting unit 107 and a receiving unit 108 (e.g., equivalent to a communication circuit) communicate with a terminal 200 according to the retransmission control.

[0062] Figure 3 is a block diagram showing a structural example of a portion of a terminal 200 according to an embodiment of the present invention. In the terminal 200 shown in Figure 3, the control unit 205 (e.g., equivalent to a control circuit) performs retransmission control for multiple TBs in units of CBGs containing at least one CB, where the CB is one of more than one TB. The receiving unit 201 and the transmitting unit 209 (e.g., equivalent to a communication circuit) communicate with the base station 100 according to the retransmission control.

[0063] [Base station structure]

[0064] Figure 4 is a block diagram showing a structural example of the base station 100 according to Embodiment 1. In Figure 4, the base station 100 includes a control unit 101, a higher layer control signal generation unit 102, a downlink control information generation unit 103, an encoding unit 104, a modulation unit 105, a signal distribution unit 106, a transmission unit 107, a receiving unit 108, an extraction unit 109, a demodulation unit 110, and a decoding unit 111.

[0065] The control unit 101 determines, for example, information related to multi-TB scheduling and retransmission control for the terminal 200, and outputs the determined information to the higher-layer control signal generation unit 102 or the downlink control information generation unit 103.

[0066] Information related to multi-TB scheduling may include, for example, information related to the number of TBs allocated. Additionally, information related to retransmission control may include, for example, information related to the number of CBGs and information related to PUCCH resource allocation.

[0067] For example, in order to receive PUCCH, information related to multi-TB scheduling and information related to retransmission control can be output to the extraction unit 109, demodulation unit 110 and decoding unit 111.

[0068] Additionally, the control unit 101 may, for example, determine information related to the reception of downlink data signals (e.g., PDSCH) for the terminal 200, and output the determined information to the higher-layer control signal generation unit 102. The information related to PDSCH reception may, for example, include information related to the Time Domain Resource Allocation (TDRA) table.

[0069] Additionally, the control unit 101 determines, for example, information related to downlink data signals, higher-layer control signals (e.g., RRC signals), or downlink signals used to transmit downlink control information (e.g., DCI). This information related to downlink signals may include, for example, information such as the modulation and coding scheme (MCS) and radio resource allocation. The control unit 101 outputs the determined information to, for example, the coding unit 104, the modulation unit 105, and the signal allocation unit 106. Furthermore, the control unit 101 outputs, for example, information related to downlink signals such as higher-layer control signals to the downlink control information generation unit 103.

[0070] Additionally, upon receiving a response signal (e.g., HARQ-ACK) from terminal 200, control unit 101 can generate retransmission control-related information based on the HARQ-ACK bit string input from decoding unit 111. This retransmission control-related information may include, for example, an identification number related to retransmission control (e.g., HARQ process number), new data notification information (e.g., NDI: New Data Indicator), redundancy version (RV), CBG transmission information (CBGTI), or CBG flushing information (CBGFI). For example, the retransmission control-related information can be output to encoding unit 104, downlink control information generation unit 103, and decoding unit 111.

[0071] In addition, for example, when information related to multi-TB scheduling or retransmission control is notified by DCI, this information can also be output to the downlink control information generation unit 103.

[0072] In addition, the control unit 101 may, for example, determine information related to the uplink signal (e.g., coding / modulation method (MCS) and radio resource allocation) for the terminal 200 to transmit uplink data signals (e.g., PUSCH), and output the determined information to the higher layer control signal generation unit 102, the downlink control information generation unit 103, the extraction unit 109, the demodulation unit 110, and the decoding unit 111.

[0073] The higher-level control signal generation unit 102 generates a higher-level control signal bit string based on information input from the control unit 101, and outputs the higher-level control signal bit string to the encoding unit 104.

[0074] The downlink control information generation unit 103 generates a downlink control information (e.g., DCI) bit string based on information input from the control unit 101, and outputs the generated DCI bit string to the encoding unit 104. Furthermore, the control information is sometimes sent to multiple terminals.

[0075] The encoding unit 104 encodes, for example, the downlink data signal, the bit string input from the higher-layer control signal generation unit 102, or the DCI bit string input from the downlink control information generation unit 103 based on information input from the control unit 101. The encoding unit 104 outputs the encoded bit string to the modulation unit 105. For example, for the downlink data signal, the encoding unit 104 can generate a codeword through CB segmentation, rate matching, or CB linking, and apply scrambling.

[0076] Additionally, for example, during the initial transmission, the encoding unit 104 can output the encoded data signal to the modulation unit 105 and retain the encoded data signal. Furthermore, for example, after receiving retransmission control-related information from the control unit 101, the encoding unit 104 can output the corresponding retained data to the data modulation unit. Additionally, for example, after receiving ACKs for all TBs or CBs in the HARQ process, the encoding unit 104 can delete the corresponding retained data.

[0077] The modulation unit 105 modulates the encoded bit string input from the encoding unit 104 based on information input from the control unit 101, and outputs the modulated signal (e.g., symbol string) to the signal distribution unit 106.

[0078] The signal allocation unit 106 maps the symbol string (e.g., containing downlink data signals or control signals) input from the modulation unit 105 to the radio resources, for example, based on information representing radio resources input from the control unit 101. The signal allocation unit 106 then outputs the mapped downlink signal to the transmission unit 107.

[0079] The transmitting unit 107 performs transmission waveform generation processing on the signal input from the signal distribution unit 106, for example, using orthogonal frequency division multiplexing (OFDM). Additionally, in the case of OFDM transmission with an added cyclic prefix (CP), the transmitting unit 107 performs inverse fast fourier transform (IFFT) processing on the signal, adding CP to the IFFT-generated signal. Furthermore, the transmitting unit 107 performs RF (radio frequency) processing on the signal, such as D / A (digital / analog) conversion and up-conversion, and transmits the wireless signal to the terminal 200 via an antenna.

[0080] The receiving unit 108 performs RF processing, such as down-conversion or A / D (Analog / Digital) conversion, on the uplink signal received from the terminal 200 via the antenna. Additionally, in the case of OFDM transmission, the receiving unit 108 performs Fast Fourier Transform (FFT) processing on the received signal and outputs the obtained frequency domain signal to the extraction unit 109.

[0081] The extraction unit 109 extracts, for example, the radio resource portion of the uplink signal (e.g., PUSCH or PUCCH) transmitted by the terminal 200 based on the information input from the control unit 101, and outputs the extracted radio resource portion to the demodulation unit 110.

[0082] The demodulation unit 110 demodulates the uplink signal input from the extraction unit 109 based on information input from the control unit 101. The demodulation unit 110 outputs the demodulation result to the decoding unit 111, for example.

[0083] The decoding unit 111 performs error correction decoding on the uplink signal (e.g., PUSCH or PUCCH) based on information input from the control unit 101 and demodulation results input from the demodulation unit 110, thereby obtaining the decoded received bit sequence (e.g., UL data signal or UCI). The decoding unit 111 may, for example, output the HARQ-ACK bit string contained in the UCI to the control unit 101.

[0084] [Terminal Structure]

[0085] Figure 5 is a block diagram showing a structural example of a terminal 200 according to an embodiment of the present invention. For example, in Figure 5, the terminal 200 includes a receiving unit 201, an extraction unit 202, a demodulation unit 203, a decoding unit 204, a control unit 205, an encoding unit 206, a modulation unit 207, a signal distribution unit 208, and a transmitting unit 209.

[0086] The receiving unit 201 receives downlink signals (e.g., downlink data signals, higher-layer control signals, or downlink control information) from the base station 100 via an antenna, and performs RF processing such as down-conversion or A / D conversion on the received wireless signal to obtain a received signal (baseband signal). Additionally, when receiving OFDM signals, the receiving unit 201 performs FFT processing on the received signal to convert it to the frequency domain. The receiving unit 201 then outputs the received signal to the extraction unit 202.

[0087] For example, based on radio resource-related information concerning downlink control information input from the control unit 205, the extraction unit 202 extracts radio resource portions that may contain downlink control information from the received signal input from the receiving unit 201, and outputs them to the demodulation unit 203. Additionally, based on radio resource-related information concerning data signals input from the control unit 205, the extraction unit 202 extracts radio resource portions containing downlink data signals or higher-layer control signals, and outputs them to the demodulation unit 203.

[0088] The demodulation unit 203 demodulates the signal input from the extraction unit 202 based on the information input from the control unit 205, and outputs the demodulation result to the decoding unit 204.

[0089] The decoding unit 204, for example, performs error correction decoding on the PDCCH or PDSCH based on the demodulation result input from the demodulation unit 203, to obtain downlink received data, higher-layer control signals, or downlink control information. The decoding unit 204 outputs the higher-layer control signals and downlink control information to the control unit 205. Alternatively, the decoding unit 204 may, for example, generate a HARQ-ACK bit string based on the decoding result of the downlink received data and output it to the encoding unit 206.

[0090] The control unit 205 may, for example, determine radio resources for downlink reception (e.g., reception of PDCCH or PDSCH) and uplink transmission (e.g., transmission of PUSCH or PUCCH) based on information related to multi-TB scheduling, retransmission control, or radio resource allocation obtained from higher-layer control signals and downlink control information input from the decoding unit 204. The control unit 205 may output the determined information to the extraction unit 202, demodulation unit 203, encoding unit 206, and signal allocation unit 208.

[0091] The encoding unit 206 encodes uplink signals (e.g., UCI or uplink data signals such as HARQ-ACK bit strings) based on information input from the control unit 205, and outputs the encoded bit strings to the modulation unit 207.

[0092] The modulation unit 207 modulates, for example, the encoded bit string input from the encoding unit 206, and outputs the modulated signal (symbol string) to the signal distribution unit 208.

[0093] The signal distribution unit 208, for example, maps the signal input from the modulation unit 207 to the radio resources based on the information input from the control unit 205, and outputs the mapped uplink signal to the transmission unit 209.

[0094] The transmitting unit 209 generates a transmit signal waveform, such as OFDM, from the signal input from the signal distribution unit 208. Additionally, in the case of OFDM transmission using CP, the transmitting unit 209 performs IFFT processing on the signal and appends CP to the IFFT-generated signal. Alternatively, in the case of generating a single-carrier waveform, the transmitting unit 209 may add a DFT (Discrete Fourier Transform) section (not shown) after the modulation unit 207 or before the signal distribution unit 208. Furthermore, the transmitting unit 209 performs RF processing such as D / A conversion and up-conversion on the transmit signal and transmits the wireless signal to the base station 100 via an antenna.

[0095] [Example of operation of base station 100 and terminal 200]

[0096] This section describes an example of the operation of a base station 100 and a terminal 200 with the above structure.

[0097] This section describes the transmit and receive processing related to NR retransmission control.

[0098] Figure 6 is a diagram illustrating an example of transmission processing when CB segmentation is applied. On the transmission side, for example, if the size of a TB with added Cyclic Redundancy Check (CRC) bits (e.g., TB-CRC) exceeds a threshold, CB segmentation, which divides the TB (or may include TB-CRC) into multiple CBs, can be applied. For example, in the case of using the NR Low-Density Parity-check Code (LDPC) base graph 1, the threshold can be 8424 bits; in the case of using the LDPC base graph 2, the threshold can be 3840 bits, or other bit numbers different from 8424 bits and 3840 bits. For example, the CB size can be set to the size corresponding to the encoder; therefore, the threshold can also be, for example, the maximum number of bits corresponding to the encoder.

[0099] As shown in Figure 6, CRC bits (e.g., CB-CRC) can be added to the CB segments (e.g., CB#0, CB#1, and CB#2) respectively, and then encoded according to a set coding rate (e.g., LDPC encoding). Through encoding, for example, system bits and parity bits can be generated.

[0100] Additionally, in NR, a circular buffer can be used, for example, for retransmission control (see, for example, non-patent document 5). The circular buffer can be, for example, a memory that stores system bits and parity bits, and the number of bits read from the beginning of the read in the circular buffer (e.g., RV: Redundancy Version) corresponds to the amount of allocated resources (e.g., also known as "rate matching").

[0101] Each CB, composed of the read encoded bits, can be concatenated into a codeword, and scrambling, data modulation, and other processing can be applied to the concatenated codeword.

[0102] Additionally, the DCI containing scheduling information such as resource allocation from base station 100 can be transmitted via PDCCH, for example. Terminal 200 can receive PDSCH, for example, based on the resource allocation indicated by the DCI on PDCCH.

[0103] Terminal 200 can, for example, determine the size of the TB received using the PDSCH based on the MCS, time resource quantity, and frequency resource quantity of the PDSCH, and determine the number of CBs based on the TB size. Additionally, terminal 200 can, for example, decode each CB and use the CB-CRC bits appended to each CB for error detection of each CB. Furthermore, when CB segmentation is applied, terminal 200 can recover the TB and use the TB-CRC appended to the TB for overall error detection of the TB.

[0104] In NR, for example, if CBG-based retransmission is not configured for terminal 200 (e.g., if the higher-layer parameter "PDSCH - Code Block Group Transmission" is not configured), terminal 200 can send a response signal (e.g., ACK / NACK or HARQ-ACK) for the entire TB to the transmitting side (e.g., base station 100) based on the error detection result of the entire TB. For example, if terminal 200 notifies of NACK, base station 100 can retransmit the entire TB.

[0105] Furthermore, in NR, for example, when terminal 200 is configured to retransmit based on CBG (e.g., when the higher-layer parameter "PDSCH code block group transmission" is set), terminal 200 can perform retransmission control in units of CBGs composed of multiple CBs. For example, terminal 200 can send a response signal (e.g., ACK / NACK or HARQ-ACK) to base station 100 based on the error detection result of the CBG. For example, if all CBs contained in the CBG are received without error, terminal 200 can notify ACK; if at least one CB in the CBG is found to be erroneous, terminal 200 can notify NACK. Base station 100 can, for example, retransmit the CBG for which terminal 200 has notified NACK. In other words, base station 100 can, for example, not retransmit the CBG for which terminal 200 has notified ACK.

[0106] Furthermore, in NR, regardless of whether a TB is divided into multiple CBs, a HARQ process is assigned to each TB. Here, the HARQ process is the processing unit for retransmission control, and each HARQ process can be identified by its HARQ process number. For example, multiple HARQ processes can be set for terminal 200, and data can be retransmitted until an ACK is received for a TB with the same HARQ process number or for all CBGs. For example, the HARQ process number, NDI, and RV can be included in the DCI that assigns the PDSCH to the transmitting TB, thereby controlling retransmission. Here, the NDI is, for example, a notification indicating whether it is an initial transmission or a retransmission. For example, if the NDI is not toggled in the same HARQ process (e.g., if it is the same value as the previous one), the NDI indicates a retransmission; if the NDI is toggled (e.g., if it is a different value than the previous one), the NDI indicates an initial transmission.

[0107] In NR, for example, CBG-based retransmission control is specified for scheduling of a single TB. On the other hand, NR does not specify CBG-based retransmission for multi-TB scheduling. Therefore, in this embodiment, for example, a CBG-based retransmission control is described that utilizes the aforementioned NR retransmission control as much as possible and applies multi-TB scheduling.

[0108] In this embodiment, for example, a common (e.g., the same) HARQ process number can be assigned to multiple TBs after multi-TB scheduling. Base station 100 and terminal 200 can, for example, perform retransmission control in units of CBGs containing at least one CB, based on the number of TBs allocated by multi-TB scheduling, where the CB is a CB in one or more of the multiple TBs.

[0109] Here, as an example, the number of TBs allocated by the multi-TB scheduler (e.g., the number of TBs allocated) is set to "N" (e.g., N>1).

[0110] The transmitting side (e.g., base station 100) may apply processes such as CB segmentation, encoding of each CB, rate matching, CB linking, scrambling, and data modulation to each TB.

[0111] Additionally, a DCI containing scheduling information such as resource allocation from base station 100 can be transmitted to terminal 200 via PDCCH, for example. Terminal 200 can receive PDSCH based on the resource allocation indicated by the DCI on PDCCH, for example. In multi-TB scheduling, for example, a single DCI can be used to allocate multiple PDSCHs to different time or frequency resources. Furthermore, each PDSCH can contain different TBs, for example. In other words, a single DCI can be used to schedule multiple TBs received in different time or frequency resources. Moreover, the MCS, time resource amount (e.g., number of symbols), or frequency resource amount (e.g., number of resource blocks) of the PDSCH allocated to each TB can be different, or at least one of them can be common (e.g., the same) among the TBs.

[0112] Terminal 200 can, for example, determine the size of the TB received in each PDSCH based on the MCS, time resource amount, and frequency resource amount of each PDSCH, and determine the number of CBs based on the TB size. Additionally, terminal 200 can, for example, decode each CB and use the CB-CRC bits appended to each CB to perform error detection for each CB. Furthermore, when CB segmentation is used, terminal 200 can, for example, recover the TB and use the TB-CRC appended to the TB to perform overall error detection for the TB.

[0113] In this embodiment, the terminal 200 can be configured with a number of CBGs "M" in multiple (e.g., N) TBs as a parameter related to CBG-based retransmission. The terminal 200 can, for example, allocate a number of TBs N, the number of CBGs M in the N TBs, and the number of CBGs "C" in each TB. n (n=0~N-1), which determines the number of CBs contained in CBG.

[0114] Terminal 200 may, for example, send a response signal for CBG to base station 100 based on the error detection result of CBG. For example, if all CBs contained in CBG are received without error, terminal 200 may notify ACK; if at least one CB in CBG is detected as faulty, terminal 200 may notify NACK. Base station 100 may, for example, retransmit the CBG corresponding to the NACK notified by terminal 200.

[0115] As an example, Figure 7 shows a structural example of a CBG when the number of TBs N=2, the number of CBGs M=4, and the number of CBs C0=C1=4 for each TB. As shown in Figure 7, the N=2 TBs allocated by multi-TB scheduling contain 8 CBs. Therefore, for example, each of the M=4 CBGs contains 2 CBs. Furthermore, the number of CBs contained in each CBG can be the same or different.

[0116] Furthermore, the CBG number M set for terminal 200 can also be the maximum CBG number M. max In this case, the actual number of CBGs M can be determined, for example, according to the following formula (1).

[0117] [Formula 1]

[0118] (1)

[0119] Additionally, for example in

[0120] [Equation 2]

[0121]

[0122] When the integer value is used, the number of CBs contained in each CBG can be set as follows:

[0123] [Formula 3]

[0124] .

[0125] On the other hand,

[0126] [Formula 4]

[0127]

[0128] When the number of CBs is not an integer, for example, the number of CBs contained in CBG#0 to CBG#M-2 can be set to...

[0129] [Formula 5]

[0130]

[0131] The number of CBs contained in CBG#M-1 can be set to

[0132] [Formula 6]

[0133] .

[0134] This contains

[0135] [Formula 7]

[0136]

[0137] The CBG of a CB is not limited to CBG#M-1; it can be CBG#0 or other CBGs.

[0138] Furthermore, the method for determining the number of CBs contained in CBG is not limited to the examples above. For example, it can be set as follows:

[0139] [Formula 8]

[0140]

[0141] The number of CBs contained in CBG#0 to CBG#M1-1 is set to

[0142] [Formula 9]

[0143]

[0144] The number of CBs contained in CBG#M1 to CBG#M-1 is set to

[0145] [Formula 10]

[0146] .

[0147] Additionally, as mentioned above, a common (e.g., identical) HARQ process can be assigned to multiple TBs after multi-TB scheduling. For example, data can be retransmitted for the same HARQ process number until ACK is received for all TBs or all CBGs.

[0148] For example, retransmission can be controlled using a DCI that includes the HARQ process number, NDI, and RV. Alternatively, CBG-based retransmission can be controlled using a DCI that includes CBGTI and CBGFI.

[0149] For example, if NDI is not activated in the same HARQ process (e.g., in the case of a retransmission), CBGTI can represent the retransmitted CBG. For example, if the number of CBGs is 4, CBGTI=0001 can indicate that CBG#3 is retransmitted but CBG#0 to CBG#2 are not retransmitted.

[0150] Additionally, CBGFI can be, for example, a notification indicating whether a retransmitted CBG can be combined with a previously sent CBG. In other words, CBGFI can be, for example, a notification indicating whether the cache of previously received CBGs is valid. For instance, CBGFI=0 indicates that the cache of previously received CBGs by terminal 200 is invalid, while CBGFI=1 indicates that the cache of previously received CBGs by terminal 200 is valid.

[0151] According to this implementation, even in multi-TB scheduling, the number of CBs contained in a CBG is determined based on the number of CBGs, the number of allocated TBs, and the number of CBs in each TB. This allows for the use (in other words, appropriation) of notifications from NR's HARQ process, NDI, RV, CBGTI, and CBGFI to control CBG retransmission.

[0152] In addition, the number of transport blocks N, the number of codeblock groups M, and the number of codeblocks C of each transport block n (n = 0 to N - 1) have the following relationship.

[0153] <Case where M = 1>

[0154] FIG. 8 is a diagram showing a structural example of a codeblock group in the case where M = 1.

[0155] In the case where M = 1, all the codeblocks included in the multiple transport blocks subjected to multi-transport block scheduling can be included in one codeblock group. For example, in FIG. 8, the eight (= 4 codeblocks × 2 transport blocks) codeblocks included in the N = 2 transport blocks subjected to multi-transport block scheduling can be included in one codeblock group #0.

[0156] For example, it can be that when all the codeblocks included in the codeblock group are received without error, the terminal 200 notifies the base station 100 of ACK, and when at least one codeblock among the codeblocks included in the codeblock group is detected to have an error, the terminal 200 notifies the base station 100 of NACK.

[0157] The operation in the case where M = 1 is equivalent to, for example, the operation of bundling response signals for multiple transport blocks. [[ID=​​​​​​​​​​​​​​​The operation in the case of 1 < M < N is equivalent to, for example, the operation of bundling response signals for multiple TBs within one CBG. Additionally, for example, the operation in the case of 1 < M < N is equivalent to the operation of multiplexing response signals for multiple TBs between different CBGs (e.g., the operation of including each HARQ-ACK bit in one HARQ-ACK codebook).

[0164] Furthermore, as shown in the upper part of FIG. 9, the boundary of the CBG can be aligned with the TB boundary, or as shown in the lower part of FIG. 9, the boundary of the CBG can be not aligned with the TB boundary. For example, in the case where the CBG boundary is aligned with the TB boundary as shown in the upper part of FIG. 9, when the number of CBs contained in each TB is the same, the number of TBs N can be set to a value that is an integer multiple of the number of CBGs M.

[0165] <Case where M = N>

[0166] FIG. 10 is a diagram showing a structural example of a CBG in the case of M = N. For example, FIG. 10 shows an example where M = N = 4. Additionally, FIG. 10 shows an example where the number of CBs contained in each TB is the same.

[0167] In the case of M = N, a CBG can contain, for example, the CBs for each TB. In the example shown in FIG. 10, one CBG can be composed of 4 CBs contained in each TB.

[0168] For example, it can be that when all the CBs contained in the CBG are received without error, the terminal 200 notifies the base station 100 of ACK, and when at least one CB among the CBs contained in the CBG is detected with an error, the terminal 200 notifies the base station 100 of NACK.

[0169] The operation in the case of M = N is equivalent to, for example, the operation of multiplexing response signals for multiple TBs (e.g., the operation of including each HARQ-ACK bit in one HARQ-ACK codebook).

[0170] <Case where N < M>

[0171] FIG. 11 is a diagram showing a structural example of a CBG in the case of N < M. For example, the upper part of FIG. 11 shows an example where N = 4 and M = 8, and the lower part of FIG. 11 shows an example where N = 2 and M = 3.

[0172] In the case of N < M, multiple CBs contained in one TB can be included in different CBGs. For example, in the upper part of FIG. 11, 4 CBs for one TB can be included in one of the 2 CBGs. Similarly, for example, in the lower part of FIG. 11, 4 CBs for one TB can be included in one of the 2 CBGs.

[0173] For example, it can be that when all the CBs included in the CBG are received without error, the terminal 200 notifies the base station 100 of ACK, and when at least one CB among the CBs included in the CBG is detected with an error, the terminal 200 notifies the base station 100 of NACK. Therefore, retransmission control based on CBG (in other words, a unit smaller than the TB size) can be performed for one TB.

[0174] Here, as shown in the upper part of FIG. 11, each CBG can be composed of CBs for one TB. In other words, as shown in the upper part of FIG. 11, the CBG can be formed in a manner that is closed within one TB. Or, as shown in the lower part of FIG. 11, each CBG can be formed in a manner that spans multiple TBs. For example, when the CBG is composed of CBs within one TB as shown in the upper part of FIG. 11, when the number of CBs included in each TB is the same, the number M of CBGs can be set to a value that is an integer multiple of the number N of TBs.

[0175] Above, the relationship of allocating the number N of TBs, the number M of CBGs, and the number C of CBs in each TB n (n = 0 to N - 1) has been described.

[0176] In this way, for example, according to the number M of CBGs, ACK / NACK bundling, ACK / NACK multiplexing, and retransmission control based on CBG can be flexibly set for multi-TB scheduling.

[0177] In addition, the terminal 200 can also, for example, determine, according to the notification of the number M of CBGs, the method of retransmission control (for example, ACK / NACK bundling, ACK / NACK multiplexing, and retransmission control based on CBG). Or, the terminal 200 can also be explicitly notified of each method of retransmission control. In this case, the value of the number M of CBGs corresponding to each retransmission control can be set. For example, it can be that when explicitly notified of ACK / NACK bundling, M = 1 is set, when explicitly notified of ACK / NACK multiplexing, M = N is set, and when explicitly notified of retransmission control based on CBG, a value of M that satisfies 1 < M < N or N < M is set.

[0178] In addition, the response signal (for example, ACK / NACK or HARQ-ACK) can be sent by an uplink control channel (for example, PUCCH), and when the PUCCH resource overlaps with the PUSCH resource in time, it can also be sent on the PUSCH resource. For example, the terminal 200 can use a common (for example, the same) uplink resource (for example, PUCCH resource or PUSCH resource) to send a response signal in units of multiple TBs.

[0179] Additionally, the PUCCH resources for sending response signals can be controlled, for example, by a DCI containing a PUCCH Resource Indicator (PRI). Terminal 200 can, for example, control the allocation based on the number of TBs N, the number of CBGs M, and the number of CBs C for each TB. n (n=0~N-1), which determines the retransmission control method and the number of HARQ-ACK bits for multi-TB scheduling. For example, when the number of CBGs is M, the number of HARQ-ACK bits can be M bits.

[0180] Furthermore, regarding the determination of PUCCH resources used for transmitting HARQ-ACK bit strings for multi-TB scheduling, a method can be employed, for example, to notify the PUCCH resources used by terminal 200 from among multiple PUCCH resources (e.g., candidates) contained in a set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically configured to terminal 200 by base station 100, for example, using terminal-specific higher-layer signals (RRC signals), and the PUCCH resources used by terminal 200 in the PUCCH resource set can be notified by DCI (e.g., PRI field).

[0181] Additionally, if the number of PUCCH resources in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (RFU) of the PDCCH transmitting the DCI, i.e., the Control Channel Element (CCE), can also be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., Physical Resource Block (PRB) number, PRB number, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0182] Figure 12 is a flowchart illustrating an example of operations related to the transmission and retransmission control of downlink signals (e.g., PDSCH) in the base station 100 of this embodiment.

[0183] Base station 100 may, for example, utilize higher layers to notify terminal 200 of information related to retransmission control settings (S101). This information related to retransmission control settings may include, for example, information related to the number of CBGs or information related to PUCCH resources.

[0184] Base station 100 may generate a TB to be transmitted (S102). Base station 100 may send information related to multi-TB scheduling for the generated multiple TBs to terminal 200 (S103). The information related to multi-TB scheduling may be sent by PDCCH (e.g., DCI).

[0185] For example, base station 100 may send PDSCH (S104) containing multiple TBs allocated by multi-TB scheduling to terminal 200.

[0186] Base station 100 may, for example, receive PUCCH (or PUSCH) sent from terminal 200 and demodulate and decode it (S105). The PUCCH may, for example, contain a response signal to the PDSCH sent due to multi-TB scheduling.

[0187] Base station 100 may determine, for example, whether an ACK for all TBs or all CBGs is received in a certain HARQ process (e.g., HARQ process #n) (S106).

[0188] If no ACK is received for all TBs or all CBGs in the HARQ process #n (S106: No), base station 100 may send scheduling information for retransmitting PDSCH to terminal 200 (S107). The scheduling information may be sent, for example, by PDCCH (e.g., DCI). In addition, base station 100 may, for example, send (in other words, retransmit) the PDSCH corresponding to the CBG that has been notified of NACK (S108).

[0189] Base station 100 may repeatedly perform the processing of S105 to S108 until ACK for all TBs or all CBGs is received in HARQ process #n, or until the specified (or set) number of retransmissions is reached.

[0190] On the other hand, when an ACK for all TBs or all CBGs is received in HARQ process #n (S106: Yes), base station 100 determines, for example, whether a new TB has been transmitted (S109). If a new TB has been transmitted (S109: Yes), base station 100 may activate NDI of HARQ process #n (S110) and perform the processing of S102. If no new TB has been transmitted (S109: No), base station 100 may terminate the processing shown in FIG12.

[0191] Figure 13 is a flowchart illustrating an example of the operation related to downlink signal reception and retransmission control in the terminal 200 of this embodiment.

[0192] Terminal 200 may, for example, obtain information related to the setting of retransmission control (S201). The information related to the setting of retransmission control may, for example, be notified by a higher layer.

[0193] Terminal 200 may, for example, receive a PDCCH (e.g., DCI) containing information related to multi-TB scheduling (S202). Alternatively, terminal 200 may, for example, receive a PDSCH containing multiple TBs based on the received multi-TB scheduling information (S203).

[0194] Terminal 200 may, for example, determine the TB size, number of CBs, and CBG (e.g., number of CBGs and CBG size) for the allocated multiple TBs based on information related to multi-TB scheduling (S204). Next, terminal 200 may, for example, demodulate and decode the received PDSCH (S205).

[0195] Terminal 200 may, for example, perform error detection of PDSCH and generate HARQ-ACK (e.g., ACK or NACK) based on the error detection result (S206). For example, terminal 200 may generate HARQ-ACK according to the determined CBG.

[0196] Terminal 200 may, for example, use PUCCH or PUSCH to send the generated HARQ-ACK (S207) to base station 100.

[0197] The above describes the operation examples of base station 100 and terminal 200.

[0198] According to this embodiment, base station 100 and terminal 200 perform retransmission control on multiple TBs after multi-TB scheduling, using CBGs containing at least one CB as units, and communicate according to the retransmission control. The CB is a CB in one or more of the multiple TBs. In this embodiment, for example, it is based on the number of multiple TBs N, the number of CBGs M in the multiple TBs, and the number of CBs C contained in each TB#n. n This determines the number of CBs contained in the CBG (e.g., the CBG size).

[0199] Therefore, in multi-TB scheduling, terminal 200 can, for example, determine the number of HARQ-ACK bits in multi-TB scheduling based on the number of CBGs, the number of allocated TBs, and the number of CBs in each TB. Furthermore, in this embodiment, even in multi-TB scheduling, it is possible to utilize NR's PUCCH resource control. Thus, according to this embodiment, appropriate CBG-based retransmission control can be performed in multi-TB scheduling.

[0200] (A variation of Implementation Method 1)

[0201] In Implementation 1, for example, the following situation is described: in multi-TB scheduling, the number of CBs contained in a CBG is determined based on the number of CBGs, the number of TBs allocated, and the number of CBs in each TB.

[0202] For example, as mentioned above, the size of the TB received by the terminal 200 in the PDSCH can be determined based on the MCS, time resource quantity, and frequency resource quantity of each PDSCH, and the number of CBs can be determined based on the TB size.

[0203] Alternatively, the number of allocated TBs can be semi-statically notified to terminal 200 using a higher layer (e.g., an RRC signal), or the number of allocated TBs can be dynamically notified to terminal 200 using a DCI that allocates PDSCHs for each TB. When dynamically notifying the number of allocated TBs using a DCI, the bit field for notifying the number of TBs can be set independently in the DCI, or the number of TBs can be notified together with the time domain resources in the TDRA field of the time domain resources in the DCI.

[0204] Alternatively, the number of CBGs or the maximum number of CBGs can be semi-statically notified to terminal 200 using a higher layer (e.g., an RRC signal), or the number of CBGs or the maximum number of CBGs can be dynamically notified to terminal 200 using a DCI that allocates PDSCHs for each TB. When dynamically notifying the number of CBGs or the maximum number of CBGs using a DCI, for example, the bit field for notifying the number of CBGs or the maximum number of CBGs can be set independently in the DCI, or the number of CBGs or the maximum number of CBGs can be notified together with the time domain resources in the TDRA field of the time domain resources of the DCI. Alternatively, for example, the number of CBGs or the maximum number of CBGs can also be notified together with the bit field for notifying the number of TBs.

[0205] Alternatively, terminal 200 may determine the number of CBGs or the maximum number of CBGs based on the number of allocated TBs. For example, when the number of CBGs or the maximum number of CBGs for each TB is notified to terminal 200, terminal 200 may also set the number of CBGs or the maximum number of CBGs for multi-TB scheduling to a multiplicative value between the number of CBGs or the maximum number of CBGs for each TB and the number of allocated TBs.

[0206] As mentioned above, when determining the number of CBGs for multi-TB scheduling or the number of CBGs per TB, the more the number of CBGs increases, the fewer CBs are contained in a single CBG.

[0207] Alternatively, the number of CBs contained in a CBG can also be fixed. In this case, terminal 200 can, for example, allocate the number of TBs N and the number of CBs C in each TB. n (n=0~N-1), determine the number of CBGs, the retransmission control method, and the number of HARQ-ACK bits for multi-TB scheduling. In this case, allocate the number of TBs N and the number of CBs C for each TB. n As n=0~N-1 increases, the number of CBGs also increases.

[0208] (Implementation Method 2)

[0209] The structure of the base station 100 and terminal 200 in this embodiment can be the same as that in embodiment 1.

[0210] In Implementation 1, a case was described in which a common (e.g., the same) HARQ process number was assigned to multiple TBs. In this implementation, for example, a case is described in which different HARQ process numbers are assigned to multiple TBs.

[0211] The transmitting side (e.g., base station 100) may apply processes such as CB segmentation, encoding of each CB, rate matching, CB linking, scrambling, and data modulation to each TB (e.g., N>1).

[0212] Additionally, a DCI containing scheduling information such as resource allocation from base station 100 can be transmitted to terminal 200 via PDCCH, for example. Terminal 200 can receive PDSCH based on the resource allocation indicated by the DCI on PDCCH, for example. In multi-TB scheduling, for example, a single DCI can be used to allocate multiple PDSCHs to different time or frequency resources. Furthermore, each PDSCH can contain different TBs, for example. In other words, a single DCI can be used to schedule multiple TBs received in different time or frequency resources. Moreover, the MCS, time resource amount (e.g., number of symbols), or frequency resource amount (e.g., number of resource blocks) of the PDSCH allocated to each TB can be different, or at least one of them can be common (e.g., the same) among the TBs.

[0213] Terminal 200 can, for example, determine the size of the TB received in each PDSCH based on the MCS, time resource amount, and frequency resource amount of each PDSCH, and determine the number of CBs based on the TB size. Additionally, terminal 200 can, for example, decode each CB and use the CB-CRC bits appended to each CB to perform error detection for each CB. Furthermore, when CB segmentation is used, terminal 200 can, for example, recover the TB and use the TB-CRC appended to the TB to perform overall error detection for the TB.

[0214] In this embodiment, terminal 200 may, for example, control retransmission for each of the multiple TBs allocated by multi-TB scheduling.

[0215] For example, if CBG-based retransmission is not configured for terminal 200 (e.g., if the higher-layer parameter "PDSCH code block group transmission" is not configured), terminal 200 can send a response signal (e.g., ACK / NACK or HARQ-ACK) to base station 100 for each TB based on the overall error detection result of the TB. Base station 100 can, for example, retransmit the entire TB for the TB that terminal 200 has notified of NACK.

[0216] Furthermore, for example, if CBG-based retransmission is configured for terminal 200 (e.g., if the higher-layer parameter "PDSCH code block group transmission" is configured), terminal 200 can perform retransmission control on a CBG-by-CBG basis. For example, terminal 200 can send a response signal (e.g., ACK / NACK or HARQ-ACK) to base station 100 for each TB based on the error detection result of the CBG. For example, if all CBs contained in the CBG are received without error, terminal 200 may notify base station 100 with an ACK; if at least one CB in the CBG is detected as faulty, terminal 200 may notify base station 100 with a NACK. Base station 100 may, for example, retransmit the CBG for which terminal 200 has notified a NACK.

[0217] For example, in this embodiment, the terminal 200 can be configured with multiple (e.g., N) CBG numbers "M" as parameters related to CBG-based retransmission. The terminal 200 can, for example, use the CBG number M for each of the N TBs and the CBG number "C" for each of the N TBs. n (n=0~N-1), which determines the number of CBs contained in CBG.

[0218] Furthermore, in this embodiment, regardless of whether each TB is divided into multiple CBs, a different HARQ process can be assigned to each TB after multi-TB scheduling. For example, for the same HARQ process number, data can be retransmitted until an ACK is received for the TB or all CBGs.

[0219] For example, retransmission can be controlled using a DCI that includes the HARQ process number, NDI, and RV. Alternatively, CBG-based retransmission can be controlled using a DCI that includes CBGTI and CBGFI.

[0220] For example, if NDI is not activated in the same HARQ process (e.g., in the case of a retransmission), CBGTI indicates the retransmitted CBG. Alternatively, CBGFI could be a notification indicating whether the retransmitted CBG can be combined with previously sent CBGs.

[0221] According to this embodiment, independent retransmission control can be applied to each of the multiple scheduled TBs. For example, in multi-TB scheduling, base station 100 can transmit the initially transmitted TB and the retransmitted TB together. Thus, according to this embodiment, more flexible downlink transmission can be achieved, thereby improving downlink transmission efficiency.

[0222] Response signals (e.g., ACK / NACK or HARQ-ACK) may be sent via an uplink control channel (e.g., PUCCH), and may also be sent on a PUSCH resource if the PUCCH resource overlaps with the PUSCH resource in time.

[0223] Additionally, the PUCCH resources for sending response signals can be controlled, for example, by a DCI that includes PRI. For example, regarding the determination of the PUCCH resources used to send HARQ-ACK bits for multi-TB scheduling, terminal 200 can apply one of the following options (Option) 1 to Option 5.

[0224] <Option 1: ACK / NACK bundling and single PUCCH resource>

[0225] In Option 1, terminal 200 may, for example, utilize a PUCCH resource to send a response signal based on the overall error detection result of multiple TBs. For instance, terminal 200 may generate an ACK if all TBs in the multi-TB schedule are received without error, and generate a NACK if at least one TB in the multi-TB schedule is found to have an error. In other words, in Option 1, for example, the HARQ-ACK bit count for the multi-TB schedule is 1 bit.

[0226] Regarding the determination of PUCCH resources used for transmitting HARQ-ACK bits for multi-TB scheduling, for example, the method can be adopted to notify the PUCCH resources used by terminal 200 among the multiple PUCCH resources contained in the set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically set by base station 100 to terminal 200, for example, using the terminal's inherent higher-layer signal (RRC signal), and the PUCCH resources used by terminal 200 in the PUCCH resource set can be notified by DCI (e.g., PRI field).

[0227] Additionally, if the number of PUCCH resources in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (CCE) of the PDCCH transmitting the DCI can be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0228] Figure 14 is a diagram illustrating an example of PUCCH resources for sending HARQ-ACK in Option 1. In Figure 14, as an example, the number of allocated TBs N=2 based on multi-TB scheduling. As shown in Figure 14, terminal 200 can generate a 1-bit HARQ-ACK based on the error detection results of N=2 TB#0 and TB#1. Terminal 200 can, for example, send the generated HARQ-ACK to base station 100 in the PUCCH.

[0229] In Option 1, for example, HARQ-ACKs corresponding to the error detection results of multiple TBs allocated by multi-TB scheduling are sent, thus reducing the number of HARQ-ACK bits and PUCCH resources. For example, in Option 1, the overhead associated with PRI notifications in multi-TB scheduling can be suppressed to the same extent as NR (or, in the case of scheduling 1TB).

[0230] <Option 2: ACK / NACK multiplexing and single PUCCH resource>

[0231] In option 2, terminal 200 may, for example, utilize a PUCCH resource to send a signal multiplexed from response signals based on error detection results in units of multiple TB.

[0232] For example, terminal 200 can be based on the number of CBGs M and the number of CBs C for each TB in the multi-TB scheduling. n (n=0~N-1), which determines the number of HARQ-ACK bits. For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB can be M bits. Additionally, terminal 200 can, for example, multiplex the response signals for multiple TBs. In other words, terminal 200 can include the HARQACK bit string for each TB in a single HARQ-ACK codebook.

[0233] Therefore, the number of HARQ-ACK bits for multi-TB scheduling with N TBs allocated can be M×N bits.

[0234] Similarly to Option 1, the determination of the PUCCH resources used for transmitting HARQ-ACK bits for multi-TB scheduling can be achieved, for example, by notifying the PUCCH resources used by the terminal 200 among the multiple PUCCH resources contained in the set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically configured to the terminal 200 by the base station 100, for example, using the terminal's inherent higher-layer signals (RRC signals), and the PUCCH resources used by the terminal 200 in the PUCCH resource set can be notified by DCI (e.g., the PRI field).

[0235] Additionally, if the number of PUCCH resources in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (CCE) of the PDCCH transmitting the DCI can be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0236] Figure 15 is a diagram illustrating an example of PUCCH resources for sending HARQ-ACK in Option 2. In Figure 15, as an example, the number of TBs allocated based on multi-TB scheduling is N=2, and the number of CBGs in each TB is M=2. As shown in Figure 15, terminal 200 can multiplex a 2-bit HARQ-ACK bit string based on the error detection results of M=2 CBGs in each of N=2 TB#0 and TB#1 (e.g., error detection results for 4 CBGs) and generate a 4-bit HARQ-ACK codebook. Terminal 200 can, for example, send the generated HARQ-ACK codebook to base station 100 in the PUCCH.

[0237] In Option 2, for example, HARQ-ACKs for multiple TBs allocated by multi-TB scheduling are sent using a single PUCCH resource, thus reducing the number of HARQ-ACK bits and PUCCH resources. For example, in Option 2, the overhead associated with PRI notifications in multi-TB scheduling can be suppressed to the same extent as NR (or, as in the case of scheduling 1TB). Additionally, in Option 2, for example, CBG-based retransmission control can be performed for each TB.

[0238] <Option 3: Multiple PUCCH resources and multiple PRI>

[0239] In option 3, terminal 200 may, for example, utilize multiple PUCCH resources to send a response signal based on error detection results in units of multiple TB. Additionally, in option 3, terminal 200 may, for example, receive multiple PRIs (in other words, multiple information sets) representing multiple PUCCH resources.

[0240] For example, terminal 200 can be based on the number of CBGs M and the number of CBs C for each TB in the multi-TB scheduling. n (n=0~N-1), which determines the number of HARQ-ACK bits. For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB can be M bits. Alternatively, the terminal 200 can, for example, utilize different PUCCH resources to send the HARQ-ACK bit string for each TB.

[0241] Similarly to Option 1, the determination of the PUCCH resources used for transmitting HARQ-ACK bits for multi-TB scheduling can be achieved, for example, by notifying the PUCCH resources used by the terminal 200 among the multiple PUCCH resources contained in the set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically configured to the terminal 200 by the base station 100, for example, using the terminal's inherent higher-layer signals (RRC signals), and the PUCCH resources used by the terminal 200 in the PUCCH resource set can be notified by DCI (e.g., the PRI field).

[0242] In option 3, for example, the DCI may contain multiple PRI fields. For instance, each PRI field may contain information indicating a PUCCH resource that sends HARQ-ACK bit strings for multiple TBs after multi-TB scheduling.

[0243] Additionally, if the number of PUCCH resources in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (CCE) of the PDCCH transmitting the DCI can be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0244] Figure 16 is a diagram illustrating an example of the PUCCH resources for sending HARQ-ACK in Option 3. In Figure 16, as an example, the number of allocated TBs N=2 based on multi-TB scheduling, and the number of CBGs in each TB M=2. Furthermore, in Figure 16, the HARQ-ACK bit string for N=2 TBs can be sent using two PUCCH resources, #0 and #1.

[0245] As shown in Figure 16, terminal 200 can generate a 2-bit HARQ-ACK bit string based on the error detection results of each of M=2 CBGs for N=2 TB#0s and TB#1s respectively. Then, terminal 200 can, for example, send the generated HARQ-ACK bit string to base station 100 in PUCCH resources #0 and #1 corresponding to TB#0 and TB#1 respectively.

[0246] In Option 3, terminal 200 can, for example, send HARQ-ACK in different PUCCHs for each TB, thus enabling sequential decoding of TBs and transmission of PUCCHs starting from the received TB. For example, this can reduce the latency of TBs transmitted in earlier time slots. Furthermore, in Option 3, because there are multiple PRIs, PUCCH resource allocation for each TB can be flexibly performed.

[0247] <Option 4: Multiple PUCCH resources and a single PRI (RRC table)>

[0248] In option 4, terminal 200 may, for example, utilize multiple PUCCH resources to send response signals based on the error detection results of each of the multiple TBs. Additionally, in option 4, terminal 200 may, for example, receive information representing a combination of multiple PUCCH resources (e.g., PRI).

[0249] For example, terminal 200 can be based on the number of CBGs M and the number of CBs C for each TB in the multi-TB scheduling. n (n=0~N-1), which determines the number of HARQ-ACK bits. For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB can be M bits. Alternatively, the terminal 200 can, for example, utilize different PUCCH resources to send the HARQ-ACK bit string for each TB.

[0250] Similarly to Option 1, the determination of the PUCCH resources used for transmitting HARQ-ACK bits for multi-TB scheduling can be achieved, for example, by notifying the PUCCH resources used by the terminal 200 among the multiple PUCCH resources contained in the set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically configured to the terminal 200 by the base station 100, for example, using the terminal's inherent higher-layer signals (RRC signals), and the PUCCH resources used by the terminal 200 in the PUCCH resource set can be notified by DCI (e.g., the PRI field).

[0251] In Option 4, for example, in a PUCCH resource set that is semi-statically notified by higher layers, a combination of multiple PUCCH resources for multi-TB scheduling can be included. For example, in Option 4, the PRI field contained in the DCI can be a field representing one of the combinations of multiple PUCCH resources. For example, a PRI can be used to notify a combination of multiple PUCCH resources used to send HARQ-ACK bit strings.

[0252] Additionally, if the number of combinations of PUCCH resources contained in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (CCE) of the PDCCH transmitting the DCI can also be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0253] Figure 17 is an example of the PUCCH resources for sending HARQ-ACK in Option 4. Figure 18 is an example of the correspondence between PRI values ​​and combinations of multiple PUCCH resources.

[0254] In Figure 17, as an example, the number of TBs allocated based on multi-TB scheduling is N=2, and the number of CBGs in each TB is M=2. In Figure 17, the HARQ-ACK bit string for N=2 TBs can be sent by two PUCCH resources #0 (e.g., one of PUCCH resources #0-0 to #0-7 shown in Figure 18) and PUCCH resource #1 (e.g., one of PUCCH resources #1-0 to #1-7 shown in Figure 18).

[0255] As shown in Figure 17, terminal 200 can generate 2-bit HARQ-ACK bit strings based on the error detection results of each of M=2 CBGs for N=2 TB#0 and TB#1 respectively. Alternatively, terminal 200 can, for example, determine the PUCCH resources #0 and #1 corresponding to TB#0 and TB#1 respectively based on a received PRI and the correspondence shown in Figure 18, and send the generated HARQ-ACK bit strings to base station 100.

[0256] In option 4, terminal 200 can, for example, send HARQ-ACK in a different PUCCH for each TB, thus enabling sequential decoding of TBs and transmission of PUCCHs starting from the received TB. For example, this can reduce the latency of TBs transmitted in earlier time slots.

[0257] Additionally, in option 4, the combination of multiple PUCCH resources is notified by a single PRI, thus enabling the overhead associated with PRI notification in multi-TB scheduling to be suppressed to the same extent as NR (or, in the case of scheduling 1TB).

[0258] <Option 5: Multiple PUCCH resources and a single PRI (implicit relation)>

[0259] In option 5, terminal 200 may, for example, utilize multiple PUCCH resources to send response signals based on the error detection results of each of the multiple TBs. Alternatively, in option 5, terminal 200 may, for example, receive information (e.g., PRI) representing a portion of the multiple PUCCH resources, and based on that portion of the resources, determine other resources among the multiple PUCCH resources that differ from the portion of resources.

[0260] For example, terminal 200 can, for each TB in multi-TB scheduling, base its CBG number M on the CBG number M and the CB number C of each TB. n (n=0~N-1), which determines the number of HARQ-ACK bits. For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB can be M bits. Alternatively, the terminal 200 can, for example, utilize different PUCCH resources to send the HARQ-ACK bit string for each TB.

[0261] In option 5, for example, regarding the determination of PUCCH resources used to send HARQ-ACK bits for a portion of a TB (e.g., TB#0) in a multi-TB schedule, a method can be employed that notifies the PUCCH resources used by terminal 200 among the multiple PUCCH resources contained in the set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically configured to terminal 200 by base station 100, for example, using terminal-specific higher-layer signals (RRC signals), and the PUCCH resources used by terminal 200 in the PUCCH resource set can be notified by DCI (e.g., PRI field).

[0262] Additionally, if the number of combinations of PUCCH resources contained in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (CCE) of the PDCCH transmitting the DCI can also be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0263] Additionally, in option 5, for example, regarding the determination of PUCCH resources for sending HARQ-ACK bit strings for other TBs that are different from a portion of the TBs (e.g., TB#0) in a multi-TB schedule, terminal 200 may implicitly determine the PUCCH resources based on the PUCCH resources for sending HARQ-ACK bit strings for TB#0.

[0264] For example, terminal 200 may determine the following PUCCH resource as a PUCCH resource for transmitting HARQ-ACK bit strings for other TBs, wherein the parameters of the above PUCCH resource are the same as those of the PUCCH resource for transmitting HARQ-ACK bit strings for TB#0, but the slot number is different. Alternatively, terminal 200 may, for example, determine the following PUCCH resource as a PUCCH resource for transmitting HARQ-ACK bit strings for other TBs, wherein the parameters of the above PUCCH resource are the same as those of the PUCCH resource for transmitting HARQ-ACK bit strings for the previous TB in time, and with an additional fixed time shift. For example, HARQ-ACK bit strings for other TBs may also be transmitted starting from the next slot or symbol after the last slot or symbol of the following PUCCH resource, which transmits the HARQ-ACK bit string for the previous TB of the aforementioned other TBs.

[0265] Figure 19 is a diagram illustrating an example of the PUCCH resource for sending HARQ-ACK in option 5.

[0266] In Figure 19, as an example, the number of TBs allocated based on multi-TB scheduling is N=2, and the number of CBGs in each TB is M=2. Additionally, in Figure 19, the HARQ-ACK bit string for N=2 TBs can be sent by two PUCCH resources #0 and #1.

[0267] As shown in Figure 19, terminal 200 can generate a 2-bit HARQ-ACK bit string based on the error detection results of each of the M=2 CBGs for N=2 TB#0s and TB#1s respectively. Alternatively, terminal 200 can, for example, determine the PUCCH resource #0 corresponding to TB#0 based on a received PRI, and send the generated HARQ-ACK bit string to base station 100. Furthermore, terminal 200 can, for example, determine the PUCCH resource #1 corresponding to TB#1 based on the PUCCH resource #0 corresponding to TB#0 determined according to the PRI, and send the generated HARQ-ACK bit string to base station 100.

[0268] In option 5, terminal 200 can, for example, send HARQ-ACK in a different PUCCH for each TB, thus enabling sequential decoding of TBs and transmission of PUCCHs starting from the received TB. For example, this can reduce the latency of TBs transmitted in earlier time slots.

[0269] Additionally, in option 5, a portion of the multiple PUCCH resources are notified by PRI, and other resources are determined based on the aforementioned portion of the resources. Therefore, the overhead associated with PRI notification in multi-TB scheduling can be suppressed to the same extent as NR (or, as in the case of scheduling 1TB).

[0270] Additionally, option 5 can reduce the overhead of information notifications from higher levels, for example, compared to option 4.

[0271] The above describes options 1 to 5 related to the determination of the following PUCCH resources, which are used to send HARQ-ACK bits for each TB of a multi-TB schedule.

[0272] Furthermore, the choice of which option from options 1 to 5 to apply can be predetermined in the standard, communicated to terminal 200 via higher-layer signals or DCI, or preset within terminal 200. Alternatively, at least two of options 1 to 5 can be applied in combination.

[0273] (A variation of Implementation Method 2)

[0274] In Implementation 2, a DCI-based retransmission control is described, whereby the DCI includes the HARQ process number, NDI, and RV for each TB after multi-TB scheduling. In this retransmission control, for example, as the number of allocated TBs increases, the overhead of the DCI used to notify the HARQ process number, NDI, and RV increases.

[0275] In a variation of Implementation 2, an example of a method for suppressing the increase in DCI overhead will be described.

[0276] For example, regarding RV, the RV for each TB may not be included in the DCI. This can suppress the increase in DCI overhead. For example, it is also possible to set RV=0 in the case of the initial transmission (e.g., when NDI is activated), and to set RV corresponding to the number of retransmissions in the case of retransmissions (e.g., when NDI is not activated in the same HARQ process). For example, it is also possible to set RV=3 in the first retransmission, RV=2 in the second retransmission, and RV=1 in the third retransmission. Furthermore, the setting of RV is not limited to the above examples.

[0277] Additionally, for example, regarding notifications about HARQ process numbers, one of the options i to v shown below can also be applied.

[0278] <Option i>

[0279] In option i, for example, the HARQ process number that can be assigned to each TB after multi-TB scheduling can also be a consecutive HARQ process number.

[0280] For example, if the HARQ process number for TB#0 is "HPN0", then the HARQ process number for TB#n (n=0~N-1) can be set to "HPN". n =(HPN0+n) mod N HP Here, N represents the number of TBs allocated. HP This indicates the maximum number of HARQ processes.

[0281] In option i, for example, if a HARQ process number is set for a certain TB (e.g., TB#0), then the HARQ process numbers for other TBs can be calculated.

[0282] In option i, for example, the number of bits used to notify the HARQ process number is...

[0283] [Equation 11]

[0284] Bit,

[0285] The number of bits associated with the HARQ process notification does not depend on the number of TBs allocated.

[0286] <Option ii>

[0287] In option ii, similarly to option i, the HARQ process numbers that can be assigned to each TB after multi-TB scheduling are consecutive HARQ process numbers. Option ii can also set (or limit) an upper limit on the number of HARQ process numbers that can be assigned by multi-TB scheduling.

[0288] For example, N can be assigned to terminal 200 HP HARQ processes #0 to #N HP In -1, the HARQ process number that can be allocated by multi-TB scheduling can also be set (or restricted) to N. Limit (e.g., #0 to #N) Limit -1). Here, it could be N. Limit <N HP Furthermore, the starting number of the HARQ process number that can be allocated by the multi-TB scheduler is not limited to HARQ process #0, but can also be other numbers.

[0289] In option ii, for example, the number of HARQ processes that can be allocated by multi-TB scheduling is less than the maximum number of HARQ processes, thus suppressing the increase in DCI overhead.

[0290] For example, in option 2, the number of bits used to notify the HARQ process number is...

[0291] [Equation 12]

[0292] Bit,

[0293] And N Limit <N HP Therefore, compared to option i, it is possible to reduce the number of bits used to notify the HARQ process.

[0294] <Option iii>

[0295] In option iii, for example, arbitrary HARQ process numbers can be assigned to each TB after multi-TB scheduling.

[0296] In option iii, for example, the number of bits used to notify the HARQ process number is...

[0297] [Equation 13]

[0298] Bit.

[0299] Here, nChoosek(x, y) represents the number of combinations of choosing y items from x items. Additionally, N represents the number of TBs to allocate. HP This indicates the maximum number of HARQ processes.

[0300] In option iii, for example, as the number of TBs N allocated increases, the number of bits used to notify the HARQ process also increases. Option iii allows for flexible allocation of HARQ process numbers to each TB after multi-TB scheduling, for example.

[0301] <Option iv>

[0302] In option iv, similar to option iii, arbitrary HARQ process numbers can be assigned to each TB after multi-TB scheduling. Option iv also allows setting (or limiting) an upper limit on the number of HARQ process numbers that can be assigned by multi-TB scheduling.

[0303] For example, N can be assigned to terminal 200 HP HARQ processes #0 to #N HP In -1, the HARQ process number that can be allocated by multi-TB scheduling can also be set (or restricted) to N. Limit (e.g., #0 to #N) Limit -1). Here, it could be N.Limit <N HP Furthermore, the starting number of the HARQ process number that can be allocated by the multi-TB scheduler is not limited to HARQ process #0, but can also be other numbers.

[0304] In option iv, for example, the number of HARQ processes that can be allocated by multi-TB scheduling is less than the maximum number of HARQ processes, thus suppressing the increase in DCI overhead.

[0305] In option iv, for example, the number of bits used to notify the HARQ process number is...

[0306] [Formula 14]

[0307] Bit,

[0308] And N Limit <N HP Therefore, compared to option iii, it is possible to reduce the number of bits used to notify the HARQ process.

[0309] <Option v>

[0310] In option v, for example, HARQ process numbers can be divided into multiple sets. For instance, HARQ process numbers can be divided into set #0{#a, #b, #c, #d} and set #1{#e, #f, #g, #h}.

[0311] Additionally, for example, regarding the notification of HARQ process numbers for a subset of multiple TBs (e.g., TB#0) that are subject to multi-TB scheduling, a specific HARQ process number in set #0 can be explicitly notified.

[0312] Furthermore, regarding the determination of HARQ process numbers for TBs other than TB#0, terminal 200 can, for example, implicitly determine the HARQ process number from set #1 based on the HARQ process number of set #0 that has been explicitly notified. For example, in the above example, each HARQ process #a to #d in set #0 can also be made to correspond one-to-one with each HARQ process #e to #h in set #1. For example, if HARQ process #a in set #0 is notified as the HARQ process number for TB#0, terminal 200 can also set HARQ process #e in set #1 as the HARQ process number for TB#1.

[0313] In this case, if the number of HARQ processes contained in set #0 is set to N1, then the number of bits used to notify the HARQ process number is...

[0314] [Formula 15]

[0315] Bit.

[0316] In option v, for example, it is sufficient to notify only the HARQ process numbers of sets that are part of a subset of multiple sets. In other words, it is possible not to notify the HARQ process numbers contained in sets that are different from the subset of multiple sets, thus reducing the number of bits used to notify the HARQ processes.

[0317] In addition, in option v, the number of sets that divide the HARQ process IDs can also be more than 3.

[0318] Additionally, the set used for notifying HARQ process numbers can also be explicitly notified to terminal 200. For example, in the above example, set #0 could be explicitly notified to terminal 200, and one HARQ process number contained in set #0 could be assigned to each TB. For example, the HARQ process number for TB#0 could be set to #a, and the HARQ process number for TB#1 could be set to #b. In this case, if the number of sets is set to N... set The number of bits used to notify the HARQ process number is

[0319] [Formula 16]

[0320] Bit,

[0321] It can reduce the number of bits used to notify the HARQ process.

[0322] The above explains options i to v related to the notification of the HARQ process number.

[0323] In implementation 2, for example, the initial TB and the retransmitted TB can be sent together in a multi-TB scheduling. In this case, a different HARQ process can be assigned to each TB after multi-TB scheduling.

[0324] For example, as shown in Figure 20, in terminal 200, the order of receiving PDSCH or sending PUCCH for each TB after multi-TB scheduling can also be the order of HARQ process numbers.

[0325] Alternatively, as shown in Figure 21, in terminal 200, the order of receiving PDSCH or sending PUCCH for each TB after multi-TB scheduling can also be such that the retransmitted TB is earlier than the initially sent TB. Based on this order, it may be possible to reduce the impact of retransmission delay.

[0326] For example, in multi-TB scheduling, if the TB includes the initial transmission (but not the retransmitted TB), or if the TB includes the retransmitted TB (but not the initial transmission TB), the order in which the terminal 200 receives the PDSCH or transmits the PUCCH for each TB can be set to the order of the HARQ process numbers as shown in Figure 20. Alternatively, for example, in multi-TB scheduling where the initial transmission TB and the retransmitted TB are transmitted together, as shown in Figure 21, the terminal 200 can first receive the PDSCH or transmit the PUCCH for the retransmitted TB, and then receive the PDSCH or transmit the PUCCH for the initial transmission TB.

[0327] (Implementation Method 3)

[0328] The structure of the base station 100 and terminal 200 in this embodiment can be the same as that in embodiment 1.

[0329] In Implementation 1, for example, a case was described in which a common (e.g., the same) HARQ process number was assigned to multiple TBs after multi-TB scheduling. In Implementation 2, a case was described in which different HARQ process numbers were assigned to multiple TBs after multi-TB scheduling. In this implementation, for example, a case was described in which multiple TBs allocated by multi-TB scheduling (in other words, one DCI) were divided into multiple groups (hereinafter referred to as "TB groups"), common (e.g., the same) HARQ process numbers were assigned to TBs within the same TB group, and different HARQ process numbers were assigned to TBs in different TB groups.

[0330] For example, base station 100 can send information related to retransmission control to terminal 200, which includes information related to the number of CBGs, information related to PUCCH resource allocation, and information related to the number of TB groups.

[0331] Thus, a compromise between Embodiment 1 and Embodiment 2 can be achieved, for example. Furthermore, the case where the number of TB groups is one is equivalent to Embodiment 1, and the case where the number of TB groups is the same as the number of allocated TBs is equivalent to Embodiment 2.

[0332] Figure 22 is a diagram showing an example of the structure of the TB group in this embodiment. Figure 22 shows an example of the case where the number of TBs N=4 and the number of TB groups is 2.

[0333] In Figure 22, for example, TB#0 and TB#1 are contained in TB group #0, and TB#2 and TB#3 are contained in TB group #1. Furthermore, as shown in Figure 22, a common HARQ process number #m can be assigned to TB#0 and TB#1 contained in TB group #0, and a common HARQ process number #n can be assigned to TB#2 and TB#3 contained in TB group #1. In other words, different HARQ process numbers can be assigned to TB#0 and TB#1 contained in TB group #0, and TB#2 and TB#3 contained in TB group #1.

[0334] The transmitting side (e.g., base station 100) may apply processes such as CB segmentation, encoding of each CB, rate matching, CB linking, scrambling, and data modulation to each TB (e.g., N>1).

[0335] Additionally, a DCI containing scheduling information such as resource allocation from base station 100 can be transmitted to terminal 200 via PDCCH, for example. Terminal 200 can receive PDSCH based on the resource allocation indicated by the DCI on PDCCH, for example. In multi-TB scheduling, for example, a single DCI can be used to allocate multiple PDSCHs to different time or frequency resources. Furthermore, each PDSCH can contain different TBs, for example. In other words, a single DCI can be used to schedule multiple TBs received in different time or frequency resources. Moreover, the MCS, time resource amount (e.g., number of symbols), or frequency resource amount (e.g., number of resource blocks) of the PDSCH allocated to each TB can be different, and at least one of them can also be common (e.g., the same) among TBs.

[0336] Terminal 200 can, for example, determine the size of the TB received in each PDSCH based on the MCS, time resource amount, and frequency resource amount of each PDSCH, and determine the number of CBs based on the TB size. Additionally, terminal 200 can, for example, decode each CB and use the CB-CRC bits appended to each CB to perform error detection for each CB. Furthermore, when CB segmentation is used, terminal 200 can, for example, recover the TB and use the TB-CRC appended to the TB to perform overall error detection for the TB.

[0337] In this embodiment, terminal 200 may, for example, control retransmission for each TB group among multiple TBs allocated by multi-TB scheduling.

[0338] For example, terminal 200 can apply the same actions as in implementation method 1 to multiple TBs within a TB group (e.g., TBs assigned a common HARQ process number). For example, terminal 200 can set one of the parameters related to CBG-based retransmission, namely the CBG number M. For example, terminal 200 can allocate the number of TBs N based on the CBG number M of each TB group. TBGand the number of CBs for each TB n (n=0~N TBG -1), determines the number of CBs contained in CBG.

[0339] Terminal 200 may, for example, send a response signal (e.g., ACK / NACK or HARQ-ACK) to base station 100 for the CBG based on the error detection result of the CBG. For example, if all CBs contained in the CBG are received without error, terminal 200 may notify ACK; if at least one CB in the CBG is detected to be faulty, terminal 200 may notify NACK. Base station 100 may, for example, retransmit the CBG corresponding to the NACK notified by terminal 200.

[0340] Furthermore, in this embodiment, for example, regardless of whether each TB group is divided into multiple CBs, a different HARQ process can be assigned to each TB group. For example, terminal 200 can apply the same actions as in embodiment 2 to different TB groups.

[0341] For example, for a TB group containing multiple TBs that have been assigned the same HARQ process number, data can be retransmitted until an ACK is received for all TBs or all CBGs.

[0342] For example, retransmission can be controlled using a DCI that includes the HARQ process number, NDI, and RV. Alternatively, CBG-based retransmission can be controlled using a DCI that includes CBGTI and CBGFI.

[0343] Additionally, response signals (e.g., ACK / NACK or HARQ-ACK) can be sent via an uplink control channel (e.g., PUCCH), and can also be sent on a PUSCH resource if the PUCCH resource overlaps with the PUSCH resource in time.

[0344] Additionally, the PUCCH resources for sending response signals can be controlled, for example, by a DCI that includes PRI. Terminal 200 can, for example, allocate the number of TBs N based on the number of CBGs M contained in the TB group. TBG and the number of CBs for each TB n (n=0~N TBG -1), determines the retransmission control method and the number of HARQ-ACK bits for multi-TB scheduling. For example, when the number of CBGs is M, the number of HARQ-ACK bits can be M bits.

[0345] Furthermore, regarding the determination of PUCCH resources used to transmit HARQ-ACK bit strings for each TB group, for example, a method can be adopted to notify the PUCCH resources used by the terminal 200 from among multiple PUCCH resources (e.g., candidates) contained in the set of PUCCH resources (PUCCH resource set). Alternatively, the PUCCH resource set can be semi-statically set by the base station 100 to the terminal 200, for example, using the terminal's inherent higher-layer signals (RRC signals), and the PUCCH resources used by the terminal 200 in the PUCCH resource set can be notified by DCI (e.g., PRI field).

[0346] Additionally, for example, regarding the determination of PUCCH resources for sending HARQ-ACK bits for each TB group, terminal 200 may replace TB with TB group in one of the options 1 to 5 related to the determination of PUCCH resources in Implementation 2.

[0347] Additionally, if the number of PUCCH resources in a PUCCH resource set exceeds a threshold (e.g., 8), in addition to using the PRI field of the DCI, information related to the radio resource unit (CCE) of the PDCCH transmitting the DCI can be used to control the PUCCH resources. Here, PUCCH resources can be composed of parameters such as PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence number or orthogonal code number). Furthermore, multiple PUCCH resource sets can be set for the terminal 200, or the PUCCH resource set used by the terminal 200 can be determined based on the number of HARQ-ACK bits.

[0348] Thus, according to this embodiment, by dividing the multiple TBs allocated by the multi-TB scheduling into multiple TB groups, notifications from the base station 100 to the terminal 200 (e.g., DCI-based notifications) can be performed on a TB group basis, thereby suppressing the increase in DCI overhead.

[0349] (A variation of implementation method 3)

[0350] The number of TB groups set for terminal 200 can also be, for example, the maximum number of TB groups T. max In this case, the actual number of TB groups can also be determined according to the following formula (2).

[0351] [Equation 17]

[0352] (2)

[0353] Here, N represents the number of TBs allocated.

[0354] Additionally, for example, if N / T is an integer, each TB group can contain N / M TBs. Also, for example, if N / M is not an integer, it can be included in TB groups #0 to #T-2.

[0355] [Formula 18]

[0356] indivual

[0357] TB, and include it in TB group #T-1

[0358] [Formula 19]

[0359] indivual

[0360] TB. This contains...

[0361] [Formula 20]

[0362] indivual

[0363] The TB group is not limited to TB group #T-1; it can be TB group #0 or other TB groups.

[0364] Furthermore, the method for determining the number of TBs contained in a TB group is not limited to the method described above. For example, it could also be set as T1 = mod(N, M), containing TBs from TB group #0 to TB group T1-1.

[0365] [Equation 21]

[0366] indivual

[0367] TB is contained in TB group #T1 to TB group T-1.

[0368] [Equation 22]

[0369] indivual

[0370] TB.

[0371] For example, the number of TB groups or the maximum number of TB groups can be semi-statically notified to terminal 200 using a higher layer (e.g., an RRC signal), or the number of TB groups or the maximum number of TB groups can be dynamically notified to terminal 200 using DCI. When dynamically notifying the number of TB groups or the maximum number of TB groups using DCI, for example, the bit field for notifying the number of TB groups or the maximum number of TB groups can be set independently in the DCI, or the number of TB groups or the maximum number of TB groups can be notified together with the time domain resource in the TDRA field of the notification time domain resource in the DCI. Alternatively, for example, the number of TB groups or the maximum number of TB groups can also be notified together with the bit field for notifying the number of TB groups.

[0372] Alternatively, a TB group can contain a fixed number of TBs. In this case, terminal 200 can, for example, determine the number of TB groups based on the allocated number of TBs N, and determine the retransmission control method and the number of HARQ-ACK bits for multi-TB scheduling.

[0373] The above describes various embodiments of one example of the present invention.

[0374] Furthermore, in NR, for example, a priority can be set for HARQ-ACK. For instance, when there are two priority levels, a priority index of 0 (e.g., low priority) or 1 (e.g., high priority) can be set for HARQ-ACK. In multi-TB scheduling, for example, a priority can be set for HARQ-ACK on a per-TB or per-TB group basis. Additionally, for example, in implementation 3, the priority of HARQ-ACK can be determined corresponding to the HARQ process number.

[0375] Furthermore, in NR, for example, DCI format 1-1, which schedules PDSCH, has the function of allocating 2 codewords. According to this function, for example, NDI and RV can be notified in each codeword. Therefore, for example, in embodiment 2 or embodiment 3, the NDI and RV fields of each codeword in DCI format 1-1 can also be separately set (in other words, misappropriated) to multiple TBs or multiple TB groups. Moreover, in embodiment 2, the number of allocated TBs is set (or limited) to 2, and in embodiment 3, the number of TB groups is set (or limited) to 2. Additionally, for example, in the case of applying multi-TB scheduling, it is also possible to transmit without using 2 codewords.

[0376] Furthermore, although the above embodiments illustrate an example of transmitting or receiving one TB in one time slot, they are not limited to this. For example, multiple TBs can be transmitted or received in one time slot, or one TB can be transmitted or received in multiple time slots.

[0377] Furthermore, while the above embodiments describe retransmission control of PDSCH—in other words, the reception of PDSCH in terminal 200 and the transmission of HARQ-ACK in PUCCH or PUSCH from base station 100—they are not limited thereto. One embodiment of this disclosure can also be applied to retransmission control of PUSCH, in other words, to the transmission of PUSCH in terminal 200 and the reception of HARQ-ACK from base station 100. Alternatively, one embodiment of this disclosure can also be applied to, for example, data transmission in a sidelink and the HARQ-ACK feedback channel.

[0378] In addition, an embodiment of the present disclosure can also be applied to scenarios with a longer round trip time (RTT), such as non-terrestrial networks (NTN) or operations in frequency bands above 52.6 GHz. In such scenarios, for example, compared with the RTT, the number of HARQ processes may decrease. For example, it is possible that the slot length × the number of HARQ processes < RTT. Therefore, for example, as in Embodiment 1, by assigning a common HARQ process number to multiple scheduled TBs using one DCI, the impact of insufficient HARQ processes can be alleviated.

[0379] In addition, each parameter applied in the above embodiment (for example, the number of allocated TBs N, the number of CBGs M, the number of CBs C included in TB#n n or the number of CBs included in a CBG) is an example, and other values may also be used. In addition, in the above embodiment, the number of CBs or CBGs included in multiple TBs may also be different.

[0380] (Control signal)

[0381] In an embodiment of the present disclosure, the downlink control signal (or downlink control information) can be, for example, a signal (or information) transmitted in the physical downlink control channel (PDCCH) of the physical layer, or a signal (or information) transmitted in the medium access control (MAC) or radio resource control (RRC) of the higher layer. In addition, for the signal (or information), it is not limited to being notified by the downlink control signal, and it can be pre-specified in the specification (or standard), or pre-set in the base station and the terminal.

[0382] In one embodiment of this disclosure, the uplink control signal (or uplink control information) may be, for example, a signal (or information) transmitted in the physical layer PDCCH, or a signal (or information) transmitted in the higher layer MAC or RRC. Furthermore, the signal (or information) is not limited to being notified by the uplink control signal; it may be predefined in the specification (or standard) or pre-set in the base station and terminal. Additionally, the uplink control signal may also be replaced, for example, with uplink control information (UCI), first-stage sidelink control information (SCI), or second-stage SCI.

[0383] (Base station)

[0384] In one embodiment of this disclosure, the base station can also be a Transmission Reception Point (TRP), cluster head, access point, Remote Radio Head (RRH), eNodeB (eNB), gNodeB (gNB), Base Station (BS), Base Transceiver Station (BTS), host, gateway, etc. Alternatively, in sidelink communication, a terminal can replace the base station. Furthermore, a relay device communicating with the relay terminal of the higher-level node can replace the base station.

[0385] (Uplink / Downlink / Sidelink)

[0386] An embodiment of this disclosure can be applied to any of the uplink, downlink, and sidelinks. For example, an embodiment of this disclosure can be applied to the Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Physical Random Access Channel (PRACH) of the uplink, the Physical Downlink Shared Channel (PDSCH), PDCCH, Physical Broadcast Channel (PBCH) of the downlink, or the Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Broadcast Channel (PSBCH) of the sidelink.

[0387] Furthermore, PDCCH, PDSCH, PUSCH, and PUCCH are examples of downlink control channel, downlink data channel, uplink data channel, and uplink control channel, respectively. Additionally, PSCCH and PSSCH are examples of sidelink control channel and sidelink data channel, respectively. Furthermore, PBCH and PSBCH are examples of broadcast channels, and PRACH is an example of a random access channel.

[0388] (Data Channel / Control Channel)

[0389] One embodiment of this disclosure can be applied to any channel in the data channel and the control channel. For example, the channel in one embodiment of this disclosure can also be replaced with one of the following channels: PDSCH, PUSCH, PSSCH of the data channel, or PDCCH, PUCCH, PBCH, PSCCH, PSBCH of the control channel.

[0390] (Reference signal)

[0391] In one embodiment of this disclosure, the reference signal is, for example, a signal known to both the base station and the mobile station, and is sometimes referred to as a "Reference Signal (RS)" or "pilot signal". The reference signal can be any of the following: demodulation reference signal (DMRS), channel state information-reference signal (CSI-RS), tracking reference signal (TRS), phase tracking reference signal (PTRS), cell-specific reference signal (CRS), or sounding reference signal (SRS).

[0392] (Time interval)

[0393] In one embodiment of this disclosure, the unit of time resource is not limited to one or a combination of time slots and symbols. For example, it can be a frame, superframe, subframe, time slot, time slot subslot, minislot, or symbol, Orthogonal Frequency Division Multiplexing (OFDM) symbol, Single Carrier-Frequency Division Multiplexing (SC-FDMA) symbol, or other time resource units. Furthermore, the number of symbols contained in one time slot is not limited to the number of symbols exemplified in the above embodiments; it can also be other numbers of symbols.

[0394] (frequency band)

[0395] One embodiment of this disclosure can be applied to either a licensed band or an unlicensed band.

[0396] (communication)

[0397] One embodiment of this disclosure can be applied to any communication, including communication between a base station and a terminal, communication between terminals (sidelink communication, Uu link communication), and communication in vehicle-to-everything (V2X) wireless communication technology. For example, the channel in one embodiment of this disclosure can be replaced with one of the following channels: PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, or PBCH.

[0398] Furthermore, one embodiment of this disclosure can be applied to any network, including terrestrial networks and non-terrestrial networks (NTNs) that use satellites or high-altitude pseudo-satellites (HAPS). Additionally, one embodiment of this disclosure can also be applied to terrestrial networks with large cell sizes and ultra-wideband transmission networks, where transmission delays exceed the symbol length or time slot length.

[0399] (Antenna Port)

[0400] In one embodiment of this disclosure, an antenna port refers to a logical antenna (antenna group) composed of one or more physical antennas. For example, an antenna port may not necessarily refer to a single physical antenna; sometimes it refers to an array antenna composed of multiple antennas. For instance, instead of specifying how many physical antennas constitute an antenna port, it may be defined as the smallest unit that the terminal can transmit a reference signal. Additionally, an antenna port is sometimes also defined as the smallest unit multiplied by a precoding vector.

[0401] <5G NR System Architecture and Protocol Stack>

[0402] To realize the next version of fifth-generation mobile phone technology (also known simply as "5G"), which includes the development of a new radio access technology (NR) operating in the frequency range up to 100 GHz, 3GPP is continuing its work. The first version of the 5G standard was completed at the end of 2017, thus enabling the transition to the trial production of terminals (e.g., smartphones) according to the 5G NR standard and commercial deployment.

[0403] For example, the overall system architecture envisions a gNB-RAN (Next Generation Radio Access Network). The gNB provides the UE (User Equipment) side termination for the NG radio access protocols (SDAP (Service Data Adaptation Protocol) / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC (Medium Access Control) / PHY (Physical Layer)) and control plane (RRC). gNBs are interconnected via the Xn interface. Additionally, gNBs are connected to the NGC (Next Generation Core) via the Next Generation (NG) interface, and more specifically, to the AMF (Access and Mobility Management Function) (e.g., a specific core entity implementing the AMF) via the NG-C interface, and to the UPF (User Plane Function) (e.g., a specific core entity implementing the UPF) via the NG-U interface. Figure 23 illustrates the NG-RAN architecture (e.g., refer to 3GPP TS 38.300 v15.6.0, section 4).

[0404] The user plane protocol stack for NR (e.g., see 3GPP TS 38.300, section 4.4.1) comprises the PDCP (Packet Data Convergence Protocol, see TS 38.300, section 6.4) sublayer, RLC (Radio Link Control, see TS 38.300, section 6.3) sublayer, and MAC (Media Access Control, see TS 38.300, section 6.2) sublayer, which terminates on the network side in the gNB. Additionally, a new Access Stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) has been incorporated into PDCP (e.g., see 3GPP TS 38.300, section 6.5). Furthermore, a control plane protocol stack is defined for NR (e.g., see TS 38.300, section 4.4.2). A summary of Layer 2 functionality is described in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in Sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in Section 7 of TS 38.300.

[0405] For example, the media access control layer handles the multiplexing of logical channels, scheduling of processing involving various parameter sets, and various functions associated with scheduling.

[0406] For example, the Physical Layer (PHY) is responsible for encoding, PHY HARQ (Physical Layer Hybrid Automatic Repeat Request) processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. Additionally, the Physical Layer handles the mapping of physical channels to transport channels. The Physical Layer provides services to the MAC Layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used to transmit a specific transport channel; each transport channel is mapped to a corresponding physical channel. For example, in physical channels, uplink physical channels include PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), while downlink physical channels include PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0407] In NR use cases / extended scenarios, enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) may have multiple necessary conditions in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates approximately three times that of IMT-Advanced (20Gbps in downlink and 10Gbps in uplink) and effective (user-experienced) data rates. On the other hand, in the case of URLLC, more stringent necessary conditions are proposed for ultra-low latency (0.5ms latency in both UL and DL) and high reliability (within 1ms, 1-10-5). Finally, in mMTC, high connection density (1,000,000 devices / km in urban environments) is preferably required. 2 ), wide coverage in harsh environments and extremely long battery life (15 years) for inexpensive devices.

[0408] Therefore, a set of OFDM (Orthogonal Frequency Division Multiplexing) parameters suitable for one use case (e.g., subcarrier spacing (SCS), OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may be ineffective for other use cases. For example, in low-latency services, it is preferable to have shorter symbol lengths (and thus larger subcarrier spacings) and / or fewer symbols per scheduling interval (also known as "TTI"). Moreover, in extended scenarios with large channel delay spreads, it is preferable to have longer CP lengths than in scenarios with shorter delay spreads. The subcarrier spacing can also be optimized depending on the situation to maintain the same CP overhead. NR supports more than one subcarrier spacing value. Correspondingly, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc., are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related according to the formula Δf = 1 / Tu. Similar to the LTE (Long Term Evolution) system, the term "resource element" can be used to represent the smallest resource unit consisting of a subcarrier with a length corresponding to one OFDM / SC-FDMA (Single-Carrier Frequency Division Multiple Access) symbol.

[0409] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined in both the uplink and downlink for each parameter set and each carrier. Each element of the resource grid is called a "resource element," which is determined based on the frequency index in the frequency domain and the symbol position in the time domain (refer to 3GPP TS 38.211 v15.6.0).

[0410] <Functional Separation between NG-RAN and 5GC in 5G NR>

[0411] Figure 24 illustrates the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is either gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF (Session Management Function).

[0412] For example, gNB and ng-eNB host the following main functions:

[0413] - Functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, and Radio Resource Management (RRM) that dynamically allocates (schedules) resources to the UE in both the uplink and downlink links;

[0414] - Data IP (Internet Protocol) header compression, encryption, and integrity protection;

[0415] - Selection of AMF when attaching a UE in situations where the route to the AMF cannot be determined based on the information provided by the UE;

[0416] - Routing to user plane data towards UPF;

[0417] - Routing of control plane information toward AMF;

[0418] - Setting and canceling connections;

[0419] - Scheduling and sending paging messages;

[0420] - The scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, and Maintenance functions (OAM));

[0421] - Setting up measurements and measurement reports for mobility and scheduling;

[0422] - Packet markings for transmission class in the uplink;

[0423] -Session management;

[0424] -Support for network slicing;

[0425] - QoS (Quality of Service) flow management and mapping to data radio bearers;

[0426] Support for UEs in RRC_INACTIVE (RRC inactive) state;

[0427] - NAS (Non-Access Stratum) message distribution function;

[0428] - Sharing of wireless access networks;

[0429] - Dual connectivity;

[0430] - Close collaboration between NR and E-UTRA (Evolved Universal Terrestrial Radio Access).

[0431] The Access and Mobility Management Function (AMF) administers the following main functions:

[0432] - Function to terminate Non-Access Stratum (NAS) signaling;

[0433] -Security of NAS signaling;

[0434] - Security controls at the access layer (AS);

[0435] - Core Network (CN) inter-node signaling for mobility between 3GPP access networks;

[0436] - The possibility of a UE reaching idle mode (including control and execution of paging retransmission);

[0437] - Management of the registered area;

[0438] - Support for intra-system mobility and inter-system mobility;

[0439] -Access authentication;

[0440] - Access licenses that include roaming permission checks;

[0441] - Mobility management controls (subscription and policies);

[0442] -Support for network slicing;

[0443] - Selection of Session Management Function (SMF).

[0444] In addition, the User Face Function (UPF) hosts the following main functions:

[0445] - Anchor points for intra-RAT (Radio Access Technology) mobility / inter-RAT (where applicable) mobility;

[0446] - External PDU (Protocol Data Unit) session points used for interconnection with data networks;

[0447] - Packet routing and forwarding;

[0448] - Enforcement of policy rules in group checks and user-facing aspects;

[0449] - Reports on business usage;

[0450] - Uplink classifier used to support routing of service flows toward the data network;

[0451] - Branching points used to support multi-homed PDU sessions;

[0452] - For user plane QoS processing (e.g., packet filtering, gating, UL / DL rate enforcement);

[0453] - Uplink service verification (SDF (Service Data Flow) mapping to QoS flow);

[0454] - Downlink packet buffering and downlink data notification triggering functions.

[0455] Finally, the Session Management Function (SMF) administers the following main functions:

[0456] -Session management;

[0457] - The allocation and management of UE IP addresses;

[0458] -Selection and control of UPF;

[0459] - A function for setting traffic steering in the User Plane Function (UPF) to direct traffic to the appropriate destination;

[0460] - Enforcing policies and QoS in the control section;

[0461] - Notification of downlink data.

[0462] <The process of setting up and resetting RRC connection>

[0463] Figure 25 illustrates several interactions between the UE, gNB, and AMF (5GC entity) when the UE in the NAS transitions from RRC_IDLE (RRC idle) to RRC_CONNECTED (RRC connected) (refer to TS 38.300 v15.6.0).

[0464] RRC is a higher-level signaling (protocol) used for UE and gNB configuration. Through this transition, the AMF prepares UE context data (which includes, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB along with an initial context setting request. Next, the gNB and UE activate AS security together. The gNB sends a SecurityModeCommand message to the UE, and the UE responds with a SecurityModeComplete message, thereby activating AS security. Then, the gNB sends an RRCReconfiguration message to the UE, and receives an RRCReconfigurationComplete message from the UE for this message, thus performing the reconfiguration of Signaling RadioBearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, since SRB2 and DRB are not configured, the steps related to RRC reconfiguration can be omitted. Finally, the gNB notifies the AMF that the configuration process is complete using the Initial Context Setup Reply.

[0465] Therefore, this invention provides a fifth-generation core network (5GC) entity (e.g., AMF, SMF, etc.) comprising: a control circuit that, upon operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmission unit that, upon operation, transmits an initial context setting message to the gNodeB via the NG connection to set the signaling radio bearer between the gNodeB and the User Equipment (UE). Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling containing an Information Element (IE) to the UE via the signaling radio bearer. The UE then performs uplink transmission or downlink reception based on the resource allocation settings.

[0466] <Application Scenarios of IMT after 2020>

[0467] Figure 26 illustrates several use cases for 5G NR. Within the 3rd Generation Partnership Project New Radio (3GPP NR), three use cases supporting a wide variety of services and applications have been explored through the IMT-2020 concept. The planning and development of the first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes the gradual expansion of eMBB support, as well as standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). Figure 26 illustrates several examples of IMT's conceptual application scenarios beyond 2020 (see, for example, Figure 2 of ITU-R M.2083).

[0468] URLLC use cases have strict requirements related to performance aspects such as throughput, latency, and availability. URLLC is conceived as a key technology for enabling wireless control of future industrial production or manufacturing processes, remote medical surgery, automation of power transmission and distribution in smart grids, and traffic safety applications. Ultra-high reliability of URLLC is supported by defining technologies that meet the requirements set by TR38.913. In NR URLLC version 15, a crucial requirement is a target user plane latency of 0.5ms in the UL (uplink) and 0.5ms in the DL (downlink). For a single packet transmission, the overall requirement for URLLC is a block error rate (BLER) of 1E-5 for a 32-byte packet size with a user plane latency of 1ms.

[0469] Considering the physical layer, numerous methods are available to improve reliability. Current possibilities for reliability enhancement include defining alternative CQI (Channel Quality Indicator) tables for URLLC, a more compact DCI (Downlink Control Information) format, and PDCCH iteration. However, as NR (a crucial prerequisite for NR URLLC) becomes more stable and is further developed, this scope can be expanded to achieve ultra-high reliability. Specific use cases for NR URLLC in version 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and other critical applications.

[0470] Furthermore, technical enhancements targeting NR URLLC aim to improve latency and reliability. Latency enhancements include configurable parameter sets, non-slot-based scheduling utilizing flexible mapping, unlicensed (already licensed) uplinks, slot-level repetition in the data channel, and pre-emption in the downlink. Pre-emption refers to stopping transmissions with allocated resources and using those resources for later-requested transmissions that require lower latency / higher priority. Therefore, a permitted transmission is replaced by a subsequent transmission. Pre-emption can be applied regardless of the specific service type. For example, a transmission in service type A (URLLC) can be replaced by a transmission in service type B (eMBB, etc.). Reliability enhancements include a dedicated CQI / MCS (Modulation and Coding Scheme) table for a target BLER of 1E-5.

[0471] The use cases for mMTC (massive machine-type communications) are characterized by a large number of connected devices that transmit relatively small amounts of data that are not easily affected by latency. These devices require low cost and very long battery life. From NR's perspective, utilizing very narrow bandwidth is a solution to save UE power and extend its battery life.

[0472] As mentioned above, the potential for improved reliability in NR is further expanded. It is one of the essential conditions for all situations; for example, high or ultra-high reliability is a crucial requirement related to URLLC and mMTC. From both wireless and network perspectives, reliability can be improved through several mechanisms. Generally, there are two to three important areas that could potentially contribute to improved reliability. These areas include compact control channel information, data / control channel iteration, and diversity related to the frequency, time, and / or spatial domains. These areas can be used universally to improve reliability, independent of specific communication scenarios.

[0473] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power transmission. Stricter requirements refer to high reliability (reaching level 10⁻⁶), high availability, a packet size of 256 bytes, and time synchronization of approximately several microseconds (μs) (capable of corresponding to use cases, with values ​​set to 1 μs or several microseconds depending on the frequency range and short latency of approximately 0.5ms to 1ms (e.g., 0.5ms latency in the target user plane)).

[0474] Furthermore, from a physical layer perspective, there are several technical enhancements to NR URLLC. These enhancements include strengthening the PDCCH (Physical Downlink Control Channel) associated with compact DCI, PDCCH repetition, and increased PDCCH monitoring. Additionally, enhancements to UCI (Uplink Control Information) are related to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Furthermore, there may be enhancements to PUSCH and retransmission / repetition related to micro-slot-level frequency hopping. The term "micro-slot" refers to a transmission time interval (TTI) containing fewer symbols than a time slot (a time slot has 14 symbols).

[0475] <QoS Control>

[0476] 5G's QoS (Quality of Service) model is based on QoS flows, supporting both QoS flows that require guaranteed bit rate (GBR) and QoS flows that do not require guaranteed bit rate (non-GBR QoS flows). Therefore, at the NAS level, QoS flows represent the finest granular QoS classification within a PDU session. QoS flows are determined within a PDU session based on the QoS Flow ID (QFI) transmitted via the encapsulation header through the NG-U interface.

[0477] For each UE, the 5GC establishes one or more PDU sessions. For each UE, in conjunction with the PDU session, the NG-RAN establishes at least one Data Radio Bearer (DRB), as illustrated above with reference to Figure 25. Additionally, DRBs can be subsequently configured in QoS flows added to that PDU session (when this is configured depends on the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC are used to associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0478] Figure 27 illustrates the non-roaming reference architecture for 5G NR (refer to TS 23.501 v16.1.0, section 4.23). Application Functions (AFs) (e.g., external application servers hosting the 5G services illustrated in Figure 26) interact with the 3GPP core network to provide services. For example, they may access Network Exposure Functions (NEFs) to support applications that impact service routing, or they may interact with policy frameworks (refer to Policy Control Functions (PCFs)) for policy control (e.g., QoS control). Based on operator deployment, operators deem trusted application functions capable of directly interacting with associated Network Functions. Application functions not permitted by the operator to directly access Network Functions interact with associated Network Functions via the NEF, using an externally accessible release framework.

[0479] Figure 27 also illustrates the further functional units of the 5G architecture: Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN: Data Network, such as services provided by operators, internet access, or services provided by third parties). All or part of the core network's functions and application services can also be deployed and operate in a cloud computing environment.

[0480] Therefore, the present invention provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitting unit that, in order to establish a PDU session containing a radio bearer between a g node B and a UE corresponding to QoS requirements, sends at least one of the following functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to the 5GC during operation: a request containing QoS requirements for at least one of URLLC service, eMMB service, and mMTC service; and a control circuit that, during operation, performs services using the established PDU session.

[0481] This invention can be implemented in software, hardware, or software in cooperation with hardware. The functional blocks used in the above embodiments are implemented partially or wholly as LSIs (Large Scale Integrations), and the processes described in the above embodiments can also be controlled partially or wholly by a single LSI or a combination of LSIs. An LSI can be composed of individual chips, or it can be composed of a single chip containing some or all of the functional blocks. An LSI can also include data input and output. Depending on the degree of integration, an LSI can also be called an "IC (Integrated Circuit)," a "System LSI," a "Super LSI," or an "Ultra LSI."

[0482] The method of integrating LSIs is not limited to LSIs; it can also be implemented using dedicated circuits, general-purpose processors, or special-purpose processors. Alternatively, it can utilize FPGAs (Field Programmable Gate Arrays) that can be programmed after LSI fabrication, or reconfigurable processors that can reconfigure the connections or settings of the circuit blocks within the LSI. This invention can also be implemented for digital or analog processing.

[0483] Furthermore, if advancements in semiconductor technology or the emergence of other derivative technologies lead to integrated circuit technologies that can replace LSIs, these technologies could also be used to integrate functional blocks. There are also possibilities for applications such as biotechnology.

[0484] This invention can be implemented in all kinds of devices, apparatuses, and systems with communication capabilities (collectively referred to as "communication devices"). A communication device may also include a wireless transceiver and processing / control circuitry. The wireless transceiver may also include a receiving unit and a transmitting unit, or perform the functions of these units. The wireless transceiver (transmitting unit, receiving unit) may also include an RF (Radio Frequency) module and one or more antennas. The RF module may also include an amplifier, an RF modulator / demodulator, or similar devices. Non-limiting examples of communication devices include: telephones (mobile phones, smartphones, etc.), tablet computers, personal computers (PCs) (laptops, desktops, laptops, etc.), cameras (digital cameras, digital camcorders, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, e-book readers, remote health / telemedicine (remote healthcare / medical prescription) devices, vehicles or transportation vehicles with communication capabilities (cars, airplanes, ships, etc.), and combinations of the various devices described above.

[0485] Communication devices are not limited to portable or movable devices, but also include all kinds of devices, equipment, and systems that cannot be carried or fixed. Examples include: smart home devices (home appliances, lighting equipment, smart meters or meters, control panels, etc.), vending machines, and all other "things" that can exist on the IoT (Internet of Things) network.

[0486] In addition to data communication via cellular systems, wireless LAN (Local Area Network) systems, and communication satellite systems, communication also includes data communication via a combination of these systems.

[0487] In addition, the communication device also includes devices such as controllers or sensors that are connected or linked to the communication equipment performing the communication functions described in this invention. For example, it includes controllers or sensors that generate control signals or data signals used by the communication equipment performing the communication functions of the communication device.

[0488] In addition, the communication device includes infrastructure equipment that communicates with or controls the various devices described above (not limited to these), such as base stations, access points, and all other devices, equipment, and systems.

[0489] One embodiment of the present disclosure includes a terminal comprising: a control circuit for retransmitting multiple transmission blocks in units of a group of code blocks containing at least one code block, the code block being a code block in one or more of the multiple transmission blocks; and a communication circuit for communicating according to the retransmission control.

[0490] In one embodiment of this disclosure, the control circuit determines the number of code blocks contained in the code block group based on the number of the plurality of transport blocks, the number of code block groups in the plurality of transport blocks, and the number of code blocks contained in the plurality of transport blocks.

[0491] In one embodiment of this disclosure, the identification number associated with retransmission control assigned to the plurality of transport blocks is common among the plurality of transport blocks.

[0492] In one embodiment of this disclosure, the communication circuit utilizes common uplink resources to send response signals based on error detection results in units of the plurality of transport blocks.

[0493] In one embodiment of this disclosure, the control circuit determines the number of code blocks contained in the code block group based on the number of code block groups in each of the plurality of transport blocks and the number of code blocks in each of the plurality of transport blocks.

[0494] In one embodiment of this disclosure, the identification number associated with retransmission control assigned to the plurality of transport blocks is different on a per-transport-block basis.

[0495] In one embodiment of this disclosure, the communication circuit utilizes an uplink resource to send a response signal based on the overall error detection result of the plurality of transport blocks.

[0496] In one embodiment of this disclosure, the communication circuit utilizes an uplink resource to transmit a signal multiplexed from response signals based on error detection results in units of the plurality of transport blocks.

[0497] In one embodiment of this disclosure, the communication circuit utilizes multiple uplink resources to send response signals based on error detection results in units of the multiple transport blocks.

[0498] In one embodiment of this disclosure, the communication circuit receives multiple sets of information representing the plurality of uplink resources.

[0499] In one embodiment of this disclosure, the communication circuit receives information representing a combination of the plurality of uplink resources.

[0500] In one embodiment of this disclosure, the communication circuit receives information representing a portion of the plurality of uplink resources, and the control circuit determines other resources in the plurality of uplink resources that are different from the portion of resources based on the portion of resources.

[0501] In one embodiment of this disclosure, the control circuit determines the number of code blocks contained in the code block group based on the number of code block groups in each of the plurality of groups formed by dividing the plurality of transport blocks, and the number of code blocks in each of the plurality of transport blocks.

[0502] A base station according to an embodiment of this disclosure includes: a control circuit for retransmitting multiple transmission blocks in units of code block groups containing at least one code block, the code block being a code block in one or more of the multiple transmission blocks; and a communication circuit for communicating according to the retransmission control.

[0503] In a communication method according to one embodiment of this disclosure, a terminal performs retransmission control on multiple transmission blocks in units of a group of code blocks containing at least one code block, and communicates according to the retransmission control, wherein the code block is a code block in one or more of the multiple transmission blocks.

[0504] In a communication method according to one embodiment of the present disclosure, a base station performs retransmission control on multiple transmission blocks in units of a group of code blocks containing at least one code block, and communicates according to the retransmission control, wherein the code block is a code block in one or more of the multiple transmission blocks.

[0505] The entire contents of the specification, drawings and abstract of the specification contained in Japanese Patent Application No. 2020-133858, filed on August 6, 2020, are incorporated herein by reference.

[0506] Industrial applicability

[0507] One embodiment of the present invention is useful for wireless communication systems.

Claims

1. A terminal, comprising: The control circuit performs retransmission control for multiple transmission blocks in units of code block groups containing at least one code block, wherein the code block is a code block in one or more of the multiple transmission blocks; And a communication circuit, which communicates according to the retransmission control.

2. The terminal as described in claim 1, wherein, The control circuit determines the number of code blocks contained in the code block group based on the number of the plurality of transport blocks, the number of code block groups in the plurality of transport blocks, and the number of code blocks contained in the plurality of transport blocks.

3. The terminal as described in claim 1, wherein, The identification number associated with retransmission control assigned to the plurality of transport blocks is common among the plurality of transport blocks.

4. The terminal as described in claim 2, wherein, The communication circuit utilizes common uplink resources to send response signals based on error detection results in units of the plurality of transport blocks.

5. The terminal as described in claim 1, wherein, The control circuit determines the number of code blocks contained in the code block group based on the number of code block groups in each of the plurality of transport blocks and the number of code blocks in each of the plurality of transport blocks.

6. The terminal as described in claim 1, wherein, The identification number assigned to the plurality of transport blocks in relation to retransmission control is different for each of the plurality of transport blocks.

7. The terminal as described in claim 5, wherein, The communication circuit utilizes an uplink resource to send a response signal based on the overall error detection result of the multiple transport blocks.

8. The terminal as described in claim 5, wherein, The communication circuit utilizes an uplink resource to transmit a signal multiplexed from response signals based on error detection results in units of the plurality of transport blocks.

9. The terminal as described in claim 5, wherein, The communication circuit utilizes multiple uplink resources to send response signals based on error detection results in units of the multiple transport blocks.

10. The terminal as described in claim 9, wherein, The communication circuit receives multiple sets of information representing the multiple uplink resources.

11. The terminal as claimed in claim 9, wherein, The communication circuit receives information representing a combination of the plurality of uplink resources.

12. The terminal as described in claim 9, wherein, The communication circuit receives information representing a portion of the plurality of uplink resources, and the control circuit determines, based on the portion of resources, other resources in the plurality of uplink resources that are different from the portion of resources.

13. The terminal as claimed in claim 1, wherein, The control circuit determines the number of code blocks contained in the code block group based on the number of code block groups in each of the multiple groups formed by dividing the multiple transport blocks, and the number of code blocks in each of the multiple transport blocks.

14. A base station, comprising: The control circuit performs retransmission control for multiple transmission blocks in units of code block groups containing at least one code block, wherein the code block is a code block in one or more of the multiple transmission blocks; And a communication circuit, which communicates according to the retransmission control.

15. A communication method, wherein, The terminal performs retransmission control on multiple transport blocks in units of code block groups containing at least one code block, and communicates according to the retransmission control, wherein the code block is a code block in one or more of the multiple transport blocks.

16. A communication method, wherein, The base station performs retransmission control for multiple transport blocks in units of code block groups containing at least one code block, and communicates according to the retransmission control, wherein the code block is a code block in one or more of the multiple transport blocks.

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