Base station, communication method, and integrated circuit

Abstract

To provide a base station capable of improving the efficiency of retransmission control in a downlink.SOLUTION: The base station includes: a control circuit that generates a piece of downstream control information, which includes a piece of resending information, and generates plural Physical Downlink Shared Channels (PDSCH) for instruction by a piece of downstream control information; and a transmitter that transmits a piece of downstream control information and plural PDSCHs. The retransmission of plural PDSCHs is controlled based on the HARQ process number, and the HARQ process number is different for each of the plural PDSCHs. The plural PDSCHs have consecutive HARQ process numbers. The upper limit of the number of HARQ process numbers that can be assigned by scheduling plural PDSCHs is set to be equal to or less than the maximum number of HARQ process numbers.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a terminal, a base station, and a communication method. [Background technology]

[0002] In recent years, the expansion and diversification of wireless services has led to expectations for the dramatic development of the Internet of Things (IoT). Mobile communications are expanding from smartphones and other information terminals to a wide range of applications, including automobiles, homes, home appliances, and industrial equipment. To support this diversification, significant improvements in the performance and functionality of mobile communication systems are required, addressing various requirements, such as increased system capacity, an increased number of connected devices, and low latency. Fifth-generation mobile communication systems (5G) will provide flexible wireless communications to meet a wide variety of needs through enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC).

[0003] The 3rd Generation Partnership Project (3GPP), an international standardization organization, is working on the specification of New Radio (NR) as one of the 5G wireless interfaces. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] RP-201386, “Revised SID on Study on support of reduced capability NR devices,” Ericsson, June 29 - July 3, 2020. [Non-patent document 2] RP-200938, “Revised WID UE Power Saving Enhancements for NR,” MediaTek Inc., June 29 - July 3, 2020. [Non-patent document 3] 3GPP TS36.212, “Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding (Release 16),” March 2020. [Non-patent document 4] 3GPP TS36.213, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 17),” March 2020. [Non-Patent Document 5] 3GPP TS38.212, “NR; Multiplexing and channel coding (Release 16),” March 2020. [Non-patent document 6] 3GPP TS38.214, “NR; Physical layer procedures for data (Release 16),” March 2020. Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is room for further study regarding retransmission control in the downlink (DL).

[0006] Non-limiting examples of the present disclosure contribute to providing a terminal, a base station, and a communication method that can improve the efficiency of downlink retransmission control. [Means for solving the problem]

[0007] A terminal according to one embodiment of the present disclosure includes a control circuit that performs retransmission control for a plurality of transport blocks in units of a code block group that includes at least one code block in one or more of the plurality of transport blocks, and a communication circuit that performs communication in accordance with the retransmission control.

[0008] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. [Effects of the Invention]

[0009] According to an embodiment of the present disclosure, it is possible to improve the efficiency of downlink retransmission control.

[0010] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0011] [Figure 1] An example of multiple Transport Block (TB) scheduling [Figure 2] Block diagram showing an example of the configuration of a portion of a base station [Figure 3] Block diagram showing an example of the configuration of a part of a terminal [Figure 4] Block diagram showing an example of the configuration of a base station [Figure 5]Block diagram showing an example of a terminal configuration [Figure 6] FIG. 10 is a diagram showing an example of code block division. [Figure 7] FIG. 1 shows an example of the configuration of a Code Block Group (CBG) according to a first embodiment. [Figure 8] FIG. 1 shows an example of the configuration of a CBG according to a first embodiment. [Figure 9] FIG. 1 shows an example of the configuration of a CBG according to a first embodiment. [Figure 10] FIG. 1 shows an example of the configuration of a CBG according to a first embodiment. [Figure 11] FIG. 1 shows an example of the configuration of a CBG according to a first embodiment. [Figure 12] Flowchart showing an example of operation of the base station according to the first embodiment [Figure 13] Flowchart showing an example of the operation of the terminal according to the first embodiment [Figure 14] FIG. 10 is a diagram showing an example of setting a Physical Uplink Control Channel (PUCCH) resource according to a second embodiment. [Figure 15] FIG. 10 shows an example of PUCCH resource configuration according to the second embodiment. [Figure 16] FIG. 10 shows an example of PUCCH resource configuration according to the second embodiment. [Figure 17] FIG. 10 shows an example of PUCCH resource configuration according to the second embodiment. [Figure 18] FIG. 10 is a diagram showing an example of a combination of PUCCH resources according to a second embodiment. [Figure 19] FIG. 10 shows an example of PUCCH resource configuration according to the second embodiment. [Figure 20] FIG. 10 is a diagram showing an example of retransmission control according to the second embodiment. [Figure 21] FIG. 10 is a diagram showing an example of retransmission control according to the second embodiment. [Figure 22] FIG. 10 shows an example of setting a TB group according to the third embodiment. [Figure 23] Diagram of an example architecture of a 3GPP NR system [Figure 24] Schematic diagram showing functional separation between NG-RAN and 5GC [Figure 25] Sequence diagram of the Radio Resource Control (RRC) connection setup / reconfiguration procedure [Figure 26] Schematic diagram showing usage scenarios for enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Figure 27] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0013] In the future, for example, further development of 5G and technological development of 6th generation mobile communication systems (6G) are expected. For example, the majority of early 5G terminals compatible with NR will be high-end models. Furthermore, in Rel. 16, studies have been conducted on specifications for high-performance IoT, such as industrial IoT, which has strict requirements. On the other hand, low power consumption terminals are expected for devices with relatively simple structures, such as industrial cameras, wearable products, and low-cost smartphones (see, for example, Non-Patent Documents 1 and 2).

[0014] One example of a technique for reducing the power consumption of a terminal is a method in which the terminal receives a downlink control channel (e.g., a Physical Downlink Control Channel (PDCCH)) intermittently, thereby reducing the number of blind decoding operations for receiving the PDCCH. However, for example, the less frequently the PDCCH is received due to the intermittent reception of the PDCCH, the fewer opportunities there are for allocating data that can be scheduled by the PDCCH, which may result in a decrease in transmission efficiency.

[0015] One method for suppressing a decrease in transmission efficiency and reducing the frequency of receiving PDCCH to thereby suppress power consumption of a terminal is, for example, multiple transport block (TB) scheduling (e.g., multi-TB scheduling).

[0016] 1 is a diagram illustrating an example of multiple TB scheduling. For example, a downlink control signal (e.g., DCI: Downlink Control Information) including scheduling information such as resource allocation from a base station (e.g., also referred to as a gNB) may be transmitted on a PDCCH. A terminal (e.g., also referred to as a User Equipment (UE)) may receive a downlink data signal (e.g., PDSCH: Physical Downlink Shared Channel) or transmit an uplink data signal (e.g., PUSCH: Physical Uplink Shared Channel) according to the resource allocation indicated by the DCI on the PDCCH.

[0017] In scheduling different from multi-TB scheduling, for example, one DCI indicates one PDSCH or PUSCH, and the number of TBs (also called data blocks) included in one PDSCH or one PUSCH may be one, or two in the case of spatial multiplexing in the same time and frequency resources. On the other hand, as shown in FIG. 1, in multi-TB scheduling, for example, one DCI can allocate multiple PDSCHs or PUSCHs (for example, represented as PDSCH / PUSCHs) that are transmitted and received at different times or frequencies. Also, for example, in multi-TB scheduling, as shown in FIG. 1, each PDSCH or PUSCH may include multiple different TBs. In this way, in multi-TB scheduling, for example, one DCI can schedule multiple TBs that are transmitted and received at different times or frequencies.

[0018] Multi-TB scheduling has been adopted, for example, in uplink transmissions using NR unlicensed bands (also referred to as NR-Unlicensed (NR-U)), and in uplink and downlink transmissions of Long Term Evolution (LTE) enhanced Machine Type Communication (eMTC) and Narrow Band-IoT (NB-IoT) (see, for example, Non-Patent Documents 3 to 6).

[0019] In NR, multiple TB scheduling is adopted for uplink transmission using unlicensed bands, but is not applied to downlink transmission. For example, when multiple TB scheduling is applied to downlink transmission, a terminal may transmit a response signal for a PDSCH for retransmission control. However, in NR, there is room for consideration for retransmission control including feedback of a response signal for downlink data (e.g., PDSCH) allocated by multiple TB scheduling. Note that the response signal may be called, for example, an Acknowledgement / Negative Acknowledgement (ACK / NACK) or a Hybrid Automatic Repeat Request-ACK (HARQ-ACK).

[0020] Furthermore, for example, in eMTC or NB-IoT of LTE, multiple TB scheduling is adopted for uplink transmission and downlink transmission, and retransmission control including ACK / NACK feedback for multiple TB scheduled data (e.g., PDSCH or PUSCH) is specified in the standard. However, while LTE specifies a method (e.g., TB-based retransmission) in which the entire TB transmitted and received for the first time is retransmitted, NR specifies a method (e.g., CBG-based retransmission) in which, when a TB includes multiple code blocks (e.g., CBs), an erroneous CBG among CBGs (Code Block Groups) including at least one CB is retransmitted instead of the entire TB. For this reason, there is room for further study on CBG-based retransmission control and ACK / NACK feedback methods for data allocated by multiple TB scheduling.

[0021] Therefore, in a non-limiting embodiment of the present disclosure, for example, a CBG-based retransmission control method in multiple TB scheduling will be described. According to a non-limiting embodiment of the present disclosure, for example, CBG-based retransmission control can be appropriately performed in multiple TB scheduling.

[0022] (Embodiment 1) [Communication System Overview] A communication system according to each embodiment of the present disclosure includes a base station 100 and a terminal 200.

[0023] 2 is a block diagram illustrating a configuration example of a portion of a base station 100 according to an embodiment of the present disclosure. In the base station 100 illustrated in FIG. 2, a control unit 101 (e.g., corresponding to a control circuit) performs retransmission control for multiple TBs in units of CBGs that include at least one CB in one or more of the multiple TBs. A transmitting unit 107 and a receiving unit 108 (e.g., corresponding to a communication circuit) communicate with a terminal 200 in accordance with the retransmission control.

[0024] 3 is a block diagram illustrating a configuration example of a portion of a terminal 200 according to an embodiment of the present disclosure. In the terminal 200 illustrated in FIG. 3, a control unit 205 (e.g., corresponding to a control circuit) performs retransmission control for multiple TBs in units of CBGs that include at least one CB in one or more of the multiple TBs. A receiving unit 201 and a transmitting unit 209 (e.g., corresponding to a communication circuit) communicate with the base station 100 in accordance with the retransmission control.

[0025] [Base station configuration] Fig. 4 is a block diagram showing an example configuration of a base station 100 according to embodiment 1. In Fig. 4, the base station 100 includes a control unit 101, a higher control signal generation unit 102, a downlink control information generation unit 103, an encoding unit 104, a modulation unit 105, a signal allocation unit 106, a transmission unit 107, a reception unit 108, an extraction unit 109, a demodulation unit 110, and a decoding unit 111.

[0026] The control unit 101 determines information relating to multiple TB scheduling and retransmission control for the terminal 200, and outputs the determined information to the higher control signal generation unit 102 or the downlink control information generation unit 103, for example.

[0027] The information on multi-TB scheduling may include, for example, information on the number of allocated TBs, and the information on retransmission control may include, for example, information on the number of CBGs and information on PUCCH resource allocation.

[0028] The information relating to multi-TB scheduling and the information relating to retransmission control may be output to, for example, the extraction unit 109, the demodulation unit 110, and the decoding unit 111 for PUCCH reception.

[0029] Furthermore, control unit 101 may determine information related to reception of a downlink data signal (for example, a PDSCH) for terminal 200, and output the determined information to higher control signal generation unit 102. The information related to PDSCH reception may include, for example, information related to a Time Domain Resource Allocation (TDRA) table.

[0030] Furthermore, the control unit 101 determines information related to a downlink signal for transmitting, for example, a downlink data signal, an upper control signal (for example, an RRC signal), or downlink control information (for example, DCI). The information related to the downlink signal may include, for example, information such as a modulation and coding scheme (MCS) and radio resource allocation. The control unit 101 outputs the determined information to, for example, the encoding unit 104, the modulation unit 105, and the signal allocation unit 106. Furthermore, the control unit 101 outputs information related to the downlink signal, for example, an upper control signal, to the downlink control information generation unit 103.

[0031] Furthermore, for example, when receiving a response signal (e.g., HARQ-ACK) from terminal 200, control unit 101 may generate information related to retransmission control based on the HARQ-ACK bit sequence input from decoding unit 111. The information related to retransmission control may include setting information such as 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 out Information (CBGFI). The information related to retransmission control may be output to coding unit 104, downlink control information generation unit 103, and decoding unit 111, for example.

[0032] For example, when information related to multi-TB scheduling or information related to retransmission control is notified by DCI, this information may be output to the downlink control information generation unit 103.

[0033] Furthermore, the control unit 101 may, for example, determine information (e.g., modulation and coding scheme (MCS) and radio resource allocation) regarding the uplink signal used by the terminal 200 to transmit an uplink data signal (e.g., PUSCH), and output the determined information to the higher 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.

[0034] The higher-level control signal generating section 102 generates a higher-level layer control signal bit sequence based on information input from the control section 101 , for example, and outputs the higher-level layer control signal bit sequence to the encoding section 104 .

[0035] The downlink control information generating unit 103 generates a downlink control information (e.g., DCI) bit string based on, for example, information input from the control unit 101, and outputs the generated DCI bit string to the encoding unit 104. Note that the control information may be transmitted to multiple terminals.

[0036] For example, based on information input from the control unit 101, the coding unit 104 codes the downlink data signal, the bit string input from the higher control signal generation unit 102, or the DCI bit string input from the downlink control information generation unit 103. The coding unit 104 outputs the coded bit string to the modulation unit 105. For example, the coding unit 104 may generate a codeword for the downlink data signal by CB division, rate matching, or CB concatenation, and apply scrambling.

[0037] Furthermore, for example, at the time of the first transmission, coding section 104 may output the coded data signal to modulation section 105 and may also hold the coded data signal. Furthermore, when information on retransmission control is input from control section 101, coding section 104 may output the corresponding held data to the data modulation section. Furthermore, when coding section 104 receives ACKs for all TBs or CBs of the HARQ process, for example, coding section 104 may delete the corresponding held data.

[0038] The modulation unit 105 modulates the coded bit sequence input from the coding unit 104, for example, based on information input from the control unit 101, and outputs the modulated signal (for example, a symbol sequence) to the signal allocation unit 106.

[0039] The signal allocation unit 106 maps the symbol sequence (including, for example, a downlink data signal or a control signal) input from the modulation unit 105 to the radio resource, for example, based on information indicating the radio resource input from the control unit 101. The signal allocation unit 106 outputs the downlink signal onto which the signal has been mapped to the transmission unit 107.

[0040] For example, transmitting unit 107 performs a transmission waveform generation process such as orthogonal frequency division multiplexing (OFDM) on the signal input from signal allocation unit 106. Furthermore, in the case of OFDM transmission that adds a cyclic prefix (CP), transmitting unit 107 performs an inverse fast Fourier transform (IFFT) process on the signal and adds a CP to the signal after IFFT. Furthermore, transmitting unit 107 performs RF processing such as D / A conversion and up-conversion on the signal, and transmits the radio signal to terminal 200 via an antenna.

[0041] The receiving unit 108 performs RF processing such as downconvert or A / D conversion on an uplink signal received from the terminal 200 via an antenna. In addition, in the case of OFDM transmission, the receiving unit 108 performs Fast Fourier Transform (FFT) processing on the received signal, and outputs the resulting frequency domain signal to the extracting unit 109.

[0042] The extraction unit 109 extracts a radio resource portion from which an uplink signal (e.g., PUSCH or PUCCH) transmitted by the terminal 200 is transmitted, based on information input from the control unit 101, and outputs the extracted radio resource portion to the demodulation unit 110.

[0043] The demodulation unit 110 demodulates the uplink signal input from the extraction unit 109, for example, based on information input from the control unit 101. The demodulation unit 110 outputs the demodulation result to the decoding unit 111, for example.

[0044] The decoding unit 111 performs error correction decoding on an uplink signal (for example, a PUSCH or a PUCCH) based on, for example, information input from the control unit 101 and a demodulation result input from the demodulation unit 110, and obtains a decoded received bit sequence (for example, a UL data signal or a UCI). The decoding unit 111 may output, for example, a HARQ-ACK bit sequence included in the UCI to the control unit 101.

[0045] [Device configuration] 5 is a block diagram illustrating a configuration example of a terminal 200 according to an embodiment of the present disclosure. For example, in FIG. 5, the terminal 200 includes a receiving unit 201, an extracting unit 202, a demodulating unit 203, a decoding unit 204, a control unit 205, an encoding unit 206, a modulating unit 207, a signal allocating unit 208, and a transmitting unit 209.

[0046] The receiver 201 receives, for example, a downlink signal (e.g., a downlink data signal, an upper control signal, or downlink control information) from the base station 100 via an antenna, and performs RF processing such as downconvert or A / D conversion on the radio received signal to obtain a received signal (baseband signal). When receiving an OFDM signal, the receiver 201 performs FFT processing on the received signal to convert the received signal into the frequency domain. The receiver 201 outputs the received signal to the extractor 202.

[0047] For example, based on information relating to the radio resource of the downlink control information input from the control unit 205, the extraction unit 202 extracts a radio resource portion that may include downlink control information from the received signal input from the receiving unit 201, and outputs the extracted radio resource portion to the demodulation unit 203. Furthermore, based on information relating to the radio resource of the data signal input from the control unit 205, the extraction unit 202 extracts a radio resource portion that includes a downlink data signal or a higher control signal, and outputs the extracted radio resource portion to the demodulation unit 203.

[0048] Demodulation section 203 demodulates the signal input from extraction section 202 based on information input from control section 205 , for example, and outputs the demodulation result to decoding section 204 .

[0049] The decoding unit 204 performs error correction decoding on the PDCCH or PDSCH based on, for example, the demodulation result input from the demodulation unit 203, and obtains downlink reception data, an upper layer control signal, or downlink control information. The decoding unit 204 outputs the upper layer control signal and the downlink control information to the control unit 205. Furthermore, the decoding unit 204 may generate a HARQ-ACK bit string based on, for example, the decoding result of the downlink reception data, and output the HARQ-ACK bit string to the coding unit 206.

[0050] The control unit 205 may 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, for example, information on multiple TB scheduling, information on retransmission control, or information on radio resource allocation obtained from the higher layer control signal and downlink control information input from the decoding unit 204. The control unit 205 outputs the determined information to, for example, the extraction unit 202, the demodulation unit 203, the encoding unit 206, and the signal allocation unit 208.

[0051] The encoding unit 206 encodes an uplink signal (e.g., UCI such as a HARQ-ACK bit sequence or an uplink data signal) based on, for example, information input from the control unit 205, and outputs the encoded bit sequence to the modulation unit 207.

[0052] The modulation unit 207 modulates the coded bit sequence input from the coding unit 206 , for example, and outputs the modulated signal (symbol sequence) to the signal allocation unit 208 .

[0053] The signal allocation unit 208 maps the signal input from the modulation unit 207 to radio resources based on, for example, information input from the control unit 205, and outputs the uplink signal onto which the signal has been mapped to the transmission unit 209.

[0054] Transmitting unit 209 generates a transmission signal waveform, such as OFDM, for the signal input from signal allocating unit 208. Furthermore, in the case of OFDM transmission using a CP, for example, transmitting unit 209 performs IFFT processing on the signal and adds a CP to the signal after IFFT. Alternatively, when transmitting unit 209 generates a single-carrier waveform, a DFT (Discrete Fourier Transform) unit may be added (not shown) after modulating unit 207 or before signal allocating unit 208, for example. Furthermore, transmitting unit 209 performs RF processing, such as D / A conversion and up-conversion, on the transmission signal, and transmits the radio signal to base station 100 via an antenna.

[0055] [Example of Operation of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 having the above configuration will be described.

[0056] Here, the transmission and reception process related to NR retransmission control will be explained.

[0057] 6 is a diagram illustrating an example of a transmission process when CB partitioning is applied. On the transmitting side, for example, when the size of a TB to which a Cyclic Redundancy Check (CRC) bit (e.g., TB-CRC) is added exceeds a threshold, CB partitioning may be applied to divide the TB (or may include the TB-CRC) into multiple CBs. The threshold may be, for example, 8424 bits when an NR Low-Density Parity-check Code (LDPC) base graph 1 is used, or 3840 bits when an LDPC base graph 2 is used, or may be any number of bits other than 8424 bits and 3840 bits. For example, since the CB size can be set to a size corresponding to the encoder, the threshold may be, for example, the maximum number of bits supported by the encoder.

[0058] As shown in Fig. 6, for example, CRC bits (for example, CB-CRC) may be added to each of the CBs (for example, CB#0, CB#1, and CB#2) after CB division, and may be coded (for example, LDPC coded) at a set coding rate. For example, systematic bits and parity bits may be generated by coding.

[0059] In addition, in NR, for example, a circular buffer may be used for retransmission control (see, for example, Non-Patent Document 5). The circular buffer may be, for example, a memory that stores systematic bits and parity bits, and a number of bits according to the amount of allocated resources may be read from a read start position (for example, RV: Redundancy Version) in the circular buffer (for example, this is also called rate matching).

[0060] Each CB formed by the read coded bits may be concatenated as a code word, and processing such as scrambling and data modulation may be applied to the concatenated code word.

[0061] Furthermore, DCI including scheduling information such as resource allocation from base station 100 may be transmitted on, for example, the PDCCH. Terminal 200 may receive the PDSCH in accordance with, for example, the resource allocation indicated by the DCI on the PDCCH.

[0062] Terminal 200 may determine the size of the TB received on the PDSCH based on, for example, the MCS of the PDSCH, the amount of time resources, and the amount of frequency resources, and may determine the number of CBs based on the TB size. Terminal 200 may also decode each CB and perform error detection on each CB using CB-CRC bits added to each CB. When CB division is applied, terminal 200 may restore the TB and perform error detection on the entire TB using the TB-CRC added to the TB.

[0063] In NR, for example, when CBG-based retransmission is not configured for terminal 200 (for example, when the upper layer parameter "PDSCH-CodeBlockGroupTransmission" is not configured), terminal 200 may transmit a response signal (for example, ACK / NACK or HARQ-ACK) for the entire TB to the transmitting side (for example, base station 100) in accordance with the error detection result for the entire TB. For example, when base station 100 is notified of a NACK from terminal 200, base station 100 may retransmit the entire TB.

[0064] Furthermore, in NR, for example, when CBG-based retransmission is configured for terminal 200 (for example, when the upper layer parameter "PDSCH-CodeBlockGroupTransmission" is configured), terminal 200 may perform retransmission control in units of CBGs, which are groups of multiple CBs. For example, terminal 200 may transmit a response signal for the CBG (for example, ACK / NACK or HARQ-ACK) to base station 100 according to the result of error detection for the CBG. For example, terminal 200 may notify base station 100 of an ACK when all CBs included in the CBG are received without error, and may notify base station 100 of a NACK when an error is detected in at least one of the CBs included in the CBG. For example, base station 100 may retransmit a CBG for which a NACK has been notified from terminal 200. In other words, base station 100 does not need to retransmit a CBG for which an ACK has been notified from terminal 200.

[0065] Furthermore, in NR, for example, a HARQ process is assigned to each TB regardless of whether the TB is divided into multiple CBs. Here, the HARQ process is a processing unit for retransmission control, and each HARQ process may be identified by an HARQ process number. For example, multiple HARQ processes may be configured in terminal 200, and data may be retransmitted until an ACK is received for a TB having the same HARQ process number or for all CBGs. Retransmission can be controlled, for example, by including an HARQ process number, an NDI, and an RV in DCI that allocates a PDSCH for transmitting the TB. Here, the NDI is, for example, a notification indicating whether this is an initial transmission or a retransmission. For example, if the NDI is not toggled in the same HARQ process (for example, if it has the same value as the previous time), it may indicate a retransmission, and if the NDI is toggled (for example, if it has a different value from the previous time), it may indicate an initial transmission.

[0066] In NR, for example, CBG-based retransmission control for one TB scheduling is defined. On the other hand, NR does not define CBG-based retransmission for multiple TB scheduling. Therefore, in this embodiment, for example, the design of the above-mentioned NR retransmission control is reused as much as possible, and CBG-based retransmission control when multiple TB scheduling is applied is described.

[0067] In this embodiment, for example, a common (for example, the same) HARQ process number may be assigned to multiple TBs that have been subjected to multiple TB scheduling. Base station 100 and terminal 200 may perform retransmission control in units of CBGs that include at least one of the CBs in one or more of the multiple TBs, based on the number of TBs assigned by multiple TB scheduling, for example.

[0068] In the following, as an example, the number of TBs allocated by multi-TB scheduling (for example, the number of allocated TBs) is set to "N" (for example, N>1).

[0069] The transmitting side (for example, base station 100) may apply processes such as CB division, coding for each CB, rate matching, CB concatenation, scrambling, and data modulation for each TB.

[0070] Furthermore, DCI including scheduling information such as resource allocation from base station 100 may be transmitted to terminal 200 by, for example, the PDCCH. Terminal 200 may receive the PDSCH according to, for example, the resource allocation indicated by the DCI on the PDCCH. In multi-TB scheduling, for example, one DCI may allocate multiple PDSCHs to different time or frequency resources. Furthermore, each PDSCH may include, for example, a different TB. In other words, one DCI can schedule multiple TBs received in different time or frequency resources. Note that the MCS, amount of time resources (e.g., number of symbols), or amount of frequency resources (e.g., number of resource blocks) of the PDSCH allocated for each TB may be different, or at least one may be common (e.g., the same) between TBs.

[0071] Terminal 200 may determine the size of the TB received in each PDSCH based on the MCS, amount of time resources, and amount of frequency resources of the PDSCH, and may determine the number of CBs based on the TB size. Terminal 200 may also decode each CB and perform error detection for each CB using CB-CRC bits added to each CB. When CB division is used, terminal 200 may, for example, restore the TB and perform error detection for the entire TB using the TB-CRC added to the TB.

[0072] In this embodiment, for example, the number of CBGs "M" in a plurality of (for example, N) TBs may be configured in terminal 200 as a parameter related to CBG-based retransmission. For example, terminal 200 may set the number of allocated TBs N, the number of CBGs M in N TBs, and the number of CBs included in each TB "C n The number of CBs contained in the CBG may be determined based on (n=0 to N-1).

[0073] For example, terminal 200 may transmit a response signal for the CBG to base station 100 in accordance with the result of error detection for the CBG. For example, terminal 200 may notify ACK when all CBs included in the CBG are received without error, and may notify NACK when an error is detected in at least one of the CBs included in the CBG. Base station 100 may retransmit the CBG corresponding to the NACK notified from terminal 200, for example.

[0074] Fig. 7 is a diagram showing an example of the CBG configuration when the number of allocated TBs N=2, the number of CBGs M=4, and the number of CBs for each TB C0=C1=4. As shown in Fig. 7, the number of CBs included in N=2 TBs allocated by multi-TB scheduling is 8, so for example, the number of CBs included in each of M=4 CBGs is 2. Note that the number of CBs included in each CBG may be the same or different.

[0075] The number of CBGs M set in the terminal 200 is the maximum number of CBGs M max In this case, the actual CBG number M may be determined, for example, according to the following formula (1):

number

[0076] Also, for example,

number

number

[0077] On the other hand,

number

number

number

[0078] where:

number

[0079] The method for determining the number of CBs contained in CBG is not limited to the above-mentioned example. For example,

number

number

number

[0080] As described above, a common (e.g., the same) HARQ process may be assigned to multiple TBs scheduled for multi-TB. For example, data may be retransmitted using the same HARQ process number until ACKs are received for all TBs or all CBGs.

[0081] Retransmission can be controlled by DCI including, for example, HARQ process number, NDI, and RV, and CBG-based retransmission can be controlled by DCI including, for example, CBGTI and CBGFI.

[0082] For example, when NDI is not toggled in the same HARQ process (e.g., in the case of retransmission), CBGTI may indicate the CBG to be retransmitted. For example, when the number of CBGs is 4, CBGTI = 0001 may indicate that CBG#0 to CBG#2 are not retransmitted and CBG#3 is retransmitted.

[0083] Also, CBGFI may be a notification indicating, for example, whether the retransmitted CBG can be combined with the CBG transmitted in the past. In other words, CBGFI may be a notification indicating, for example, whether the buffer of the CBG received in the past is valid. For example, when CBGFI = 0, it may indicate that the buffer of the CBG received by terminal 200 in the past is invalid, and when CBGFI = 1, it may indicate that the buffer of the CBG received by terminal 200 in the past is valid.

[0084] According to this embodiment, even in the case of multiple TB scheduling, by determining the number of CBs included in a CBG based on the number of CBGs, the number of allocated TBs, and the number of CBs of each TB, the CBG retransmission can be controlled using the notifications of the NR HARQ process, NDI, RV, CBGTI, and CBGFI (in other words, diverted).

[0085] Note that the relationship between the number of allocated TBs N, the number of CBGs M, and the number of CBs C of each TB n (n = 0 to N - 1) is as follows.

[0086] <When M = 1> FIG. 8 is a diagram showing a configuration example of a CBG when M = 1.

[0087] When M = 1, all the CBs included in the multiple TBs scheduled by multiple TB scheduling may be included in one CBG. For example, in FIG. 8, the eight (= 4CB × 2TB) CBs included in the N = 2 TBs scheduled by multiple TB scheduling may be included in one CBG#0.

[0088] The terminal 200 may notify the base station 100 of ACK when all the CBs included in the CBG are received correctly, and may notify the base station 100 of NACK when an error is detected in at least one of the CBs included in the CBG.

[0089] The operation in the case of M = 1 is equivalent to, for example, the operation of bundling response signals for a plurality of TBs.

[0090] <When 1 < M < N> FIG. 9 is a diagram showing a configuration example of a CBG in the case of 1 < M < N.

[0091] In the case of 1 < M < N, one CBG includes, for example, CBs for a plurality of TBs. In other words, a CBG may include CBs of different TBs.

[0092] For example, the upper part of FIG. 9 shows an example of M = 2 and N = 4. In the upper part of FIG. 9, for example, one CBG may be composed of 8 CBs included in 2 TBs. Similarly, the lower part of FIG. 9 shows an example of M = 3 and N = 4. In the lower part of FIG. 9, for example, one CBG may be composed of 5 or 6 CBs included in 2 TBs.

[0093] The terminal 200 may notify the base station 100 of ACK when all the CBs included in the CBG are received correctly, and may notify the base station 100 of NACK when an error is detected in at least one of the CBs included in the CBG.

[0094] The operation in the case of 1 < M < N is equivalent to, for example, the operation of bundling response signals for a plurality of TBs within one CBG. Also, for example, the operation in the case of 1 < M < N is equivalent to the operation of multiplexing response signals for a plurality of TBs between different CBGs (for example, the operation of including each HARQ-ACK bit in one HARQ-ACK codebook).

[0095] Note that, as shown in the upper part of FIG. 9, the boundary of CBG and the TB boundary may be aligned, or as shown in the lower part of FIG. 9, the boundary of CBG and the TB boundary may not be aligned. For example, as shown in the upper part of FIG. 9, when the CBG boundary and the TB boundary are aligned, if the number of CBs included in each TB is the same, the number of TBs N may be set to a value that is an integer multiple of the number of CBGs M.

[0096] <When M = N> FIG. 10 is a diagram showing a configuration example of CBG when M = N. For example, FIG. 10 shows an example where M = N = 4. Note that FIG. 10 shows an example where the number of CBs included in each TB is the same.

[0097] When M = N, one CBG may include, for example, CBs for each TB. In the example shown in FIG. 10, one CBG may be composed of 4 CBs included in each TB.

[0098] The terminal 200 may notify the base station 100 of ACK, for example, when all the CBs included in the CBG are received without error, and may notify the base station 100 of NACK when an error is detected in at least one of the CBs included in the CBG.

[0099] The operation when M = N is equivalent to, for example, an operation of multiplexing response signals for a plurality of TBs (for example, an operation of including each HARQ-ACK bit in one HARQ-ACK codebook).

[0100] <When N < M> FIG. 11 is a diagram showing a configuration example of CBG when 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.

[0101] When N < M, a plurality of CBs included in one TB may be included in different CBGs. For example, in the upper part of FIG. 11, 4 CBs for one TB may be included in either of the two CBGs. Similarly, for example, in the lower part of FIG. 11, 4 CBs for one TB may be included in either of the two CBGs.

[0102] When all the CBs included in the CBG are received correctly, for example, the terminal 200 notifies the base station 100 of ACK, and when an error is detected in at least one of the CBs included in the CBG, 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.

[0103] Here, as shown in the upper part of FIG. 11, each CBG may be composed of CBs for one TB. In other words, as shown in the upper part of FIG. 11, the CBG may be configured to be closed to one TB. Or, as shown in the lower part of FIG. 11, each CBG may be configured to span a plurality of TBs. For example, when the CBG is composed of CBs within one TB as shown in the upper part of FIG. 11, if the number of CBs included in each TB is the same, the number M of CBGs may be set to a value that is an integer multiple of the number N of TBs.

[0104] Above, the relationship between the allocated 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.

[0105] As described above, for example, according to the number M of CBGs, it is possible to flexibly set ACK / NACK bundling, ACK / NACK multiplexing, and retransmission control based on CBG for multiple TB schedulings.

[0106] Note that the terminal 200 may determine, for example, a retransmission control method (for example, ACK / NACK bundling, ACK / NACK multiplexing, and retransmission control based on CBG) based on, for example, notification of the number M of CBGs. Or, the terminal 200 may be explicitly notified of each retransmission control method. In that case, the value of the number M of CBGs corresponding to each retransmission control may be set. For example, when ACK / NACK bundling is explicitly notified, M = 1 is set, when ACK / NACK multiplexing is explicitly notified, M = N is set, and when retransmission control based on CBG is explicitly notified, a value of M that satisfies 1 < M < N or N < M may be set.

[0107] Furthermore, the response signal (e.g., ACK / NACK or HARQ-ACK) may be transmitted, for example, by an uplink control channel (e.g., PUCCH), or may be transmitted on a PUSCH resource if the PUCCH resource overlaps with a PUSCH resource in time. For example, terminal 200 may transmit response signals in units of multiple TBs by a common (e.g., the same) uplink resource (e.g., PUCCH resource or PUSCH resource).

[0108] Furthermore, the PUCCH resource for transmitting the response signal can be controlled by, for example, DCI including a PUCCH resource indicator (PRI). n The retransmission control method and the number of HARQ-ACK bits for multiple TB scheduling may be determined based on (n=0 to N-1). For example, when the number of CBGs is M, the number of HARQ-ACK bits may be M bits.

[0109] Furthermore, with regard to specifying a PUCCH resource for transmitting a HARQ-ACK bit sequence for multiple TB scheduling, for example, a method of reporting a PUCCH resource to be used by terminal 200 from multiple PUCCH resources (e.g., candidates) included in a PUCCH resource set may be adopted. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resource to be used by terminal 200 from the PUCCH resource set may be reported by DCI (e.g., PRI field).

[0110] Also, for example, when the number of PUCCH resources included in a PUCCH resource set is greater than a threshold (e.g., 8), the PUCCH resources may be controlled using information on Control Channel Elements (CCEs), which are radio resource units of PDCCH that transmit DCI, in addition to the PRI field of DCI. Here, the PUCCH resources may be configured with parameters such as a PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., Physical Resource Block (PRB) numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Also, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0111] FIG. 12 is a flowchart showing an example of an operation relating to transmission and retransmission control of a downlink signal (for example, PDSCH) in the base station 100 according to this embodiment.

[0112] Base station 100 may, for example, notify terminal 200 of information related to the configuration of retransmission control via an upper layer (S101). The information related to the configuration of retransmission control may include, for example, information related to the number of CBGs or information related to PUCCH resources.

[0113] The base station 100 may, for example, generate a TB to be transmitted (S102). The base station 100 may, for example, transmit information regarding multiple TB scheduling for the generated multiple TBs to the terminal 200 (S103). The information regarding multiple TB scheduling may, for example, be transmitted by the PDCCH (for example, DCI).

[0114] Base station 100 may transmit, for example, a PDSCH including multiple TBs allocated by multiple TB scheduling to terminal 200 (S104).

[0115] Base station 100 may receive, demodulate, and decode, for example, a PUCCH (or a PUSCH) transmitted from terminal 200 (S105). The PUCCH may include, for example, a response signal to a PDSCH transmitted by multiple TB scheduling.

[0116] For example, the base station 100 may determine whether or not ACKs for all TBs or all CBGs have been received in a certain HARQ process (for example, HARQ process #n) (S106).

[0117] If ACKs for all TBs or all CBGs are not received in HARQ process #n (S106: No), base station 100 may transmit scheduling information for retransmission of PDSCH to terminal 200 (S107). The scheduling information may be transmitted by, for example, a PDCCH (for example, DCI). Furthermore, base station 100 may transmit (in other words, retransmit) a PDSCH corresponding to a CBG for which a NACK has been notified (S108).

[0118] The base station 100 may repeat the processes of S105 to S108 until it receives ACKs for all TBs or all CBGs in the HARQ process #n, or until it has performed a specified (or set) number of retransmissions.

[0119] On the other hand, if ACKs for all TBs or all CBGs are received in HARQ process #n (S106: Yes), the base station 100 determines, for example, whether there is a new TB transmission (S109). If there is a new TB transmission (S109: Yes), the base station 100 may, for example, toggle the NDI of HARQ process #n (S110) and perform the process of S102. If there is no new TB transmission (S109: No), the base station 100 may end the process shown in FIG. 12.

[0120] FIG. 13 is a flowchart showing an example of operations relating to reception and retransmission control of downlink signals in terminal 200 according to this embodiment.

[0121] Terminal 200 may, for example, acquire information relating to the setting of retransmission control (S201). The information relating to the setting of retransmission control may, for example, be notified by an upper layer.

[0122] Terminal 200 may, for example, receive a PDCCH (for example, DCI) including information related to multi-TB scheduling (S202). Terminal 200 may also receive a PDSCH including multiple TBs based on the received information related to multi-TB scheduling (S203).

[0123] Terminal 200 may determine the TB size, the number of CBs, and CBGs (e.g., the number of CBGs and CBG size) for the allocated multiple TBs, for example, based on information related to multiple TB scheduling (S204). Then, terminal 200 may demodulate and decode the received PDSCH, for example (S205).

[0124] Terminal 200 may, for example, perform error detection on the PDSCH and generate a HARQ-ACK (for example, an ACK or a NACK) based on the error detection result (S206). For example, terminal 200 may generate a HARQ-ACK for each determined CBG.

[0125] Terminal 200 may transmit the generated HARQ-ACK to base station 100, for example, via PUCCH or PUSCH (S207).

[0126] An example of the operation of base station 100 and terminal 200 has been described above.

[0127] According to this embodiment, base station 100 and terminal 200 perform retransmission control for multiple TBs scheduled in units of CBGs including at least one of the CBs in one or more of the multiple TBs, and perform communication according to the retransmission control. In this embodiment, for example, the number N of multiple TBs, the number M of CBGs in the multiple TBs, and the number C of CBs included in each TB #n are n Based on this, the number of CBs contained in the CBG (e.g., the CBG size) is determined.

[0128] As a result, in multi-TB scheduling, terminal 200 can determine the number of HARQ-ACK bits in multi-TB scheduling based on, for example, the number of CBGs, the number of allocated TBs, and the number of CBs for each TB. Also, in this embodiment, for example, NR PUCCH resource control can be utilized in multi-TB scheduling. Thus, according to this embodiment, CBG-based retransmission control can be appropriately performed in multi-TB scheduling.

[0129] (Modification of the first embodiment) In the first embodiment, for example, in multi-TB scheduling, the case has been described in which the number of CBs included in a CBG is determined based on the number of CBGs, the number of allocated TBs, and the number of CBs for each TB.

[0130] For example, as described above, the size of the TB received by terminal 200 in the PDSCH may be determined based on the MCS, amount of time resources, and amount of frequency resources of each PDSCH, and the number of CBs may be determined based on the TB size.

[0131] Furthermore, the number of allocated TBs may be semi-statically notified to terminal 200 by a higher layer (for example, an RRC signal), or may be dynamically notified by DCI that allocates a PDSCH that transmits each TB. When the number of allocated TBs is dynamically notified by DCI, for example, a bit field that notifies the number of TBs may be set independently in DCI, or the number of TBs may be notified together with the time domain resource in the TDRA field that notifies the time domain resource of DCI.

[0132] Furthermore, the number of CBGs or the maximum number of CBGs may be semi-statically notified to terminal 200 by a higher layer (for example, an RRC signal), or may be dynamically notified by DCI that allocates a PDSCH that transmits each TB. When the number of CBGs or the maximum number of CBGs is dynamically notified by DCI, for example, a bit field that notifies the number of CBGs or the maximum number of CBGs may be set independently in the DCI, or the number of CBGs or the maximum number of CBGs may be notified together with the time domain resource in the TDRA field that notifies the time domain resource of the DCI. Alternatively, the number of CBGs or the maximum number of CBGs may be notified together with, for example, a bit field that notifies the number of TBs.

[0133] Furthermore, terminal 200 may determine, for example, the number of CBGs or the maximum number of CBGs based on the number of allocated TBs. For example, when the number of CBGs per TB or the maximum number of CBGs is notified to terminal 200, terminal 200 may set the number of CBGs or the maximum number of CBGs for multi-TB scheduling to the product of the number of CBGs per TB or the maximum number of CBGs and the number of allocated TBs.

[0134] As described above, when the number of CBGs for multiple TB scheduling or the number of CBGs per TB is determined, the number of CBs included in one CBG decreases as the number of CBGs increases.

[0135] Also, for example, the number of CBs included in one CBG may be fixed. In this case, the terminal 200 determines, for example, the number of allocated TBs N and the number of CBs C for each TB. n (n=0 to N-1), the number of CBGs may be determined, and the retransmission control method and the number of HARQ-ACK bits for multi-TB scheduling may be determined. In this case, the number of allocated TBs N and the number of CBs C for each TB may be determined. n As (n=0 to N-1) increases, the number of CBGs also increases.

[0136] (Embodiment 2) The configurations of base station 100 and terminal 200 according to this embodiment may be the same as those in the first embodiment, for example.

[0137] In the first embodiment, a case where a common (for example, the same) HARQ process number is assigned to a plurality of TBs has been described. In the present embodiment, a case where a different HARQ process number is assigned to each of a plurality of TBs will be described.

[0138] The transmitting side (for example, base station 100) may apply processes such as CB division, per-CB coding, rate matching, CB concatenation, scrambling, and data modulation to each TB (for example, N>1).

[0139] Furthermore, DCI including scheduling information such as resource allocation from base station 100 may be transmitted to terminal 200 by, for example, the PDCCH. Terminal 200 may receive the PDSCH according to, for example, the resource allocation indicated by the DCI on the PDCCH. In multi-TB scheduling, for example, one DCI may allocate multiple PDSCHs to different time or frequency resources. Furthermore, each PDSCH may include, for example, a different TB. In other words, one DCI can schedule multiple TBs received in different time or frequency resources. Note that the MCS, amount of time resources (e.g., number of symbols), or amount of frequency resources (e.g., number of resource blocks) of the PDSCH allocated for each TB may be different, or at least one may be common (e.g., the same) between TBs.

[0140] Terminal 200 may determine the size of the TB received in each PDSCH based on the MCS, amount of time resources, and amount of frequency resources of the PDSCH, and may determine the number of CBs based on the TB size. Terminal 200 may also decode each CB and perform error detection for each CB using CB-CRC bits added to each CB. When CB division is used, terminal 200 may, for example, restore the TB and perform error detection for the entire TB using the TB-CRC added to the TB.

[0141] In this embodiment, terminal 200 may control retransmission for each of multiple TBs allocated by multiple TB scheduling, for example.

[0142] For example, when CBG-based retransmission is not configured for terminal 200 (for example, when the upper layer parameter "PDSCH-CodeBlockGroupTransmission" is not configured), terminal 200 may transmit a response signal (for example, ACK / NACK or HARQ-ACK) for the entire TB according to the error detection result for the entire TB for each TB to base station 100. Base station 100 may retransmit the entire TB for a TB for which terminal 200 has notified it of a NACK, for example.

[0143] Furthermore, for example, when CBG-based retransmission is configured for terminal 200 (for example, when the upper layer parameter "PDSCH-CodeBlockGroupTransmission" is configured), terminal 200 may perform retransmission control for each CBG. Terminal 200 may transmit a response signal for the CBG (for example, ACK / NACK or HARQ-ACK) to base station 100 for each TB, depending on the result of error detection for the CBG. For example, terminal 200 may notify base station 100 of an ACK when all CBs included in the CBG are received without error, and may notify base station 100 of a NACK when an error is detected in at least one of the CBs included in the CBG. Base station 100 may retransmit the CBG for which a NACK has been notified from terminal 200, for example.

[0144] For example, in this embodiment, the number of CBGs "M" in a plurality of (for example, N) TBs may be configured in terminal 200 as a parameter related to CBG-based retransmission. For example, terminal 200 may configure the number of CBGs M for each of N TBs and the number of CBs "C n The number of CBs contained in the CBG may be determined based on (n=0 to N-1).

[0145] Furthermore, in this embodiment, for example, regardless of whether each TB is divided into multiple CBs, a different HARQ process may be assigned to each TB scheduled for multiple TBs. For example, with the same HARQ process number, data may be retransmitted until ACK is received for the TB or all CBGs.

[0146] Retransmission can be controlled by DCI including, for example, HARQ process number, NDI, and RV, and CBG-based retransmission can be controlled by DCI including, for example, CBGTI and CBGFI.

[0147] For example, if NDI is not toggled (e.g., in case of retransmission) in the same HARQ process, CBGTI may indicate the CBG to be retransmitted, and CBGFI may be, for example, an indication of whether the retransmitted CBG can be combined with a previously transmitted CBG.

[0148] According to this embodiment, it is possible to apply independent retransmission control to each of the multiple scheduled TBs. For example, in multiple TB scheduling, base station 100 may transmit the first transmission TB and the retransmission TB together. As a result, according to this embodiment, it is possible to realize more flexible downlink transmission and improve downlink transmission efficiency.

[0149] The response signal (e.g., ACK / NACK or HARQ-ACK) may be transmitted, for example, by an uplink control channel (e.g., PUCCH) or on a PUSCH resource if the PUCCH resource overlaps with the PUSCH resource in time.

[0150] Furthermore, the PUCCH resource for transmitting the response signal can be controlled by, for example, DCI including PRI. Terminal 200 may apply any of the following Options 1 to 5, for example, to identify the PUCCH resource for transmitting the HARQ-ACK bit for multiple TB scheduling.

[0151] <option 1:ack nackバンドリング及びシングルpucchリソース> In Option 1, terminal 200 may transmit, for example, a response signal based on the error detection result for all of the multiple TBs using one PUCCH resource. For example, terminal 200 may generate an ACK when all TBs in the multiple TB scheduling are received without error, and may generate a NACK when an error is detected in at least one of the multiple TBs in the multiple TB scheduling. In other words, in Option 1, for example, the number of HARQ-ACK bits for the multiple TB scheduling is 1 bit.

[0152] Regarding the specification of the PUCCH resource for transmitting the HARQ-ACK bit for multiple TB scheduling, for example, a method of reporting the PUCCH resource to be used by terminal 200 from among multiple PUCCH resources included in a PUCCH resource set may be employed. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resource to be used by terminal 200 from the PUCCH resource set may be reported by DCI (for example, a PRI field).

[0153] Also, for example, when the number of PUCCH resources included in a PUCCH resource set is greater than a threshold (e.g., 8), the PUCCH resources may be controlled using information on CCE, which is the radio resource unit of PDCCH that transmits DCI, in addition to the PRI field of DCI. Here, the PUCCH resources may be configured with parameters such as the PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., PRB numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Also, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0154] Fig. 14 is a diagram showing an example of PUCCH resources for transmitting a HARQ-ACK according to Option 1. In Fig. 14, as an example, the number of TBs allocated by multi-TB scheduling is N=2. As shown in Fig. 14, terminal 200 may generate a 1-bit HARQ-ACK based on error detection results for N=2 TBs, TB #0 and TB #1. Terminal 200 may transmit the generated HARQ-ACK to base station 100, for example, on the PUCCH.

[0155] In Option 1, for example, an HARQ-ACK corresponding to the error detection result for all of the multiple TBs allocated by multi-TB scheduling is transmitted, so that the number of HARQ-ACK bits and the number of PUCCH resources can be reduced. For example, in Option 1, the overhead related to the notification of PRI in multi-TB scheduling can be suppressed to the same level as in NR (or when scheduling 1 TB).

[0156] < / option> <option 2:ack nack多重及びシングルpucchリソース> In Option 2, terminal 200 may transmit, for example, a signal in which response signals based on error detection results in units of a plurality of TBs are multiplexed, using one PUCCH resource.

[0157] For example, the terminal 200 determines the number of CBGs M per TB in the multi-TB scheduling and the number of CBs C for each TB. n (n=0 to N-1), the number of HARQ-ACK bits may be determined based on the number of CBGs per TB. For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB may be M bits. Furthermore, terminal 200 may multiplex response signals for multiple TBs, for example. In other words, terminal 200 may include HARQACK bit sequences for each TB in one HARQ-ACK codebook.

[0158] Therefore, the number of HARQ-ACK bits for multi-TB scheduling with N allocated TBs may be M×N bits.

[0159] Also, similar to Option 1, with regard to specifying a PUCCH resource for transmitting a HARQ-ACK bit for multiple TB scheduling, for example, a method of reporting a PUCCH resource to be used by terminal 200 from among multiple PUCCH resources included in a PUCCH resource set may be employed. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resource to be used by terminal 200 from the PUCCH resource set may be reported by DCI (for example, a PRI field).

[0160] Also, for example, when the number of PUCCH resources included in a PUCCH resource set is greater than a threshold (e.g., 8), the PUCCH resources may be controlled using information on CCE, which is the radio resource unit of PDCCH that transmits DCI, in addition to the PRI field of DCI. Here, the PUCCH resources may be configured with parameters such as the PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., PRB numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Also, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0161] Fig. 15 is a diagram showing an example of PUCCH resources for transmitting HARQ-ACK according to Option 2. In Fig. 15, as an example, the number of allocated TBs by multi-TB scheduling is N=2, and the number of CBGs in each TB is M=2. As shown in Fig. 15, terminal 200 may multiplex 2-bit HARQ-ACK bit sequences based on error detection results for each of M=2 CBGs (e.g., error detection results for four CBGs) in each of N=2 TB#0 and TB#1, to generate a 4-bit HARQ-ACK codebook. Terminal 200 may transmit the generated HARQ-ACK codebook to base station 100, for example, on the PUCCH.

[0162] In Option 2, for example, HARQ-ACK for multiple TBs allocated by multi-TB scheduling is transmitted using one PUCCH resource, so the number of HARQ-ACK bits and the number of PUCCH resources can be reduced. For example, in Option 2, the overhead related to PRI notification in multi-TB scheduling can be kept to the same level as in NR (or when scheduling 1 TB). Furthermore, in Option 2, for example, CBG-based retransmission control for each TB becomes possible.

[0163] < / option> <option 3:複数pucchリソース及び複数pri> In Option 3, terminal 200 may transmit a response signal based on an error detection result in units of multiple TBs, for example, using multiple PUCCH resources. Also, in Option 3, terminal 200 may receive multiple PRIs (in other words, multiple information sets) indicating multiple PUCCH resources, for example.

[0164] For example, the terminal 200 determines the number of CBGs M per TB in the multi-TB scheduling and the number of CBs C for each TB. n (n=0 to N-1). For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB may be M bits. Furthermore, terminal 200 may transmit HARQ-ACK bit sequences for each TB using different PUCCH resources, for example.

[0165] Also, similar to Option 1, with regard to specifying a PUCCH resource for transmitting a HARQ-ACK bit for multiple TB scheduling, for example, a method of reporting a PUCCH resource to be used by terminal 200 from among multiple PUCCH resources included in a PUCCH resource set may be employed. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resource to be used by terminal 200 from the PUCCH resource set may be reported by DCI (for example, a PRI field).

[0166] In Option 3, for example, multiple PRI fields may be included in the DCI. For example, each PRI field may include information indicating a PUCCH resource for transmitting a HARQ-ACK bit sequence for each of multiple TBs scheduled for multiple TBs.

[0167] Also, for example, when the number of PUCCH resources included in a PUCCH resource set is greater than a threshold (e.g., 8), the PUCCH resources may be controlled using information on CCE, which is the radio resource unit of PDCCH that transmits DCI, in addition to the PRI field of DCI. Here, the PUCCH resources may be configured with parameters such as the PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., PRB numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Also, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0168] Fig. 16 is a diagram showing an example of PUCCH resources for transmitting HARQ-ACK according to Option 3. In Fig. 16, as an example, the number of TBs allocated by multi-TB scheduling is N=2, and the number of CBGs for each TB is M=2. Also, in Fig. 16, HARQ-ACK bit sequences for N=2 TBs may be transmitted using two PUCCH resources #0 and #1.

[0169] 16, terminal 200 may generate a 2-bit HARQ-ACK bit sequence based on the error detection result for each of M=2 CBGs, for each of N=2 TBs #0 and #1. Terminal 200 may then transmit the generated HARQ-ACK bit sequence to base station 100, for example, in PUCCH resources #0 and #1 corresponding to TB #0 and TB #1, respectively.

[0170] In Option 3, terminal 200 can transmit HARQ-ACK in a different PUCCH for each TB, for example, and can decode TBs and transmit PUCCHs in order from the received TB. For example, it is possible to reduce the delay of TBs transmitted in earlier slots. Furthermore, in Option 3, having multiple PRIs allows for flexible allocation of PUCCH resources to each TB.

[0171] < / option> <option 4:複数pucchリソース及びシングルpri(rrcテーブル)> In Option 4, terminal 200 may transmit, for example, a response signal based on the error detection results of each of a plurality of TBs using a plurality of PUCCH resources. Also, in Option 4, terminal 200 may receive, for example, information indicating a combination of a plurality of PUCCH resources (for example, PRI).

[0172] For example, the terminal 200 determines the number of CBGs M per TB in the multi-TB scheduling and the number of CBs C for each TB. n (n=0 to N-1). For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB may be M bits. Furthermore, terminal 200 may transmit HARQ-ACK bit sequences for each TB using different PUCCH resources, for example.

[0173] Also, similar to Option 1, with regard to specifying a PUCCH resource for transmitting a HARQ-ACK bit for multiple TB scheduling, for example, a method of reporting a PUCCH resource to be used by terminal 200 from among multiple PUCCH resources included in a PUCCH resource set may be employed. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resource to be used by terminal 200 from the PUCCH resource set may be reported by DCI (for example, a PRI field).

[0174] In Option 4, for example, a PUCCH resource set semi-statically notified by a higher layer may include a combination of multiple PUCCH resources for multiple TB scheduling. For example, in Option 4, the PRI field included in DCI may be a single field indicating one of a plurality of PUCCH resource combinations. For example, a single PRI may indicate a combination of multiple PUCCH resources used to transmit a HARQ-ACK bit sequence.

[0175] Furthermore, for example, when the number of PUCCH resource combinations included in a PUCCH resource set is greater than a threshold (e.g., 8), PUCCH resources may be controlled using information on CCE, which is the radio resource unit of PDCCH that transmits DCI, in addition to the PRI field of DCI. Here, PUCCH resources may be configured with parameters such as a PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., PRB numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Furthermore, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0176] Fig. 17 is a diagram showing an example of PUCCH resources for transmitting HARQ-ACK according to Option 4. Fig. 18 is a diagram showing an example of association between PRI values and combinations of a plurality of PUCCH resources.

[0177] In Fig. 17, as an example, the number of TBs allocated by multi-TB scheduling is N = 2, and the number of CBGs for each TB is M = 2. In Fig. 17, HARQ-ACK bit sequences for N = 2 TBs may be transmitted using two PUCCH resources #0 (for example, any of PUCCH resources #0-0 to #0-7 shown in Fig. 18) and PUCCH resource #1 (for example, any of PUCCH resources #1-0 to #1-7 shown in Fig. 18).

[0178] 17, terminal 200 may generate a 2-bit HARQ-ACK bit sequence based on the error detection results for each of M=2 CBGs for each of N=2 TBs #0 and #1. Furthermore, terminal 200 may identify PUCCH resources #0 and #1 corresponding to TB #0 and TB #1, respectively, based on, for example, one received PRI and the association shown in FIG.

[0179] In Option 4, terminal 200 can transmit HARQ-ACKs in different PUCCHs for each TB, for example, and can therefore decode TBs and transmit PUCCHs in order from the received TBs. For example, it is possible to reduce the delay of TBs transmitted in earlier slots.

[0180] In addition, in Option 4, a combination of multiple PUCCH resources is notified by one PRI, so the overhead associated with notifying PRIs in multi-TB scheduling can be kept to the same level as, for example, NR (or when scheduling 1 TB).

[0181] < / option> <option 5:複数pucchリソース及びシングルpri(implicit relation)> In Option 5, terminal 200 may transmit, for example, a response signal based on the error detection results of each of a plurality of TBs using a plurality of PUCCH resources. Also, in Option 5, terminal 200 may receive, for example, information indicating some of the plurality of PUCCH resources (for example, PRI), and may determine other resources different from the some of the plurality of PUCCH resources based on the some of the resources.

[0182] For example, the terminal 200 determines the number of CBGs M for each TB in the multi-TB scheduling and the number of CBs C for each TB. n (n=0 to N-1). For example, when the number of CBGs per TB is M, the number of HARQ-ACK bits for each TB may be M bits. Furthermore, terminal 200 may transmit HARQ-ACK bit sequences for each TB using different PUCCH resources, for example.

[0183] In Option 5, for example, with regard to specifying PUCCH resources for transmitting HARQ-ACK bits for some TBs (e.g., TB#0) in multiple TB scheduling, a method may be adopted in which, for example, PUCCH resources to be used by terminal 200 among multiple PUCCH resources included in a PUCCH resource set are notified. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resources to be used by terminal 200 among the PUCCH resource set may be notified by DCI (e.g., PRI field).

[0184] Furthermore, for example, when the number of PUCCH resource combinations included in a PUCCH resource set is greater than a threshold (e.g., 8), PUCCH resources may be controlled using information on CCE, which is the radio resource unit of PDCCH that transmits DCI, in addition to the PRI field of DCI. Here, PUCCH resources may be configured with parameters such as a PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., PRB numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Furthermore, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0185] In addition, in Option 5, for example, with regard to identifying a PUCCH resource for transmitting a HARQ-ACK bit sequence for a TB other than some TBs (e.g., TB#0) in multiple TB scheduling, for example, terminal 200 may implicitly identify the PUCCH resource based on the PUCCH resource for transmitting the HARQ-ACK bit sequence for TB#0.

[0186] For example, terminal 200 may specify a PUCCH resource having the same parameters as the PUCCH resource for transmitting a HARQ-ACK bit sequence for TB #0 but a different slot number as the PUCCH resource for transmitting a HARQ-ACK bit sequence for another TB. Alternatively, terminal 200 may specify a PUCCH resource having the same parameters as the PUCCH resource for transmitting a HARQ-ACK bit sequence for a TB immediately preceding in time but with a fixed time offset added as the PUCCH resource for transmitting a HARQ-ACK bit sequence for another TB. For example, the HARQ-ACK bit sequence for another TB may be transmitted from the slot or symbol next to the last slot or symbol of the PUCCH resource for transmitting a HARQ-ACK bit sequence for the TB immediately preceding the other TB.

[0187] FIG. 19 is a diagram illustrating an example of a PUCCH resource for transmitting a HARQ-ACK according to Option 5. In FIG.

[0188] In Fig. 19, as an example, the number of TBs allocated by multi-TB scheduling is N = 2, and the number of CBGs for each TB is M = 2. Also, in Fig. 19, HARQ-ACK bit sequences for N = 2 TBs may be transmitted using two PUCCH resources #0 and #1.

[0189] 19 , terminal 200 may generate a 2-bit HARQ-ACK bit sequence based on the error detection results for each of M=2 CBGs for each of N=2 TBs #0 and #1. Terminal 200 may also identify PUCCH resource #0 corresponding to TB #0 based on a received PRI, for example, and transmit the generated HARQ-ACK bit sequence to base station 100. Terminal 200 may also identify PUCCH resource #1 corresponding to TB #1 based on PUCCH resource #0 corresponding to TB #0 identified based on the PRI, for example, and transmit the generated HARQ-ACK bit sequence to base station 100.

[0190] In Option 5, terminal 200 can transmit HARQ-ACKs in different PUCCHs for each TB, for example, and can therefore decode TBs and transmit PUCCHs in order from the received TBs. For example, it is possible to reduce the delay of TBs transmitted in earlier slots.

[0191] In addition, in Option 5, some of the multiple PUCCH resources are notified by PRI, and other resources are identified based on these some resources, so the overhead associated with notifying PRI in multiple TB scheduling can be kept to the same level as, for example, NR (or when scheduling 1 TB).

[0192] Also, for example, Option 5 can reduce the overhead of information notified by higher layers compared to Option 4.

[0193] The above has described Option 1 to Option 5 relating to specifying PUCCH resources for transmitting HARQ-ACK bits for each TB in multi-TB scheduling.

[0194] Which of Option 1 to Option 5 is applied may be specified in advance in a standard, may be notified to terminal 200 by higher layer signaling or DCI, or may be set in advance in terminal 200. Also, at least two of Option 1 to Option 5 may be applied in combination.

[0195] (Modification of the second embodiment) In the second embodiment, retransmission control using DCI including an HARQ process number, an NDI, and an RV for each TB scheduled for multiple TBs has been described. In this retransmission control, for example, as the number of allocated TBs increases, the overhead of DCI for notifying the HARQ process number, the NDI, and the RV may increase.

[0196] In a modification of the second embodiment, an example of a method for suppressing an increase in DCI overhead will be described.

[0197] For example, with regard to RV, the RV for each TB does not need to be included in the DCI. This makes it possible to suppress an increase in DCI overhead. For example, in the case of the first transmission (for example, when NDI is toggled), RV=0 may be set, and in the case of a retransmission (for example, when NDI is not toggled in the same HARQ process), an RV may be set according to the number of retransmissions. For example, in the first retransmission, RV=3 may be set, in the second retransmission, RV=2, and in the third retransmission, RV=1. Note that the RV settings are not limited to this example.

[0198] Furthermore, for example, with regard to notification of the HARQ process number, any of the following options i to v may be applied.

[0199] < / option> <option i> In Option i, for example, the HARQ process numbers that can be assigned to each TB in multi-TB scheduling may be consecutive HARQ process numbers.

[0200] For example, if the HARQ process number of TB#0 is "HPN0", the HARQ process number of TB#n (n=0 to N-1) is "HPN n =(HPN0+ n) mod N HP " where N represents the number of allocated TBs, and N HP indicates the maximum number of HARQ processes.

[0201] In Option i, for example, when the HARQ process number of a certain TB (for example, TB#0) is set, the HARQ process numbers of other TBs can be calculated.

[0202] In Option i, for example, the number of bits used to signal the HARQ process number is

number

[0203] < / option> <option ii> In Option ii, for example, similar to Option i, the HARQ process numbers that can be assigned to each TB in multi-TB scheduling are consecutive HARQ process numbers. In Option ii, an upper limit may be set (or limited) on the number of HARQ process numbers that can be assigned by multi-TB scheduling.

[0204] For example, N that can be assigned to the terminal 200 HP HARQ processes #0 to #N HP -1, the number of HARQ process numbers that can be assigned by multi-TB scheduling is N Limit (e.g., #0 to #N Limit -1), where N Limit <N HP The starting number of HARQ process numbers that can be assigned by multi-TB scheduling is not limited to HARQ process #0, and may be another number.

[0205] In Option ii, for example, the number of HARQ processes that can be allocated by multiple TB scheduling is smaller than the maximum number of HARQ processes, so that an increase in DCI overhead can be suppressed.

[0206] For example, in Option 2, the number of bits used to signal the HARQ process number is

number

[0207] < / option> <option iii> In Option iii, for example, an arbitrary HARQ process number may be assigned to each TB that is subject to multi-TB scheduling.

[0208] In Option iii, for example, the number of bits used to signal the HARQ process number is

number

[0209] In Option iii, for example, the number of bits used to notify HARQ processes increases as the number of allocated TBs N increases. Option iii allows, for example, flexible allocation of HARQ process numbers to each TB scheduled for multiple TBs.

[0210] < / option> <option iv> In Option iv, for example, as in Option iii, any HARQ process number may be assigned to each TB scheduled by multi-TB scheduling. Option iv may also set (or limit) an upper limit on the number of HARQ process numbers that can be assigned by multi-TB scheduling.

[0211] For example, N that can be assigned to the terminal 200 HP HARQ processes #0 to #N HP -1, the number of HARQ process numbers that can be assigned by multi-TB scheduling is N Limit (e.g., #0 to #N Limit -1), where N Limit <N HP The starting number of HARQ process numbers that can be assigned by multi-TB scheduling is not limited to HARQ process #0, and may be another number.

[0212] In Option iv, for example, the number of HARQ processes that can be allocated by multiple TB scheduling is smaller than the maximum number of HARQ processes, so that an increase in DCI overhead can be suppressed.

[0213] In Option iv, for example, the number of bits used to signal the HARQ process number is

number

[0214] < / option> <option v> In Option v, for example, the HARQ process numbers may be divided into multiple sets. For example, the HARQ process numbers may be divided into set #0 {#a, #b, #c, #d} and set #1 {#e, #f, #g, #h}.

[0215] Furthermore, for example, when notifying HARQ process numbers for some TBs (for example, TB#0) among multiple TBs that are multi-TB scheduled, any HARQ process number in set #0 may be explicitly notified.

[0216] Furthermore, regarding identification of HARQ process numbers for TBs other than TB #0, terminal 200 may, for example, implicitly identify HARQ process numbers from set #1 based on the HARQ process numbers of set #0 that are explicitly notified. For example, in the above example, HARQ processes #a to #d in set #0 may be associated one-to-one with HARQ processes #e to #h in set #1, respectively. For example, when terminal 200 is notified that HARQ process #a in set #0 is the HARQ process number for TB #0, terminal 200 may set HARQ process #e in set #1 as the HARQ process number for TB #1.

[0217] In this case, the number of bits used to notify the HARQ process number is, assuming that the number of HARQ processes included in set #0 is N1,

number

[0218] In Option v, for example, it is sufficient that HARQ process numbers included in some sets among a plurality of sets are notified. In other words, HARQ process numbers included in a set different from some sets among a plurality of sets do not need to be notified, so the number of bits used for notifying HARQ processes can be reduced.

[0219] In Option v, the number of sets into which the HARQ process numbers are divided may be three or more.

[0220] Furthermore, regarding notification of HARQ process numbers, the set to be used may be explicitly notified to terminal 200. For example, in the above example, set #0 may be explicitly notified to terminal 200, and one of the HARQ process numbers included in the notified set #0 may be set to each TB. For example, the HARQ process number for TB #0 may be set to #a, and the HARQ process number for TB #1 may be set to #b. In this case, the number of bits used to notify the HARQ process numbers is set to N / 2, where N is the number of sets. set Then,

number

[0221] Option i to Option v relating to notification of HARQ process numbers have been explained above.

[0222] In the second embodiment, for example, in multi-TB scheduling, it is possible to transmit a TB for initial transmission and a TB for retransmission together. In this case, a different HARQ process can be assigned to each multi-TB scheduled TB.

[0223] For example, as shown in FIG. 20, in terminal 200, the order of receiving PDSCHs or transmitting PUCCHs for each TB for which multi-TB scheduling is performed may be in the order of HARQ process numbers.

[0224] 21, the order of receiving PDSCH or transmitting PUCCH for each TB for which multi-TB scheduling is performed may be such that a retransmitted TB is received before an initially transmitted TB in terminal 200. This order may reduce the effect of retransmission delay.

[0225] For example, in multi-TB scheduling, when an initial transmission TB is included (when a retransmission TB is not included) or when a retransmission TB is included (when an initial transmission TB is not included), the order in which terminal 200 receives PDSCHs or transmits PUCCHs for each TB may be set in the order of HARQ process numbers as shown in Fig. 20. Also, for example, when an initial transmission TB and a retransmission TB are transmitted together in multi-TB scheduling, terminal 200 may first receive PDSCHs or transmit PUCCHs for retransmission TBs, and then receive PDSCHs or transmit PUCCHs for the initial transmission TBs, as shown in Fig. 21.

[0226] (Embodiment 3) The configurations of base station 100 and terminal 200 according to this embodiment may be the same as those in the first embodiment, for example.

[0227] In the first embodiment, for example, a case has been described in which a common (for example, the same) HARQ process number is assigned to multiple TBs that have undergone multi-TB scheduling. Also, in the second embodiment, a case has been described in which different HARQ process numbers are assigned to multiple TBs that have undergone multi-TB scheduling. In this embodiment, for example, a case will be described in which multiple TBs assigned by multi-TB scheduling (in other words, one DCI) are divided into multiple groups (hereinafter referred to as "TB groups"), and a common (for example, the same) HARQ process number is assigned to TBs in the same TB group, and different HARQ process numbers are assigned to TBs in different TB groups.

[0228] For example, base station 100 may transmit to terminal 200 information on the number of CBGs, information on PUCCH resource allocation, and information on retransmission control including information on the number of TB groups.

[0229] This makes it possible to achieve a trade-off between, for example, embodiment 1 and embodiment 2. Note that when the number of TB groups is one, it is equivalent to embodiment 1, and when the number of TB groups is the same as the number of allocated TBs, it is equivalent to embodiment 2.

[0230] Fig. 22 is a diagram showing an example of the configuration of a TB group according to this embodiment. Fig. 22 shows an example in which the number of allocated TBs N is 4 and the number of TB groups is 2.

[0231] In Figure 22, for example, TB #0 and TB #1 are included in TB group #0, and TB #2 and TB #3 are included in TB group #1. Also, as shown in Figure 22, a common HARQ process number #m may be assigned to TB #0 and TB #1 included in TB group #0, and a common HARQ process number #n may be assigned to TB #2 and TB #3 included in TB group #1. In other words, different HARQ process numbers are assigned to TB #0 and TB #1 included in TB group #0 and TB #2 and TB #3 included in TB group #1.

[0232] The transmitting side (for example, base station 100) may apply processes such as CB division, per-CB coding, rate matching, CB concatenation, scrambling, and data modulation to each TB (for example, N>1).

[0233] Furthermore, DCI including scheduling information such as resource allocation from base station 100 may be transmitted to terminal 200 by, for example, the PDCCH. Terminal 200 may receive the PDSCH according to, for example, the resource allocation indicated by the DCI on the PDCCH. In multi-TB scheduling, for example, one DCI may allocate multiple PDSCHs to different time or frequency resources. Furthermore, each PDSCH may include, for example, a different TB. In other words, one DCI can schedule multiple TBs received in different time or frequency resources. Note that the MCS, amount of time resources (e.g., number of symbols), or amount of frequency resources (e.g., number of resource blocks) of the PDSCH allocated for each TB may be different, or at least one may be common (e.g., the same) between TBs.

[0234] Terminal 200 may determine the size of the TB received in each PDSCH based on the MCS, amount of time resources, and amount of frequency resources of the PDSCH, and may determine the number of CBs based on the TB size. Terminal 200 may also decode each CB and perform error detection for each CB using CB-CRC bits added to each CB. When CB division is used, terminal 200 may, for example, restore the TB and perform error detection for the entire TB using the TB-CRC added to the TB.

[0235] In this embodiment, terminal 200 may control retransmission for each TB group for multiple TBs allocated by multiple TB scheduling, for example.

[0236] For example, terminal 200 may apply the same operation as in embodiment 1 to multiple TBs in a TB group (for example, TBs to which a common HARQ process number is assigned). For example, terminal 200 may set the number of CBGs M, which is one of the parameters related to CBG-based retransmission. For example, terminal 200 may set the number of CBGs M for each TB group, the number of allocated TBs N TBG , and the number of CBs in each TB, C n (n=0~N TBG -1) The number of CBs contained in the CBG may be determined based on the above.

[0237] Terminal 200 may transmit a response signal (e.g., ACK / NACK or HARQ-ACK) for the CBG to base station 100, for example, in accordance with the result of error detection for the CBG. For example, terminal 200 may notify ACK when all CBs included in the CBG are received without error, and may notify NACK when an error is detected in at least one of the CBs included in the CBG. Base station 100 may retransmit the CBG corresponding to the NACK notified from terminal 200, for example.

[0238] Furthermore, in this embodiment, for example, a different HARQ process may be assigned to each TB group regardless of whether each TB group is divided into multiple CBs. For example, terminal 200 may apply the same operation as in embodiment 2 to different TB groups.

[0239] For example, in a TB group that includes multiple TBs assigned the same HARQ process number, data may be retransmitted until an ACK is received for all TBs or all CBGs.

[0240] Retransmission can be controlled by DCI including, for example, HARQ process number, NDI, and RV, and CBG-based retransmission can be controlled by DCI including, for example, CBGTI and CBGFI.

[0241] Furthermore, the response signal (e.g., ACK / NACK or HARQ-ACK) may be transmitted, for example, by an uplink control channel (e.g., PUCCH), or may be transmitted on a PUSCH resource if the PUCCH resource overlaps with the PUSCH resource in time.

[0242] Furthermore, the PUCCH resource for transmitting the response signal can be controlled by, for example, DCI including PRI. TBG , and the number of CBs in each TB, C n (n=0~N TBG -1) may determine the retransmission control method and the number of HARQ-ACK bits for multiple TB scheduling. For example, when the number of CBGs is M, the number of HARQ-ACK bits may be M bits.

[0243] Furthermore, with regard to specifying the PUCCH resource for transmitting the HARQ-ACK bit sequence for each TB group, for example, a method of notifying terminal 200 of the PUCCH resource to be used from among a plurality of PUCCH resources (e.g., candidates) included in a PUCCH resource set may be employed. Note that the PUCCH resource set may be semi-statically configured from base station 100 to terminal 200 by terminal-specific higher layer signaling (RRC signaling), for example, and the PUCCH resource to be used by terminal 200 from the PUCCH resource set may be notified by DCI (e.g., PRI field).

[0244] Furthermore, terminal 200 may, for example, replace TB in any of Options 1 to 5 relating to the identification of PUCCH resources in the second embodiment with TB group when identifying PUCCH resources for transmitting HARQ-ACK bits for each TB group.

[0245] Also, for example, when the number of PUCCH resources included in a PUCCH resource set is greater than a threshold (e.g., 8), the PUCCH resources may be controlled using information on CCE, which is the radio resource unit of PDCCH that transmits DCI, in addition to the PRI field of DCI. Here, the PUCCH resources may be configured with parameters such as the PUCCH format, time resources (e.g., symbol positions or number of symbols), frequency resources (e.g., PRB numbers, number of PRBs, or whether frequency hopping is applied), and code resources (e.g., cyclic shift sequence numbers or orthogonal code numbers). Also, multiple PUCCH resource sets may be configured in terminal 200, and the PUCCH resource set to be used by terminal 200 may be determined based on the number of HARQ-ACK bits, for example.

[0246] Thus, according to this embodiment, by dividing multiple TBs allocated by multiple TB scheduling into multiple TB groups, for example, notification from base station 100 to terminal 200 (e.g., notification by DCI) can be performed on a TB group basis, thereby suppressing an increase in DCI overhead.

[0247] (Modification of the third embodiment) The number of TB groups set in the terminal 200 is, for example, the maximum number of TB groups T max In this case, the actual number of TB groups may be determined according to the following equation (2).

number

[0248] Here, N indicates the number of allocated TBs.

[0249] Also, for example, if N / T is an integer, each TB group may include N / M TBs. Also, for example, if N / M is not an integer, TB group #0 to TB group #T-2 may include

number

number

number

[0250] The method for determining the number of TBs included in a TB group is not limited to the above. For example, if T1=mod(N, M), then TB group #0 to TB group T1-1 are determined as follows:

number

number

[0251] The number of TB groups or the maximum number of TB groups may be semi-statically notified to terminal 200 by a higher layer (e.g., an RRC signal), or may be dynamically notified by DCI. When the number of TB groups or the maximum number of TB groups is dynamically notified by DCI, for example, a bit field notifying the number of TB groups or the maximum number of TB groups may be set independently in the DCI, or the number of TB groups or the maximum number of TB groups may be notified together with the time domain resource in the TDRA field notifying the time domain resource of the DCI. Alternatively, the number of TB groups or the maximum number of TB groups may be notified together with, for example, a bit field notifying the number of TBs.

[0252] Also, for example, the number of TBs included in one TB group may be fixed. In this case, terminal 200 may determine the number of TB groups based on, for example, the number of allocated TBs N, and may determine the retransmission control method and the number of HARQ-ACK bits for multiple TB scheduling.

[0253] The above describes the embodiments according to the example of the present disclosure.

[0254] In NR, for example, a priority can be set for HARQ-ACK. For example, when there are two priority levels, either priority index=0 (for example, low priority) or priority index=1 (for example, high priority) can be set for HARQ-ACK. In multi-TB scheduling, for example, a priority may be set for HARQ-ACK for each TB or TB group. Also, for example, in the third embodiment, the priority of HARQ-ACK may be determined in association with the HARQ process number.

[0255] Furthermore, in NR, for example, DCI format 1-1 for scheduling PDSCH has a function of allocating two codewords. This function makes it possible to notify, for example, NDI and RV for each codeword. Therefore, for example, in the second or third embodiment, the NDI and RV fields for each codeword in DCI format 1-1 may be set (in other words, reused) for each of multiple TBs or multiple TB groups. Note that in the second embodiment, the number of allocated TBs is set (or limited) to 2, and in the third embodiment, the number of TB groups is set (or limited) to 2. Furthermore, for example, when multiple TB scheduling is applied, two-codeword transmission may not be used.

[0256] In addition, in the above-described embodiments, an example in which one TB is transmitted or received in one slot has been described. However, the present invention is not limited to this. For example, a plurality of TBs may be transmitted or received in one slot, or one TB may be transmitted or received over a plurality of slots.

[0257] In addition, in the above-described embodiments, retransmission control for PDSCH, in other words, reception of PDSCH in the terminal 200, and transmission of HARQ-ACK in PUCCH or PUSCH to the base station 100 have been described. However, the present invention is not limited to this. One embodiment of the present disclosure can also be applied to, for example, retransmission control for PUSCH, in other words, transmission of PUSCH in the terminal 200, and reception of HARQ-ACK from the base station 100. Alternatively, one embodiment of the present disclosure may be applied to, for example, sidelink data transmission and HARQ-ACK feedback channels.

[0258] One embodiment of the present disclosure may also be applied to scenarios with a longer Round Trip Time (RTT), such as, for example, Non-Terrestrial Network (NTN) or operation in a frequency band of 52.6 GHz or higher. In this scenario, for example, the number of HARQ processes may be smaller compared to the RTT. For example, slot length × number of HARQ processes < RTT may hold. Therefore, for example, by assigning a common HARQ process number to a plurality of TBs scheduled by one DCI as in Embodiment 1, the impact of insufficient HARQ processes can be reduced.

[0259] In addition, each parameter applied in the above-described embodiments (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. Also, in the above-described embodiments, the number of CBs or CBGs included in a plurality of TBs may be different.

[0260] (Control signal) In one embodiment of the present disclosure, the downlink control signal (or downlink control information) may be, for example, a signal (or information) transmitted in a Physical Downlink Control Channel (PDCCH) of the physical layer, or a signal (or information) transmitted in a Medium Access Control (MAC) or Radio Resource Control (RRC) of a higher layer. Furthermore, the signal (or information) is not limited to being notified by a downlink control signal, but may be predefined in a specification (or standard) or may be preconfigured in a base station and a terminal.

[0261] In one embodiment of the present disclosure, the uplink control signal (or uplink control information) may be, for example, a signal (or information) transmitted in a PDCCH of the physical layer, or a signal (or information) transmitted in a MAC or RRC of a higher layer. Furthermore, the signal (or information) is not limited to being notified by an uplink control signal, but may be predefined in a specification (or standard), or may be preconfigured in a base station and a terminal. Furthermore, the uplink control signal may be replaced with, for example, uplink control information (UCI), 1st stage sidelink control information (SCI), or 2nd stage SCI.

[0262] (base station) In an embodiment of the present disclosure, the base station may be a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a parent device, a gateway, etc. In addition, in sidelink communication, a terminal may be used instead of the base station. In addition, a relay device that relays communication between an upper node and a terminal may be used instead of the base station.

[0263] (Uplink / Downlink / Sidelink) An embodiment of the present disclosure may be applied to, for example, any of an uplink, a downlink, and a sidelink. For example, an embodiment of the present disclosure may be applied to a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), or a Physical Random Access Channel (PRACH) in the uplink, a Physical Downlink Shared Channel (PDSCH), a PDCCH, or a Physical Broadcast Channel (PBCH) in the downlink, or a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Control Channel (PSCCH), or a Physical Sidelink Broadcast Channel (PSBCH) in the sidelink.

[0264] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0265] (Data channel / Control channel) An embodiment of the present disclosure may be applied to, for example, either a data channel or a control channel. For example, the channel in an embodiment of the present disclosure may be replaced with any of the data channels PDSCH, PUSCH, and PSSCH, or the control channels PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0266] (reference signal) In one embodiment of the present disclosure, the reference signal is a signal known by both the base station and the mobile station, and may be referred to as a Reference Signal (RS) or a pilot signal. The reference signal may be any of a Demodulation Reference Signal (DMRS), a Channel State Information - Reference Signal (CSI-RS), a Tracking Reference Signal (TRS), a Phase Tracking Reference Signal (PTRS), a Cell-specific Reference Signal (CRS), or a Sounding Reference Signal (SRS).

[0267] (time interval) In an embodiment of the present disclosure, the unit of time resource is not limited to one or a combination of slots and symbols, but may be, for example, a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot subslot, a minislot, or a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or a Single Carrier-Frequency Division Multiplexing (SC-FDMA) symbol, or another time resource unit. Furthermore, the number of symbols included in one slot is not limited to the number of symbols exemplified in the above-mentioned embodiment, and may be another number of symbols.

[0268] (frequency band) An embodiment of the present disclosure may be applied to either a licensed band or an unlicensed band.

[0269] (communication) An embodiment of the present disclosure may be applied to any of communication between a base station and a terminal, communication between terminals (sidelink communication, Uu link communication), and Vehicle to Everything (V2X) communication. For example, the channel in an embodiment of the present disclosure may be replaced with any of PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0270] An embodiment of the present disclosure may be applied to a terrestrial network, a non-terrestrial network (NTN) using a satellite or a high altitude pseudo satellite (HAPS), or a terrestrial network in which transmission delay is large compared to the symbol length or slot length, such as a network with a large cell size or an ultra-wideband transmission network.

[0271] (antenna port) In one embodiment of the present disclosure, an antenna port refers to a logical antenna (antenna group) consisting of one or more physical antennas. For example, an antenna port does not necessarily refer to a single physical antenna, but may refer to an array antenna consisting of multiple antennas. For example, the number of physical antennas that an antenna port is composed of is not specified, and the antenna port may be specified as the smallest unit by which a terminal station can transmit a reference signal. Furthermore, an antenna port may also be specified as the smallest unit for multiplying a weighting factor of a precoding vector.

[0272] <5G NR system architecture and protocol stack> 3GPP is working on the next release of fifth-generation cellular technology (also known as 5G), which includes the development of New Radio Access Technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for the prototyping and commercial deployment of 5G NR compliant devices (e.g., smartphones).

[0273] For example, the system architecture assumes a Next Generation - Radio Access Network (NG-RAN) with gNBs as a whole. The gNBs provide UE-side termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other via an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) via a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity that performs AMF) via an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity that performs UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 23 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0274] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the Packet Data Convergence Protocol (PDCP) sublayer (see, for example, TS 38.300, section 6.4), the Radio Link Control (RLC) sublayer (see, for example, TS 38.300, section 6.3), and the Medium Access Control (MAC) sublayer (see, for example, TS 38.300, section 6.2), which are terminated on the network side at the gNB. A new Access Stratum (AS) sublayer (Service Data Adaptation Protocol (SDAP)) has also been introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack has also been defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is given in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in clauses 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0275] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0276] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical 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 for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), the Physical Uplink Shared Channel (PUSCH), and the Physical Uplink Control Channel (PUCCH) as uplink physical channels, and the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Broadcast Channel (PBCH) as downlink physical channels.

[0277] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communication (mMTC), which have diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in the downlink and 10 Gbps in the uplink) and effective (user-experienced) data rates that are approximately three times higher than those offered by IMT-Advanced. On the other hand, URLLC imposes stricter requirements for ultra-low latency (0.5 ms user-plane latency for UL and DL, respectively) and high reliability (1-10-5 within 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments). 2 ), wide coverage in adverse environments, and extremely long battery life (15 years) for low-cost devices may be desired.

[0278] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. Subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. Similar to LTE systems, the term "resource element" can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0279] In the new radio system 5G-NR, a resource grid of subcarriers and OFDM symbols is defined for each numerology and each carrier in the uplink and downlink. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0280] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 24 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0281] For example, the gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, encryption, and integrity protection of data; - AMF selection at UE attach time if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data towards UPF; - Routing of control plane information towards AMF; - Setting up and tearing down connections; - scheduling and sending of paging messages; - Scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, Maintenance (OAM) Function); - Configuring measurements and measurement reporting for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Network slicing support; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Sharing of radio access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0282] The Access and Mobility Management Function (AMF) hosts the following main functions: - Ability to terminate Non-Access Stratum (NAS) signaling; - NAS signaling security; - Access Stratum (AS) security control; - 3GPP Core Network (CN) inter-node signaling for mobility between access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Managing the registration area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization, including checking roaming privileges; - Mobility management control (subscription and policy); - Network slicing support; - Selection of Session Management Function (SMF).

[0283] Additionally, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and policy rule enforcement for the user plane part; - Traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - Branching Point for supporting multi-homed PDU session; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping to QoS flows of SDFs); - Downlink packet buffering and triggering function for downlink data notification.

[0284] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Enforcement of control part policies and QoS; - Notification of downlink data.

[0285] <Procedures for RRC connection setup and reconfiguration> Figure 25 shows some of the interactions between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE transitions from RRC_IDLE to RRC_CONNECTED (see TS 38.300 v15.6.0).

[0286] RRC is a higher layer signaling protocol used to configure the UE and the gNB. With this transition, the AMF prepares UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message. The gNB then sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures the UE to set up a Signaling Radio Bearer 2 (SRB2) and a Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration steps are omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0287] Therefore, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes: control circuitry that, in operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that, in operation, transmits an initial context setup message to the gNodeB via the NG connection so that a signaling radio bearer between the gNodeB and a user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling that includes a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. Then, the UE performs uplink transmission or downlink reception based on the resource allocation configuration.

[0288] <IMT usage scenarios from 2020 onwards> Figure 26 shows some use cases for 5G NR. The 3rd Generation Partnership Project New Radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 26 shows some example use scenarios envisioned for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0289] URLLC use cases have stringent performance requirements, such as throughput, latency, and availability. URLLC use cases are envisioned as one of the enabling technologies for future applications, such as wireless control of industrial production or manufacturing processes, remote medical surgery, automated power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the uplink (UL) and 0.5 ms on the downlink (DL). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size at a user plane latency of 1 ms.

[0290] From a physical layer perspective, reliability can be improved in many possible ways. Current reliability improvement room includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and developed. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0291] Additionally, technology enhancements targeted by NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means that a transmission with previously allocated resources is stopped and the allocated resources are used for another transmission with a later requested lower latency / higher priority requirement. Thus, a previously allowed transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0292] The use case for massive machine-type communication (mMTC) is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to latency. These devices are required to be low cost and have very long battery life. From an NR perspective, using very narrow bandwidth portions is one solution that saves power and allows for long battery life from the UE perspective.

[0293] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, for example for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0294] For NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution: high reliability (up to 10-6 level), high availability, packet sizes up to 256 bytes, and time synchronization down to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the 0.5 ms to 1 ms range (e.g., 0.5 ms latency on the targeted user plane)).

[0295] Furthermore, for NR URLLC, several technical enhancements may be available from the perspective of the physical layer. These technical enhancements include enhancements to the Physical Downlink Control Channel (PDCCH) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. In addition, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. There may also be enhancements to the PUSCH related to mini-slot level hopping, and enhancements to retransmission / repetition. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0296] <QoS Control> The 5G Quality of Service (QoS) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header over the NG-U interface.

[0297] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for each PDU session, e.g., as shown above with reference to Figure 25. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and the 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and the NG-RAN associate UL and DL QoS flows with DRBs.

[0298] Figure 27 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services, as illustrated in Figure 26) interacts with the 3GPP core network to provide services. For example, it accesses a Network Exposure Function (NEF) to support applications that affect traffic routing, or interacts with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on the operator's deployment, Application Functions that are considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions that are not authorized by the operator to directly access Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0299] Figure 27 further illustrates further functional units of the 5G architecture, namely, 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, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0300] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0301] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0302] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0303] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0304] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a wireless transceiver and processing / control circuitry. The wireless transceiver may include a receiver and a transmitter, or both functions. The wireless transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0305] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0306] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0307] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0308] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0309] A terminal according to one embodiment of the present disclosure includes a control circuit that performs retransmission control for a plurality of transport blocks in units of a code block group that includes at least one code block in one or more of the plurality of transport blocks, and a communication circuit that performs communication in accordance with the retransmission control.

[0310] In one embodiment of the present disclosure, the control circuit determines the number of code blocks included in the code block group based on the number of the plurality of transport blocks, the number of the code block groups in the plurality of transport blocks, and the number of the code blocks included in the plurality of transport blocks.

[0311] In one embodiment of the present disclosure, the identification number related to retransmission control assigned to the plurality of transport blocks is common to the plurality of transport blocks.

[0312] In one embodiment of the present disclosure, the communication circuit transmits a response signal based on the error detection result in units of the plurality of transport blocks using a common uplink resource.

[0313] In one embodiment of the present disclosure, the control circuit determines the number of code blocks included in the code block group based on the number of code block groups for each of the plurality of transport blocks and the number of code blocks for each of the plurality of transport blocks.

[0314] In one embodiment of the present disclosure, the identification numbers related to retransmission control assigned to the plurality of transport blocks are different for each of the plurality of transport blocks.

[0315] In one embodiment of the present disclosure, the communication circuit transmits a response signal based on an error detection result for all of the plurality of transport blocks using one uplink resource.

[0316] In one embodiment of the present disclosure, the communication circuit transmits, using one uplink resource, a signal obtained by multiplexing response signals based on the error detection results in units of the plurality of transport blocks.

[0317] In one embodiment of the present disclosure, the communication circuit transmits a response signal based on the error detection result in units of the plurality of transport blocks using a plurality of uplink resources.

[0318] In one embodiment of the present disclosure, the communication circuitry receives a plurality of sets of information indicating the plurality of uplink resources.

[0319] In one embodiment of the present disclosure, the communication circuit receives information indicating a combination of the plurality of uplink resources.

[0320] In one embodiment of the present disclosure, the communication circuit receives information indicating a portion of the plurality of uplink resources, and the control circuit determines other resources of the plurality of uplink resources that are different from the portion of the resources based on the portion of the resources.

[0321] In one embodiment of the present disclosure, the control circuit determines the number of code blocks included in the code block group based on the number of code block groups for each of a plurality of groups into which the plurality of transport blocks are divided and the number of code blocks for each of the plurality of transport blocks.

[0322] A base station according to one embodiment of the present disclosure includes a control circuit that performs retransmission control for a plurality of transport blocks in units of code block groups each including at least one code block in one or more of the plurality of transport blocks, and a communication circuit that performs communication in accordance with the retransmission control.

[0323] In a communication method according to one embodiment of the present disclosure, a terminal performs retransmission control for a plurality of transport blocks in units of code block groups each including at least one code block in one or more of the plurality of transport blocks, and performs communication in accordance with the retransmission control.

[0324] In a communication method according to one embodiment of the present disclosure, a base station performs retransmission control for a plurality of transport blocks in units of code block groups each including at least one code block in one or more of the plurality of transport blocks, and performs communication in accordance with the retransmission control.

[0325] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2020-133858, filed on August 6, 2020, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0326] One embodiment of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0327] 100 base stations 101,205 Control unit 102 Upper control signal generation unit 103 Downlink control information generation unit 104,206 Encoding section 105,207 Modulation section 106,208 Signal allocation section 107,209 Transmitter 108,201 Receiver 109,202 Extraction part 110,203 Demodulation section 111,204 Decoding section 200 devices< / option>

Claims

1. a control circuit that generates one piece of downlink control information including information regarding retransmission, and generates a plurality of Physical Downlink Shared Channels (PDSCHs) indicated by the one piece of downlink control information; a transmitter for transmitting the one piece of downlink control information and the plurality of PDSCHs; Retransmission of the plurality of PDSCHs is controlled based on an HARQ process number, the HARQ process number is different for each of the plurality of PDSCHs, and the plurality of PDSCHs have consecutive HARQ process numbers; An upper limit of the number of the HARQ process numbers that can be assigned by scheduling the plurality of PDSCHs is set to be equal to or less than the maximum number of the HARQ process numbers. Base station.

2. The downlink control information includes different time resource information for each of the plurality of PDSCHs. The base station of claim 1 .

3. The downlink control information includes common frequency resource information or common MCS information for the plurality of PDSCHs. The base station of claim 1 .

4. Retransmission of the plurality of PDSCHs is controlled for each transport block. The base station of claim 1 .

5. Retransmission of the plurality of PDSCHs is controlled based on a new data indicator and a redundancy version. The base station of claim 1 .

6. Response signals to the plurality of PDSCHs are transmitted on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH). The base station of claim 1 .

7. The PUCCH is determined based on a PUCCH resource indicator (PRI) included in the downlink control information. The base station of claim 6.

8. A plurality of response signals for the plurality of PDSCHs are transmitted on a PUCCH. The base station of claim 1 .

9. The HARQ process number for a first PDSCH among the plurality of PDSCHs is set by downlink control information (DCI), and the HARQ process numbers for other PDSCHs among the plurality of PDSCHs are calculated according to a modulo operation using the HARQ process number for the first PDSCH and the upper limit. The base station of claim 1 .

10. generating one piece of downlink control information including information regarding retransmission, and generating a plurality of Physical Downlink Shared Channels (PDSCHs) indicated by the one piece of downlink control information; Transmitting the one piece of downlink control information and the plurality of PDSCHs; Retransmission of the plurality of PDSCHs is controlled based on an HARQ process number, and the HARQ process number is different for each of the plurality of PDSCHs; the plurality of PDSCHs have consecutive HARQ process numbers, An upper limit of the number of the HARQ process numbers that can be assigned by scheduling the plurality of PDSCHs is set to be equal to or less than the maximum number of the HARQ process numbers. Communication method.

11. The downlink control information includes different time resource information for each of the plurality of PDSCHs. The communication method according to claim 10.

12. The downlink control information includes common frequency resource information or common MCS information for the plurality of PDSCHs. The communication method according to claim 10.

13. Retransmission of the plurality of PDSCHs is controlled for each transport block. The communication method according to claim 10.

14. Retransmission of the plurality of PDSCHs is controlled based on a new data indicator and a redundancy version. The communication method according to claim 10.

15. Response signals to the plurality of PDSCHs are transmitted on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH). The communication method according to claim 10.

16. The PUCCH is determined based on a PUCCH resource indicator (PRI) included in the downlink control information. The communication method according to claim 15.

17. A plurality of response signals for the plurality of PDSCHs are transmitted on a PUCCH. The communication method according to claim 10.

18. The HARQ process number for a first PDSCH among the plurality of PDSCHs is set by downlink control information (DCI), and the HARQ process numbers for other PDSCHs among the plurality of PDSCHs are calculated according to a modulo operation using the HARQ process number for the first PDSCH and the upper limit. The communication method according to claim 10.

19. A process of generating one piece of downlink control information including information on retransmission, and generating a plurality of Physical Downlink Shared Channels (PDSCHs) indicated by the one piece of downlink control information; and controlling a process of decoding the one piece of downlink control information and the plurality of PDSCHs; Retransmission of the plurality of PDSCHs is controlled based on an HARQ process number, and the HARQ process number is different for each of the plurality of PDSCHs; the plurality of PDSCHs have consecutive HARQ process numbers, An upper limit of the number of the HARQ process numbers that can be assigned by scheduling the plurality of PDSCHs is set to be equal to or less than the maximum number of the HARQ process numbers. Integrated circuit.

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