Communication devices, communication methods, and integrated circuits

Abstract

In the present invention, a terminal is provided with: a control circuit that determines data size on the basis of information relating to the number of repetitions of a transmission signal, and / or to a scheduling coefficient of the unit data size of the repetition; and a transmission circuit that transmits a transmission signal on the basis of the data size.

Description

[Technical Field]

[0001] This disclosure relates to communication devices and communication methods. [Background technology]

[0002] In the standardization of 5G, a new radio access technology (NR) was specified by 3GPP, and the NR Release 15 (Rel.15) specification was issued. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP, TR38.821 V16.0.0, “Solutions for NR to support non-terrestrial networks (NTN) (Release 16),” 2019-12 [Non-Patent Document 2] 3GPP, TR38.811 V15.3.0, “Study on New Radio (NR) to support non-terrestrial networks (Release 15),” 2020-07 [Overview of the Initiative]

[0004] However, there is room for further consideration regarding methods to improve throughput in wireless communication.

[0005] Non-limiting embodiments of this disclosure contribute to providing communication devices and communication methods that can improve throughput in wireless communication.

[0006] A communication device according to one embodiment of the present disclosure comprises a control circuit that determines the data size based on information relating to the number of repetitions of a transmission signal and at least one of the scaling factors of the unit data size in the repetitions, and a transmission circuit that transmits the transmission signal based on the data size.

[0007] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0008] According to one embodiment of the present disclosure, throughput in wireless communication can be improved.

[0009] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows an example of Hybrid Automatic Repeat Request (HARQ) processing. [Figure 2] Block diagram showing a part of the configuration of the base station according to Embodiment 1 [Figure 3] Block diagram showing a part of the configuration of the terminal according to Embodiment 1 [Figure 4] Block diagram showing an example of the base station configuration according to Embodiment 1 [Figure 5] Block diagram showing an example of the configuration of a terminal according to Embodiment 1 [Figure 6] Sequence diagram showing an example of operation of a base station and terminal according to Embodiment 1. [Figure 7] A diagram showing an example of a Code Block Group according to Embodiment 2. [Figure 8] Block diagram showing an example of the base station configuration according to Embodiment 3 [Figure 9] Block diagram showing an example of the configuration of a terminal according to Embodiment 3. [Figure 10] Diagram of a representative architecture of a 3GPP NR system [Figure 11] Schematic diagram showing the functional separation between NG-RAN (Next Generation - Radio Access Network) and 5GC (5th Generation Core) [Figure 12] Sequence diagram of the setup / reconfiguration procedure for RRC (Radio Resource Control) connection. [Figure 13] This schematic diagram illustrates usage scenarios for high-capacity, high-speed communication (eMBB: enhanced Mobile Broadband), massive machine type communications (mMTC: massive machine type communications), and highly reliable, ultra-low-latency communications (URLLC: Ultra Reliable and Low Latency Communications). [Figure 14] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described in detail below with reference to the drawings.

[0012] [Expansion to non-terrestrial networks (NTN: Non-Terrestrial Network)] Rel. 15 is a specification for wireless access technologies for terrestrial networks, for example. On the other hand, NR is being considered for extension to non-terrestrial networks (NTN), such as communications using satellites or high-altitude platform stations (HAPS) (for example, Non-Patent Document 1).

[0013] In an NTN environment, the satellite coverage area (e.g., one or more cells) for ground terminals (e.g., user equipment (UE)) or terminals installed on aircraft is formed, for example, by beams transmitted from the satellite.

[0014] In an NTN environment, the round-trip time for radio wave propagation is determined by factors such as the satellite's altitude (e.g., up to approximately 36,000 km) or the angle viewed from the terminal. For example, the round-trip propagation delay time (e.g., Round Trip Time (RTT)) between a ground base station (e.g., gNB) and a terminal via satellite is approximately 541 ms for geostationary satellites (e.g., GEO: Geostationary Earth Orbit satellites) and approximately 42 ms for low-Earth orbit satellites (LEO: Low Earth Orbit satellites) at an altitude of 1,200 km (or non-stationary satellites) (see, for example, Non-Patent Document 1).

[0015] [Hybrid automatic repeat request(HARQ)] In Long Term Evolution (LTE) or 5G NR, for example, HARQ is applied to retransmission control during data transmission.

[0016] In HARQ, the sender performs channel coding (FEC: Forward Error Correction) on the data, such as turbo coding or Low Density Parity Check (LDPC) coding, before transmission. The receiver, during data decoding, stores the received data (e.g., a soft decision value) in a buffer if there is an error in the received data (in other words, buffering, storage, or retention). This buffer is also called a HARQ soft buffer or simply a soft buffer. When retransmitting data, the receiver combines (soft combines) the received data (in other words, the retransmitted data or the data related to the retransmission request) with the previously received data (in other words, the stored data), and decodes the combined data.

[0017] As a result, with HARQ, the receiver can decode using data with improved reception quality (e.g., SNR: Signal to Noise Ratio). Also, with HARQ, the transmitter can improve the coding gain by sending a different parity bit (e.g., a different Redundancy version (RV)) than the previous transmission. Furthermore, with HARQ, continuous data transmission is possible by using multiple processes (e.g., also called HARQ processes) to account for propagation delay or processing delays on both the transmitter and receiver (see, for example, Figure 1). In this case, the receiver stores the received data in buffers, separated by process ID (sometimes referred to as "PID"), which is identification information that identifies the process (or data).

[0018] Furthermore, in LTE or NR, for example, when allocating data, the base station notifies the terminal of HARQ-related information such as the process ID, New Data Indicator (NDI), and RV. The terminal then performs data reception processing (e.g., soft synthesis processing) based on the HARQ-related information notified by the base station.

[0019] In NR Rel. 15 or Release 16 (Rel. 16), for example, data is scheduled in slot units, and HARQ processing is also performed in slot units. Also, in Rel. 15 / 16, for example, the number of HARQ processes is limited to a maximum of 16.

[0020] The above explains an example of how HARQ works.

[0021] However, in satellite communications, which have a larger round-trip propagation delay (e.g., RTT) compared to terrestrial networks, if retransmission control is performed based on the HARQ process specified in Rel.15 / 16 (e.g., a maximum of 16 HARQ processes), the number of available transmission slots within the RTT may not be sufficient, potentially reducing (or degrading) user throughput. In other words, in satellite communications, if retransmission control is performed based on the HARQ process specified in Rel.15 / 16, a shortage of HARQ processes may result in periods where no data is transmitted within the RRT.

[0022] Increasing the number of HARQ processes may improve user throughput. However, increasing the number of HARQ processes too much may increase the required HARQ buffer size at base stations or terminals, or introduce new requirements such as methods for notifying the number of processes (in other words, it may have an impact on the standard (or specification)), thus increasing the complexity of terminals, base stations, and systems.

[0023] Therefore, in one embodiment of this disclosure, a method for improving user throughput in a wireless communication system, for example, with an existing or predetermined number of HARQ processes, will be described.

[0024] (Embodiment 1) [Overview of Wireless Communication Systems] A wireless communication system according to one embodiment of the present disclosure comprises, for example, at least a base station 100 and a terminal 200. The wireless communication system may be, for example, a satellite communication system in an NTN environment, or another wireless communication system.

[0025] For example, in this embodiment, at least one of the base station 100 and the terminal 200 expands the transport block (TB) size based on the number of repetitions in the repetition transmission as defined in NR Rel. 15 / 16 to transmit data. This data transmission can increase the amount of data that can be transmitted using the number of HARQ processes defined in NR Rel. 15 / 16, thereby improving user throughput.

[0026] Repeat transmission is a transmission method in which the same data, in other words, TB, is transmitted across multiple slots. For example, in NR Rel.15 / 16, different Redundancy Versions (RVs) may be transmitted in each slot during repeat transmission.

[0027] Figure 2 is a block diagram showing a partial configuration example of a base station 100 according to an embodiment of the present disclosure. In the base station 100 shown in Figure 2, on the downlink, the control unit 11 (corresponding to, for example, a control circuit) determines the data size (e.g., TB size) based on information regarding the number of repetitions of the transmission signal (e.g., number of repetitions) and at least one scaling factor of the unit data size in the repetitions, and the communication unit 12 (corresponding to, for example, a transmission circuit) transmits the transmission signal based on the data size. Also, in the base station 100 shown in Figure 2, on the uplink, the control unit 11 determines the data size based on information regarding the number of repetitions of the received signal (e.g., number of repetitions) and at least one scaling factor of the unit data size in the repetitions, and the communication unit 12 (corresponding to, for example, a receiving circuit) receives the received signal based on the data size.

[0028] Figure 3 is a block diagram showing some configuration examples of a terminal 200 according to an embodiment of the present disclosure. In the terminal 200 shown in Figure 3, on the downlink, the control unit 21 (corresponding to, for example, a control circuit) determines the data size (e.g., TB size) based on information regarding the number of repetitions of the received signal (e.g., Repetition count) and at least one scaling factor of the unit data size in the repetitions. The communication unit 22 (corresponding to, for example, a receiving circuit) receives the received signal based on the data size. Also, in the terminal 200 shown in Figure 3, on the uplink, the control unit 21 determines the data size (e.g., TB size) based on information regarding the number of repetitions of the transmitted signal (e.g., Repetition count) and at least one scaling factor of the unit data size in the repetitions. The communication unit 22 (corresponding to, for example, a transmitting circuit) transmits the transmitted signal based on the data size.

[0029] [Base station configuration] Figure 4 is a block diagram showing an example of the configuration of a base station 100 according to this embodiment. The base station 100 includes, for example, a transmission data generation unit 101, a data coding and modulation unit 102, a repetition unit 103, a control information generation unit 104, a control information coding and modulation unit 105, a wireless transmission unit 106, a wireless reception unit 107, a data demodulation and decoding unit 108, a control channel (CH) demodulation and decoding unit 109, and an ACK (Acknowledgement) / NACK (Negative Acknowledgement) determination unit 110.

[0030] For example, the control unit 11 shown in Figure 2 may include the transmission data generation unit 101, data encoding / modulation unit 102, repetition unit 103, control information generation unit 104, control information encoding / modulation unit 105, data demodulation / decoding unit 108, control channel demodulation / decoding unit 109, and ACK / NACK determination unit 110 shown in Figure 4. Also, the communication unit 12 shown in Figure 2 may include the wireless transmission unit 106 and wireless reception unit 107 shown in Figure 4.

[0031] The transmission data generation unit 101 generates, for example, transmission data (e.g., downlink data), in other words, transport blocks (TBs). For example, when performing multi-layer transmission using Multiple-Input Multiple-Output (MIMO), the transmission data generation unit 101 may generate multiple TBs. Also, when performing repeat transmission (or repeated transmission), the transmission data generation unit 101 may determine the TB size (or the number of information bits of the transmission data) based on at least one of the number of repetitions or the scaling factor of the unit data size (e.g., the data size per slot). The transmission data generation unit 101 outputs, for example, the generated transmission data to the data encoding and modulation unit 102.

[0032] An example of how to set the TB size in the transmission data generation unit 101 will be described later.

[0033] The data encoding and modulation unit 102 encodes and modulates the transmission data input from the transmission data generation unit 101, for example, and outputs the modulated signal to the Repetition unit 103. The data encoding method may be error-correcting encoding such as turbo coding, LDPC coding, and polar coding, or other encoding methods. The data modulation method may be Quadrature Phase Shift Keying (QPSK) and Quadrature Amplitude Modulation (QAM), or other modulation methods.

[0034] Furthermore, the data encoding and modulation unit 102 may, for example, if the TB size of a TB is greater than or equal to a threshold, divide the TB into multiple code blocks (CBs) and perform error correction encoding on a CB-by-CB basis. The data encoding and modulation unit 102 may also, for example, extract a bit sequence corresponding to the Redundancy Version (RV) used for transmission as the transmission data. In addition, when performing repeat transmission, the data encoding and modulation unit 102 may, for example, use a predetermined pattern of RV for each slot (for example, as defined in TS38.214 V16.1.0 Table 5.1.2.1-2 or Table 5.1.2.1-3).

[0035] Furthermore, the data encoding and modulation unit 102 may, for example, hold the transmission data and, based on the judgment result input from the ACK / NACK determination unit 110, perform the same processing on the held data (in other words, the retransmitted data) as described above. For example, the data encoding and modulation unit 102 may, for example, extract the bit sequence corresponding to the RV to be used this time from the data encoded during the previous transmission as the transmission data for a TB or CB group (CBG) to be retransmitted, in other words, a TB or CBG for which a NACK judgment result has been input from the ACK / NACK determination unit 110. Also, the data encoding and modulation unit 102 may, for example, discard the held data if the judgment result input from the ACK / NACK determination unit 110 indicates that there is no error in the transmission data.

[0036] The Repetition unit 103 maps the data input from the data encoding and modulation unit 102 to time-domain and frequency-domain resources corresponding to a predetermined number of slots (or time intervals). The time-domain and frequency-domain resources may be defined, for example, by symbols and subcarriers, or by resource blocks. Furthermore, the unit of repetition is not limited to slots, but may be defined by other units such as symbols or frames. The Repetition unit 103 outputs the data mapped to the resources to the wireless transmission unit 106.

[0037] The control information generation unit 104 may generate control information relating to the scheduling of at least one of the downlink and uplink. The scheduling information may include, for example, at least one resource allocation information in the time domain and frequency domain, Demodulation Reference Signal (DMRS) port information, coding rate and modulation scheme information (e.g., Modulation and Coding Scheme (MCS) information), and HARQ information (e.g., process ID, NDI, RV). The control information generation unit 104 may also generate information relating to the number of repetitions, and information relating to the scaling factor of the TB size (e.g., scaling factor).

[0038] The control information encoding and modulation unit 105 encodes and modulates the control information input from the control information generation unit 104, for example, and outputs the modulated signal to the wireless transmission unit 106.

[0039] The wireless transmission unit 106 performs transmission processing such as D / A conversion, upconversion, and amplification on data signals input from the Repetition unit 103 and control information input from the control information coding / modulation unit 105, and transmits the resulting wireless signal from the antenna.

[0040] For example, in the downlink of LTE or 5G NR, data signals correspond to signals transmitted via the Physical Downlink Shared Channel (PDSCH), and control information corresponds to signals transmitted via Downlink Control Information (DCI) or the Physical Downlink Control Channel (PDCCH).

[0041] The wireless receiver 107 performs reception processing such as down-conversion and A / D conversion on signals from the terminal 200 (e.g., data signals and ACK / NACK signals) received via the antenna. The wireless receiver 107 outputs the data signals obtained through the reception processing to the data demodulation / decoding unit 108, and outputs the control information obtained through the reception processing to the control channel demodulation / decoding unit 109.

[0042] For example, in the uplink of LTE or 5G NR, data signals correspond to signals transmitted via the Physical Uplink Shared Channel (PUSCH), and control information corresponds to signals transmitted via the Physical Uplink Control Channel (PUCCH).

[0043] The data demodulation / decoding unit 108 performs channel estimation, demodulation, and decoding on a data reception signal, such as PUSCH, input from the wireless receiver unit 107. For example, during decoding, the data demodulation / decoding unit 108 may perform decoding by assuming a TB size based on the number of repetitions or scaling factor specified when allocating data for the uplink. The data demodulation / decoding unit 108 may output the decoded data signal (in other words, the received data).

[0044] The control channel demodulation / decoding unit 109 performs channel estimation, demodulation, and decoding processing on the received signal of a control channel such as PUCCH, and outputs the ACK / NACK signal included in the received signal to the ACK / NACK determination unit 110.

[0045] The ACK / NACK determination unit 110 determines whether an ACK or NACK has been issued for transmitted data (e.g., TB) based on the ACK / NACK signal input from the control channel demodulation / decoding unit 109. The ACK / NACK determination unit 110 outputs the determination result to the data encoding / modulation unit 102. The ACK / NACK determination unit 110 may, for example, instruct the data encoding / modulation unit 102 to retransmit TB or CBG if the ACK / NACK signal is NACK. The ACK / NACK determination unit 110 may also receive ACK / NACK information equal to the number of CBGs from the terminal 200.

[0046] [Device Configuration] Figure 5 is a block diagram showing an example of the configuration of a terminal 200 according to this embodiment. The terminal 200 includes, for example, a wireless receiving unit 201, a control information demodulation / decoding unit 202, a data demodulation / decoding unit 203, an ACK / NACK generation unit 204, a transmission data generation unit 205, an encoding / modulation unit 206, a repetition unit 207, and a wireless transmission unit 208.

[0047] For example, the control unit 21 shown in Figure 3 may include the control information demodulation / decoding unit 202, data demodulation / decoding unit 203, ACK / NACK generation unit 204, transmission data generation unit 205, encoding / modulation unit 206, and repetition unit 207 shown in Figure 5. Also, the communication unit 22 shown in Figure 3 may include the wireless receiving unit 201 and wireless transmitting unit 208 shown in Figure 5.

[0048] The wireless receiver 201 performs reception processing such as down-converting and A / D conversion of the signal received from the base station 100 via the antenna. After reception processing, it outputs the control channel (e.g., PDCCH) of the received signal to the control information demodulation / decoding unit 202 and the data channel (e.g., PDSCH) to the data demodulation / decoding unit 203.

[0049] The control information demodulation / decoding unit 202 may, for example, demodulate and decode a control channel (e.g., PDCCH) input from the wireless receiver unit 201 and output the obtained control information to other components (e.g., data demodulation / decoding unit 203, transmission data generation unit 205, encoding / modulation unit 206, or repetition unit 207) (not shown). The control information may include, for example, scheduling information for at least one of the downlink and uplink.

[0050] The data demodulation / decoding unit 203 demodulates and error-corrects the data channel (e.g., PUSCH) input from the wireless receiver unit 201. When processing the data signal, the data demodulation / decoding unit 203 may, for example, identify the modulation scheme and coding rate based on the downlink scheduling information included in the control information, calculate the TB size, and perform processing based on the calculated TB size.

[0051] For example, the data demodulation / decoding unit 203 may determine (e.g., calculate) the TB size based on information regarding the number of repetitions or the scaling factor. The data demodulation / decoding unit 203 may also determine, for example, whether the received data is the initial transmission data or the retransmission data based on NDI. If the received data is the initial transmission data, the data demodulation / decoding unit 203 may perform error correction decoding on the received data and perform a Cyclic Redundancy Check (CRC) determination. On the other hand, if the received data is the retransmission data, the data demodulation / decoding unit 203 may, for example, combine the current received data with past received data, perform error correction decoding, and then perform a CRC determination. Furthermore, if repetition transmission is set, the data demodulation / decoding unit 203 may, for example, save the demodulated data and perform the decoding process after receiving data from multiple slots used for repetition transmission.

[0052] The ACK / NACK generation unit 204 generates ACK / NACK signals based on the CRC judgment result input from the data demodulation / decoding unit 203. For example, the ACK / NACK generation unit 204 generates an ACK if the CRC is OK (no error) and a NACK if the CRC is NG (error). The ACK / NACK generation unit 204 outputs the generated ACK / NACK signals to the wireless transmission unit 208.

[0053] Furthermore, if multiple TBs or CBs are transmitted, the ACK / NACK generation unit 204 may generate an ACK / NACK signal for each TB or CB and generate an ACK / NACK code block containing multiple ACK / NACK signals.

[0054] The transmission data generation unit 205 generates, for example, transmission data (e.g., uplink data), in other words, transport blocks (TBs). For example, when performing multi-layer transmission using MIMO, the transmission data generation unit 205 may generate multiple TBs. For example, when performing repeat transmission, the transmission data generation unit 205 may determine the TB size (or the number of bits in the transmission data) based on the number of repeats or a scaling factor. The transmission data generation unit 205 outputs, for example, the generated transmission data to the encoding and modulation unit 206.

[0055] An example of how to set the TB size in the transmission data generation unit 205 will be described later.

[0056] The encoding and modulation unit 206 encodes and modulates the transmission data input from the transmission data generation unit 205, for example, and outputs the modulated signal to the Repetition unit 207. The encoding and modulation unit 206 may set the coding rate and modulation method based on the received uplink scheduling information, for example. The data encoding method may be error-correcting coding such as turbo coding, LDPC coding, and polar coding, or other coding methods. The data modulation method may be QPSK and QAM, or other modulation methods.

[0057] Furthermore, the encoding and modulation unit 206 may, for example, if the TB size of a TB is greater than or equal to a threshold, divide the TB into multiple CBs and perform error correction encoding on a CB-by-CB basis. The encoding and modulation unit 206 may also, for example, extract a bit sequence corresponding to the Redundancy Version (RV) used for transmission as transmission data. In addition, when performing repeat transmission, the encoding and modulation unit 206 may, for example, use a predetermined RV pattern for each slot (for example, as defined in TS38.214 V16.1.0 Table 6.1.2.1-2).

[0058] Furthermore, the encoding and modulation unit 206 may, for example, hold the transmission data and, based on the ACK / NACK signal from the base station 100, perform the same processing on the held data (in other words, the retransmitted data) as described above. For example, the encoding and modulation unit 206 may extract the bit sequence corresponding to the RV to be used this time from the data that was encoded during the previous transmission for a TB or CB group (CBG) to be retransmitted. Also, the encoding and modulation unit 206 may, for example, discard the held data if the ACK / NACK signal from the base station 100 indicates that there are no errors in the transmission data.

[0059] The Repetition unit 207 maps the data input from the encoding and modulation unit 206 to time-domain and frequency-domain resources corresponding to a specified number of slots. The time-domain and frequency-domain resources may be defined, for example, by symbols and subcarriers, or by resource blocks. The Repetition unit 207 outputs the data mapped to the resources to the wireless transmission unit 208.

[0060] The wireless transmission unit 208 performs transmission processing such as D / A conversion, upconversion, and amplification on the data signal input from the Repetition unit 207 and the ACK / NACK signal input from the ACK / NACK generation unit 204, and transmits the resulting wireless signal from the antenna.

[0061] Although Figures 4 and 5 mainly describe retransmission control for downlink data, the base station 100 and terminal 200 may also perform retransmission control for uplink data in the same way as for downlink data. For example, the base station 100 may generate an ACK / NACK signal based on the CRC judgment result for uplink data and transmit it to terminal 200. Alternatively, terminal 200 may perform an ACK / NACK judgment based on the ACK / NACK signal for uplink data and control the retransmission of uplink data (e.g., TB or CBG).

[0062] [Example of operation of base station 100 and terminal 200] Next, we will describe an example of the operation of the base station 100 and terminal 200 mentioned above.

[0063] Figure 6 is a sequence diagram showing an example of the operation of the base station 100 and the terminal 200.

[0064] In Figure 6, the base station 100 may, for example, set information regarding the determination of the TB size (S101). This information may include, for example, the number of repetitions or the scaling factor, which will be described later.

[0065] The base station 100 may, for example, transmit control information to the terminal 200 that includes information regarding the determination of the set TB size (S102).

[0066] The base station 100 determines the TB size of at least one of the downlink data (e.g., transmitted data) and uplink data (e.g., received data) based on information regarding the determination of the set TB size (S103).

[0067] Similarly, terminal 200 determines the TB size of at least one of the downlink data (e.g., received data) and uplink data (e.g., transmitted data) based on information regarding the determination of the TB size contained in the received control information (S104).

[0068] The base station 100 and the terminal 200 perform data communication on at least one of the downlink and uplink, for example, based on the determined TB size (S105).

[0069] The following explains an example of how to set the TB size.

[0070] <Setup Method 1> In configuration method 1, for example, the TB size may be set based on the number of repetitions. In other words, the TB size may be set based on the number of slots (e.g., time intervals) used for a repetition, which is one of the repeated transmissions.

[0071] For example, in NR Rel.15 / 16, the TB size (e.g., the number of information bits) is a value calculated according to the following equation (1) (also called the intermediate variable) "N info It is set based on (for example, as described in TS38.214 V16.1.0 sections 5.1.3 and 6.1.4). The TB size is, for example, N info It may be determined by further adjustments depending on the value of N. info The larger the value, the larger the TB size can be set.

number

[0072] In setting method 1, for example, the number of repetitions is set to "N rep If this is the case, the TB size is calculated according to the following equation (2): info It may be set based on the following.

number

[0073] From equation (2), for example, the number of repetitions N repThe more repetitions there are, the larger the TB size will be set. Therefore, for example, the number of repetitions N rep The more slots there are, the more information bits are transmitted in each slot used for repeat transmission, thus improving user throughput.

[0074] Furthermore, for example, the same HARQ process is used for multiple slots used for Repeat transmissions. Therefore, Repeat transmissions allow the use of more slots within the RTT without increasing the number of HARQ processes. For example, in environments where the RTT is extremely long compared to the slot length, such as NTN environments, user throughput can be improved by expanding the TB size based on the number of repeats, without increasing the number of HARQ processes.

[0075] Furthermore, for example, with Repeat transmission, the TB size increases based on the increase in the number of slots used for data transmission, so the effective coding rate (e.g., MCS) can be set in the same way as the coding rate (e.g., MCS) set when Repeat transmission is not performed. Therefore, even when Repeat transmission is performed, the decrease in frequency utilization efficiency (spectral efficiency) can be suppressed, and transmission with a necessary and sufficient error rate (e.g., BLER: Block Error Rate) is possible.

[0076] Note that when setting the TB size, the number of repetitions N repWhether to apply it (for example, which of Formula (1) and Formula (2) to apply) may be separately notified to the terminal 200 by, for example, an RRC message (or also called RRC signaling, upper layer parameter), a MAC CE (Control Element), or DCI. With this notification, for example, for the terminal 200 or traffic type for which an improvement in data rate is expected, by applying Formula (2), a larger TB size can be set to improve throughput. On the other hand, for terminals or traffic types different from the above, by applying Formula (1), a smaller TB size can be set to improve reliability by repetition (in other words, transmission with a low error rate).

[0077] Also, in NTN, for example, disabling retransmission by HARQ (for example, setting "HARQ-feedback disable") is being considered for traffic that requires low latency. When retransmission by HARQ is disabled, since retransmission by HARQ is not performed, transmission with higher reliability (for example, a lower error rate) is expected.

[0078] Therefore, in Setting Method 1, for example, when retransmission by HARQ is effective (for example, HARQ-feedback enable is set), or for a HARQ process in which retransmission by HARQ is effective, N in the setting of the TB size may be applied as in Formula (2). rep For example, when retransmission control by HARQ is applied (for example, when "HARQ-feedback enable" is set), or for data (or HARQ process) to which retransmission control by HARQ is applied, the base station 100 and the terminal 200 may determine the TB size according to Formula (2) based on the repetition number N rep When retransmission by HARQ is ineffective (for example, HARQ-feedback disable is set), or for a HARQ process in which retransmission by HARQ is ineffective, N in the TB size setting is as in Formula (1). repSince this rule does not apply, reliability can be improved through repetition (for example, transmission with a low error rate).

[0079] Note that the number of repetitions is N. rep (Or, parameters for deriving the number of repetitions) may be notified to terminal 200, for example, by an RRC message and at least one of DCI.

[0080] For example, the RRC message used to set the number of repetitions may be "pdsch-AggregationFactor" (message for downlinks), "pusch-AggregationFactor" (message for uplinks) as defined in TS38.331 V16.1.0, or "repK" (parameter for uplink configured grant) in "ConfigureGrantConfig", or other messages may be used.

[0081] Furthermore, the number of repetitions may be notified (or set) to terminal 200 of multiple candidates by an RRC message, for example, and one of the multiple candidates may be notified to terminal 200 by DCI for each PDSCH or PUSCH assignment (e.g., scheduling information). In this case, the RRC message used to set multiple candidates may be, for example, "repetitionNumber-r16" in "PDSCH-TimeDomainResourceAllocationList-r16" (message for downlink) or "PUSCH-TimeDomainResourceAllocationList-r16" (message for uplink), or other messages may be used.

[0082] This notification of the number of repetitions allows for the reuse of notification mechanisms in existing standards, thereby reducing the complexity of processing on terminal 200.

[0083] Furthermore, in these notifications of the number of repetitions, the number of repetitions is explicitly notified to terminal 200. For example, scheduling information may be notified to terminal 200 by DCI at the time of the initial transmission, and the same TB (e.g., data of the same TB size) based on that scheduling information may be transmitted in consecutive slots. In other words, scheduling information does not need to be notified by DCI in each slot after the slot corresponding to the initial transmission of the repetition transmission.

[0084] Furthermore, in the downlink, the base station 100 (for example, the Repetition unit 103) may, for example, transmit the same TB in multiple slots (for example, repeatedly transmit) without notifying the terminal 200 of the number of repetitions. Such a transmission method (or retransmission method) is sometimes called, for example, "Blind retransmission" or "Open loop HARQ". In this case, scheduling information may be notified to the terminal 200 by DCI in each slot. For example, the base station 100 may retransmit without waiting to receive an ACK / NACK signal from the terminal 200. In this case, the base station 100 may, for example, transmit the same TB in consecutive slots or in non-contiguous slots. Furthermore, in the uplink, the base station 100 may, for example, notify (or instruct) the terminal 200 to retransmit the same TB using DCI without waiting to receive uplink data (for example, PUSCH) from the terminal 200, and have the terminal 200 transmit the same TB using multiple slots. In setting method 1, even with such a transmission method, the base station 100 and terminal 200, for example, have a repeat count of N. rep You may set the TB size based on this.

[0085] <Setup Method 2> In configuration method 2, for example, the TB size may be set based on a scaling factor. In other words, the TB size may be set based on a scaling factor for the TB size in multiple slots (e.g., time intervals) used for repeated transmission.

[0086] In setting method 2, for example, the scaling factor is set to "N scaling If this is the case, the TB size is calculated according to the following formula (3): info It may be set based on the following.

number

[0087] From equation (3), for example, the scaling coefficient N scaling The larger the scaling factor N, the larger the TB size will be set. scaling The larger the value, the more information bits are transmitted in each slot used for repeated transmission, thus improving user throughput.

[0088] Methods for setting the scaling factor include, for example, setting (or notifying) terminal 200 semi-statically via RRC messages, and setting (or notifying) terminal 200 dynamically via DCI.

[0089] Furthermore, the scaling factor may be set to a value of 1 or greater. Also, the scaling factor may be an integer value or a decimal value. If the scaling factor is set to a decimal value, a ceiling (carry-up) or floor (borrow-down) operation may be performed in equation (3).

[0090] In the method of setting the scaling factor semi-statically, for example, the scaling factor may be notified to terminal 200 semi-statically by an RRC message. For example, the RRC message used to set the scaling factor may be "PDSCH-TimeDomainResourceAllocationList" or "PUSCH-TimeDomainResourceAllocationList", or it may be "PDSCH-Config" or "PUSCH-Config", or other messages may be used.

[0091] Furthermore, for example, a scaling factor may be applied in the TB size setting when Repeat transmission is performed (e.g., application of equation (3)). In other words, if Repeat transmission is not performed, a scaling factor may not be applied in the TB size setting (e.g., application of equation (1)). In other words, the base station 100 and terminal 200 may, for example, determine the TB size based on a scaling factor when Repeat transmission is applied, but not based on a scaling factor when Repeat transmission is not applied. Alternatively, information indicating whether or not to apply a scaling factor in the TB size setting may be notified to terminal 200. This information may be notified to terminal 200 by DCI for each data scheduling, for example.

[0092] Furthermore, the scaling factor may be set individually for each HARQ process, for example. If the number of repetitions is set individually for each HARQ process, the scaling factor may be applied to HARQ processes that send repetitions, while it may not be applied to HARQ processes that do not send repetitions.

[0093] Thus, when retransmission by HARQ is enabled or applied to the HARQ process, throughput can be improved by applying a scaling factor. Conversely, when retransmission by HARQ is disabled (e.g., HARQ-feedback disable is set) or applied to the HARQ process, transmission reliability due to repetition can be improved by not applying a scaling factor.

[0094] The above explains how to set the scaling factor to semi-static.

[0095] In addition, in the method of setting the scaling factor to Dynamic, for example, the scaling factor may be notified to terminal 200 by DCI, which notifies data scheduling information.

[0096] Alternatively, for example, multiple candidate scaling factors may be set on terminal 200 via an RRC message, and one of the multiple candidate scaling factors may be notified to terminal 200 via DCI for each data scheduling.

[0097] For example, the scaling factor may be included in information regarding time domain resource allocation (e.g., Time Domain Resource Allocation (TDRA)) (e.g., time domain resource allocation patterns). TDRA information may be represented, for example, in a table format (e.g., a TDRA table). In other words, the scaling factor may be defined in the TDRA table. In this case, for example, multiple candidates for TDRA information may be set on terminal 200 by an RRC message (e.g., PDSCH-TimeDomainResourceAllocationList-r16 or PUSCH-TimeDomainResourceAllocationList-r16), and DCI may notify terminal 200 of one of the multiple candidates' allocation patterns (including the scaling factor).

[0098] Alternatively, the scaling factor may be included in information that includes scaling factors (e.g., values ​​less than or equal to 1) for paging or random access processing (e.g., Random Access Channel (RACH) response). Information that includes scaling for paging or random access processing may be represented, for example, by a table. In other words, a table containing scaling factors for paging or random access processing may also specify scaling factors for repeated transmissions.

[0099] In this case, for example, a table may be defined that includes scaling factors (e.g., values ​​less than or equal to 1) for paging (e.g., P-RNTI) or random access processing (e.g., RA-RNTI) as defined in Table 5.1.3.2-2 of TS38.214 V16.1.0, as well as scaling factors (e.g., values ​​greater than or equal to 1) for repeated transmissions. Alternatively, for example, multiple candidate scaling factors may be set on terminal 200 by an RRC message, and one of the multiple candidate scaling factors may be notified to terminal 200 by DCI (e.g., TB scaling field).

[0100] The above explains how to set the scaling factor to Dynamic.

[0101] By notifying the scaling factor in the manner described above, the scaling factor can be notified using the notification mechanism in existing standards, thereby reducing the complexity of processing on terminal 200.

[0102] According to configuration method 2, for example, by expanding the TB size based on a scaling factor in multiple slots used for repeated transmissions such as Repetition transmission or Blind retransmission, more slots within the RTT can be used without increasing the number of HARQ processes. For example, in environments where the RTT is extremely long compared to the slot length, such as NTN environments, user throughput can be improved by expanding the TB size based on a scaling factor without increasing the number of HARQ processes.

[0103] Furthermore, since the TB size increases based on the increase in the number of slots used for data transmission due to repeated transmissions, for example, the actual coding rate (e.g., MCS) can be controlled based on a scaling factor. Therefore, even with repeated transmissions, the decrease in spectral efficiency can be suppressed by controlling the scaling factor (or coding rate or MCS), and transmission with a necessary and sufficient error rate (e.g., BLER) is possible.

[0104] Furthermore, according to setting method 2, for example, a scaling factor can be set for terminal 200 independently of the repetition count. Therefore, even when blind retransmission is applied, in which the repetition count is not explicitly notified to terminal 200, the base station 100 and terminal 200 can set the TB size based on the number of transmissions or slots of the same TB using the scaling factor.

[0105] Furthermore, for example, the larger the value set for the scaling factor, the greater the amount of data transmitted, and the lower the transmission reliability. In other words, the smaller the value set for the scaling factor, the less data is transmitted, and the higher the transmission reliability. In this way, by adjusting the scaling factor, the trade-off between throughput and transmission reliability can be adjusted, making it possible to efficiently accommodate various types of traffic with different delay or reliability requirements.

[0106] The above explains an example of how to set the TB size.

[0107] Note that setting methods 1 and 2 may be combined. For example, setting method 1 (TB size setting based on the number of repetitions) may be applied to either the downlink or the uplink, and setting method 2 (TB size setting based on a scaling factor) may be applied to the other of the downlink or the uplink. Alternatively, for example, the TB size may be set to the number of repetitions N. rep and scaling coefficient N scalingIt may be set based on both of the following. For example, for equation (1), the number of repetitions N rep and scaling coefficient N scaling and may be multiplied together.

[0108] Thus, according to this embodiment, the base station 100 and the terminal 200 have a repeatation count of N. rep or scaling factor N scaling The TB size is determined based on this.

[0109] This allows for improved user throughput, for example, in satellite communications, where round-trip propagation delay (e.g., RTT) is greater compared to terrestrial networks. Even when using the number of HARQ processes specified in Rel.15 / 16 (e.g., up to 16), the number of information bits that can be transmitted within RTT can be increased by expanding the TB size in each HARQ process based on the number of slots used for repeated transmission.

[0110] Furthermore, by improving user throughput through the expansion of the TB size, this embodiment can suppress an increase in the number of HARQ processes. Therefore, for example, it is possible to suppress an increase in the required HARQ buffer amount at the base station 100 or terminal 200, and to suppress the occurrence of new specifications such as the method of notifying the number of processes, thereby suppressing an increase in the complexity of terminal 200, base station 100, and wireless communication system.

[0111] Furthermore, after increasing the number of HARQ processes to a certain extent (for example, up to 32), the number of repetitions N rep or scaling factor N scaling The TB size may be determined based on this. In this case, the number of repetitions N is required to transmit a sufficient number of information bits within the RTT. rep or scaling factor N scaling Because this can be kept under control to some extent, the TB size will not become too large.

[0112] The upper limit of the scaling factor for setting the TB size may be set to, for example, RTT(slot) / HARQ process count, or to the number of configurable repetitions.

[0113] Also, for example, in the case of disabling HARQ retransmission (HARQ-feedback disable), N for the TB size setting rep or N scaling In cases where it does not apply, N rep = 1 or N scaling The figure = 1 may also be shown.

[0114] Also, for example, N for a TB size setting rep or N scaling The applicability of this may be notified to terminal 200 by System Information Block (SIB) for each cell. Alternatively, the N for TB size setting may be notified. rep or N scaling The applicability of this may be set and notified for each terminal 200, for example, depending on the capabilities of the terminal 200 (e.g., UE capability). rep or N scaling Applicability or applicability of N rep or N scaling The terminal 200 notifies the base station 100 of the upper limit, and the base station 100 determines N based on the notification from the terminal 200. rep or N scaling You may set it to that.

[0115] Also, for example, N rep or N scaling The TB size calculated by applying this may be set within a range that does not exceed the upper limit of the TB size supported by terminal 200.

[0116] (Embodiment 2) The configuration of the base station and terminal according to one embodiment of this disclosure may be the same as in Embodiment 1.

[0117] In this embodiment, the base station 100 and the terminal 200 determine (e.g., expand) the number of code block groups (CBGs) based on information such as the number of repetitions or scaling factors.

[0118] For example, NR Rel.15 / 16 allows the use of multiple CBGs. For instance, ACK / NACK is generated for each CBG, and erroneous CBGs are retransmitted by HARQ, while CBGs without errors are not. This CBG-level retransmission improves retransmission efficiency.

[0119] For example, information regarding the number of CBGs (e.g., the maximum number of CBGs) may be notified to terminal 200 via an RRC message. For example, since there is an upper limit to the number of bits in a single code block, multiple code blocks may be generated for TB-sized data exceeding this limit. A CBG may be composed of multiple code blocks grouped together, for example.

[0120] In this embodiment, the base station 100 and terminal 200 increase the number of CBGs when the TB size is set (for example, increased) based on the number of repetitions or scaling factor described in Embodiment 1.

[0121] For example, in a downlink, if the base station 100 (e.g., the transmission data generation unit 101) sets the TB size based on the number of repetitions or the scaling factor, it may determine the number of CBGs based on the TB size setting (e.g., the setting of the number of repetitions or the scaling factor). Also, in a downlink, the terminal 200 (e.g., the data demodulation / decoding unit 203) may demodulate and decode the received data for each number of CBGs based on the TB size setting.

[0122] Similarly, for example, in an uplink, if terminal 200 (e.g., transmission data generation unit 205) sets the TB size based on the number of repetitions or scaling factor, it may determine the number of CBGs based on the TB size setting (e.g., setting the number of repetitions or scaling factor). Also, in an uplink, base station 100 (e.g., data demodulation / decoding unit 108) may demodulate and decode the received data for each number of CBGs based on the TB size setting.

[0123] Figure 7 shows an example of CBG settings. The example in Figure 7 shows an example of CBG settings when Repetition transmission is not applied, and an example of CBG settings when Repetition transmission with Repetition count = 2 is applied.

[0124] As shown in Figure 7, if Repetition transmission is not applied, two CBGs (CBG1 and CBG2) containing three CBs are configured. In this case, for example, two ACK / NACK signals may be transmitted for each CBG for each TB transmitted on a slot-by-slot basis.

[0125] Also, as shown in Figure 7, the number of repetitions = 2 (for example, N in equation (2)). rep When Repetition transmission (=2) is applied, the TB size is doubled compared to when Repetition transmission is not applied. For example, the number of CBGs may be set to twice the number compared to when Repetition transmission is not applied. In Figure 7, for example, four CBGs (CBG1, CBG2, CBG3, and CBG4) are set, each containing three CBs. In this case, for example, four ACK / NACK signals may be transmitted for each CBG for the TB transmitted in two slots.

[0126] Thus, the number of CBGs is higher compared to when Repeat transmission is not applied, compared to the number of Repeats N. rep It may be set to double. Also, the scaling factor N is used in determining the TB size. scaling When applying this, the number of repetitions is N.rep Similarly, the number of CBGs may be set to be N times the scaling factor compared to the case where Repetition transmission is not applied. scaling It may be set to be N times.

[0127] Note that an upper limit value may be defined for the set value of the number of CBGs. By defining the upper limit value, for example, it is possible to suppress the number of CBGs from being set extremely large depending on the value taken by the Repetition number N rep or the scaling factor N. scaling This can prevent the number of CBGs from being set extremely large depending on the value taken by the Repetition number N

[0128] Here, for example, among the scheduling information notified to the terminal 200 by DCI, there is CBG transmission information (CBG TI). The CBG TI field is set to a size (e.g., number of bits) depending on the value of the CBG, for example. Therefore, for example, the size of the CBG TI field may be set to N times, N times, or a size based on the maximum value of the number of CBGs corresponding to the maximum number of CBGs. Thereby, for example, since the size of the CBG TI field can be set to a fixed value, it is possible to suppress the change in the DCI size depending on the applicability of N times or N times in the TB size setting, and suppress the increase in the number of blind decoding times of the terminal 200. rep times, N scaling times, or a size based on the maximum value of the number of CBGs corresponding to the maximum number of CBGs. rep times or N scaling This can suppress the change in the DCI size depending on the applicability of N times or N times in the TB size setting, and suppress the increase in the number of blind decoding times of the terminal 200.

[0129] Also, for example, as shown in FIG. 7, since the number of ACK / NACK bits changes (e.g., increases) due to an increase in the number of CBGs, the base station 100 and the terminal 200 may determine the amount of PUCCH resources for transmitting ACK / NACK based on the number of CBGs. Hereinafter, an example of the usage method of the PUCCH resources for transmitting ACK / NACK will be described.

[0130] <Usage method 1 of PUCCH resources> In usage method 1, for example, the base station 100 and the terminal 200 may use the PUCCH resources set for the terminal 200 by RRC message or DCI over the same number of slots as the Repetition number of the data.

[0131] The base station 100 and the terminal 200 may perform at least one of transmission and reception of increased ACK / NACK bits by means of the PUCCH resources set for the terminal 200 over, for example, the same number of slots as the repetition count of data. In Usage Method 1, for example, the number of bits of the ACK / NACK signal transmitted over a plurality of slots may be common among the slots.

[0132] Usage Method 1 may be applied, for example, when the number of bits that can be transmitted by the PUCCH resources set for the terminal 200 is small (for example, when it is below a threshold value). As an example, Usage Method 1 is effective when using PUCCH resources (for example, PUCCH format 0) capable of transmitting 1 to 2 bits.

[0133] <Usage Method 2 of PUCCH Resources> In Usage Method 2, for example, the base station 100 and the terminal 200 may increase the number of bits (transmission bit number) that can be transmitted in the PUCCH resources set for the terminal 200 by means of an RRC message or DCI.

[0134] The base station 100 and the terminal 200 may transmit increased ACK / NACK bits by means of the PUCCH resources with an increased number of bits.

[0135] Usage Method 2 may be applied, for example, when the number of bits that can be transmitted by the PUCCH resources set for the terminal 200 is large (for example, when it is more than a threshold value). As an example, Usage Method 2 is effective when using PUCCH resources (for example, PUCCH format 2) capable of transmitting more than 2 bits.

[0136] As described above, according to this embodiment, even if the TB size increases based on the method described in Embodiment 1, for example, the number of CBGs also increases in proportion to the increase in TB size, so the deterioration of retransmission efficiency can be suppressed. Also, for example, since the number of CBGs increases in proportion to the increase in TB size, the number of ACK / NACK bits per amount of transmitted data does not increase, so the ACK / NACK overhead can be suppressed.

[0137] (Embodiment 3) In this embodiment, the TB size may be set (or determined) based, for example, on the number of slots (e.g., the number of time intervals) used to transmit downlink data (e.g., PDSCH) or uplink data (e.g., PUSCH).

[0138] [Example of base station configuration] Figure 8 is a block diagram showing an example of the configuration of base station 100a according to this embodiment. In Figure 8, components similar to those of base station 100 in Embodiment 1 are denoted by the same reference numerals. For example, base station 100a may include a mapping unit 103a instead of the Repetition unit 103 in Embodiment 1.

[0139] Base station 100a may transmit downlink data (for example, PDSCH, also called multi-slot PDSCH) transmitted across multiple slots for the downlink to terminal 200a (see, for example, Figure 9 described later). Here, the setting of the number of slots used for PDSCH transmission may be notified to terminal 200a by, for example, DCI and RRC signaling.

[0140] The transmission data generation unit 101 determines the TB size based, for example, on the number of slots used for PDSCH transmission. An example of how the TB size is determined at base station 100a will be described later.

[0141] The mapping unit 103a maps the modulated data to time-domain and frequency-domain resources (e.g., subcarriers and OFDM symbols) across the number of slots set for PDSCH transmission. The mapping unit 103a may also map to RS resources, such as the Demodulation Reference Signal (DMRS).

[0142] Furthermore, the base station 100a may receive, for example, uplink data (for example, PUSCH, also called multi-slot PUSCH) transmitted by the terminal 200 across multiple slots. The data demodulation / decoding unit 108 performs channel estimation, demodulation, and decoding on the received PUSCH signal. For example, the data demodulation / decoding unit 108 may perform channel estimation using DMRS mapped to multiple slots. Also, in the decoding process, the data demodulation / decoding unit 108 may perform the decoding process assuming a TB size based on the number of slots used for PUSCH transmission.

[0143] [Example of device configuration] Figure 9 is a block diagram showing an example of the configuration of terminal 200a according to this embodiment. In Figure 9, components similar to those of terminal 200 in Embodiment 1 are denoted by the same reference numerals. For example, terminal 200a may include a mapping unit 207a instead of the Repetition unit 207 in Embodiment 1.

[0144] Terminal 200a may transmit uplink data (e.g., PUSCH) to base station 100a using time-domain and frequency-domain resources allocated across multiple slots from base station 100a. Here, the number of slots used for PUSCH transmission may be notified to terminal 200a by, for example, DCI and RRC signaling.

[0145] The transmission data generation unit 205 determines the TB size based, for example, on the number of slots used for PUSCH transmission. An example of how the TB size is determined in terminal 200a will be described later.

[0146] The mapping unit 207a maps the modulated data to time-domain and frequency-domain resources (e.g., subcarriers and OFDM symbols) across a number of slots set for PUSCH transmission. The mapping unit 207a may also map to RS resources such as DMRS.

[0147] Furthermore, terminal 200a may receive, for example, downlink data (e.g., PDSCH) transmitted across multiple slots by base station 100a. The data demodulation / decoding unit 203 performs channel estimation, demodulation, and decoding on the received PDSCH signal. For example, the data demodulation / decoding unit 203 may perform channel estimation using DMRS mapped to multiple slots. Also, in the decoding process, the data demodulation / decoding unit 203 may perform the decoding process assuming a TB size based on the number of slots used to transmit the PDSCH.

[0148] [How to determine TB size] An example of a method for determining the TB size in this embodiment will be described.

[0149] Similar to Embodiment 1, the TB size is represented by formula (1) as described in TS38.214 V16.1.0 sections 5.1.3 (PDSCH) and 6.1.4 (PUSCH), for example, "N info It may be set based on the following. In this embodiment, the base station 100a and terminal 200a are set, for example, based on the number of slots used for transmitting PDSCH or PUSCH, N info Determine the value.

[0150] For example, base station 100a and terminal 200a are N info The calculation formula (for example, formula (1)) includes N REThe number of REs used for data transmission may be calculated based on the number of slots used for PDSCH or PUSCH transmission (in other words, transmitted or received signals). For example, N RE This can be expressed by the following equation (4).

number

[0151] In equation (4), N′ RE n indicates the number of REs in one resource block (Resource Blok (RB) or Physical Resource Block (PRB)) within the slot used for data transmission. PRB This indicates the number of resource blocks allocated to the data. Also, in equation (4), for example, the upper limit of the number of REs in the slot used to calculate the TB size is set to 156 so that the TB size does not exceed the supported data rate of terminal 200a. Note that the upper limit is not limited to 156.

[0152] The following describes the number of REs (N) in this embodiment. RE Two methods (for example, calculation method A and calculation method B) are described as examples of how to calculate ).

[0153] <Calculation method A> In calculation method A, N RE This can be calculated according to the following formula (5).

number

[0154] In equation (5), N′ RE This indicates the number of REs allocated in the multiple slots used for data transmission (e.g., PDSCH or PUSCH). For example, N′ RE N is used for data transmission. slot The sum of the number of REs within one resource block in each of the individual slots may be shown. Also, in equation (5), N slotThis indicates the number of slots used for data transmission (e.g., PDSCH or PUSCH).

[0155] For example, N′ RE This can be calculated according to the following formula (6).

number

[0156] For example, N SC RB is, N SC RB =12 is also acceptable, and other values ​​are also acceptable. Also, N oh PRB For example, notifications may be sent to terminal 200a via "PDSCH-ServingCellConfig" for PDSCH and "PUSCH-ServingCellConfig" for PUSCH. Also, the overhead coefficient N oh PRB This can be a coefficient used to account for the overhead of signals different from DMRS, and is specified as {0, 6, 12, or 18} in Rel.15 / 16 NR.

[0157] Furthermore, in this embodiment, the overhead coefficient N oh PRB For this purpose, values ​​for multiple-slot transmission may be added, or the values ​​may be extended by multiplying coefficients. For example, the coefficient could be the number of slots N used for data transmission. slot You may apply N′ RE This can be calculated according to the following formula (7).

number

[0158] Equation (7) allows the use of the conventional overhead coefficient specified in Rel. 15 / 16, thus eliminating the need for new notifications and simplifying processing and reducing notification overhead.

[0159] Also, N′ RE As a modification of the calculation of N′ RE may be calculated according to the following formula (8).

Equation

[0160] In Equation (8), N DMRS PRB represents the number of resource elements of DMRS in a resource block per slot assigned for PDSCH or PUSCH transmission. According to Equation (8), for example, even during multi-slot transmission, the N DMRS PRB and N oh PRB defined in Rel. 15 / 16 NR can be applied, so that the processing in the terminal 200a can be simplified.

[0161] In Equation (6) or Equation (7), N DMRS PRB represents the number of resource elements of DMRS per resource block within the slot interval (interval of N slot ) assigned for PDSCH or PUSCH transmission. Therefore, for example, even when the number of DMRS is set individually for each slot (for example, when it is different for each slot), the accurate number of resource elements of DMRS can be represented, and the base station 100a and the terminal 200a can more accurately calculate the number of resource elements used for data transmission (that is, N′ RE ).

[0162] According to Equation (5), since the value N′ RE obtained by summing up the number of REs used for data transmission in each of the multiple slots is used for calculating the TB size, the base station 100a and the terminal 200a can set the TB size according to the number of slots used for data transmission.

[0163] Also, for example, even when the number of REs is different for each slot, the total value N′ RESince it is used for calculating the TB size, the base station 100a and the terminal 200a can set the TB size based on the accurate N value in a plurality of slots. RE The setting of the TB size based on the value of N is possible.

[0164] Also, by setting the value obtained by multiplying the upper limit value 156 of the number of REs in a slot by the number of slots N to the upper limit value of N, it is possible to suppress the TB size from being set extremely large depending on the value that N' takes. slot by RE being set to the upper limit value of N, it is possible to suppress the TB size from being set extremely large depending on the value that N' takes. RE can be suppressed.

[0165] <Calculation Method B> In calculation method B, N may be calculated according to the following equation (9). RE In equation (9), N' indicates the number of REs in one resource block per slot of a plurality of slots used for data (e.g., PDSCH or PUSCH) transmission. Also, N indicates the number of slots used for data (e.g., PDSCH or PUSCH) transmission.

Equation

[0166] In equation (9), N' RE indicates the number of REs in one resource block per slot of a plurality of slots used for data (e.g., PDSCH or PUSCH) transmission. Also, N slot indicates the number of slots used for data (e.g., PDSCH or PUSCH) transmission.

[0167] Calculation method B may be premised on the case where the number of REs per one resource block in each of a plurality of slots used for data transmission is the same. On the other hand, when the number of REs per one resource block in each of a plurality of slots used for data transmission is different, for N', for example, the number of REs in the slot with fewer (e.g., the fewest) REs may be applied, or the number of REs in a specific slot such as the first slot (also referred to as, for example, the first slot) or the last slot may be applied. Or, for N' RE a value based on the average value of the number of REs in each of a plurality of slots may be applied. RE a value based on the average value of the number of REs in each of a plurality of slots may be applied.

[0168] Calculation method B uses the number of REs in one slot to calculate the TB size, making it possible to calculate the TB size more simply compared to calculation method A, for example.

[0169] Note that instead of equation (9), N is calculated according to equation (10) below. RE The following may be calculated.

number

[0170] The above explains calculation methods A and B.

[0171] Note that while calculation methods A and B describe an example where the min calculation is performed with an upper limit of 156 REs for one slot, N RE The calculation method is not limited to these. For example, the upper limit for the number of REs in a single slot may be a value other than 156. For example, in a single slot interval, the number of resource elements in a single resource block is 168 (=12 subcarriers × 14 symbols). Of the 168 resource elements, 1 symbol's worth of resource elements (=12) correspond to overhead such as DMRS, and the remaining 156 are defined as the upper limit for the number of resource elements allocated to data. For example, when transmitting with multiple slots, the upper limit for the number of resource elements may be set to 156 in a specific slot (e.g., the first slot), and to 168 in other slots (e.g., the second slot and beyond). In this case, N RE The min operation in the calculation formula is min(156 + 12·14·(N slot - 1), N′ RE ) may be replaced with this. This allows for an appropriate setting of the upper limit on the number of resource elements, for example, when overhead such as DMRS is mapped to the first symbol in multiple slots used for data transmission and not to the other symbols.

[0172] Furthermore, for example, there is no need to set an upper limit on the number of resource elements. In this case, for example, in calculation method A, "N RE = N′ RE ·n PRB " or, in calculation method B, "N RE = N′ RE ·N slot ·n PRB According to N RE The following may be calculated.

[0173] According to the TB size setting method of this embodiment, the base station 100a and terminal 200a set the TB size according to, for example, the number of slots used for data (e.g., PDSCH or PUSCH) transmission. In other words, the base station 100a and terminal 200a determine the TB size based on information related to the amount of resources (e.g., number of slots) used for data (e.g., transmission signals). For example, the more slots used for data transmission, the greater the number of information bits transmitted in each slot used for data transmission. This TB size setting increases the amount of data that can be transmitted in a single HARQ process, thus improving throughput even with a defined (e.g., limited) number of HARQ processes.

[0174] Furthermore, in this embodiment, the TB size is set according to the number of slots used for data (e.g., PDSCH or PUSCH) transmission. Therefore, for example, the number of information bits transmitted (e.g., data volume) also increases as the number of slots increases, so throughput can be improved while suppressing an increase in the number of resource blocks, that is, while suppressing a decrease in transmit power spectrum density (PSD). As a result, data transmission with suppressed PSD reduction becomes possible, for example, the coverage area where a certain data rate can be achieved can be expanded.

[0175] Furthermore, for example, data allocation to multiple slots can be notified to terminal 200a via a single DCI, thus reducing control overhead. In addition, the consumption of HARQ processes (in other words, the increase in the number of HARQ processes used) can be suppressed, allowing for terminal simplification by reducing the number of HARQ processes.

[0176] Furthermore, in Repetition, data transmission and reception processing such as encoding or modulation is performed individually for each slot. However, in this embodiment, the base station 100a and terminal 200a can improve channel estimation accuracy and reduce the error rate by, for example, performing channel estimation for multiple slots collectively, demodulating and decoding, when transmitting data across multiple slots (e.g., PDSCH or PUSCH).

[0177] Furthermore, for example, DMRS may be mapped to a specific slot (e.g., the first slot) among multiple slots used for data transmission, while DMRS may not be mapped to the remaining slots. This DMRS mapping allows the base station 100a and terminal 200a to transmit more data. Therefore, according to this embodiment, even if DMRS mapping is set individually for each slot (e.g., different for each slot), the TB size can be set appropriately.

[0178] The number of slots used for data transmission (e.g., PDSCH or PUSCH) can also be rephrased as, for example, "the number of slots that constitute a unit of TB processing."

[0179] Furthermore, the multiple slots used for data transmission (e.g., PDSCH or PUSCH) may be temporally consecutive or non-contiguous. Also, the frequency resources (e.g., resource blocks) to which data is allocated in each of the multiple slots may be set individually (e.g., to different resources).

[0180] Also, the number of slots N slotThe number of repetitions may also be set. In other words, the number of slots N slot This may also correspond to the number of repetitions.

[0181] Furthermore, this embodiment may be combined with Embodiment 1 (or Embodiment 2). For example, the base station 100a and terminal 200a may determine the TB size based on information regarding at least one of the following: the number of data repetitions (e.g., the number of repetitions of the transmission signal), the scaling factor, and the number of slots used to transmit the data (e.g., the number of time intervals). As an example, in the method for calculating the TB size according to this embodiment, the calculated N info Furthermore, a scaling factor may be multiplied to it. For example, N info When a scaling factor less than 1 is multiplied by this, it becomes possible to transmit data at a lower MCS (or Spectral Efficiency), thereby expanding the coverage area.

[0182] Also, the number of slots N slot This can be an integer or a decimal. For example, N slot If = 2.5, then two slots and a half-slot (half of a slot) may be used for data transmission (e.g., PDSCH or PUSCH). Also, the number of slots N slot This can be expressed as the number of symbols used for data transmission. For example, N slot If =2, then 28 symbols, N slot If the value is 2.5, it may be expressed as 42 symbols.

[0183] The embodiments of this disclosure have been described above.

[0184] Furthermore, one embodiment of this disclosure can be applied regardless of the type of satellite, such as GEO, MEO (Medium Earth Orbit satellite), LEO (Low Earth Orbit satellite), or HEO (Highly Elliptical Orbit satellite). Also, one embodiment of this disclosure may be applied to non-terrestrial communications, such as HAPS (High Aerospace Platforms) or drone base stations.

[0185] Furthermore, although the embodiments described above were explained using an NTN environment (e.g., a satellite communication environment) as an example, this disclosure is not limited thereto. This disclosure may be applied to other communication environments (e.g., LTE and / or NR terrestrial cellular environments). For example, it may be applied to terrestrial communications in environments with large cell sizes and long propagation delays between base stations and terminals. Also, for example, the higher the carrier frequency, the wider the subcarrier spacing (SCS) and the shorter the slot length may become. A shorter slot length allows for a larger number of slots in the RTT, and a larger number of HARQ processes is desirable. For this reason, one embodiment of this disclosure may be applied, for example, to terrestrial communications systems with higher carrier frequencies (e.g., systems of 52.6 GHz or higher).

[0186] Furthermore, the shorter the slot length, the more the decoding frequency (or number of attempts) of control information (e.g., PDCCH) can be reduced to once per slot (or fewer than the number of slots) for multiple slots, in order to reduce the processing load or power consumption of the terminal. In this case as well, as in the above embodiment, by determining the TB size based on the number of slots to which the data transmitted by multiple slots is allocated, it becomes possible to transmit a data amount corresponding to the number of slots, thereby improving throughput. Moreover, in each of the above embodiments, in addition to improving throughput, data transmission using multiple slots can expand the coverage area in which a certain data rate can be realized, so an embodiment of this disclosure may be applied to terrestrial communications different from the communications described above.

[0187] Furthermore, while the embodiments described above have explained, as an example, the case in which data allocation (e.g., scheduling) is notified to terminal 200 by DCI, the invention is not limited to this. One embodiment of this disclosure can also be applied, for example, to transmissions using semi-persistent scheduling or configured grants that are scheduled periodically in advance. For example, the scaling factor may be notified (or set) to terminal 200 by the RRC message "SPS-Config" for semi-persistent scheduling. Alternatively, the scaling factor may be notified (or set) to terminal 200 by the RRC message "configuredGrantConfig" for configured uplink grants.

[0188] Furthermore, ACK / NACK is sometimes referred to as HARQ-ACK or HARQ-Feedback information.

[0189] Repetition is also sometimes called slot aggregation, slot bundling, TTI aggregation, or TTI bundling.

[0190] Furthermore, the number of repetitions in Embodiments 1 and 2 is the number of slots N used for data transmission (PDSCH or PUSCH). slot This can also be substituted. In other words, the number of repetitions is equal to the number of slots N. slot It may also be possible to accommodate this.

[0191] Furthermore, although the above-described embodiments describe the transmission of both downlink data (e.g., PDSCH) and uplink data (e.g., PUSCH), one embodiment of the present disclosure may be applied to either downlink data or uplink data, but not to the other.

[0192] Furthermore, in each of the embodiments described above, the form of satellite communication may be a configuration in which the base station functions reside on the satellite (e.g., "regenerative satellite"), or a configuration in which the base station functions reside on the ground and the satellite relays communication between the base station and the terminal (e.g., "transparent satellite"). In other words, for example, in one embodiment of this disclosure, the downlink and uplink may be links between the terminal and the satellite, or links via the satellite.

[0193] Furthermore, the notation "...part" in the above-described embodiment may be replaced with other notations such as "...circuitry," "...device," "...unit," or "...module."

[0194] (Control signal) In this disclosure, the downlink control signal (or downlink control information) related to one embodiment of this disclosure may be, for example, a signal (or information) transmitted in a Physical Downlink Control Channel (PDCCH) at the physical layer, or a signal (or information) transmitted in a Medium Access Control Control Element (MAC CE) or Radio Resource Control (RRC) at a higher layer. Furthermore, the signal (or information) is not limited to being notified by the downlink control signal, but may be predetermined in a specification (or standard), or may be pre-configured in the base station and terminal.

[0195] In this disclosure, the uplink control signal (or uplink control information) related to one embodiment of this disclosure may be, for example, a signal (or information) transmitted in the physical layer PUCCH, or a signal (or information) transmitted in the upper layer MAC CE or RRC. Furthermore, the signal (or information) is not limited to being notified by the uplink control signal, but may be predetermined in the specification (or standard), or may be pre-configured in the base station and terminal. In addition, the uplink control signal may be replaced with, for example, uplink control information (UCI), 1st stage sidelink control information (SCI), or 2nd stage SCI.

[0196] (base station) In one embodiment of this disclosure, the base station may be a Transmission Reception Point (TRP), cluster head, access point, Remote Radio Head (RRH), eNodeB (eNB), gNodeB (gNB), Base Station (BS), Base Transceiver Station (BTS), master unit, gateway, etc. Also, in sidelink communication, a terminal may be used instead of a base station. Also, a relay device that relays communication between a higher node and a terminal may be used instead of a base station. It may also be a roadside unit.

[0197] (Uphill rink / Downhill rink / Side rink) One embodiment of the present disclosure may be applied to, for example, an uplink, a downlink, or a sidelink. For example, one embodiment of the present disclosure may be applied to the Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Physical Random Access Channel (PRACH) of an uplink, the Physical Downlink Shared Channel (PDSCH), PDCCH, Physical Broadcast Channel (PBCH) of a downlink, or the Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), Physical Sidelink Broadcast Channel (PSBCH) of a sidelink.

[0198] PDCCH, PDSCH, PUSCH, and PUCCH are examples of downlink control channels, downlink data channels, uplink data channels, and uplink control channels, respectively. PSCCH and PSSCH are examples of sidelink control channels and sidelink data channels. PBCH and PSBCH are examples of broadcast channels, and PRACH is an example of a random access channel.

[0199] (Data channel / Control channel) One embodiment of the present disclosure may be applied to either a data channel or a control channel, for example. For example, the channel in one embodiment of the present disclosure may be replaced with any of the data channels PDSCH, PUSCH, PSSCH, or the control channels PDCCH, PUCCH, PBCH, PSCCH, PSBCH.

[0200] (reference signal) In one embodiment of the present disclosure, the reference signal is, for example, a signal known to both the base station and the mobile station, and may be called a Reference Signal (RS) or pilot signal. The reference signal may be any of the following: Demodulation Reference Signal (DMRS), Channel State Information - Reference Signal (CSI-RS), Tracking Reference Signal (TRS), Phase Tracking Reference Signal (PTRS), Cell-specific Reference Signal (CRS), or Sounding Reference Signal (SRS).

[0201] (Time interval) In one embodiment of the present disclosure, the unit of time resource is not limited to one or a combination of slots and symbols, but may also be a time resource unit such as a frame, superframe, subframe, slot, time slot subslot, minislot, or symbol, Orthogonal Frequency Division Multiplexing (OFDM) symbol, Single Carrier - Frequency Division Multiplexing (SC-FDMA) symbol, or any other time resource unit. Furthermore, the number of symbols contained in one slot is not limited to the number of symbols exemplified in the above embodiment, but may be any other number of symbols.

[0202] (Frequency band) One embodiment of this disclosure may be applied to either a licensed band or an unlicensed band.

[0203] (communication) One embodiment of the present disclosure may be applied to communication between a base station and a terminal (Uu-link communication), communication between terminals (Sidelink communication), or Vehicle to Everything (V2X) communication. For example, the channel in one embodiment of the present disclosure may be replaced with any of PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, or PBCH.

[0204] Furthermore, one embodiment of this disclosure may be applied to any of the following: a terrestrial network, a satellite, or a non-terrestrial network (NTN) using a high-altitude pseudo-satellite (HAPS). Also, one embodiment of this disclosure may be applied to terrestrial networks with large cell sizes, ultra-wideband transmission networks, and other networks where transmission delay is large relative to symbol length or slot length.

[0205] (Antenna port) In one embodiment of this disclosure, an antenna port refers to a logical antenna (antenna group) composed of one or more physical antennas. For example, an antenna port does not necessarily refer to a single physical antenna, but may refer to an array antenna composed of multiple antennas. For example, the number of physical antennas that make up an antenna port is not specified, and it may be defined as the smallest unit on which a terminal station can transmit a reference signal. Alternatively, an antenna port may be defined as the smallest unit on which the weighting of a precoding vector is multiplied.

[0206] <5G NR System Architecture and Protocol Stack> 3GPP is continuing work on the next release of fifth-generation mobile phone technology (also simply called "5G"), which includes the development of new radio access technologies (NR) operating in the frequency range up to 100 GHz. The initial version of the 5G standard was completed at the end of 2017, which will enable the prototyping and commercial deployment of devices (e.g., smartphones) that comply with the 5G NR standard.

[0207] For example, the system architecture as a whole assumes an NG-RAN (Next Generation - Radio Access Network) with gNBs. The gNBs provide the UE-side termination for the user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols of the NG radio access. The gNBs are connected to each other by Xn interfaces. Furthermore, the gNBs are connected to the NGC (Next Generation Core) by Next Generation (NG) interfaces, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity performing AMF) by NG-C interfaces, and to the UPF (User Plane Function) (e.g., a specific core entity performing UPF) by NG-U interfaces. The NG-RAN architecture is shown in Figure 10 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0208] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the PDCP (Packet Data Convergence Protocol (see section 6.4 of TS 38.300)) sublayer, RLC (Radio Link Control (see section 6.3 of TS 38.300)) sublayer, and MAC (Medium Access Control (see section 6.2 of TS 38.300)) sublayer, which are terminated on the network side in gNB. Additionally, a new Access Stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). Furthermore, a control plane protocol stack is defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functionality is described in section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in section 7 of TS 38.300.

[0209] For example, the Medium-Access-Control layer handles scheduling and scheduling-related functions, including the multiplexing of logical channels and the handling of various neural networks.

[0210] For example, the Physical Layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. The Physical Layer also handles the 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 particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include uplink physical channels such as PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), and downlink physical channels such as PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0211] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications (mMTC), each with diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps on the downlink and 10 Gbps on the uplink) and effective (user-experienced) data rates approximately three times that of IMT-Advanced. URLLC, on the other hand, imposes more stringent requirements for ultra-low latency (0.5 ms for both UL and DL for user plane latency) and high reliability (1-10⁻⁵ within 1 ms). Finally, mMTC preferably has a high connectivity density (1,000,000 devices / km² in urban environments). 2 ), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for low-cost devices may be required.

[0212] Therefore, an OFDM neurology suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may not be effective for other use cases. For example, low-latency services may preferably require a shorter symbol length (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with short delay spreads. The subcarrier spacing may be optimized on a case-by-case basis to maintain similar CP overhead. There may be one or more subcarrier spacing values ​​supported by NR. Accordingly, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc. are currently being 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.

[0213] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each neurology and each carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0214] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 11 shows the functional separation between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0215] For example, gNB and ng-eNB host the following main functions: - Functions of radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic allocation (scheduling) of resources to the UE in both the uplink and downlink; - IP header compression, encryption, and integrity protection of data; - Selection of the AMF at the time of UE attachment when it is not possible to determine the routing to the AMF from the information provided by the UE; - Routing of user plane data towards the UPF; - Routing of control plane information towards the AMF; - Setup and release of connections; - Scheduling and transmission of paging messages; - Scheduling and transmission of system information messages (source: AMF or operation, admission, maintenance function (OAM)); - Configuration of measurements and measurement reports for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Support for network slicing; - Management of QoS flows and mapping to data radio bearers; - Support for UEs in the RRC_INACTIVE state; - Delivery function of NAS messages; - Sharing of the radio access network; - Dual connectivity; - Tight cooperation between NR and E-UTRA.

[0216] The Access and Mobility Management Function (AMF) hosts the following main functions: - A function to terminate Non-Access Stratum (NAS) signaling; - Security of NAS signaling; - Security control of Access Stratum (AS); - Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; - Reachability of the UE in idle mode (including control and execution of paging retransmissions); - Management of registration areas; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming permission checks; - Mobility management and control (enrollment and policies); - Support for network slicing; - Selection of Session Management Function (SMF).

[0217] Furthermore, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT mobility / inter-RAT mobility (where applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Routing and forwarding of packets; - Packet inspection and enforcement of policy rules in the user plane. - Reporting traffic usage; - Uplink classifier to support routing of traffic flow to data networks; - Branching Point to support multi-homed PDU sessions; - 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.

[0218] 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) to route traffic to the appropriate destination; - Enforcement of control plane policies and QoS; - Notification of downlink data.

[0219] <Procedures for RRC connection setup and reconfiguration> Figure 12 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).

[0220] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. During this transition, the AMF prepares UE context data (including, for example, PDU session context, security key, UE Radio Capability, UE Security Capabilities, etc.) and sends it to the gNB along 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, to which the UE responds with a SecurityModeComplete message. Subsequently, the gNB sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures itself to set up the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, gNB notifies AMF that the setup procedure is complete with an Initial Context Setup Response.

[0221] Accordingly, this disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) comprising a control circuit that establishes a Next Generation (NG) connection with a gNodeB during operation, and a transmission unit that sends an initial context setup message to the gNodeB via the NG connection during operation so that a signaling radio bearer between the gNodeB and the user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling, including an Information Element (IE), to the UE via the signaling radio bearer. The UE then transmits on the uplink or receives on the downlink based on the resource allocation setting.

[0222] <IMT Usage Scenarios from 2020 Onward> Figure 13 shows some use cases for 5G NR. The 3rd generation partnership project for 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 specification development for enhanced mobile-broadband (eMBB) has been completed. Current and future work will include expanding eMBB support, as well as standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). Figure 13 shows some examples of conceptual use scenarios for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0223] URLLC use cases have strict requirements for performance such as throughput, latency (delay), and availability. The URLLC use case is envisioned as one of the enabling technologies to realize these future applications such as wireless control of industrial production processes or manufacturing processes, telemedicine surgery, automation of power transmission and distribution in smart grids, and traffic safety. The ultra-high reliability of URLLC is supported by identifying technologies that meet the requirements set by TR 38.913. In NR URLLC in Release 15, important requirements include that the target user plane latency is 0.5 ms in UL (uplink) and 0.5 ms in DL (downlink). The general URLLC requirement for a single packet transmission is that when the user plane latency is 1 ms, the block error rate (BLER) is 1E-5 for a packet size of 32 bytes.

[0224] From the perspective of the physical layer, reliability can be improved in many ways. The current room for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, repetition of PDCCH, etc. However, this room can expand for the realization of ultra-high reliability as NR becomes more stable and more developed (regarding the important requirements of NR URLLC). Specific use cases of NR URLLC in Release 15 include extended reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0225] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable neurology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level iteration on data channels, and preemption on downlink. Preemption means that a transmission for which a resource has already been allocated is stopped, and that allocated resource is used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, transmissions that were already permitted are replaced by later transmissions. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be replaced by a transmission of service type B (eMBB, etc.). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for the 1E-5 target BLER.

[0226] A key characteristic of mMTC (massive machine type communication) use cases is the extremely large number of connected devices that typically transmit relatively small amounts of data that are less susceptible to latency. These devices require low cost and very long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth is one solution that saves power from the user interface (UE) and extends battery life.

[0227] As mentioned above, the scope of reliability improvements in NR is expected to broaden. High reliability or very high reliability is a critical requirement in all cases, for example, for URLLC and mMTC. Several mechanisms can improve reliability from both a radio and 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 improvements regardless of the specific communication scenario.

[0228] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include high reliability (up to 10⁻⁶ levels), high availability, packet size up to 256 bytes, and time synchronization down to a few microseconds (depending on the use case, the value can be 1 microsecond or a few microseconds depending on the frequency range and short latency of approximately 0.5 ms to 1 ms (e.g., 0.5 ms latency in the target user plane)).

[0229] Furthermore, for NR URLLC, several technical enhancements are possible 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. Also, the enhancement of Uplink Control Information (UCI) is related to the enhancement of enhanced Hybrid Automatic Repeat Request (HARQ) and CSI feedback. In addition, enhancements to the Physical Uplink Shared Channel (PUSCH) related to mini-slot level hopping, and enhancements to retransmission / repetition may be possible. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0230] <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 (Guaranteed Bit Rate QoS flows, GBR) 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 of QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI) that is carried in an encapsulation header via the NG-U interface.

[0231] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearers (DRB) in accordance with the PDU session, as shown above, for example, referring to Figure 12. Additional DRBs for the QoS flow of that PDU session can be configured later (when this is done is up to the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0232] Figure 14 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (for example, an external application server hosting 5G services, as illustrated in Figure 13) interacts with the 3GPP core network to provide services. This may involve accessing the Network Exposure Function (NEF) to support applications that affect traffic routing, or interacting with the policy framework for policy control (e.g., QoS control) (see Policy Control Function (PCF)). Based on operator deployment, Application Functions considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions not authorized by the operator to directly access the Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0233] Figure 14 further illustrates the functional units of the 5G architecture, namely the 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 services, internet access, or third-party services). All or part of the core network functions and application services may be deployed and operate in a cloud computing environment.

[0234] Accordingly, the Disclosure provides an application server (e.g., AF in a 5G architecture) comprising: a transmitter that, in operation, transmits a request to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) that includes QoS requirements for at least one of the URLLC service, eMMB service, and mMTC service, in order to establish a PDU session including a radio bearer between the gNodeB and UE in accordance with QoS requirements; and a control circuit that, in operation, performs the service using the established PDU session.

[0235] This disclosure can be implemented in software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be implemented in part or in whole as an integrated circuit (LSI), and each process described in the above embodiments may be controlled in part or in whole by a single LSI or a combination of LSIs. An LSI may consist of individual chips, or it may consist of a single chip that includes some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs.

[0236] The method of integration is not limited to LSIs; it may also be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (Field Programmable Gate Arrays) that can be programmed after LSI manufacturing, or reconfigurable processors that allow for the reconfiguration of the connections and settings of circuit cells within the LSI, may also be used. This disclosure may be implemented as digital or analog processing.

[0237] Furthermore, if advancements in semiconductor technology or related technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, these technologies could be used to integrate functional blocks. The application of biotechnology, for example, is a possible possibility.

[0238] This disclosure is applicable to all types of devices, systems, and equipment having communication capabilities (collectively referred to as communication equipment). Communication equipment may include a radio transceiver and a processing / control circuit. A radio transceiver may include a receiver and a transmitter, or both as functions. A radio transceiver (transmitter, receiver) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or similar. Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, vehicles or mobile transport with communication capabilities (cars, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0239] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0240] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0241] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0242] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment.

[0243] A communication device according to one embodiment of the present disclosure comprises a control circuit that determines the data size based on information relating to the number of repetitions of a transmission signal and at least one of the scaling factors of the unit data size in the repetitions, and a transmission circuit that transmits the transmission signal based on the data size.

[0244] In one embodiment of the present disclosure, the information indicates the number of time intervals for the repetition.

[0245] In one embodiment of the present disclosure, the control circuit determines the data size based on the number of iterations when retransmission control is applied, and not based on the number of iterations when retransmission control is not applied.

[0246] In one embodiment of the present disclosure, the control circuit determines the data size based on the scaling factor when the iteration is applied, and not based on the scaling factor when the iteration is not applied.

[0247] In one embodiment of the present disclosure, the control circuit determines the data size based on the scaling factor in the retransmission process to which the iteration is applied among a plurality of retransmission processes.

[0248] In one embodiment of the present disclosure, if the communication device is a terminal, the terminal receives the information from a base station, and if the communication device is a base station, the base station transmits the information to the terminal.

[0249] In one embodiment of the present disclosure, the scaling factor is defined in the information relating to time-domain resource allocation.

[0250] In one embodiment of the present disclosure, the scaling factor is defined in information that includes scaling factors for paging and random access.

[0251] In one embodiment of the present disclosure, the scaling factor is an integer or decimal value of 1 or more.

[0252] In one embodiment of the present disclosure, the control circuit determines the number of groups of code blocks obtained by dividing the data contained in the transmission signal based on the information.

[0253] In one embodiment of the present disclosure, the control circuit determines the amount of resources for the response signal to the data based on the number of groups.

[0254] A communication device according to one embodiment of the present disclosure comprises a control circuit that determines the data size based on information relating to the number of repetitions of a received signal and at least one of the scaling factors of the unit data size in the repetitions, and a receiving circuit that receives the received signal based on the data size.

[0255] In a communication method according to one embodiment of the present disclosure, the communication device determines the data size based on information relating to the number of repetitions of the transmission signal and at least one of the scaling factors of the unit data size in the repetitions, and transmits the transmission signal based on the data size.

[0256] In a communication method according to one embodiment of the present disclosure, the communication device determines the data size based on information relating to the number of repetitions of the received signal and at least one of the scaling factors of the unit data size in the repetitions, and receives the received signal based on the data size.

[0257] A communication device according to one embodiment of the present disclosure comprises a control circuit that determines the data size based on information regarding the number of time intervals used for a transmission signal, and a transmission circuit that transmits the transmission signal based on the data size.

[0258] In one embodiment of the present disclosure, the control circuit determines the data size based on the number of resource elements allocated to the transmission signal in the time interval used for the transmission signal.

[0259] In one embodiment of the present disclosure, the number of time intervals corresponds to the number of repetitions of the transmitted signal.

[0260] All disclosures in the specifications, drawings, and abstracts included in the Japanese applications 2020-176833, filed on October 21, 2020, and 2021-005151, filed on January 15, 2021, are incorporated herein by reference. [Industrial applicability]

[0261] One aspect of this disclosure is useful for wireless communication systems. [Explanation of Symbols]

[0262] 100,100a base station 101,205 Transmission data generation unit 102 Data Encoding and Modulation Section 103,207 Repetition part 103a, 207a Mapping section 104 Control Information Generation Unit 105 Control Information Encoding and Modulation Section 106,208 Wireless Transmitter 107,201 Wireless receiver 108,203 Data demodulation / decoding section 109 Control CH Demodulation / Decoding Section 110 ACK / NACK judgment section 200,200a terminal 202 Control Information Demodulation / Decoding Unit 204 ACK / NACK generation section 206 Encoding and Modulation Section

Claims

1. A control circuit that determines the transport block size based on information about the number of slots used to process a single transport block spanning multiple slots, A transmission circuit that transmits the single transport block across the multiple slots in the PUSCH (Physical Uplink Shared Channel) based on the transport block size, It is equipped with, The total number of resource elements allocated to the PUSCH is determined by multiplying the number of slots, the number of resource blocks allocated to the PUSCH, and the number of resource elements per resource block. The transport block size is determined by adjustments based on the value of an intermediate variable calculated by the sum of the resource elements. The number of slots is set separately from the number of repetitions of the single transport block. Communication device.

2. The control circuit determines the size of the single transport block based on the number of resource elements. The communication device according to claim 1.

3. The number of slots is set in accordance with the number of repetitions of the single transport block. The communication device according to claim 1.

4. The aforementioned information is set by RRC (Radio Resource Control) signaling. The communication device according to claim 1.

5. The control circuit, in determining the transport block size, is based on the number of slots when the single transport block is transmitted across the multiple slots, and not on the number of slots when the single transport block is not transmitted across the multiple slots. The communication device according to claim 1.

6. The communication device is a terminal, and the terminal receives the information from the base station. The communication device according to claim 1.

7. The number of the aforementioned slots is an integer or a decimal. The communication device according to claim 1.

8. Communication equipment, Based on information regarding the number of slots used to process a single transport block spanning multiple slots, the transport block size is determined. Based on the transport block size, the single transport block is transmitted across the multiple slots in the PUSCH (Physical Uplink Shared Channel). The total number of resource elements allocated to the PUSCH is determined by multiplying the number of slots, the number of resource blocks allocated to the PUSCH, and the number of resource elements per resource block. The transport block size is determined by adjustments based on the value of an intermediate variable calculated by the sum of the resource elements. The number of slots is set separately from the number of repetitions of the single transport block. Communication method.

9. An integrated circuit that controls the processing of a communication device, wherein the processing is A process to determine the transport block size based on information about the number of slots used to process a single transport block spanning multiple slots, Based on the transport block size, the process involves transmitting the single transport block across the multiple slots in the PUSCH (Physical Uplink Shared Channel), Includes, The total number of resource elements allocated to the PUSCH is determined by multiplying the number of slots, the number of resource blocks allocated to the PUSCH, and the number of resource elements per resource block. The transport block size is determined by adjustments based on the value of an intermediate variable calculated by the sum of the resource elements. The number of slots is set separately from the number of repetitions of the single transport block. Integrated circuit.

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