Terminal, base station, and communication method

Abstract

The present invention repeatedly transmits a downlink signal in an appropriate manner. The terminal comprises: a control circuit that determines a repeated transmission setting for a downlink signal that is transmitted before individual terminal settings become available, on the basis of a setting of another signal different from the downlink signal; and a communication circuit that receives the downlink signal on the basis of the repeated transmission setting.

Description

Terminal, Base Station, and Communication Method

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

[0002] New radio access technology (NR) for 5G has been standardized by 3GPP, and specifications up to Release 18 (Rel.18) of NR have been issued.

[0003] 3GPP, TR 38.821, V16.1.0 “Solutions for NR to support non-terrestrial networks (NTN) (Release 16)”

[0004] However, there is room for consideration regarding the method of repeatedly transmitting downlink signals.

[0005] Non-limiting examples of the present disclosure contribute to providing a terminal, a base station, and a communication method that can appropriately perform repeated transmission of downlink signals.

[0006] A terminal according to an embodiment of the present disclosure includes a control circuit that determines a setting for repeated transmission of a downlink signal transmitted before individual settings of the terminal become available, based on a setting of another signal different from the downlink signal, and a communication circuit that receives the downlink signal based on the setting for repeated transmission.

[0007] These general or specific aspects may be implemented in a system, apparatus, method, integrated circuit, computer program, or recording medium, or may be implemented in any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0008] According to an embodiment of the present disclosure, repeated transmission of downlink signals can be appropriately performed.

[0009] Further advantages and effects in an embodiment of the present disclosure will be clarified from the specification and drawings. Such advantages and / or effects are provided by some embodiments and the features described in the specification and drawings, respectively, but not all are necessarily provided in order to obtain one or more identical features.

[0010] Block diagram showing some example configurations of a terminal Block diagram showing some example configurations of a base station Block diagram showing an example configuration of a terminal Block diagram showing an example configuration of a base station Diagram showing an example of an initial access procedure Flowchart showing an example of terminal operation Diagram of an exemplary architecture of a 3GPP NR system Diagram of exemplary functional partitioning in G O-RAN

[0011] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings.

[0012] NR Rel.15 is specified as a wireless access technology for terrestrial networks. 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) (see, for example, Non-Patent Document 1).

[0013] In satellite-based communications, the long distance between the satellite and the terminal (also known as user equipment (UE)) makes propagation attenuation more likely. To achieve sufficiently high reception quality on the satellite, methods such as repeatedly transmitting multiple data points at the terminal (e.g., repetition transmission) are expected. Similarly, in ground-based communications, for example, when using high-frequency radio waves such as millimeter waves, or when communicating with terminals located underground, in shelters, or in tunnels, attenuation due to distance or reflection / diffraction is likely to be significant, making the use of repetition transmission a desirable method.

[0014] In specifications (or standards) up to Rel.18, repetition was mainly introduced for uplinks, including repetition in RRC CONNECTED mode, and random access channels (PRACH: Physical Random Access Channel) in RRC IDLE / INACTIVE mode, PUSCH (Physical Uplink Shared Channel) for Msg3 (Msg3 PUSCH), and PUCCH (Physical Uplink Control Channel) for Msg4 (Msg4 PUCCH).

[0015] Rel.19 considers, for example, extensions for NTN, such as support for repetition on downlinks in RRC IDLE / INACTIVE mode. Specifically, it is being considered to apply repetition to PDCCH using Common Search Space (CSS), PDSCH (Physical Downlink Shared Channel) for SIB1 (System Information Block 1), and PDSCH for Msg4 (Msg4 PDSCH).

[0016] Msg4 PDSCH is sent to individual terminals performing initial access during the initial access procedure. In specifications up to Rel.18, the PDSCH repetition count (e.g., repetition factor) can be communicated through terminal-specific signaling (configuration). However, because Msg4 PDSCH is a signal or channel sent before terminal-specific signaling becomes available (or terminal-specific configuration becomes effective), it is difficult for terminals to determine whether repetition is used (or applied) to Msg4 PDSCH.

[0017] Furthermore, when applying Msg4 PDSCH repetition, the base station is expected to obtain information on whether or not the terminal supports Msg4 PDSCH repetition.

[0018] In one non-limiting embodiment of this disclosure, a method for notifying information regarding Repetition to Msg4 PDSCH (for example, whether or not the base station applies Repetition, or whether or not the terminal supports Repetition) is described.

[0019] For example, in one non-limiting embodiment of the present disclosure, a network (e.g., a base station) implicitly notifies whether or not to use (apply) the Msg4 PDSCH repetition using information or features of other signals (e.g., information about other coverage extension techniques such as the PDCCH repetition or SIB1-PDSCH repetition). For example, the base station may implicitly notify whether or not to use the Msg4 PDSCH repetition using information indicating whether or not to use other coverage extension techniques. The base station may also notify information about the number of repetitions of the Msg4 PDSCH repetition, for example, in association with the number of repetitions of the Msg4 PUCCH repetition.

[0020] In addition, in one non-limiting embodiment of this disclosure, the terminal may notify its terminal capability (UE capability) for Msg4 PDSCH repetition together with (for example, together with) its terminal capability for Msg4 PUCCH repetition.

[0021] As a result, according to one non-limiting embodiment of this disclosure, the base station can notify the terminal of information regarding whether or not Msg4 PDSCH repetition is used (applied), or the number of repetitions, with less notification information. In addition, the terminal can notify the base station of whether or not Msg4 PDSCH repetition is supported, with less information.

[0022] [Overview of the communication system] A communication system according to one embodiment of the present disclosure comprises a terminal 100 and a base station 200.

[0023] Figure 1 is a block diagram showing a partial configuration example of terminal 100. In terminal 100 shown in Figure 1, the control unit (e.g., corresponding to a control circuit) determines the repetition setting (e.g., whether or not to apply repetition or the number of repetitions) for downlink signals (e.g., Msg4 PDSCH) transmitted before terminal-specific settings become available, based on the settings of other signals different from the downlink signal (e.g., signals using other coverage extension techniques). The communication unit (e.g., corresponding to a communication circuit) receives the downlink signal based on the repetition setting.

[0024] Figure 2 is a block diagram showing a partial configuration example of a base station 200. In the base station 200 shown in Figure 2, the control unit (corresponding to, for example, a control circuit) determines the repetition setting (e.g., whether or not to apply repetition or the number of repetitions) for the downlink signal (e.g., Msg4 PDSCH) transmitted before terminal 100 can use terminal-specific settings, based on the settings of other signals different from the downlink signal (e.g., signals using other coverage extension techniques). The communication unit (corresponding to, for example, a communication circuit) transmits the downlink signal based on the repetition setting.

[0025] In one embodiment of the present disclosure, a network (e.g., a base station 200) implicitly notifies a terminal 100 of the settings for Msg4 PDSCH repetition (e.g., whether it is applied or the number of repetitions) using the settings for other coverage extension techniques (e.g., PDCCH repetition or SIB1-PDSCH repetition) (e.g., whether it is applied or the number of repetitions). The terminal 100 notifies the base station 200 of information regarding the terminal capabilities for Msg4 PDSCH, together with the terminal capabilities for Msg4 PUCCH repetition.

[0026] [Example of terminal configuration] Figure 3 is a block diagram showing an example of the configuration of a terminal 100 according to one embodiment of the present disclosure. The terminal 100 includes a wireless receiving unit 101, a receiving processing unit 102, a control unit 103, a transmission processing unit 104, and a wireless transmitting unit 105.

[0027] Furthermore, at least one of the receiving processing unit 102, control unit 103, and transmitting processing unit 104 shown in Figure 3 may be included in the control unit shown in Figure 1. Also, at least one of the wireless receiving unit 101 and wireless transmitting unit 105 shown in Figure 3 may be included in the communication unit shown in Figure 1.

[0028] The wireless receiving unit 101 performs analog reception processing such as down-conversion, A / D conversion, and filtering on the signal received from the base station 200 via the antenna, and digital reception processing, and outputs it to the receiving processing unit 102.

[0029] The receiving processing unit 102 demodulates and decodes the downlink received signal (for example, SSB, PDSCH, or PDCCH) input from the wireless receiving unit 101 based on information about downlink signal resources such as SSB (Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Block), PDSCH, or PDCCH input from the control unit 103.

[0030] The SSB may include, for example, a synchronization signal and broadcast information for the entire cell.

[0031] PDSCH may include, for example, user data, as well as broadcast information such as system information, RRC control information, MAC CE (Medium Access Control Control Element) control information, RACH (Random Access Channel) responses (e.g., Msg2), Msg4, etc.

[0032] PDCCH may include, for example, resource allocation information for PDSCH, resource allocation information for PUSCH, resource allocation information for PUCCH used for transmitting HARQ-ACK (response signal) to PDSCH, and information for MCS used for PDSCH or PUSCH.

[0033] Furthermore, the receiving processing unit 102 may perform receiving processing of the PDSCH based on resource allocation information, such as the number of resource blocks (RBs) or repetitions included in the PDCCH.

[0034] The receiving processing unit 102 extracts user data from the received signal and outputs it as received data, and outputs other signals (control information) that are different from the user data to the control unit 103.

[0035] The control unit 103 sets up transmission or reception settings based on control information input from the reception processing unit 102. For example, the control unit 103 may determine whether or not there is a possibility of Msg4 PDSCH repetition transmission based on the "coverage extension flag" contained in the MIB (Master Information Block) information contained in the SSB. The coverage extension flag may be information indicating that the cell is compatible with Msg4 PDSCH repetition transmission, information indicating whether or not it is compatible with at least one coverage extension technology, or information indicating whether or not it is compatible with all coverage extension technologies. Coverage extension technologies may include, for example, extension to an SSB transmission period longer than 20ms (SSB extension), PDCCH repetition on CSS, SIB1-PDSCH repetition, PRACH repetition, Msg3 PUSCH repetition, Msg4 PUCCH repetition, or Msg4 PDSCH repetition.

[0036] Furthermore, the control unit 103 generates information indicating whether or not the terminal 100 supports Msg4 PDSCH repetition as a UE capability and outputs it to the transmission processing unit 104. For example, the information indicating whether or not Msg4 PDSCH repetition is supported as a UE capability may be associated with at least one other coverage extension technology. For example, at least one other coverage extension technology and Msg4 PDSCH repetition may be notified of UE capability as common information. As an example, if terminal 100 supports Msg4 PDSCH repetition, the terminal 100 may also support Msg4 PUCCH repetition, and the terminal 100 may notify the base station 200 of Msg4 PDSCH repetition and Msg4 PUCCH repetition as a single UE capability.

[0037] Furthermore, when the control unit 103 notifies the base station 200 that the terminal 100 is responsive to Msg4 PDSCH repetition, it may not notify terminal capability information if the received signal level of the signal from the base station 200 (e.g., RSRP (Reference Signal Received Power)) is below a threshold (or less than or equal to the threshold), but may not notify terminal capability information if the received signal level of the signal from the base station 200 is above a threshold (or greater than the threshold). The threshold may also be the same threshold used for Msg4 PUCCH repetition, or it may be notified by SIB1. The threshold for Msg4 PDSCH repetition may be different from the threshold for Msg4 PUCCH repetition.

[0038] Furthermore, terminal capability information regarding Msg4 PDSCH repetition may be transmitted using PRACH or Msg3 PUSCH. Alternatively, terminal capability information regarding Msg4 PDSCH repetition may be transmitted, for example, using PRACH or Msg3 PUSCH, and then transmitted as an RRC message using PUSCH after transitioning to the RRC CONNECTED state.

[0039] The control unit 103 may determine whether or not a cell corresponds to Msg4 PDSCH repetition (or whether or not repetition is applied to Msg4 PDSCH) based on the frequency (carrier frequency) at which the SSB was detected. For example, the control unit 103 may determine that a cell corresponds to Msg4 PDSCH repetition if the frequency at which the SSB was detected is a frequency associated with Msg4 PDSCH repetition (for example, the Global Synchronization Channel Number (GSCN) or a frequency band for NTN).

[0040] Furthermore, the control unit 103 acquires information regarding downlink signal resources such as SSB, PDSCH, or PDCCH from the control information input from the receiving processing unit 102, and outputs it to the receiving processing unit 102.

[0041] The transmission processing unit 104 performs encoding such as LDPC (Low Density Parity Check) on the transmission data, performs modulation such as QPSK and 16QAM (Quadrature Amplitude Modulation), DFT-s-OFDM modulation processing, etc., and outputs to the wireless transmission unit 105. For example, the transmission processing unit 104 may map the transmission data to time / frequency resources based on information related to PUSCH or PUCCH resource allocation input from the control unit 103, information related to Repetition (e.g., the number of Repetitions, etc.). Also, for example, the transmission processing unit 104 may generate DMRS based on information related to antenna ports or DMRS (Demodulation Reference Signal) ports and output it to the wireless transmission unit 105.

[0042] The wireless transmission unit 105 performs analog transmission processing and digital transmission processing such as D / A conversion, filtering, up-conversion, and amplification on the signal input from the transmission processing unit 104, and transmits the wireless signal from the antenna.

[0043] [Configuration example of base station] FIG. 4 is a block diagram showing an example of the configuration of a base station 200 according to an embodiment of the present disclosure. The base station 200 includes a wireless reception unit 201, a reception processing unit 202, a control unit 203, a transmission processing unit 204, and a wireless transmission unit 205.

[0044] Note that at least one of the reception processing unit 202, control unit 203, and transmission processing unit 204 shown in FIG. 4 may be included in the control unit shown in FIG. 2. Also, at least one of the wireless reception unit 201 and wireless transmission unit 205 shown in FIG. 4 may be included in the communication unit shown in FIG. 2.

[0045] The wireless reception unit 201 performs analog reception processing and digital reception processing such as down-conversion, A / D conversion, and filtering on the signal of the terminal 100 received via the antenna, and outputs to the reception processing unit 202.

[0046] The reception processing unit 202 performs channel estimation and demodulation / decoding processing on uplink signals such as PUSCH, PUCCH, and PRACH input from the radio reception unit 201 based on settings such as reception resources input from the control unit 203. The reception processing unit 202 may, for example, extract the received data included in the PUSCH. Further, the reception processing unit 202 may output the RRC message included in the PUSCH to the control unit 203. The RRC message may include, for example, information on terminal capabilities related to coverage extension techniques. Also, the reception processing unit 202 may, for example, determine the terminal capabilities of Msg4 PDSCH repetition based on the terminal capabilities related to other coverage extension techniques. For example, the reception processing unit 202 may determine that the terminal 100 supports Msg4 PDSCH repetition if it supports the terminal capabilities of one or more specific coverage extension techniques (e.g., PDCCH repetition and SIB1 PDSCH repetition). On the other hand, the reception processing unit 202 may determine that the terminal 100 does not support Msg4 PDSCH repetition if it does not support the terminal capabilities of one or more specific coverage extension techniques.

[0047] Note that the information on these terminal capabilities is not limited to the RRC message and may be included in at least one of, for example, PRACH, MAC CE of Msg3 PUSCH, RRC message, and other uplink signals.

[0048] The control unit 203 generates control information such as system information (notification information) such as MIB and SIB and terminal-specific control information (e.g., RRC message).

[0049] System information may include, for example, configuration information for SSB, PDCCH, PDSCH, PUCCH, PUSCH, etc., which are commonly used by terminals within a cell. Here, system information may include configuration information including whether the base station 200 (or cell) supports PDCCH repetition for Common search space (CSS) and the number of repetitions, or configuration information including whether it supports Msg4 PUCCH repetition or Msg4 PDSCH repetition and the number of repetitions. In addition, MIB may include information about resources for PDCCH or SIB1 PDSCH to receive SIB1, repetition information for PDCCH (type0-PDCCH) to which SIB1 PDSCH is assigned, and repetition information for SIB1-PDSCH.

[0050] Furthermore, RRC messages may include configuration information such as PDCCH, PDSCH, PUCCH, and PUSCH, which are used individually by each terminal.

[0051] Furthermore, the control unit 203 generates Downlink Control Information (DCI) or PDCCH associated with PDSCH transmission. The DCI may include, for example, information related to PDSCH retransmission control such as NDI (New Data Indicator) and RV (Redundancy Version), information related to the MCS (Modulation and Coding Scheme) of PDSCH and PUSCH, resource allocation information for PDSCH and PUSCH (e.g., including RB or Repetition count), and resource allocation information or Repetition count information for PUCCH used for HARQ-ACK transmission to PDSCH.

[0052] The control unit 203 outputs this control information to the transmission processing unit 204, and also outputs setting values ​​related to the uplink signal based on the control information (for example, PUSCH and PUCCH resources, number of repetitions, number of TBoMS (Transport Block processing over Multiple Slots) slots, TDW (Time Domain Window) for DMRS bundling, etc.) to the reception processing unit 202.

[0053] The transmission processing unit 204 performs encoding such as polar coding and LDPC coding on the transmission data and control information input from the control unit 203, modulates them in the form of QPSK and 16QAM, and outputs them to the wireless transmission unit 205.

[0054] The wireless transmission unit 205 performs transmission processing such as D / A conversion, filtering, upconversion, and amplification on the signal input from the transmission processing unit 204, and transmits the wireless signal from the antenna.

[0055] [Examples of Terminal and Base Station Operation] The following describes examples of notification of coverage extension settings and terminal capability reporting, using the initial access procedure for establishing a link between terminal 100 and base station 200, such as when terminal 100 is powered on, as an example.

[0056] Figure 5 shows an example of the initial access procedure.

[0057] <S1> The base station 200 periodically transmits SSB. The SSB includes, for example, Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS) signals for synchronization, and Broadcast Channel (BCH). The BCH transmits, for example, MIB. The terminal 100 searches for the SSB by changing the frequency across candidate carrier frequencies. By receiving the SSB, the terminal 100 obtains time and frequency synchronization and the cell ID, and obtains information from the MIB such as resources for PDCCH (type0-PDCCH) or SIB1 PDSCH for receiving SIB1.

[0058] Furthermore, terminal 100 obtains information from the MIB, for example, that indicates whether or not it supports repeat transmission of type0-PDCCH or SIB1 PDSCH (for example, whether or not repeat transmission is applied). Terminal 100 identifies, for example, whether or not the corresponding cell or base station 200 supports repeat transmission of type0-PCCCH or SIB1 PDSCH based on the information contained in the MIB.

[0059] Furthermore, the MIB may include, for example, a coverage extension flag indicating whether or not coverage extension techniques are used. Coverage extension techniques may include, for example, at least one of SSB transmission period extension (SSB extension), PDCCH repetition on CSS, SIB1-PDSCH repetition, Msg4 PUCCH repetition, and Msg4 PDSCH repetition. The coverage extension flag may, for example, associate the application of Msg4 PDSCH repetition with the application of at least one of PDCCH repetition on CSS, SIB1-PDSCH repetition, PRACH repetition, Msg3 PUSCH repetition, and Msg4 PUCCH repetition. Based on the MIB information, terminal 100 identifies (understands) whether the corresponding cell or base station 200 supports coverage extension techniques. For example, terminal 100 may determine whether or not to apply Msg4 PDSCH repetition based on the coverage extension flag, based on whether or not at least one of the following is applied in the CSS: PDCCH repetition, SIB1-PDSCH repetition, PRACH repetition, Msg3 PUSCH repetition, and Msg4 PUCCH repetition.

[0060] In addition, instead of or in conjunction with an MIB (e.g., an explicit notification), the base station 200 may notify (e.g., implicitly) whether or not coverage extension technology is applied based on information regarding the SSB frequency (carrier frequency) or PSS / SSS sequence number detected at the terminal 100. For example, some frequencies out of a group of frequencies (e.g., frequency bands for a specific GSCN or NTN) or some PSS / SSS sequence numbers out of a group of PSS / SSS sequence numbers may be associated with the application of coverage extension technology, while other frequencies or other PSS / SSS sequence numbers may be associated with the non-application of coverage extension technology.

[0061] Terminal 100 may determine, for example, that the corresponding cell or base station 200 supports coverage extension technology if the frequency or PSS / SSS sequence number from which SSB was detected is a specific frequency or PSS / SSS sequence number (for example, a frequency or PSS / SSS sequence number associated with the application of coverage extension technology).

[0062] Alternatively, the base station 200 may include the coverage extension flag in the MIB when using some of the multiple frequencies (carrier frequencies) or multiple PSS / SSS sequence numbers, but may not include the coverage extension flag in the MIB when using other frequencies or other PSS / SSS sequence numbers.

[0063] Terminal 100 may, for example, determine whether coverage extension technology is used depending on the frequency or PSS / SSS sequence in which the SSB was detected, or determine whether a coverage extension flag is included in the MIB.

[0064] <S2, S3> The base station 200 transmits a scrambled PDCCH (type0-PDCCH) using SI-RNTI (System Information - Radio Network Temporary Identifier) ​​over the CSS, and transmits an SIB1-PDSCH using the resources indicated by the PDCCH. These resources for the PDCCH and PDSCH may be identifiable, for example, from MIB information. When coverage expansion is performed, the base station 200 may apply PDCCH repetition or SIB1-PDSCH repetition.

[0065] If terminal 100 determines that PDCCH repetition is applicable based on MIB information or information on the frequency at which SSB was detected, it may, for example, combine multiple PDCCH resources (e.g., two slots or two Control Resource Sets (CORESET)) to perform blind decoding of the PDCCH.

[0066] Furthermore, instead of determining whether PDCCH repetition is performed based on MIB information, terminal 100 may determine this by blind decoding of the PDCCH. For example, terminal 100 may perform blind decoding using two PDCCH resources (e.g., two slots or two CORESETs), and if a PDCCH is detected, it may determine that PDCCH repetition is performed, and also determine that other coverage extension techniques are being used.

[0067] In this case, terminal 100 may decide whether or not to apply Msg4 PDSCH repetition based on whether or not PDCCH repetition is applied as determined by blind decoding of PDCCH.

[0068] <S4, S5> The base station 200 transmits a PDCCH (e.g., type0A-PDCCH) on the CSS to transmit another SIB different from SIB1. The base station 200 also transmits a PDSCH (e.g., another SIB PDSCH) using the resources indicated by the PDCCH. In cells where coverage expansion is performed, the base station 200 may apply repeat transmission to at least one of the type0A-PDCCH and the SIB PDSCH.

[0069] <S6> After receiving SIB1 and the SIB used for initial access, terminal 100 transmits PRACH (Msg1) to base station 200.

[0070] Terminal 100 may, for example, notify base station 200 of terminal capability (UE capability) related to coverage extension technology using PRACH. For example, terminal 100 may notify base station 200 of terminal capability information by selecting a PRACH sequence associated with terminal capability.

[0071] In this case, terminal 100 may notify the terminal capabilities of Msg4 PDSCH repetition together with other features. For example, terminal 100 may determine a common terminal capability between Msg4 PUCCH repetition and Msg4 PDSCH repetition (for example, a single value or parameter combining Msg4 PUCCH repetition and Msg4 PDSCH repetition) and notify base station 200. As another example, terminal 100 may notify base station 200 of a common terminal capability with at least one of the following: SSB transmission period extension, PDCCH repetition on CSS, SIB1-PDSCH repetition, PRACH repetition, and Msg3 PUSCH repetition. Furthermore, terminal 100 may notify of its terminal capability for Msg4 PDSCH repetition (and Msg4 PUCCH repetition) if the RSRP level measured using SSB or PDSCH is below a threshold, and may not notify of its terminal capability for Msg4 PDSCH repetition (and Msg4 PUCCH repetition) if the RSRP level is above the threshold. The RSRP level threshold may be, for example, the threshold notified by rsrp-ThresholdMsg4HARQ-ACK-r18 for Msg4 PUCCH repetition, or a threshold defined (for example, newly defined) for Msg4 PDSCH.

[0072] <S7, S8> When the base station 200 detects a PRACH from the terminal 100, it sends a RACH response (RAR: Random Access Response) (Msg2) to the terminal 100.

[0073] Here, the base station 200 transmits RACH responses using PDCCH (for example, PDCCH scrambled using RA-RNTI (Random Access - RNTI)) and PDSCH (for example, also called Msg2 PDSCH). If the base station 200 determines, for example, that terminal 100 supports coverage expansion based on detected PRACH resources, it may apply repeat transmission to at least one of the PDCCH and PDSCH. The base station 200 may also set the number of repeats for the PDCCH and PDSCH based, for example, on a value notified by SIB1.

[0074] <S9> When terminal 100 receives a RACH response, it sends Msg3 PUSCH.

[0075] The MAC CE included in Msg3 PUSCH may include at least one of the following as terminal capabilities of terminal 100: information indicating whether or not it supports Msg4 PUCCH repetition, and information indicating whether or not it supports Msg4 PDSCH repetition (for example, common terminal capability). Here, in cells that support coverage expansion, Msg3 PUSCH may also notify whether or not it supports both Msg4 PUCCH repetition and Msg4 PDSCH repetition.

[0076] <S10, S11> When base station 200 receives Msg3 PUSCH, it transmits PDCCH (for example, type1-PDCCH) and Msg4 PDSCH to terminal 100.

[0077] In cells that support coverage extension, if base station 200 receives coverage-enabled terminal capability from terminal 100 via MAC CE of PRACH or Msg3 PUSCH, it may apply a repetition transmission to the PDCCH and / or PDSCH for terminal 100. In other words, if terminal 100 notifies of coverage-enabled terminal capability via MAC CE of PRACH or Msg3 PUSCH, it may receive a PDCCH and / or PDSCH with a repetition transmission applied from base station 200.

[0078] Examples of how to notify users of the Repeat Factor will be discussed later.

[0079] <S12> When terminal 100 receives Msg4 PDSCH, it notifies base station 200 of a HARQ-ACK for Msg4 PDSCH using Msg4 PUCCH. Here, in cells that support coverage extension, terminal 100 may apply Msg4 PUCCH repetition.

[0080] The above explains the notification of coverage extension settings and provides an example of terminal capability reporting.

[0081] In one embodiment of this disclosure, the base station 200 notifies the terminal 100 of the support for multiple coverage extension technologies (e.g., whether or not a coverage extension technology is applied) using, for example, a coverage extension flag. This reduces the amount of information required to notify the support for multiple coverage extension technologies. Furthermore, by notifying the support for multiple coverage extension technologies collectively, the terminal 100 and the base station 200 do not need to consider the combination of support or non-support (or application or non-application) for each coverage extension technology, thereby simplifying system or terminal operation.

[0082] Furthermore, in one embodiment of this disclosure, terminal 100 notifies base station 200 of the terminal capability of Msg4 PDSCH repetition together with other functions (for example, by associating them). This makes it possible to reduce the amount of information required to notify terminal capability. Also, when terminal capability is notified by PRACH, there may be a method for dividing (distinguishing) PRACH resources (for example, timing or sequence) according to the terminal capability, but in one embodiment of this disclosure, for example, the number of PRACH resource divisions can be reduced by associating the terminal capability of Msg4 PDSCH repetition with other terminal capabilities. As a result, for example, a sufficient number of PRACH sequences (number of PRACH resources) can be secured per notification information, and the probability of PRACH collisions between terminals can be reduced.

[0083] <Notification Method for the Number of Repeats of Msg4 PDSCH repetition> Next, we will explain an example of how to notify the number of repeats of Msg4 PDSCH repetition.

[0084] The base station 200 may, for example, notify the number of repetitions for Msg4 PDSCH in association with the number of repetitions for other channels.

[0085] For example, base station 200 may notify the repetition count of Msg4 PDSCH and the repetition count of Msg4 PUCCH in association. The repetition count may be notified by SIB (e.g., SIB1) or by PDCCH (or DCI) that notifies the allocation information of Msg4 PDSCH. PDCCH that notifies the allocation information of Msg4 PDSCH is, for example, a PDCCH that is scrambled by TC-RNTI (Temporary C-RNTI).

[0086] Terminal 100 may, for example, determine the number of repetitions of Msg4 PDSCH based on its association with the number of repetitions of Msg4 PUCCH.

[0087] The following describes an example of how to notify the number of repeats for Msg4 PUCCH.

[0088] <Notification Method 1> In Notification Method 1, the number of repetitions for Msg4 PDSCH is notified as a relative value to the number of repetitions for Msg4 PUCCH. For example, in the association between the number of repetitions for Msg4 PDSCH and the number of repetitions for Msg4 PUCCH, the number of repetitions for Msg4 PDSCH is set as a relative value to the number of repetitions for Msg4 PUCCH.

[0089] The relative value of the repetition count for Msg4 PUCCH may be a scaling value, for example. In Rel.18, for example, one or more candidates for the repetition count of Msg4 PUCCH are notified by SIB1. If there is one candidate, terminal 100 sends Msg4 PUCCH using the repetition count corresponding to the candidate. If there are multiple candidates, base station 200 notifies the repetition count of one of the candidates by the DAI (Downlink Assignment Index) field of the PDCCH to which Msg4 PDSCH is assigned.

[0090] In this embodiment, the number of repetitions of Msg4 PDSCH may be indicated by a relative value (e.g., a scaling value) to the number of repetitions of Msg4 PUCCH.

[0091] For example, information indicating how many times the number of repetitions of Msg4 PDSCH is compared to the number of repetitions of Msg4 PUCCH (e.g., N times, N=1 / 4, 1 / 2, 1, 2, 4) may be notified as a relative value. This information about N may be notified to terminal 100 by SIB1. For example, if there is one candidate for the number of repetitions of Msg4 PUCCH notified by SIB1, terminal 100 sets the number of repetitions of Msg4 PDSCH to be the number obtained by multiplying the number of repetitions of Msg4 PUCCH corresponding to the candidate by N. If there are multiple candidates for the number of repetitions of Msg4 PUCCH, terminal 100 sets the number of repetitions of Msg4 PDSCH to be the number obtained by multiplying the number of repetitions of Msg4 PUCCH (one of the multiple candidates) notified by the DAI field of PDCCH by N.

[0092] Note that N can be expressed as an integer, a fraction, or a decimal.

[0093] Furthermore, multiple values ​​of N may be set. Multiple N values ​​may be notified by SIB1, and which one to use may be notified by the PDCCH to which Msg4 PDSCH is assigned.

[0094] <Notification Method 2> In Notification Method 2, candidate combinations of the number of repetitions of Msg4 PDSCH and the number of repetitions of Msg4 PUCCH are notified by SIB1.

[0095] For example, in associating the number of repetitions of Msg4 PDSCH with the number of repetitions of Msg4 PUCCH, multiple candidate combinations of the number of repetitions of Msg4 PDSCH and the number of repetitions of Msg4 PUCCH may be set. Terminal 100 may, for example, set one of the multiple candidate combinations.

[0096] For example, base station 200 may notify terminal 100 of four candidate combinations of {Repetition count of Msg4 PUCCH, Repetition count of Msg4 PDSCH}: {1, 2} {2, 2} {4, 4} {8, 4}. Then, base station 200 notifies terminal 100 of the candidate combination to be used from among the multiple candidate combinations by the DAI field of the PDCCH to which Msg4 PDSCH is assigned. For example, the four candidate combinations of the number of repetitions mentioned above may be associated with DAI=00, 01, 10, and 11, respectively.

[0097] Furthermore, the information used to notify the terminal 100 of the candidate combination from among multiple candidates is not limited to the information in the DAI field, but may be other information.

[0098] Alternatively, the base station 200 may use an existing Information Element (IE) (e.g., Rel.18) and a new IE to notify the number of repetitions for Msg4 PUCCH and Msg4 PDSCH, respectively, as follows: Number of repetitions for Msg4 PUCCH: 1, 2, 4, 8 (IEs similar to Rel.18) Number of repetitions for Msg4 PDSCH: 2, 2, 4, 4 (Newly introduced IEs)

[0099] The base station 200 then notifies the terminal 100 of the candidate to be used from among several candidates by the DAI field of the PDCCH to which Msg4 PDSCH is assigned. For example, the elements of the Repeat Number of Msg4 PUCCH and Msg4 PDSCH may be associated with DAI=00, 01, 10, and 11 respectively. This makes it possible to notify the combinations of the Repeat Number of Msg4 PDSCH and the Repeat Number of Msg4 PUCCH as {1, 2}, {2, 2}, {4, 4}, and {8, 4}.

[0100] The number of repetitions of Msg4 PUCCH may also be notified, for example, by numberOfMsg4HARQ-ACK-Repetitions-r18.

[0101] Furthermore, if there is only one candidate for the number of repetitions of Msg4 PUCCH, the number of repetitions of Msg4 PDSCH (one of the candidates) may be notified by the DAI field if multiple candidates are set.

[0102] Furthermore, the base station 200 may notify existing terminals (for example, terminals with Rel.18 or earlier) of the number of repetitions of existing Msg4 PUCCH messages, and may separately notify terminals with Rel.19 or later that support coverage extension functions of the number of repetitions of both Msg4 PUCCH and Msg4 PDSCH messages.

[0103] The above explains an example of how to notify the number of repeats.

[0104] As a result, in one embodiment of this disclosure, the amount of information and overhead used to notify the Repetition setting (e.g., the number of repetitions) of Msg4 PDSCH can be reduced. Furthermore, since the number of repetitions of Msg4 PDSCH can be notified by a common bit in the DAI field of the PDCCH used to notify the number of repetitions of Msg4 PUCCH, an increase in the number of PDCCH (DCI) bits can be prevented. Note that terminals 100 in environments where Msg4 PDSCH repetition is applied (e.g., terminals 100 at the edge of the coverage area) are likely to also be applied to Msg4 PUCCH repetition. Therefore, even if the number of repetitions of Msg4 PDSCH is notified in association with the number of repetitions of Msg4 PUCCH, the flexibility of notification is unlikely to be impaired.

[0105] Figure 6 is a flowchart showing an example of the operation of terminal 100.

[0106] In Figure 6, terminal 100 performs SSB search and MIB reception (S101, S102).

[0107] Terminal 100 determines whether or not it is a coverage extension cell (for example, a cell that performs DL coverage extension) based on, for example, the frequency at which the SSB was detected and at least one of the pieces of information notified by the MIB (S103).

[0108] If it is not a coverage extension cell (S103: No), terminal 100 receives the SIB1 (not shown) according to an existing method (e.g., Rel. 18) and triggers the initial access procedure (i.e., sends a PRACH) (S104).

[0109] Terminal 100 performs RACH response processing for PRACH (not shown), receives PDCCH scrambled with TC-RNTI (S105), and receives Msg4 PDSCH (S106). At this point, terminal 100 determines that no repetition has been applied to Msg4 PDSCH and accepts Msg4 PDSCH.

[0110] On the other hand, if it is a coverage extension cell (S103: Yes), terminal 100 receives information regarding the repetition of Msg4 PDSCH in SIB1, for example (S107). The information regarding the repetition of Msg4 PDSCH may include, for example, a relative value (e.g., a scaling value) to the number of repetitions of Msg4 PUCCH.

[0111] Terminal 100 notifies base station 200 of its terminal capabilities regarding Msg4 PDSCH Repetition, for example, using PRACH (e.g., trigger for initial access procedure) (S108). Here, terminal capabilities regarding Msg4 PDSCH Repetition may be notified in combination with (for example, as common) terminal capabilities of other coverage extension technologies such as Msg4 PUCCH repetition.

[0112] Terminal 100 performs RACH response processing for PRACH (not shown) and receives PDCCH scrambled with TC-RNTI (S109). Here, terminal 100 identifies the number of repetitions of Msg4 PDSCH repetition based on the value notified by the DAI field included in PDCCH. Terminal 100 receives Msg4 PDSCH (S110). Here, terminal 100 performs Msg4 PDSCH repetition using the identified number of repetitions.

[0113] As described above, in one embodiment of the present disclosure, the base station 200 determines the Repetition setting for the Msg4 PDSCH transmitted to the terminal 100 before terminal-specific settings become available, based on the setting of another signal different from the Msg4 PDSCH (e.g., PDCCH, SIB1-PDSCH, or Msg4 PUCCH), and transmits the Msg4 PDSCH based on the determined Repetition setting. The terminal 100 also determines the Repetition setting for the Msg4 PDSCH transmitted before terminal-specific settings become available, based on the setting of another signal different from the Msg4 PDSCH (e.g., PDCCH, SIB1-PDSCH, or Msg4 PUCCH), and receives the Msg4 PDSCH based on the determined Repetition setting.

[0114] This allows terminal 100 to identify the Repetition settings for Msg4 PDSCH (e.g., whether or not to apply, or the number of repetitions) that are sent before terminal-specific settings become available. Furthermore, base station 200 can obtain information regarding whether or not the terminal supports Msg4 PDSCH repetition when applying Msg4 PDSCH repetition.

[0115] Therefore, according to one embodiment of the present disclosure, repeated transmission of downlink signals can be performed appropriately.

[0116] While the example described associates the repeat count of Msg4 PDSCH with the repeat count of Msg4 PUCCH, the example is not limited to this. The repeat count of Msg4 PDSCH may also be associated with the repeat count of other channels or signals such as PDCCH, SIB1-PDSCH, PRACH, or Msg3 PUSCH. The association of repeat counts can be done in various ways, such as setting the same repeat count, notifying a relative value, or using a scaling factor. For example, associating Msg4 PDSCH with the repeat count of a channel on the same downlink (e.g., PDCCH or SIB1-PDSCH) allows for the use of a repeat count suitable for the cell's propagation environment.

[0117] One embodiment of the present disclosure has been described above.

[0118] In the above embodiment, the Repetition of Msg4 PDSCH was described, but it is not limited to this. The Msg4 PDSCH repetition may be interpreted as, for example, a PDSCH sent before entering the RRC_CONNECTED state, a PDSCH assigned by a PDCCH on the Common Search Space (CSS), or a PDSCH until an individual RRC configuration is received. Furthermore, the same number of repetitions as for Msg4 PDSCH may be applied to these PDSCHs.

[0119] Furthermore, in the above embodiment, Msg4 PUCCH repetition may be interpreted as a PUCCH sent before entering the RRC_CONNECTED state, a PUCCH sending a HARQ-ACK to a PDSCH assigned by a PDCCH on the Common Search Space (CSS), or a PUCCH received until an individual RRC configuration is received. Additionally, the same repetition count as Msg4 PUCCH may be applied to these PUCCHs.

[0120] Furthermore, in the above embodiment, the notification regarding coverage expansion in the MIB may be a Reserve area not used up to Rel.18, another area, or a combination of multiple areas. Also, the notification regarding coverage expansion in the MIB may be an existing area that may not be used, among other areas of the MIB.

[0121] Furthermore, the above embodiment may be applied to cells that are accessible to terminals that support coverage extension technology (for example, Rel.19 terminals that support NTN) but not to terminals that do not support coverage extension technology. A cell accessible to terminals that support coverage extension technology may be, for example, a cell that transmits an SSB with a period longer than the default SSB period of 20ms assumed by terminals prior to Rel.18. In this case, since terminal 100 accessing the cell supports coverage extension technology, it does not need to notify terminal capabilities regarding coverage extension using PRACH or the like.

[0122] Furthermore, in the above embodiment, the case in which the repetition count is notified by at least one of the PDCCHs scrambled in SIB1 and TC-RNTI was described, but it may also be notified by a channel or signal different from the PDCCHs scrambled in SIB1 and TC-RNTI.

[0123] Furthermore, in the above embodiment, we described a case in which the number of repetitions of Msg4 PDSCH (or the number of repetitions of Msg4 PUCCH) is notified in the DAI field of PDCCH scrambled by TC-RNTI. However, the field that notifies the number of repetitions of Msg4 PDSCH (or the number of repetitions of Msg4 PUCCH) may be a field other than the DAI field.

[0124] Another example of a field is the MCS field. In cases where coverage expansion is required, high MCS levels are less likely to be used, so the value of the MCS field indicating the area with a high MCS level may be used to notify the number of repetitions.

[0125] Another example of a field is the Time Domain Resource Allocation (TDRA) field. The TDRA field is a field that notifies time domain resource allocation information. For example, it may be notified using a table that defines the number of repetitions along with information about the slots and symbols used for PDSCH transmission (e.g., existing parameters).

[0126] Another example of a field could be a notification field for the number of HARQ processes. In the initial access procedure, it is unlikely that a large amount of data will be sent in parallel, so it is not expected that a large number of HARQ processes will be used. Therefore, using the notification field for the number of HARQ processes in the Msg4 PDSCH repetition notification will have little impact on HARQ processing.

[0127] Another example of a field could be the PDSCH-to-HARQ timing indicator field, which indicates the timing of HARQ-ACK transmission. Since it is acceptable to reduce the flexibility of HARQ-ACK transmission in the initial access procedure, using the PDSCH-to-HARQ timing indicator field to notify the number of repetitions in Msg4 PDSCH will have little impact on HARQ processing.

[0128] Furthermore, in the above embodiment, Msg4 PDSCH may be a channel used for RACH contention resolution. Also, Msg4 PDSCH may be a channel whose allocation is notified by a PDCCH scrambled with TC-RNTI.

[0129] Furthermore, in the above embodiment, the transmission unit of Repetition may be a slot, a symbol, or any other time unit.

[0130] Furthermore, although the above embodiment described coverage extension techniques such as Msg4 PDSCH Repetition, TBoMS or DMRS bundling, which involve transmission using multiple slots, may also be used.

[0131] Furthermore, although the above embodiments were described using Rel.18 and Rel.19 as examples, the above embodiments are applicable to any release and generation of communication systems. For example, in the above description, a Rel.18 terminal may be read as a terminal prior to Rel.18, and a Rel.19 terminal may be read as a terminal from Rel.19 onwards. Also, in the above description, existing terminals and Rel.18 terminals may be read as terminals that do not support coverage extension technology or type0-PDCCH repetition. Also, in the above description, a Rel.19 terminal may be read as a terminal that supports coverage extension technology or type0-PDCCH repetition.

[0132] Furthermore, in the above embodiment, notification of information indicating whether or not coverage expansion is supported, notification of terminal capabilities, and notification of the number of repetitions of Msg4 PDSCH have been described. However, the terminal 100 and base station 200 do not have to perform all of these actions, and may perform any of them.

[0133] Furthermore, the term "base station" may be interpreted as "network" or "RAN (Radio Access Network)."

[0134] Furthermore, while the above embodiment is suitable for cases requiring broad coverage, such as NTN, it may also be applied to networks other than NTN. For example, when using high frequencies such as millimeter waves in a terrestrial network, the coverage area can be expanded by using a broad beam for data common to all terminals and a narrow beam for data specific to each terminal. In this case, one embodiment of the present disclosure may be applied to improve the coverage area of ​​a broad beam.

[0135] The method of notifying control information from the base station 200 to the terminal 100 is not limited to the example described above, and may be notified (or broadcast, instructed, or set) by at least one of system information such as MIB and SIB, RRC control information, MAC control information, or downlink control information (DCI), or it may be set in advance in the terminal 100, or it may be specified in advance in the standard.

[0136] A base station may be referred to as a gNodeB or gNB. A terminal may be referred to as a UE.

[0137] Time resource units such as symbols and slots may be replaced with system frames, time slots, mini-slots, frames, subframes, etc. Furthermore, when applying TBoMS, instead of using individual slots as the transmission unit, a TBoMS slot (a collection of multiple slots) may be used as the transmission unit.

[0138] Furthermore, the parameters used in the above embodiment (including, for example, the number of slots, slot number, number of coresets, number of repetitions, and aggregation level) are merely examples, and other values ​​may be set.

[0139] Furthermore, the notation "...part" in the above-described embodiment may be replaced with other notations such as "...circuit," "...device," "...unit," or "...module."

[0140] (Supplement) Information indicating whether or not the terminal 100 supports the functions, operations, or processes described in the above-described embodiment may be transmitted (or notified) from the terminal 100 to the base station 200 as, for example, capability information or capability parameters of the terminal 100.

[0141] The capability information may include an information element (IE) that individually indicates whether the terminal 100 supports at least one of the functions, operations, or processes shown in the embodiments described above. Alternatively, the capability information may include an information element that indicates whether the terminal 100 supports any two or more combinations of the functions, operations, or processes shown in the embodiments described above.

[0142] The base station 200 may, for example, determine (or decide or assume) which functions, operations, or processes the source terminal 100 supports (or does not support) based on capability information received from the terminal 100. The base station 200 may perform operations, processes, or controls in accordance with the determination result based on the capability information. For example, the base station 200 may control communication based on capability information received from the terminal 100.

[0143] Furthermore, the fact that terminal 100 does not support some of the functions, operations, or processes shown in the embodiments described above may be interpreted as the terminal 100 having restrictions on such some functions, operations, or processes. For example, information or requests regarding such restrictions may be notified to base station 200.

[0144] Information regarding the capabilities or limitations of terminal 100 may, for example, be defined in a standard, or it may be implicitly communicated to base station 200 in association with information known to base station 200 or information transmitted to base station 200.

[0145] (Control Signals) In this disclosure, the downlink control signals (or downlink control information) relating to one embodiment of this disclosure may be, for example, signals (or information) transmitted in a Physical Downlink Control Channel (PDCCH) at the physical layer, or signals (or information) transmitted in a Medium Access Control Control Element (MAC CE) or Radio Resource Control (RRC) at a higher layer. Furthermore, the signals (or information) are not limited to being notified by downlink control signals, but may be predetermined in a specification (or standard), or may be pre-configured in base stations and terminals.

[0146] 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.

[0147] (Base Station) In one embodiment of the present 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 side-link communication, the terminal may assume the role of a base station. Alternatively, instead of a base station, there may be a relay device that relays communication between the upper node and the terminal. There may also be a roadside unit.

[0148] (Uplink / Downlink / Sidelink) An embodiment of the present disclosure may be applied to, for example, an uplink, a downlink, or a sidelink. For example, an embodiment of the present disclosure may be applied to a Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Physical Random Access Channel (PRACH) of an uplink, a Physical Downlink Shared Channel (PDSCH), PDCCH, Physical Broadcast Channel (PBCH) of a downlink, or a Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), Physical Sidelink Broadcast Channel (PSBCH) of a sidelink.

[0149] 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.

[0150] (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.

[0151] (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).

[0152] (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 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 Access (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.

[0153] (Frequency Band) One embodiment of the present disclosure may be applied to either a licensed band or an unlicensed band.

[0154] (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.

[0155] 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.

[0156] (SBFD) In ​​one embodiment of the present disclosure, the operation for uplink, downlink, and sidelink symbols may also be applied to symbols (e.g., SBFD symbols) on which SBFD (Subband non-overlapping full duplex, Subband full duplex) operation or control is performed. In an SBFD symbol, a frequency domain (or frequency resource, frequency band) is divided into multiple frequency domains (e.g., also called subbands, RB sets, subbands, or sub-BWPs (Bandwidth parts)). A terminal transmits and receives in different directions (e.g., downlink or uplink) on a subband basis. In an SBFD symbol, a terminal may transmit and receive in either the uplink or downlink direction only, and not in the other direction. On the other hand, a base station may be able to transmit and receive both uplink and downlink simultaneously. An SBFD symbol may have a smaller frequency domain available for downlink transmission compared to a symbol that transmits and receives only downlink. Similarly, an SBFD symbol may have a smaller frequency domain available for uplink transmission compared to a symbol that transmits and receives only uplink.

[0157] Furthermore, in the SBFD symbol, a terminal may transmit and receive both uplink and downlink simultaneously. In this case, the frequency domains in which the terminal transmits and the frequency domains in which it receives may not be adjacent, and a frequency gap (also called a frequency interval) may be maintained between them.

[0158] Furthermore, sidelink transmission and reception may be included as different transmission and reception directions for each subband unit, which is a divided region.

[0159] (XDD: cross division duplex) In one embodiment of the present disclosure, the operation for uplink, downlink, and sidelink symbols may be applied to symbols (e.g., full duplex symbols) on which full duplex operation or control is performed. In full duplex symbols, both the terminal and the base station can transmit and receive uplink and downlink simultaneously. In full duplex symbols, the terminal and base station may transmit and receive simultaneously in the available frequency domain (or frequency resource, frequency band), or they may transmit and receive simultaneously in some frequency domains (i.e., they may transmit or receive in other frequency domains). In this case, the frequency domain on which the base station or terminal transmits and the frequency domain on which it receives may not be adjacent, and a frequency gap (also called a frequency gap) may be maintained between them. Alternatively, for example, to reduce interference, either the terminal or the base station may transmit and receive simultaneously (i.e., the other may transmit or receive).

[0160] Furthermore, full duplex operation may be applied to operations where the terminal can simultaneously transmit and receive sidelinks. Also, full duplex operation may be applied to operations where the terminal can simultaneously transmit and receive sidelinks and uplinks or downlinks.

[0161] (Antenna Port) In one embodiment of the present 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. An antenna port may also be defined as the smallest unit on which the weighting of a precoding vector is multiplied.

[0162] <5G NR System Architecture and Protocol Stack> The 5G NR 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 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 the AMF) by NG-C interfaces, and to the UPF (User Plane Function) (e.g., a specific core entity performing the UPF) by NG-U interfaces. The NG-RAN architecture is shown in Figure 7 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0163] <RRC Connection Setup and Reconfiguration Procedure> This describes the communication between the UE, gNB, and AMF (5GC entity) when the UE transitions from RRC_IDLE to RRC_CONNECTED in the NAS section (see TS 38.300 v15.6.0).

[0164] RRC is a higher-layer signaling (protocol) used for configuring the UE and gNB. The AMF prepares the UE context data (which includes, for example, the 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, and the UE responding to the gNB 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 SRB2 and DRB are not set up, so the RRCReconfiguration step is omitted. Finally, the gNB notifies the AMF that the setup procedure is complete with an Initial Context Setup Response.

[0165] 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 gNodeB during operation, and a transmission unit that sends an initial context setup message to gNodeB via the NG connection during operation so that a signaling radio bearer between gNodeB and User Equipment (UE) is set up. Specifically, gNodeB transmits Radio Resource Control (RRC) signaling, including a Resource Allocation Setting 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.

[0166] <QoS Control> The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows where a guaranteed flow bit rate is required (GBR: Guaranteed Bit Rate QoS flows) and QoS flows where a guaranteed flow bit rate is not required (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity of QoS within a PDU session. QoS flows are identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) carried in the encapsulation header via the NG-U interface.

[0167] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes, for example, at least one Data Radio Bearers (DRB) in accordance with the PDU session. 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 packets and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL QoS flows and DL QoS flows with DRBs.

[0168] (Open-RAN) The base station described in each embodiment (for example, a 5G NR base station called a gNB) may consist of three functional modules: a Centralized Unit (CU), a Distributed Unit (DU), and a Radio Unit (RU).

[0169] CU may be referred to as, for example, a central node, aggregation node, central station, aggregation station, or central unit. DU may be referred to as, for example, an O-DU (O-RAN Distributed Unit), a distributed node, a distributed station, or a distributed unit. RU may be referred to as, for example, an O-RU (O-RAN Radio Unit), a radio device, a radio node, a radio station, an antenna unit, or a radio unit.

[0170] The functional division configuration (or functional division point) between CU, DU, and RU has multiple division options defined. The term "functional division point" is sometimes referred to as "split," "option," or "split option."

[0171] Examples of "splitting options" include the following splitting options 1 to 8. The functions of the base station described in each embodiment may be split into CU, DU, and RU functions according to any of the following splitting options 1 to 8. For example, CU, DU, and RU may be functionally split individually, or functional split may occur only between CU and DU, or only between DU and RU. (1) Splitting option 1: Between RRC (radio resource control) and PDCP (2) Splitting option 2: Between PDCP and RLC (High-RLC) (3) Splitting option 3: Between High-RLC and Low-RLC (4) Splitting option 4: Between RLC (Low-RLC) and MAC (High-MAC) (5) Splitting option 5: Between High-MAC and Low-MAC (6) Splitting option 6: Between MAC (Low-MAC) and PHY (High-PHY) (7) Splitting option 7: Between High-PHY and Low-PHY (8) Splitting option 8: Between PHY (Low-PHY) and RF

[0172] The functional division point between the CU and O-DU may be Split Option 2. The section between the CU and O-DU is called the midhaul, and the F1 interface is defined by 3GPP. The section between the O-DU and O-RU is called the fronthaul, and its functional division point may be Split Option 7-2x, which has been adopted as the O-RAN fronthaul specification.

[0173] Figure 8 shows an example of splitting the base station functions of gNB into CU, O-DU, and O-RU using Split Option 2 and Split Option 7-2x.

[0174] The CU may, for example, include RRC (radio resource control) functionality, SDAP (service data adaptation protocol) functionality, and PDCP (packet data convergence protocol) functionality.

[0175] The O-DU may include, for example, RLC (radio link control) functionality, MAC functionality, and high-level physical layer (HIGH-PHY) functionality. The HIGH-PHY functionality may also include encoding functionality, scrambling functionality, modulation functionality, layer mapping functionality, precoding functionality, and RE (resource element) mapping functionality for downlink (DL) transmission. The HIGH-PHY functionality may also include decoding functionality, descrambling functionality, demodulation functionality, layer demapping functionality, and RE (resource element) demapping functionality for uplink (UL) reception.

[0176] The O-RU may, for example, be equipped with a LOW-PHY function and an RF function. The LOW-PHY function may also be equipped with a beamforming function, an IFFT (Inverse First Fourier Transform) + CP (Cyclic Prefix) application function, and a D / A (Digital to Analog) conversion function for downlink transmission. The LOW-PHY function may also be equipped with an A / D (Analog to Digital) conversion function, a CP removal + FFT (First Fourier Transform) function, and a beamforming function for uplink reception.

[0177] If the O-DU does not have a precoding function, the O-RU may have a precoding function.

[0178] The O-RU may also be equipped with LBT (listen before talk) functionality. In Split Option 7-2x, eCPRI (Evolved Common Public Radio Interface) is specified as the communication method between the O-DU and O-RU. In Split Option 7-2x, eCPRI transmits and receives not only the sampling sequence of the in-phase (I) and quadrature (Q) components of the OFDM signal in the frequency domain, but also information used for beamforming in the antenna and time synchronization signals.

[0179] The information transmitted by the signals described in each embodiment (PDCCH, PUCCH, PDSCH, PUSCH, MAC CE, RRC, etc.) may be transmitted between the O-DU and O-RU via the eCPRI's User Plane (U-Plan) or Control Plane (C-Plane).

[0180] If the functions described in each embodiment are executed in the O-RU by functional partitioning, the O-DU may control the O-RU by transmitting information for controlling the functions via a control signal (e.g., eCPRI) between the O-DU and the O-RU.

[0181] If the functions described in each embodiment are executed in the O-DU by functional partitioning, the O-RU may receive the result of the execution of the function in the O-DU via a control signal (e.g., eCPRI) and control the O-RU based on the received result.

[0182] The CU, O-DU, and O-RU may be deployed in physically different devices connected by optical fibers or the like, or some or all of their functions may be deployed in the same physical device.

[0183] CU and O-DU may be logical entities implemented as software running on a server such as a cloud, as a virtualized RAN (virtual Radio Access Network: vRAN). Furthermore, some or all of the functions of CU and O-DU may be provided as a service of virtualized network functions (NFV).

[0184] The transceiver does not have to be a wireless transceiver; for example, it may be a network transceiver, an optical transceiver, etc. The wireless resources allocated by the O-DU may be resources for wireless communication between the O-RU and the UE.

[0185] This disclosure can be implemented using software, hardware, or software integrated with hardware.

[0186] Each functional block used in the description of the above embodiments may be implemented partially or entirely as an integrated circuit (LSI), and each process described in the above embodiments may be controlled partially or entirely 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 also be referred to as ICs, system LSIs, super LSIs, or ultra LSIs.

[0187] The integrated circuit implementation method is not limited to LSIs; it may also be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, a Field Programmable Gate Array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that allows 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.

[0188] Furthermore, if advancements in semiconductor technology or related technologies lead to the emergence of integrated circuit technologies that can replace LSIs, then naturally, these technologies can be used to integrate functional blocks. The application of biotechnology, for example, is a possibility.

[0189] 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. The radio transceiver may include a receiver and a transmitter, or both as functions. The 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.

[0190] 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 fixtures, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0191] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0192] 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.

[0193] 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.

[0194] A terminal according to one embodiment of the present disclosure comprises a control circuit that determines the setting for repeated transmission of a downlink signal transmitted before terminal-specific settings become available, based on the setting of another signal different from the downlink signal, and a communication circuit that receives the downlink signal based on the setting for repeated transmission.

[0195] In one embodiment of this disclosure, the setting for repeated transmission is a setting for whether or not to apply the repeated transmission.

[0196] In one embodiment of the present disclosure, the downlink signal is the Msg4 signal in the initial access procedure, the other signal is the downlink control signal, the response signal to the Msg4 signal, and at least one of the SIB1 (System Information Block 1), and the control circuit determines whether or not to apply the repeated transmission to the Msg4 signal based on whether or not to apply the repeated transmission to the downlink control signal, the response signal, and at least one of the SIB1.

[0197] In one embodiment of the present disclosure, the setting for repeated transmission is the setting for the number of repeated transmissions.

[0198] In one embodiment of the present disclosure, the downlink signal is a Msg4 signal in an initial access procedure, the other signal is a response signal to the Msg4 signal, and the control circuit determines the first number of repeated transmissions of the Msg4 signal based on its association with a second number of repeated transmissions of the response signal.

[0199] In one embodiment of the present disclosure, in the association, the first number is set as a relative value to the second number.

[0200] In one embodiment of the present disclosure, in the association, a plurality of candidate combinations of the first number and the second number are set, and the control circuit sets one of the plurality of candidates.

[0201] In one embodiment of the present disclosure, the setting for repeated transmission is the setting for the terminal capability of repeated transmission.

[0202] In one embodiment of the present disclosure, the downlink signal is a Msg4 signal in the initial access procedure, the other signal is a response signal to the Msg4 signal, the control circuit determines a common terminal capability for the repeated transmissions to the Msg4 signal and the repeated transmissions to the response signal, and the communication circuit transmits information regarding the common terminal capability to the base station.

[0203] A base station according to one embodiment of the present disclosure comprises a control circuit that determines a setting for repeated transmission of a downlink signal transmitted before a terminal can use its individual settings, based on the settings of another signal different from the downlink signal, and a communication circuit that transmits the downlink signal based on the setting for repeated transmission.

[0204] In a communication method according to one embodiment of the present disclosure, the terminal determines a setting for repeated transmission of a downlink signal that is transmitted before the terminal's individual settings become available, based on the settings of another signal different from the downlink signal, and receives the downlink signal based on the setting for repeated transmission.

[0205] In a communication method according to one embodiment of the present disclosure, the base station determines a setting for repeated transmission of a downlink signal that is transmitted before the terminal's individual settings become available, based on the settings of another signal different from the downlink signal, and transmits the downlink signal based on the setting for repeated transmission.

[0206] All disclosures in the specification, drawings, and abstract contained in the Japanese application No. 2025-017703, filed on February 5, 2025, are incorporated herein by reference.

[0207] One aspect of this disclosure is useful for wireless communication systems.

[0208] 100 Terminal 101, 201 Wireless receiving unit 102, 202 Receiving processing unit 103, 203 Control unit 104, 204 Transmitting processing unit 105, 205 Wireless transmitting unit 200 Base station

Claims

A control circuit that determines the setting for repeated transmission of a downlink signal transmitted before terminal-specific settings become available, based on the settings of other signals different from the downlink signal, Based on the setting for repeated transmission, a communication circuit receives the downlink signal, A terminal equipped with the following. 　 The setting for repeated transmission is a setting to determine whether or not to apply the repeated transmission. The terminal according to claim 1. 　 The aforementioned downlink signal is the Msg4 signal in the initial access procedure, The other signals are at least one of the downlink control signal, the response signal to the Msg4 signal, and SIB1 (System Information Block 1). The control circuit determines whether or not to apply the repeated transmission to the Msg4 signal based on whether or not to apply the repeated transmission to at least one of the downlink control signal, the response signal, and the SIB1. The terminal according to claim 2. 　 The setting for repeated transmission is the setting for the number of times repeated transmissions are performed. The terminal according to claim 1. 　 The aforementioned downlink signal is the Msg4 signal in the initial access procedure, The other signals are response signals to the Msg4 signal, The control circuit determines the first number of repeated transmissions for the Msg4 signal based on its association with the second number of repeated transmissions for the response signal. The terminal according to claim 4. 　 In the aforementioned association, the first count is set as a relative value to the second count. The terminal according to claim 5. 　 In the association described above, a plurality of candidate combinations of the first number and the second number are set. The control circuit sets one of the plurality of candidates. The terminal according to claim 5. 　 The setting for repeated transmission is the setting for the terminal's capabilities for repeated transmission. The terminal according to claim 1. 　 The aforementioned downlink signal is the Msg4 signal in the initial access procedure, The other signals are response signals to the Msg4 signal, The control circuit determines the common terminal capability for the repeated transmission of the Msg4 signal and the repeated transmission of the response signal, The communication circuit transmits information regarding the common terminal capabilities to the base station. The terminal according to claim 8. 　 A control circuit that determines the setting for repeated transmission of a downlink signal transmitted before the terminal's individual settings become available, based on the settings of other signals different from the downlink signal, A communication circuit that transmits the downlink signal based on the repeat transmission setting, A base station equipped with the following. 　 The device is, The setting for repeated transmission of downlink signals, which are transmitted before individual terminal settings become available, is determined based on the settings of other signals different from the downlink signal. Based on the repeat transmission setting, the downlink signal is received. Communication method. 　 The base station is, The terminal determines the setting for repeated transmission of a downlink signal that is transmitted before terminal-specific settings become available, based on the settings of other signals different from the downlink signal. Based on the repeat transmission setting, the downlink signal is transmitted. Communication method.

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