Terminal, base station, transmission method, reception method, and integrated circuit

Abstract

To achieve appropriate timing control according to a propagation delay between a terminal and a base station.SOLUTION: A control circuit configured to control an uplink transmission timing using one of a first offset and a second offset based on information related to a control signal used for scheduling, the first offset being a cell-specific offset and the second offset being an offset based on the cell-specific offset and a terminal-specific offset, the information related to the control signal being a RadioNetworkTemporaryIdentifier (RNTI) of control information related to downlink data transmission; When scheduling is performed by downlink control information using an RNTI different from the C-RNTI, the uplink transmission timing is controlled based on the first offset.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

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

[0003] [Non-Patent Document 1] 3GPP, TR 38.821, V16.0.0 “Solutions for NR to support non-terrestrial networks (NTN) (Release 16)”, 2019-12 [Non-patent document 2] 3GPP, TS 38.321, V16.2.0 “Medium Access Control (MAC) protocol specification (Release 15)”, 2020-09 Summary of the Invention

[0004] However, there is room for further study on appropriate timing control according to the propagation delay between the terminal and the base station.

[0005] Non-limiting examples of the present disclosure contribute to providing a terminal, a base station, a transmission method, and a reception method that can realize appropriate timing control according to the propagation delay between the terminal and the base station.

[0006] A terminal according to one embodiment of the present disclosure includes a control circuit that controls uplink transmission timing using either a first offset or a second offset shorter than the first offset based on information related to a control signal for scheduling, and a transmission circuit that performs uplink transmission based on the control of the uplink transmission timing.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to an embodiment of the present disclosure, it is possible to realize appropriate timing control according to the propagation delay between a terminal and a base station.

[0009] Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0010] [Figure 1] A diagram showing an example of a four-step random access procedure [Figure 2] FIG. 10 is a diagram showing an example of timing adjustment based on terminal position information and satellite orbit information; [Figure 3] FIG. 10 is a diagram showing an example of transmission slot timing. [Figure 4] Block diagram showing an example of the configuration of a part of a terminal [Figure 5] Block diagram showing an example of the configuration of a portion of a base station [Figure 6] FIG. 1 is a block diagram showing an example of a configuration of a terminal according to a first embodiment; [Figure 7] FIG. 1 is a block diagram showing an example of a configuration of a base station according to a first embodiment; [Figure 8]FIG. 10 is a diagram showing an example of a sequence chart relating to timing control in the first embodiment. [Figure 9] FIG. 10 is a diagram showing an example of timing adjustment using a cell-specific TA offset value and a timing adjustment value based on location information. [Figure 10] FIG. 10 is a diagram showing an example of timing adjustment using each TA including TA command 2. [Figure 11] FIG. 10 is a diagram showing an example of timing adjustment using information including Kadj and UE. [Figure 12] FIG. 10 is a diagram showing an example of a sequence chart relating to timing control in the second embodiment. [Figure 13] FIG. 11 is a flowchart showing an example of timing control according to the third embodiment. [Figure 14] Diagram of an example architecture of a 3GPP NR system [Figure 15] Schematic diagram showing functional separation between NG-RAN and 5GC [Figure 16] Sequence diagram of RRC connection setup / reconfiguration procedure [Figure 17] Schematic diagram showing usage scenarios for enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Figure 18] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario DETAILED DESCRIPTION OF THE INVENTION

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

[0012] [Expansion to non-terrestrial networks (NTN)] Release 15 (Rel. 15) of the new radio access technology (NR) is specified as a radio access technology for terrestrial networks. Meanwhile, NR is being considered for extension to non-terrestrial networks (NTN), such as communications using satellites and / or high-altitude platform stations (HAPS) (see, for example, Non-Patent Document 1). In an NTN environment, for example, a terminal and a base station communicate wirelessly via a satellite. Hereinafter, the wireless link between the terminal and the satellite may be referred to as a "service link," and the wireless link between the satellite and the base station may be referred to as a "feeder link."

[0013] In an NTN environment, a satellite's coverage area (e.g., one or more cells) for a terrestrial or aircraft terminal is formed by beams from the satellite. The round-trip time for radio wave propagation between the terminal and the satellite is determined by the satellite's altitude (e.g., up to approximately 36,000 km) and / or the angle as seen from the terminal, i.e., the relative positions of the satellite and the terminal. When a base station is installed in a terrestrial gateway (GW), the round-trip time for radio wave propagation between the base station and the terminal is the sum of the round-trip time for radio wave propagation between the satellite and the terrestrial gateway.

[0014] For example, NTN discloses in Non-Patent Document 1 that the round trip time (RTT) of radio wave propagation between a base station and a terminal is approximately 540 ms at most. Non-Patent Document 1 also discloses that a maximum delay difference of approximately 10 ms occurs depending on the location of the terminal within the beam (within the cell). The maximum delay difference refers to, for example, the difference between the round trip time between the terminal located farthest from a satellite and the satellite within the beam (within the cell) and the round trip time between the terminal located closest to the satellite and the satellite.

[0015] [Random Access Procedure] In 5G NR, a terminal performs transmission using a random access channel for initial access, data transmission requests, etc. For example, the random access procedure is performed by a four-step random access (also called a 4-step Random Access Channel (RACH) or a 4-step Contention Based Random Access (CBRA)).

[0016] FIG. 1 is a diagram showing an example of a four-stage random access procedure. In four-stage random access, for example, as shown in FIG. 1, a terminal (UE: User Equipment) transmits a preamble signal of a PRACH (Physical Random Access Channel) to a base station (gNB) in the first stage of transmission (MSG1). MSG1 transmission in the terminal is performed at a transmission timing (slot timing or RACH Occasion) notified by the base station for each cell. Note that, hereinafter, transmitting a PRACH signal (e.g., a preamble signal) may be abbreviated as "PRACH transmission" or "transmitting PRACH." Note that, hereinafter, receiving a PRACH signal may be abbreviated as "PRACH reception" or "receiving PRACH." Note that transmission and reception of signals of other channels may also be abbreviated in the same manner.

[0017] The base station receives and decodes MSG1, and in the second stage of transmission (MSG2), notifies the terminal of a Random Access response (RAR) to the preamble signal of the PRACH and scheduling information including the uplink transmission timing of MSG3.

[0018] The terminal receives and decodes MSG2, and in a third-stage transmission (MSG3), uses the scheduling information indicated by MSG2 to notify the base station of information for establishing a connection, such as information about the terminal (e.g., a terminal ID). MSG3 is notified, for example, on a PUSCH (Physical Uplink Shared Channel). The information notified by MSG3 may be referred to as RRC (Radio Resource Control) connection request information.

[0019] The base station receives and decodes MSG3, and in the fourth transmission (MSG4), sends a response to establish a connection, etc.

[0020] [Timing adjustment] In 5G NR, the transmission timing of terminals is controlled so that signals from different terminals in a cell fall within a certain time period at a base station. For example, the certain time period is within the CP (Cyclic Prefix) of an Orthogonal Frequency Division Multiplexing (OFDM) signal or a Discrete Fourier Transform-Spread-OFDM (DFT-S-OFDM) signal.

[0021] In the random access procedure, the terminal transmits MSG1 at a transmission timing (RACH Occasion) notified by the base station for each cell. Here, the terminal determines the transmission timing based on the reception timing of a synchronization signal called SSB (SS (Synchronization Signal) / PBCH (Physical Broadcast channel) Block) transmitted from the base station in the downlink. Therefore, depending on the propagation delay between the base station and the terminal, the reception timing at the base station deviates from the reception timing assumed at the base station. Here, the reception timing assumed at the base station is, for example, the reception timing determined based on the transmission timing (RACH Occasion) notified by the base station for each cell.

[0022] Therefore, the base station transmits information for correcting (adjusting) the timing to the terminal in MSG2. Information for correcting (adjusting) the timing is sometimes called a TA (Timing Advance) command (see, for example, Non-Patent Document 2). The terminal corrects the transmission timing of MSG3 and onwards based on the TA command included in MSG2. Furthermore, if the base station detects a discrepancy in the reception timing when transmitting and receiving signals from MSG3 onwards, it transmits a TA command to the terminal.

[0023] In NTN, communication between base stations and terminals is long distance, so compared to terrestrial cellular systems, the propagation delay between base stations and terminals is large, and the difference in propagation delay between terminals is large. The difference in propagation delay between terminals corresponds to the difference between the propagation delay between a certain base station A and a certain terminal a and the propagation delay between base station A and terminal a and a different terminal b.

[0024] Therefore, the reception timing of PRACHs transmitted from different terminals at the base station varies greatly, making reception at the base station complicated. Furthermore, the TA command specified in Rel. 15 may not be able to compensate for the propagation delay that occurs in an NTN environment. Furthermore, if the range of the TA command value is widened to compensate for the large propagation delay, the amount of information (e.g., the number of bits) required to notify the TA command increases.

[0025] Therefore, for example, it is being considered that the terminal calculates the propagation delay based on the distance between the terminal and the satellite, which is estimated using the terminal's location information obtained by the GNSS (Global Navigation Satellite System) or the like and the satellite's location information obtained from satellite orbit information (satellite ephemeris), and the terminal autonomously adjusts the timing.

[0026] FIG. 2 is a diagram showing an example of timing adjustment based on UE location information and satellite ephemeris.

[0027] 2 illustrates downlink (DL) transmission slots and uplink (UL) reception slots of a base station (gNB), and DL reception slots and UL transmission slots of a terminal (UE). Note that the horizontal axis in FIG. 2 represents the time axis.

[0028] Fig. 2 shows that the propagation delay from the transmission timing of a certain signal at a base station to the reception timing of the signal at a terminal is expressed by the propagation delay of a feeder link (Feeder link delay) and the propagation delay of a service link (Service link delay). Fig. 2 also shows that the terminal adjusts the transmission timing of the signal using a TA determined based on the terminal's location information and satellite orbit information. In Fig. 2, the TA corresponds to, for example, twice the propagation delay of the service link.

[0029] However, in the timing adjustment of the terminal based on the distance between the satellite and the terminal, the delay between the terminal and the satellite (i.e., the service link) is corrected, but the delay between the satellite and a base station located at a terrestrial gateway (GW) (i.e., the feeder link) is not corrected. Also, in a non-line-of-sight (NLOS) environment between the satellite and the terminal, the propagation delay calculated using location information may differ from the actual propagation delay including reflection and / or diffraction that occurs in the non-line-of-sight environment.

[0030] In addition, in 5G NR, the timing of transmission slots is specified in Rel. 15.

[0031] Fig. 3 is a diagram showing an example of transmission slot timing, which shows an example of transmission slot timing in terrestrial cellular defined in Rel. 15 and an example of transmission slot timing considered by NTN.

[0032] 3 illustrates DL transmission slots and UL reception slots of a base station (gNB), and DL reception slots and UL transmission slots of a terminal (UE). Note that the horizontal axis in FIG. 3 represents the time axis.

[0033] In Figure 3, according to the transmission slot timing specifications of Rel. 15, in the nth slot, a signal including DCI (Downlink Control Information) is transmitted from the base station to the terminal, and in the (n+K2)th slot, a PUSCH signal is transmitted from the terminal to the base station.

[0034] As shown in Figure 3, NTN uses an offset K to compensate for the longer propagation delay than terrestrial cellular systems in accordance with the Rel. 15 transmission slot timing specification. offset,cell (K offset It is being considered to establish a new system (sometimes abbreviated as K). offset is broadcast for each cell.

[0035] On the other hand, the round-trip propagation delay (RTT) between the terminal and the satellite varies depending on the terminal's location within the cell, so even if an offset is set to correct for the longer propagation delay than in terrestrial cellular systems, some terminals may not be able to transmit in time or may have to wait a long time before transmitting.

[0036] Furthermore, there has been insufficient consideration of both timing control using TA and control of transmission slots.

[0037] Therefore, in one non-limiting embodiment of the present disclosure, in an environment where the propagation delay between a terminal and a base station increases, such as an NTN environment, both timing control using TA and control of transmission slots are taken into consideration, and appropriate timing control is realized according to the propagation delay between the terminal and the base station.

[0038] (Embodiment 1) [Communication System Overview] A communication system according to an embodiment of the present disclosure includes a terminal 100 (corresponding to a transmitting device) and a base station 200 (corresponding to a receiving device).

[0039] Fig. 4 is a block diagram showing an example configuration of a portion of terminal 100. In terminal 100 shown in Fig. 4, control unit 109 controls transmission timing based on first information related to control of signal transmission timing in a transmission unit of the signal and second information related to control of transmission timing in a unit finer than the transmission unit. Radio transmission unit 105 transmits signals based on the control of transmission timing by control unit 109.

[0040] Fig. 5 is a block diagram showing an example of the configuration of a portion of base station 200. In base station 200 shown in Fig. 5, control unit 209 controls reception timing based on first information related to control of signal reception timing in a signal reception unit and second information related to control of transmission timing in a unit finer than the reception unit. Radio receiving unit 202 receives signals based on the control of reception timing by control unit 209.

[0041] [Device configuration] Next, an example of the configuration of the terminal 100 will be described.

[0042] 6 is a block diagram showing an example of the configuration of terminal 100 according to the first embodiment. Terminal 100 includes PRACH generation section 101, data generation section 102, location information acquisition section 103, timing adjustment section 104, radio transmission section 105, antenna 106, radio reception section 107, and demodulation and decoding section 108. PRACH generation section 101, data generation section 102, location information acquisition section 103, timing adjustment section 104, and demodulation and decoding section 108 may be included in control section 109.

[0043] The PRACH generation unit 101 determines the transmission resource of the PRACH from, for example, candidate PRACH transmission resources available in the cell of the base station 200. For example, the PRACH generation unit 101 sets the time-frequency resource and preamble number used for PRACH transmission based on information about the time-frequency resource available for PRACH transmission and the preamble number group. The information about the time-frequency resource and preamble number group available for PRACH transmission is notified by, for example, the base station 200.

[0044] The data generating unit 102 generates an uplink transmission data sequence, and generates a data signal to be transmitted using time-frequency resources for data signal transmission allocated by the base station 200 and an MCS (Modulation and Coding Scheme).

[0045] The location information acquisition unit 103 acquires location information (information such as latitude, longitude, and altitude) of the terminal 100 and location information of a satellite with which the terminal is communicating using a GNSS function such as GPS. The location information acquisition unit 103 calculates the distance between the terminal 100 and the satellite, and outputs the calculated distance information to the timing adjustment unit 104. The satellite location information may be obtained by, for example, acquiring orbit information and / or time information called satellite ephemeris in advance.

[0046] The timing adjustment unit 104 adjusts the reception timing of the received signal and the transmission timing of the transmission signal. For example, the timing adjustment unit 104 adjusts the transmission timing based on information notified or broadcast from the base station 200 and / or information calculated by the timing adjustment unit 104.

[0047] For example, timing adjustment section 104 calculates a propagation delay time between a satellite and terminal 100 from the distance information and radio wave propagation speed output from location information acquisition section 103. Then, timing adjustment section 104 adjusts the transmission timing based on one or a combination of the reception timing of a signal transmitted from base station 200, the calculated propagation delay time, a cell-wide timing advance value broadcast from base station 200, and a timing advance value (e.g., a TA value) of terminal 100 notified from base station 200. The timing adjustment may differ depending on the channel and / or the signal to be transmitted. For example, the timing adjustment may differ depending on the PRACH, PUSCH, PUCCH (Physical Uplink Control Channel), and SRS (Sounding Reference Signal). An example of timing adjustment will be described later.

[0048] The radio transmitting unit 105 performs transmission processing such as D / A conversion and up-conversion on the signal output from the PRACH generating unit 101 and the data signal output from the data generating unit 102. The radio transmitting unit 105 transmits the radio signal obtained by the transmission processing from the antenna 106 to the base station 200 at the transmission timing adjusted by the timing adjusting unit 104.

[0049] The radio receiving unit 107 receives a received signal from the base station 200 via the antenna 106 at the reception timing adjusted by the timing adjusting unit 104. The received signal may be, for example, a downlink signal of a PDCCH (Physical Downlink Control Channel) or a PDSCH (Physical Downlink Shared Channel). The received signal may also include data and / or control information. The radio receiving unit 107 performs reception processing such as down-conversion and A / D conversion on the received signal, and outputs the signal after the reception processing to the demodulation and decoding unit 108.

[0050] The demodulation and decoding unit 108 performs demodulation and decoding processing on the signal output from the radio receiving unit 107. For example, the demodulation and decoding unit 108 demodulates and decodes a response data signal of the PRACH. For example, if the demodulated and decoded information includes information on the transmission timing and reception timing, the demodulation and decoding unit 108 outputs the information to the timing adjusting unit 104.

[0051] [Base station configuration] 7 is a block diagram showing an example of the configuration of base station 200 according to the first embodiment. Base station 200 includes antenna 201, radio receiving section 202, data reception processing section 203, PRACH detection section 204, timing control information generation section 205, data generation section 206, data transmission processing section 207, and radio transmission section 208. Data reception processing section 203, PRACH detection section 204, timing control information generation section 205, data generation section 206, and data transmission processing section 207 may be included in control section 209.

[0052] The radio receiving unit 202 performs receiving processing such as down-conversion and A / D conversion on the data signal and PRACH signal from the terminal 100 received via the antenna 201, and outputs the processed signals to the data receiving processing unit 203 and the PRACH detection unit 204.

[0053] The data reception processing unit 203 performs demodulation and decoding processing on received data signals other than the PRACH. The data reception processing unit 203 may also perform channel estimation and timing estimation based on the received data signals. The data reception processing unit 203 outputs information related to the estimated timing to the timing control information generation unit 205.

[0054] The PRACH detection unit 204 detects the preamble signal of the PRACH and estimates the transmission timing and reception timing by performing correlation processing on the received preamble signal of the PRACH with a replica signal of the preamble signal generated using a sequence number corresponding to the set preamble number and a cyclic shift amount.

[0055] The correlation processing in the PRACH detection unit 204 may be performed in the time domain to calculate a delay profile, or may be performed in the frequency domain (division processing) and then perform an IFFT (Inversed Fourier Transform) to calculate a delay profile. The calculated delay profile may be used to estimate the transmission timing and / or the reception timing.

[0056] The PRACH detection unit 204 outputs, for example, information related to the estimated transmission timing and / or reception timing to the timing control information generation unit 205. For example, the PRACH detection unit 204 calculates the difference between the reference timing of the base station 200 and the arrival timing of the received signal, and outputs the calculation result to the timing control information generation unit 205.

[0057] The timing control information generator 205 generates a TA command for the terminal 100 based on information (for example, timing estimation results) output from the PRACH detector 204 and the data reception processor 203. There may be multiple types of TA commands. The timing control information generator 205 also generates a timing adjustment value common to all cells. The timing adjustment value common to all cells is generated based on at least one of the size of the cell formed by the satellite beam, the length of the feeder link, and the amount of feeder link delay, for example.

[0058] The data generating unit 206 generates downlink data signals such as user data, a synchronization signal, system information (broadcast information), individual control information (for example, RRC control information), and MAC control information for the terminal 100. The data generating unit 206 outputs the generated downlink data signals to the data transmission processing unit 207.

[0059] The data transmission processing unit 207 encodes and modulates the downlink data signal output from the data generation unit 206 and the information output from the timing control information generation unit 205 , and outputs the modulated signal to the radio transmission unit 208 .

[0060] The radio transmitting unit 208 performs transmission processing such as D / A conversion, up-conversion, and amplification on the signal output from the data transmission processing unit 207 , and transmits the radio signal obtained by the transmission processing from the antenna 201 .

[0061] [Timing adjustment example] Next, a description will be given of timing adjustment in this embodiment 1. Terminal 100 performs timing adjustment using one or more timing adjustment values.

[0062] For example, two types of timing adjustment are performed: a relatively fine-grained timing adjustment and a relatively coarse-grained timing adjustment.

[0063] In relatively fine-grained timing adjustment, terminal 100 adjusts transmission timing in units of samples. For example, the transmission timing is adjusted so that base station 200 receives the PUSCH OFDM symbol or PRACH symbol within the CP length. In relatively coarse-grained timing adjustment, terminal 100 adjusts transmission timing in units of slots and / or OFDM symbols. For example, base station 200 adjusts transmission timing so that base station 200 receives the PUSCH OFDM symbol or PRACH symbol in a slot or OFDM symbol that base station 200 expects.

[0064] Examples of timing adjustment values ​​that perform fine-grained adjustment include the following values: Timing adjustment value based on location information calculated by the device Timing adjustment value calculated by the device using leading path tracking Timing adjustment value based on TA command 1 sent from the base station (Fine TA command)

[0065] Furthermore, examples of timing adjustment values ​​for performing coarse-grained adjustment include the following values: Cell-specific timing adjustment value (cell-specific TA offset) broadcast by the base station - Timing adjustment value for each terminal notified by the base station (K adj,UE ) Timing adjustment value based on TA command 2 sent from the base station (Coarse TA command)

[0066] Of the above-mentioned timing adjustment values, the timing adjustment value calculated by the terminal using leading path tracking will be described in the second embodiment.

[0067] Next, an example of timing control using the above-mentioned timing adjustment value will be described.

[0068] Fig. 8 is a diagram showing an example of a sequence chart related to timing control in the present embodiment 1. Fig. 8 shows an example of signals (or channels used for transmitting and receiving signals) transmitted and received between terminal 100 (UE) and base station 200 (gNB), and a timing adjustment value used by UE for signal transmission. Each process from step 101 (S101) to S109 in Fig. 8 will be described below.

[0069] <s101> The base station (gNB) transmits SSBs and SIBs (System Information Blocks). The SSBs and SIBs may be transmitted periodically. The SSBs include synchronization signals and cell-specific basic control information (e.g., Master Information Blocks). The SIBs include cell-specific information for terminals to access the base station. The SIBs may also include information indicating the satellite position (e.g., satellite ephemeris). The SIBs may also include a cell-specific TA offset and a slot offset (K ) indicating the slot position for data allocation. offset,cell ) are included.

[0070] <s102> The terminal receives the SSB and SIB and transmits a PRACH for initial access. Here, the terminal adjusts the transmission timing of the PRACH. For example, the terminal adjusts the timing using a cell-specific TA offset value broadcast from the base station and a timing adjustment value based on location information calculated by the terminal. The timing adjustment value based on location information may be written as "TA based on GNSS / ephemeris" or "GNSS / ephemeris based TA."

[0071] Here, an example of calculating a timing adjustment value based on location information will be described. The terminal acquires its location information using a GNSS function or the like. The terminal calculates the distance between the satellite and the terminal from the satellite location information that is held or notified and the terminal location information. Then, the terminal multiplies the calculated distance by the radio wave propagation speed (for example, 3×10 8 The one-way propagation delay time is calculated by dividing the calculated propagation delay time by the time (m / s). Twice the calculated propagation delay time corresponds to the round trip time (RTT). The calculated round trip delay time is a timing adjustment value based on the location information. Note that the timing adjustment value based on the location information may be a value obtained by adding the processing delay time of the terminal and / or base station to the calculated round trip propagation delay time.

[0072] The TA value is calculated by adding the timing adjustment value based on the location information to the cell-specific TA offset value broadcast by the base station.

[0073] For example, the terminal uses equations (1), (2), and (3) to determine the value TA final The TA determined by Eq. final , TA determined by Eq. (2) NTN_offset and TA determined by Eq. (3). coarse may be in units of ns (nano seconds), for example.

number

[0074] The first term on the right side of the above equation (1) is the same as the Rel.15 NR specification. As described in TS38.211 V15.8.0 Section 4.1, Tc = 0.509 ns and N TA is a correction value according to the TA command transmitted from the base station. For example, in the case of PRACH transmission, N TA becomes zero. N TAoffset is an offset value used for timing adjustment between different base stations. TA is the TA value calculated by Equation (1). final For example, the T described in Section 4.3.1 of TS38.211V15.8.0 TA The correction term TA for NTN, which is expressed by equation (2), is the same as the first term of equation (1) in the Rel.15 NR specification. NTN_offset Since the Rel.15 NR specifications can be reused, expansion to NTN can be achieved with minimal changes.

[0075] TA location represents the round-trip propagation delay time calculated based on the location information. For example, TA location may be expressed in ns.

[0076] 10 in Equation (3) 6 / 2 μ The term represents the slot length for the parameter μ representing the subcarrier spacing, and may be expressed in units of ns, for example. For example, the parameter μ representing the subcarrier spacing is set to μ = 0, 1, 2, 3, and 4 for subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz, respectively.

[0077] M offset,cell is a cell-specific TA offset. The cell-specific TA offset indicates, for example, the number of slots to be shifted. M coarse is an offset, which will be described later, and is set to zero when transmitting PRACH. Note that these offsets may indicate the time to be offset (for example, in ms units) instead of the number of slots. Note that in the case of an offset indicating time, the offset and 10 representing the slot length are used. 6 / 2 μ The multiplication by the term may not be performed, or may be multiplied or divided by another coefficient.

[0078] The terminal calculates the above TA value (TA final ) and transmit the upstream signal at a timing that is advanced by that amount.

[0079] FIG. 9 is a diagram illustrating an example of timing adjustment using a cell-specific TA offset value and a timing adjustment value based on location information.

[0080] 9 illustrates DL transmission slots and UL reception slots of a base station (gNB), and DL reception slots and UL transmission slots of a terminal (UE). Note that the horizontal axis in FIG. 9 represents the time axis.

[0081] Fig. 9 shows an example of an uplink signal transmitted at a transmission timing that is advanced by the TA value from the downlink reference reception timing. The TA value in Fig. 9 is expressed as the sum of a cell-specific offset value and a timing adjustment value based on location information.

[0082] Also, "DL-UL timing difference due to feeder link delay" in FIG. 9 indicates the DL-UL timing difference caused by the feeder link delay when the cell-specific offset value is not used.

[0083] By using a cell-specific TA offset value, the base station can reduce the DL-UL timing difference caused by, for example, feeder link delay.

[0084] The round-trip propagation delay in satellite communications can result in a DL-UL timing difference of several hundred milliseconds. Depending on the base station implementation, managing the DL-UL timing difference can be difficult. As described above, using a cell-specific TA offset allows the DL-UL timing difference to be controlled within a manageable range (e.g., within 10 milliseconds) by the base station. In the case of non-geostationary satellites such as LEOs, the feeder link propagation delay varies depending on the position of the non-geostationary satellite, which changes over time. Therefore, the shortest delay amount in the feeder link delay time can be corrected. Since the DL-UL timing difference only needs to be corrected to a manageable level by the base station, by notifying the terminal of coarse-grained values, such as slot-by-slot or OFDM-symbol-by-symbol, the increase in notification overhead can be suppressed, and long-delay satellite communications environments such as NTN environments can be supported.

[0085] <s103> The base station receives the PRACH and detects the difference between the base station reference timing and the PRACH reception timing. The base station determines a TA command 1 (Fine TA command in FIG. 8) for correcting the timing corresponding to the detected difference, and transmits a PDSCH including the determined TA command 1. The TA command 1 may be, for example, a TA command similar to Rel. 15 NR. Furthermore, the response to the terminal in S103 including the TA command 1 may be referred to as a RACH response (RAR).

[0086] The CP length of the PRACH is set to a value longer than the CP length of the PUSCH. Therefore, even if the PRACH is received within the CP length of the PRACH, the reception timing of the PUSCH transmitted by the terminal after the PRACH at the base station may deviate from the CP length. In this step, the base station transmits TA command 1 and controls the transmission timing of the terminal to fall within the CP length of the PUSCH.

[0087] <s104> The terminal transmits the PUSCH in the time-frequency resource specified by the RAR. The time resource is the K offset,cell The terminal transmits at the timing when it is received in the slot of this slot number at the base station. At this time, the terminal further adjusts the timing from the timing of PRACH transmission in accordance with the notified TA command 1. For example, in equation (1), N TA The TA command is determined using the value of TA command 1. final The timing is adjusted using the above and the PUSCH is transmitted.

[0088] Furthermore, the terminal may report timing information to the base station (TA value report in FIG. 8). For example, the terminal may report the TA determined using Equation (1) final Alternatively, the base station may notify TA NTN_offset or T.A. location In either case, the value is rounded to a coarse granularity value such as a slot length unit or an OFDM symbol length unit and notified. For example, the conversion to a coarse granularity value may be performed using a round or floor operation. This notification is used to control the allocation slots of PUSCH and / or HARQ-ACK in the base station, so it may be a coarse granularity notification such as a slot unit. By notifying with a coarse granularity, it is possible to reduce the notification overhead. In addition, the terminal may notify the TA location Instead of , you can notify the location information obtained by GNSS, or TA location The location information to be notified may be, for example, location information with a granularity of about 1 km, or location information limited to decimal points of latitude and longitude so that the calculation error of the propagation delay is within a predetermined value. Furthermore, the location information may be reused as information used for controlling band-over, etc.

[0089] <s105> The base station transmits information for contention resolution in random access and / or RRC configuration information using the PDSCH. For example, the base station transmits a MAC CE including a TA command 2 (Coarse TA command in FIG. 8). The TA command 2 is, for example, a timing adjustment command with slot-based granularity. The base station sets the TA command 2 based on the TA value information notified from the terminal in S104.

[0090] For example, the larger the TA value notified from the terminal to the base station, the longer the propagation delay, so the base station may set a smaller value for TA command 2 notified to the terminal. In this case, the slots for PUSCH and / or HARQ-ACK assigned by DCI will be slots with later timing, i.e., slots with larger slot numbers. The terminal can transmit PUSCH or HARQ-ACK after a sufficient transmission preparation time has elapsed since receiving DCI or PDSCH.

[0091] On the other hand, the smaller the TA value notified from the terminal, the shorter the propagation delay, so TA command 2 may be set to a larger value. In this case, the slot for PUSCH and / or HARQ-ACK will be an earlier timing slot, that is, a slot with a smaller slot number. If the propagation delay is relatively short, the terminal can transmit PUSCH or HARQ-ACK after a sufficient transmission preparation time has elapsed since receiving DCI or PDSCH, even if the terminal is adjusted to an earlier timing by TA command 2. For example, K offset,cell is set to match the propagation delay that occurs in the terminal located farthest from the satellite within the cell, the TA command 2 notified to the terminal located farthest from the satellite may be set to zero. In this case, the closer the terminal is to the satellite, the larger the TA command 2 value that is notified. This control enables lower delay transmission for terminals closer to the satellite.

[0092] Furthermore, when location information is notified from the terminal in S104, the base station may estimate the TA value of the terminal based on the notified location information, and set TA command 2 in the same manner as above.

[0093] Furthermore, the TA command 2 may be transmitted in the form of being included in the RRC configuration information.

[0094] <s106> In the timing adjustment for the subsequent PUSCH and HARQ-ACK transmissions, the terminal uses M coarse The TA value determined by setting final ) is used.

[0095] FIG. 10 is a diagram showing an example of timing adjustment using each TA including the TA command 2.

[0096] 10 illustrates DL transmission slots and UL reception slots of a base station (gNB), and DL reception slots and UL transmission slots of a terminal (UE). Note that the horizontal axis in FIG. 10 represents the time axis.

[0097] 10 indicates the TA notified by TA command 2. "Fine TA" in Fig. 10 indicates the TA notified by TA command 1. "TA based on GNSS / ephemeris" and "Cell specific TA offset" in Fig. 10 may be the same as "TA based on GNSS / ephemeris" and "Cell specific TA offset" shown in Fig. 9, respectively.

[0098] Furthermore, "Cell specific timing" in FIG. 10 is the timing of PUSCH reception by the base station assumed in the case of transmission without using TA command 2, such as transmission of msg3 described above. For example, in a certain cell, the timing is set to allow transmission even from the farthest terminal, taking into account the round-trip propagation delay time from the satellite to the farthest terminal. However, since this timing is tailored to the farthest terminal, unnecessary delays occur for terminals closer to the satellite. As shown in FIG. 10, by using coarse TA notified by TA command 2, the PUSCH transmission and reception timing can be made earlier than the Cell specific timing.

[0099] Here, M in equation (2) coarse may be converted depending on the granularity of the TA command 2. For example, if the granularity is in units of OFDM symbols, the value notified by the TA command 2 (value in units of slots) may be converted to a value in units of OFDM symbols by dividing it by 14, which is the number of OFDM symbols per slot.

[0100] <S107、S108> If the satellite and / or the terminal moves beyond the threshold of the moving distance, the terminal calculates the propagation delay again using the GNSS position information and the position information from the satellite ephemeris and calculates the TA location The TA is updated and the uplink is transmitted. location The update may be performed not only when the satellite and / or the terminal moves by more than a threshold, but also at a predetermined cycle, or may be performed both when the satellite and / or the terminal moves by more than a threshold and at a predetermined cycle.

[0101] TA location The frequency and cycle of updating TA or the threshold value of the moving distance may be notified from the base station. Instead of the threshold value of the moving distance, the amount of change in the TA value due to movement may be notified. location The update frequency and cycle or the threshold value of the moving distance may be set to a predetermined value.

[0102] Furthermore, if the round-trip propagation delay has changed by a predetermined value or more (for example, by a time equivalent to 1 / 2 slot or more), the terminal may notify the base station of the corrected timing value information and / or location information, as in S104. If the round-trip propagation delay has not changed by a predetermined value or more, the terminal may transmit user data without notifying the base station of the corrected timing value information and / or location information. Here, for example, when notifying the terminal's location information, even if the propagation delay has changed due to satellite movement, the base station can determine the amount of change in TA for a stationary terminal or a terminal whose movement is below a threshold based on the terminal's location information previously notified. This makes it possible to avoid frequently notifying the terminal's location information, thereby reducing the overhead of notifying location information.

[0103] <s109> If the round-trip propagation delay of the terminal changes by a predetermined value or more (for example, by one slot or more), the base station transmits TA command 2 to change the allocation slots of the PUSCH and / or HARQ-ACK of the terminal.

[0104] As shown in the sequence chart described above, the terminal performs two types of timing adjustment: a relatively fine-grained timing adjustment and a relatively coarse-grained timing adjustment. The terminal also performs different timing adjustments depending on the channel and / or the signal to be transmitted.

[0105] Note that the information notified from the base station to the terminal in the above sequence diagram is an example, and the present disclosure is not limited to this. For example, the information notified by the TA command 2 in the above S105 and S109 is an offset value (K adj,UE ) may be signaled by the offset value (K adj,UE ) is, for example, a timing adjustment value for each terminal.

[0106] Offset value (K adj,UE ), M in Eq. (3) coarse may be set to zero. Also, the offset value (K adj,UE ), the terminal assigns the PUSCH slots as "n + K2 + K offset,cell -K adj,UE Here, n is the slot in which DCI for allocating PUSCH is transmitted, and K2 is the value notified by DCI. For example, K2 is set to the time required to prepare for PUSCH transmission after receiving DCI and / or the time until the next available uplink slot for transmission. The offset value (K adj,UE ) may take negative values.

[0107] Figure 11 shows the K adj,UE FIG. 10 is a diagram illustrating an example of timing adjustment using information including:

[0108] 11 illustrates DL transmission slots and UL reception slots of a base station (gNB), and DL reception slots and UL transmission slots of a terminal (UE). Note that the horizontal axis in FIG. 11 represents the time axis.

[0109] In FIG. 11, the terminal allocates PUSCH slots to K adj,UE The slot is determined to be shifted by the offset value.

[0110] In FIG. 11, when determining the slots to allocate the PUSCH, K adj,UE However, the present disclosure is not limited to this example. For example, in determining the transmission slot for HARQ-ACK transmission and / or SRS, adj,UE An offset value of K may be applied. When the offset value is applied to HARQ-ACK transmission, n may be the PDSCH slot targeted for HARQ-ACK. When the offset value is applied to SRS transmission, n may be the DCI slot indicating the SRS transmission. Instead of a TA command, K offset,cell Since information indicating an offset from K is notified, the amount of information to be notified can be reduced. The granularity of the notified offset may be in slot units or in OFDM symbol units. By using OFDM symbol units, more precise timing control is possible. In addition, K adj,UE The offset value may not be applied, or a different offset value may be used.

[0111] As described above, in this first embodiment, by performing coarse-grained timing control in addition to fine-grained timing control, it is possible to suppress an increase in notification overhead and perform terminal transmission timing control suitable for a satellite communication environment with long propagation delays and large propagation delay differences between terminals.

[0112] (Embodiment 2) In the second embodiment, in addition to the first embodiment, timing adjustment is performed by path tracking.

[0113] [Device configuration] The configuration of a terminal according to the second embodiment may be the same as the configuration of terminal 100 shown in the first embodiment, except that processing in timing adjustment section 104 of terminal 100 shown in the first embodiment is added.

[0114] Timing adjustment section 104 tracks the reception timing of SSB, PDCCH or PDSCH received in radio reception section 107 and calculates a timing adjustment value according to the amount of change in the reception timing. When multiple paths (for example, delayed waves) are detected, the reception timing to be tracked may be the timing of the first path. Timing adjustment section 104 then performs timing adjustment using one or more of the calculated timing adjustment value based on path tracking and the timing adjustment values ​​shown in embodiment 1.

[0115] [Timing adjustment example] Next, timing adjustment in the second embodiment will be described.

[0116] For example, the terminal uses equations (4) and (5) to determine the value TA final The TA determined by equation (4) is final may be in units of ns (nano seconds), for example.

number

[0117] In addition, in equations (4) and (5), explanations of parameters similar to those in equations (1), (2), and (3) will be omitted. Equation (4) is similar to equation (1), but the second term on the right side is expressed by equation (5). In the right side of equation (5), the parameters on the right side of equation (2) are expressed as TA path will be added. TA path is the value of timing adjustment due to path tracking.

[0118] The terminal may selectively use a case where timing adjustment is performed based on location information and a case where timing adjustment is performed by path tracking in addition to timing adjustment based on location information, depending on the terminal's uplink transmission channel and / or transmission timing. For example, in the case where timing adjustment is performed based on location information (in other words, in the case where timing adjustment is not performed by path tracking), TA path may be set to zero. The terminal may be instructed by control information from the base station as to which of the two cases to use. Alternatively, a rule may be defined in advance, and the terminal may use either case in accordance with the defined rule.

[0119] For example, the following applies to two cases:

[0120] Cases in which timing adjustment is performed based on position information, that is, cases in which timing adjustment by path tracking is not performed, include the following cases, for example. PRACH transmission SRS transmission First transmission after waking up from a DRX sleep period (long sleep and / or short sleep) First transmission after the TA valid timer expires -Transmission in IDLE or INACTIVE state

[0121] The following is an example of a case in which timing adjustment based on position information and timing adjustment by path tracking are performed. RRC_CONNECTED state - Second and subsequent transmissions after waking up from sleep

[0122] Next, an example of timing control using the above-mentioned timing adjustment value will be described.

[0123] Fig. 12 is a diagram showing an example of a sequence chart related to timing control in the present embodiment 2. As in Fig. 8, Fig. 12 shows an example of signals (or channels used for transmitting and receiving signals) transmitted and received between terminal 100 (UE) and base station 200 (gNB), and an example of timing adjustment values ​​used by UE for signal transmission. Note that in Fig. 12, the same processes as in Fig. 8 are denoted by the same reference numerals, and descriptions thereof may be omitted.

[0124] <s201> The gNB (base station) transmits SSB and SIB. The SSB and SIB may be transmitted periodically. The SSB contains signals for synchronization and basic cell-specific control information. Also, the SIB contains cell-specific information for the terminal to access the base station, etc. Also, information indicating the position of the satellite (e.g., satellite ephemeris) may be included in the SIB. The SIB contains a cell-specific TA offset (Cell specific TA offset).

[0125] <S204 and S205> Based on the position information in the PRACH transmission (S102 in FIG. 12), the terminal stores the SSB reception timing (first path timing) in the calculation of the timing adjustment value TA. Then, the terminal receives the SSB, PDCCH, or PDSCH at a certain interval and monitors the change in the timing of the first path. When there is a certain amount of change, the terminal changes (updates) the transmission timing. When the amount of change in the path timing is Δ location the terminal determines TA path = 2×Δ path In equations (4) and (5), the terminal uses each timing adjustment value including TA path to determine TA path and uses the determined TA final to perform timing adjustment and transmit PUSCH. final

[0126] Also, when the amount of change in the reception timing of the path exceeds a threshold value, the terminal may update the timing. The interval for updating the TA value and / or the threshold value of the amount of change for determining whether to update the TA value may be specified by the base station or may be determined in advance.

[0127] Similar to Embodiment 1, the terminal notifies the base station of timing information (e.g., at least one of the TA value and position information) (TA value report in FIG. 12). For example, the terminal transmits TA location and TA path ​As in the first embodiment, the sum may be rounded to a value with a coarse granularity such as a slot length unit or an OFDM symbol length unit and notified.

[0128] The terminal goes to sleep when there is no data to be communicated. The sleep operation may be the same as that of Rel. 15 NR described in TS38.821. Note that the terminal sleep is not limited to the sleep of communication when there is no data to be communicated, and may be interpreted as the sleep of CPU operation, for example.

[0129] <s206> The terminal acquires the terminal's location information in the first transmission (for example, PUSCH transmission) after waking up from sleep. If the satellite position has changed, the terminal uses the changed satellite position information. Then, the terminal performs TA location , and performs timing adjustment and PUSCH transmission. path Set (reset or clear) to zero.

[0130] <s207> After the terminal wakes up from sleep, the position of the satellite or the terminal is likely to have changed. Therefore, the terminal may notify the base station of the timing information (e.g., TA value). Whether to notify the base station of the timing information may be specified by the base station (notified in SIB) depending on the type of satellite (geostationary satellite, non-geostationary satellite), etc., or may be set for each terminal depending on the moving speed and / or type of the terminal, etc., or may be notified for each terminal.

[0131] <S208 and S209> Similar to S204 and S205, the terminal updates the TA path by path tracking. Here, the terminal does not have to update the TA location

[0132] As in the sequence chart described above, the terminal performs two timing adjustments: a relatively fine-grained timing adjustment and a relatively coarse-grained timing adjustment. Also, the terminal performs different timing adjustments according to the channel and / or the signal to be transmitted. Also, the terminal determines the TA path by path tracking, and uses the timing adjustment value including the TA path to perform timing adjustment.

[0133] Although an example where the terminal sleeps in S206 and wakes up (wake up) in S207 has been shown, the present disclosure is not limited to this. For example, the same applies to the return from IDLE or INACTIVE, or the return from the expiration of the TA timer. The TA timer may be the timeAlignmentTimer described in TS38.321 V15.8.0.

[0134] In the sequence chart described above, similar to Embodiment 1, K offset,cell and K adj,UE and the TA command 2 (coarse TA) may be used, may not be used, or a predetermined value may be used. The base station may explicitly notify of invalidation or may notify a predetermined value.

[0135] ​ As described above, in this second embodiment, by performing coarse-grained timing control in addition to fine-grained timing control, it is possible to suppress an increase in notification overhead and perform terminal transmission timing control suitable for a satellite communication environment with long propagation delay and large propagation delay differences between terminals. Also, in this second embodiment, by using a timing adjustment value based on path tracking in the timing control, it is possible to perform appropriate terminal transmission timing control.

[0136] When timing is adjusted using terminal and satellite position information (for example, GNSS / ephemeris position information), an error occurs with respect to the actual propagation path in an out-of-line-of-sight environment (for example, an environment where there are no direct waves and only reflected or diffracted waves arrive). This error can be corrected by a TA command sent from the base station, but if timing adjustment is redone using GNSS / ephemeris position information every time the terminal or satellite position changes, an error will occur again, and correction using the TA command will have to be redone again.

[0137] Therefore, by performing corrections using path tracking instead of frequently redoing timing adjustments using GNSS / ephemeris positioning information, timing control accuracy can be maintained and frequent TA command transmissions from the base station can be avoided. This also improves timing accuracy and reduces overhead. Furthermore, since path tracking is likely to be ineffective in cases where no signal is received for a long period of time, such as during sleep, or during the first transmission after some functions are stopped, a certain level of timing accuracy can be maintained by performing timing adjustments using GNSS / ephemeris positioning information.

[0138] (Embodiment 3) The configurations of a terminal and a base station according to the present embodiment may be similar to the configurations of terminal 100 and base station 200 shown in Embodiment 1. However, the operations relating to timing adjustment of terminal 100 and base station 200 shown in Embodiment 1 are different.

[0139] In this embodiment, in addition to TA, timing adjustment is performed using "Koffset" that defines the transmission slot timing.

[0140] For example, in terminal 100 shown in FIG. 4, control unit 109 determines a first offset (for example, K offset,cell ), and a second offset that is shorter than the first offset (e.g., K offset,UE ) to control the uplink transmission timing (for example, transmission slot timing). The radio transmitting unit 105 performs uplink transmission based on the control of the uplink transmission timing.

[0141] Also, for example, in the base station 200 shown in FIG. 5, the control unit 209 determines the first offset (for example, K offset,cell ), and a second offset that is shorter than the first offset (e.g., K offset,UE ) to control the uplink reception timing (for example, reception slot timing). The radio reception unit 202 performs uplink reception based on the control of the uplink reception timing.

[0142] For example, Koffset may be a cell-specific value "K offset,cell " or the UE-specific value "K offset,UE For example, a terminal-specific K offset,UE is the cell-specific K offset,cell is shorter than.

[0143] For example, cell-specific K offset,cell may be notified to the terminal 100 by the SIB. offset,UE The cell-specific K is used to determine the transmission slot of the PUSCH or PUCCH, such as the transmission of the PUSCH for MSG3 at the time of initial access or the transmission of the ACK / NACK (also called HARQ-feedback) for the PDSCH for MSG4. offset,cell may be used (e.g., Koffset = K offset,cell ). In addition, the terminal 100 may, for example, use a terminal-specific K offset,UE After being notified, K is used to determine the transmission slot for PUSCH or PUCCH. offset,UE may be used (e.g., Koffset = K offset,UE ).

[0144] Also, for example, the K offset,UE may be notified to terminal 100 by at least one of a terminal-specific RRC message, a MAC CE, and a DCI. offset,UE For information about K offset,cell Relative value (or difference) from the previously notified K offset,UE Alternatively, the terminal 100 may be notified of a relative value (or a difference) from the value of the parameter .

[0145] As in the first embodiment, the K offset,UE For example, in the case of GEO, the satellites are stationary, so the K offset,UE may be updated as the terminal 100 moves. In this case, the K offset,UE Since the update frequency of K is relatively low, notification by RRC message is appropriate. On the other hand, for example, in the case of LEO, offset,UE may be updated as the satellite moves at high speed. In this case, the K offset,UE Since the update frequency is relatively high, offset,UE Regarding K , a relative value (for example, a difference) may be notified to terminal 100 by MAC CE or DCI, which can be notified and reflected in a shorter time than an RRC message. offset,UE By notifying the relative value of Koffset, the amount of information to be notified can be reduced and Koffset can be notified more quickly.

[0146] In addition, DCI provides individual K offset,UE In the case of notification, in addition to DCI for an individual terminal, DCI common to the group (for example, DCI format 2_0, etc.) may be used.

[0147] Here, in the case of notification to an individual terminal, a K offset,UE There may be misunderstandings about the value of K. offset,UE When a relative value (or difference) is notified as notification information regarding the above, the difference from the previous value, which may cause a mismatch in recognition between base station 200 and terminal 100, is notified to terminal 100, making it difficult for base station 200 and terminal 100 to realign their recognition.

[0148] Therefore, in this embodiment, terminal 100 and base station 200 determine cell-specific K based on, for example, information on DCI (or PDCCH) for scheduling. offset,cell and device-specific K offset,UE For example, when scheduling is performed by a specific method or a specific DCI, the terminal 100 and the base station 200 control the transmission and reception timing of the uplink signal using either one of the K offset,UE Even if the terminal 100 is notified of offset,UE rather than cell-specific K offset,cell is used.

[0149] An example of timing control using the above-mentioned transmission slot timing (or timing adjustment value) will now be described.

[0150] 13 is a diagram showing an example of a flowchart related to control of transmission slot timing of an uplink signal (for example, PUSCH or PUCCH) in terminal 100 according to the present embodiment. Hereinafter, each process from step 301 (S301) to S305 in FIG. 13 will be described.

[0151] <s301> The terminal 100 may use, for example, a cell-specific K offset,cell Receive the cell-specific K offset,cell may be included in the SIB, for example.

[0152] <s302> The terminal 100 may, for example, use a terminal-specific K offset,UE For example, the terminal-specific K offset,UE may be notified from base station 200 to terminal 100 at the timing of receiving PDSCH (msg4) (processing of S105) or receiving PDSCH (S109) shown in FIG. 8. Also, for example, in transmission and reception at the time of initial access or when the cell size is small (when the cell size is less than a threshold), base station 200 may notify terminal-specific K offset,UE There may also be cases where data is scheduled (for example, when a DCI for an uplink or downlink data allocation is received) without a DCI being set (in other words, notified).

[0153] <s303> Device-specific K offset,UE If terminal 100 receives the PUSCH or PUCCH notification (S302: Yes), terminal 100 determines, for example, whether transmission of the PUSCH or PUCCH has been scheduled by a specific method or specific DCI. Examples of the specific method and specific DCI will be described later.

[0154] <S304,S305> Device-specific K offset,UE If terminal 100 does not receive the cell-specific K (S302: No), or if the transmission of the PUSCH or PUCCH is scheduled by a specific method or a specific DCI (S303: Yes), terminal 100 may offset,cell The transmission slot is determined based on

[0155] On the other hand, device-specific K offset,UE (S302: Yes), and if transmission of the PUSCH or PUCCH is not scheduled by a specific method and a specific DCI (S303: No), the terminal 100 may, for example, offset,UE The transmission slot is determined based on

[0156] As explained in the flowchart above, the terminal 100 offset,UE Even if a cell receives a K offset,cell The transmission slot is determined based on

[0157] Next, methods 1 to 5 will be described as examples of specific methods and specific DCIs.

[0158] <Method 1> In method 1, for example, the offset Koffset used to determine the transmission slot is determined based on the DCI format. For example, when the format of the DCI for scheduling is DCI format 0_0 or DCI format 1_0, the terminal 100 determines the cell-specific K offset,cell In other words, in method 1, the specific DCI is, for example, DCI format 0_0 and DCI format 1_0.

[0159] Note that specific DCI formats such as DCI format 0_0 and DCI format 1_0 may be, for example, a DCI format that does not support MIMO (Multiple-Input Multiple-Output), a DCI format that has limited resource allocation notification, such as being limited to notification of consecutive resource blocks, a DCI format used for scheduling a PDSCH common to cells, or a DCI format with a small number of bits (for example, the number of bits is less than a threshold). Such DCI may be used, for example, for transmission with a smaller number of bits or low overhead.

[0160] On the other hand, DCI formats such as DCI format 0_1, DCI format 0_2, DCI format 1_1, or DCI format 1_2, which are different from the specific DCIs described above, enable notification of scheduling information with more flexibility and fewer restrictions, and may be DCI formats for high-speed data communication or highly reliable, low-latency data communication, for example.

[0161] For example, when scheduled by DCI format 0_0 or DCI format 1_0, terminal 100 uses cell-specific K offset,cell On the other hand, when scheduled by DCI format 0_1, DCI format 0_2, DCI format 1_1, or DCI format 1_2, the terminal 100 determines a transmission slot based on the terminal-specific K offset,UE The transmission slot is determined based on

[0162] For example, with respect to the PUSCH, terminal 100 assigns the transmission slot of the PUSCH scheduled by DCI format 0_0 to slot n+K2+K offset,cell The transmission slot of the PUSCH scheduled by DCI format 0_1 ​​or DCI format 0_2 is determined by slot n+K2+K offset,UE Here, slot n is the slot number in which the DCI is notified.

[0163] For example, with respect to the PDSCH, terminal 100 assigns the transmission slot of HARQ-feedback (or ACK / NACK) for the PDSCH scheduled by DCI format 1_0 to slot n'+K1+K offset,cell The transmission slot of HARQ-feedback (or ACK / NACK) for PDSCH scheduled by DCI format 1_1 or DCI format 1_2 is determined by slot n'+K1+K offset,UE where slot n' is the slot number in which the PDSCH is transmitted.

[0164] By determining this transmission slot, for example, the terminal-specific K offset,UE Even if there is a misrecognition of the value of K offset,cell Communication can continue based on this.

[0165] Furthermore, for example, when base station 200 does not detect PUSCH or HARQ-feedback (for example, PUCCH) from terminal 100 for a certain period of time, it determines that a misrecognition has occurred between base station 200 and terminal 100, and sets DCI format 0_0 or DCI format 1_0 (in other words, cell-specific K offset,cell ) may be used to communicate with the terminal 100.

[0166] For example, the base station 200 may transmit a terminal-specific K offset,UE By notifying the terminal 100 again of the value of K offset,UE The base station 200 and the terminal 100 may agree on the value of K offset,UE When the notification of K is performed by an RRC message, terminal 100 and base station 200 may reset the accumulated value of the difference information previously notified by MAC CE or DCI. offset,UE The base station 200 and the terminal 100 can share the same understanding of the value of .

[0167] For example, K for matching the recognition between the terminal 100 and the base station 200 offset,UE The notification of the cell-specific K using DCI format 0_0 or 1_0 offset,cell In addition, in a case where there is no mismatch in recognition (for example, a normal case), the terminal 100 may use DCI formats 0_1, 0_2, 1_1, 1_2, etc., which allow for more flexible scheduling, to provide a terminal-specific K offset,UE Transmission can be performed using the above.

[0168] <Method 2> In method 2, for example, the offset Koffset used to determine the transmission slot is determined based on the type of search space (SS) used for scheduling (for example, transmitting DCI). For example, when the search space used for transmitting DCI for scheduling is a search space (common search space) common to multiple terminals, terminal 100 determines the offset Koffset based on the cell-specific K offset,cell In other words, in Method 2, the specific method is, for example, a method in which DCI (or PDCCH) including scheduling information is transmitted in a common search space.

[0169] For example, when terminal 100 is scheduled by DCI (or PDCCH) transmitted in a common search space, cell-specific K offset,cell On the other hand, for example, when terminal 100 is scheduled by DCI (or PDCCH) transmitted in a UE specific search space, the terminal determines a transmission slot based on terminal specific K offset,UE The transmission slot is determined based on

[0170] For example, with respect to the PUSCH, terminal 100 may assign the transmission slot of the PUSCH scheduled by the DCI transmitted in the common search space to slot n+K2+K offset,cell The transmission slot of the PUSCH scheduled by the DCI transmitted in the terminal-specific search space is determined by slot n+K2+K offset,UE Here, slot n is the slot number in which the DCI is notified.

[0171] Furthermore, for example, with respect to the PDSCH, terminal 100 may assign a transmission slot for HARQ-feedback (or ACK / NACK) for the PDSCH scheduled by DCI transmitted in the common search space to slot n′+K1+K offset,cell The transmission slot of HARQ-feedback (or ACK / NACK) for PDSCH scheduled by DCI transmitted in the terminal-specific search space is determined by slot n'+K1+K offset,UE where slot n' is the slot number in which the PDSCH is transmitted.

[0172] By determining this transmission slot, for example, the terminal-specific K offset,UE Even if there is a misrecognition of the value of K offset,cell In normal communications, DCI for scheduling for terminal 100 can be reported to terminal 100 in a terminal-specific search space with a larger number of candidates for CCE (Control Channel Element) or a larger number of blind decoding attempts (for example, a larger number of resource candidates for mapping DCI). offset,UE If a misrecognition of the value occurs, the DCI for scheduling is notified to terminal 100 in a common search space with a smaller number of CCE candidates or fewer blind decoding attempts (e.g., fewer resource candidates to map the DCI to), thereby preventing the range of resource candidates that can be used to notify scheduling information in normal communications from being narrowed, thereby minimizing scheduling constraints.

[0173] Furthermore, for example, when base station 200 does not detect PUSCH or HARQ-feedback (for example, PUCCH) from terminal 100 for a certain period of time, it determines that a mismatch in recognition has occurred between base station 200 and terminal 100, and determines whether a common search space (in other words, a cell-specific K offset,cell ) to communicate with terminal 100. For example, base station 200 may communicate with terminal 100 by transmitting DCI using a common search space. offset,UE The value of K is notified to the terminal 100 again. offset,UE The base station 200 and the terminal 100 may agree on the value of .

[0174] <Method 3> In method 3, for example, the offset Koffset used to determine the transmission slot is determined based on the control channel transmission resource (for example, CORESET: Control Resource Set) used for scheduling (for example, DCI transmission). For example, when the CORESET used for DCI transmission for scheduling is a specific CORESET, the terminal 100 determines the cell-specific K offset,cell In other words, in Method 3, the specific method is, for example, a method in which DCI (or PDCCH) including scheduling information is transmitted in a specific CORESET.

[0175] As an example, the specific CORESET may be CORESET0. For example, the resources of CORESET0 may be broadcast by SIB and may be resources common to multiple terminals in a cell. For example, a CORESET different from CORESET0 may be a resource set individually for each terminal. Note that the number of the specific CORESET is not limited to 0. Also, the number of specific CORESETs is not limited to one.

[0176] For example, when terminal 100 is scheduled by DCI (or PDCCH) transmitted in CORESET0, cell-specific K offset,cell On the other hand, for example, when terminal 100 is scheduled by DCI (or PDCCH) transmitted in a CORESET different from CORESET0, terminal-specific K offset,UE The transmission slot is determined based on

[0177] For example, with respect to the PUSCH, terminal 100 assigns the transmission slot of the PUSCH scheduled by the DCI transmitted in CORESET0 to slot n+K2+K offset,cell The transmission slot of the PUSCH scheduled by the DCI transmitted in a CORESET different from CORESET0 is determined by slot n+K2+K offset,UE Here, slot n is the slot number in which the DCI is notified.

[0178] Furthermore, for example, with respect to the PDSCH, terminal 100 determines the transmission slot of HARQ-feedback (or ACK / NACK) for the PDSCH scheduled by DCI transmitted in CORESET0 as slot n′+K1+K offset,cell The transmission slot of HARQ-feedback (or ACK / NACK) for PDSCH scheduled by DCI transmitted in a CORESET different from CORESET0 is determined by slot n'+K1+K offset,UE where slot n' is the slot number in which the PDSCH is transmitted.

[0179] By determining this transmission slot, for example, the terminal-specific K offset,UE Even if there is a misrecognition of the value of K offset,cell Here, DCI for scheduling for terminal 100 can be notified to terminal 100 in, for example, a terminal-specific CORESET (here, a CORESET different from CORESET0) that allows more flexible resource configuration. offset,UE If a misrecognition of the value occurs, the DCI for scheduling is notified to terminal 100 in CORESET0 (for example, a CORESET common to multiple terminals), so the range of resources available for notifying scheduling information in normal times is not reduced, thereby reducing the impact on notifying scheduling information in normal times.

[0180] Furthermore, for example, when base station 200 does not detect PUSCH or HARQ-feedback (for example, PUCCH) from terminal 100 for a certain period of time, it determines that a recognition error has occurred between base station 200 and terminal 100, and offset,cell ) to communicate with terminal 100. For example, base station 200 may communicate with terminal 100 by transmitting DCI using CORESET0. offset,UE The value of K is notified to the terminal 100 again. offset,UE The base station 200 and the terminal 100 may agree on the value of .

[0181] <Method 4> In method 4, for example, the offset Koffset used to determine the transmission slot is determined based on the scheduling method. For example, when the scheduling method using DCI (or PDCCH) for scheduling is SPS (Semi-persistent scheduling), terminal 100 determines the cell-specific K offset,cell In other words, in Method 4, the specific scheduling method is, for example, SPS.

[0182] For example, terminal 100 may assign a transmission slot for HARQ-feedback (or ACK / NACK) for a PDSCH scheduled by SPS to slot n′+K1+K offset,cell The transmission slot of HARQ-feedback (or ACK / NACK) for PDSCH scheduled by a method different from SPS is determined by slot n'+K1+K offset,UE where slot n' is the slot number in which the PDSCH is transmitted.

[0183] By determining this transmission slot, for example, the terminal-specific K offset,UE Even if there is a misrecognition of the value of K offset,cell Communication can continue based on this.

[0184] For example, the device-specific K offset,UE The more frequently the PDCCH is updated according to the movement of the LEO satellite, the greater the overhead may be. Here, the SPS can reduce the PDCCH overhead for periodic traffic or small amount of data transmission. Therefore, according to Method 4, for HARQ-feedback for PDSCH scheduled by the SPS, the K offset,UE Instead of cell-specific K offset,cell By using offset,UE This eliminates the need for frequent updates, reducing overhead.

[0185] <Method 5> In method 5, for example, the offset Koffset used to determine the transmission slot is determined based on the HARQ process (retransmission process) assigned to the PUSCH or PDSCH. For example, the terminal 100 determines a cell-specific Koffset according to the HARQ process number notified by the DCI for scheduling. offset,cell and device-specific K offset,UE In Method 5, for example, the specific method is a method in which the PUSCH or the PUCCH is assigned to a specific HARQ process and transmitted.

[0186] As an example, the specific HARQ process is assumed to be the HARQ process with HARQ process number 0. The specific HARQ process may be, for example, an HARQ process (including HARQ process number 0) allocated in the SPS described in method 3. The HARQ process number may be notified to terminal 100 by, for example, DCI. For example, when the HARQ process number is 0, terminal 100 may notify offset,cell Select .

[0187] For example, when the terminal 100 is assigned the HARQ process number 0, the terminal 100 offset,cell On the other hand, for example, when a HARQ process number other than HARQ process number 0 is assigned to terminal 100, terminal-specific K offset,UE The transmission slot is determined based on

[0188] For example, with respect to the PUSCH, terminal 100 assigns the transmission slot of the PUSCH to which HARQ process number 0 is assigned as slot n+K2+K offset,cell The PUSCH transmission slot to which the HARQ process number other than HARQ process number 0 is assigned is determined by slot n+K2+K offset,UE Here, slot n is the slot number in which the DCI is notified.

[0189] For example, with respect to the PDSCH, terminal 100 assigns the transmission slot of HARQ-feedback (or ACK / NACK) for the PDSCH to which HARQ process number 0 is assigned as slot n'+K1+K offset,cell The transmission slot of HARQ-feedback (or ACK / NACK) for PDSCH assigned with HARQ process number 0 and a different HARQ process number is determined by slot n'+K1+K offset,UE where slot n' is the slot number in which the PDSCH is transmitted.

[0190] By determining this transmission slot, for example, the terminal-specific K offset,UE Even if there is a misrecognition of the value of K offset,cell For example, base station 200 may continue communication with terminal 100 by scheduling using HARQ process number 0.

[0191] Also, for example, the base station 200 may use the HARQ process number 0 (in other words, the cell-specific K offset,cell ) communication, the terminal-specific K offset,UE The value of may be notified to the terminal 100 again, so that the base station 200 and the terminal 100 can have the same recognition.

[0192] Methods 1 to 5 have been described above. At least two of Methods 1 to 5 may be combined. As an example, terminal 100 may select a cell-specific K based on a combination of a DCI format (Method 1) used for transmitting DCI for scheduling and a search space. offset,cell and device-specific K offset,UE For example, when terminal 100 is scheduled by DCI format 0_0 or 1_0 using a common search space, terminal 100 may use cell-specific K offset,cell otherwise, use the device-specific K offset,UE The same applies to other combinations of Methods 1 to 5.

[0193] In addition, the base station 200 may include a cell-specific K offset,cell and device-specific K offset,UE The user may be notified which of the two is to be used.

[0194] Thus, according to the present embodiment, terminal 100 determines a cell-specific K based on information related to DCI for scheduling (for example, a specific DCI or a specific method). offset,cell and device-specific K offset,UE In this way, if the terminal 100 and the base station 200 recognize different transmission slot timings for each terminal, the terminal-specific K offset,UE Even if the terminal 100 is notified of the cell-specific K offset,cell Therefore, according to this embodiment, it is possible to realize appropriate timing control according to the propagation delay between terminal 100 and base station 200. Note that, based on information about the PDCCH for scheduling (for example, a specific PDCCH or a specific method), the cell-specific K offset,cell and device-specific K offset,UE The same effect can be obtained by controlling the upstream transmission timing using either one of the above.

[0195] DCI format 0_0 and DCI format 1_0, which do not change depending on the settings of each terminal, are also called Fallback DCI. When scheduling is performed using Fallback DCI, the cell-specific K offset,cell otherwise, use the device-specific K offset,UE may also be used.

[0196] (Fourth embodiment) The configurations of the terminal and the base station according to this embodiment may be the same as those of the terminal 100 and the base station 200 shown in Embodiment 1. However, the operations related to the timing adjustment of the terminal 100 and the base station 200 shown in Embodiment 1 are different. For example, the terminal 100 and the base station 200 may perform timing adjustment by "Koffset" that defines the transmission slot timing, similar to Embodiment 3.

[0197] Also, in this embodiment, for example, for data transmission, a HARQ process with HARQ-feedback enabled or a HARQ process with HARQ-feedback disabled is used.

[0198] Information regarding the enabling or disabling of HARQ-feedback may be notified from the base station 200 to the terminal 100, for example, as individual information for each HARQ process.

[0199] The terminal 100, for example, transmits HARQ-feedback (e.g., ACK / NACK) for the PDSCH (or transport block) of the HARQ process with HARQ-feedback enabled, and does not transmit HARQ-feedback for the PDSCH (or transport block) of the HARQ process with HARQ-feedback disabled.

[0200] Hereinafter, Notification Method 1 and Notification Method 2 of Koffset in this embodiment will be described.

[0201] <Notification Method 1 of Koffset> In Notification Method 1, for example, Koffset (e.g., K offset,UE 、K offset,adj 、Alternatively, for the PDSCH used for the notification of Coarse TA, a HARQ process with HARQ-feedback enabled is allocated. For example, the terminal 100 may receive information regarding Koffset by means of a retransmission process with HARQ-feedback enabled. In other words, the terminal 100 does not receive information regarding Koffset by means of a retransmission process with HARQ-feedback disabled.

[0202] Also, the terminal 100 may, for example, reflect the received value of Koffset at a specified timing. For example, when Koffset is notified by means of a MAC CE, the terminal 100 may reflect Koffset 3 slots later (or X slots later) from the HARQ-ACK transmission timing for the PDSCH including the MAC CE. Also, for example, when Koffset is notified by means of RRC signaling, the terminal 100 may reflect Koffset 10 ms later from the reception slot of the PDSCH.

[0203] The base station 200 can, for example, infer whether the terminal 100 has correctly received the MAC CE by receiving the HARQ-feedback signal transmitted from the terminal 100 for the notification of Koffset. Therefore, the possibility that the recognition of the value of Koffset does not match between the base station 200 and the terminal 100 can be reduced.

[0204] Also, since the reflection timing of Koffset after Koffset is received at the terminal 100 is uniquely specified, when Koffset is correctly received at the terminal 100, the recognition of Koffset can be made consistent between the base station 200 and the terminal 100.

[0205] <Notification method 2 of Koffset> In notification method 2, for example, Koffset (for example, K offset,UE 、K offset,adj , or Coarse TA), either a HARQ process with HARQ-feedback enabled or a HARQ process with HARQ-feedback disabled may be assigned. For example, terminal 100 may receive information regarding Koffset through either a retransmission process with HARQ-feedback enabled or a retransmission process with HARQ-feedback disabled.

[0206] For example, when using an HARQ process in which HARQ-feedback is disabled, base station 200 may reduce the probability of misrecognition of transmission timing between base station 200 and terminal 100 due to an error in Koffset notification by using a low MCS or transmitting with a low target error rate (BLER: Block Error Rate), such as repetition transmission.

[0207] Furthermore, in notification method 2, terminal 100 may, for example, reflect the received value of Koffset at a specified timing, as in notification method 1. For example, when Koffset is notified by MAC CE, terminal 100 may reflect Koffset three slots later (or X slots later) from the timing of transmitting HARQ-ACK for a PDSCH including MAC CE.

[0208] On the other hand, when an HARQ process in which HARQ-feedback is disabled is used, HARQ-ACK transmission is not performed. In this case, terminal 100 may, for example, reflect Koffset three slots later (or X slots later) from the timing assumed for HARQ-ACK transmission (e.g., referred to as virtual HARQ-ACK timing) even though it is not actually transmitted.

[0209] Furthermore, the transmission timing of the HARQ-ACK is determined based on, for example, the value of K1 (offset value from the PDSCH slot) notified by DCI when scheduling the PDSCH. For example, when an HARQ process in which HARQ-feedback is disabled is used, terminal 100 does not actually transmit an HARQ-ACK, but may determine a virtual HARQ-ACK timing based on the notified value of K1.

[0210] Furthermore, when HARQ-feedback is disabled, the K1 value is essentially unnecessary, and therefore the K1 value may not be signaled by DCI, may be used for other purposes, or may be treated as an invalid field. In these cases, any value (e.g., the minimum or maximum value) among the values ​​configured as candidates for the K1 value may be used to determine the virtual HARQ-ACK timing. Alternatively, the K1 value to be used when HARQ-feedback is disabled may be configured, or a default value for the K1 value may be specified in the specifications.

[0211] Notification method 2 uniquely defines the timing of Koffset reflection regardless of, for example, whether HARQ-feedback is enabled or disabled, so that when the Koffset value is correctly received at terminal 100, base station 200 and terminal 100 can align their recognition of Koffset.

[0212] The Koffset notification method 1 and notification method 2 have been described above.

[0213] In the third and fourth embodiments, the terminal-specific K offset,UE is, for example, the adjustment value K adj,UE Using K offset,cell -K adj,UE It may also be calculated by the terminal-specific K offset,UE For example, using a coarse TA value (e.g., Coarse TA), offset,cell -TA coarse It may be calculated as follows: K adj,UE Alternatively, the coarse TA value may be reported to terminal 100 by, for example, at least one of an RRC message, a MAC CE, or a DCI.

[0214] Furthermore, for example, when Koffset is notified by a Group common DCI in which information for multiple terminals is included in one DCI, such as DCI format 2_x, terminal 100 may reflect Koffset three slots (or X slots) after the slot in which the DCI is received. offset,UE In order to minimize the occurrence of misrecognition of K offset,UE When DCI including information about the above is received, the base station 200 may transmit a HARA-ACK signal to the base station 200.

[0215] Also, for example, the K offset,UE Even if terminal 100 is notified of the cell-specific K offset,cell That is, a cell-specific K offset,cell or device-specific K offset,UE For example, for HARQ-feedback for PDSCH scheduled by DCI of RNTI other than C-RNTI, which is a terminal-specific ID, a cell-specific K offset,cell may be used.

[0216] Also, for example, the K offset,UE Even if the UE 100 is notified of the cell-specific K offset,cell may be used.

[0217] Also, for example, cell-specific K offset,cell may be a Koffset value specific to a satellite beam, or may be a Koffset value specific to an SSB beam specified in 3GPP.

[0218] Also, cell-specific K offset,cell may be the Koffset value notified by the SIB. offset,UE The Koffset may be a Koffset value notified in an RRC reconfiguration message notified for each terminal, or may be a Koffset value notified in a MAC CE or DCI.

[0219] Also, for example, an offset value (e.g., K offset,cell +K1, K offset,cell +K2 or K offset,UE +K1, K offset,UE If K2 (multiplied by the slot length for time conversion) is smaller than the TA value set in terminal 100 (the TA value converted into time), this means that the transmission slot of the PUSCH or PUCCH comes before the reception slot of the DCI or PDSCH. In this case, terminal 100 does not need to transmit the PUSCH or PUCCH. In addition, in this case, terminal 100 may initiate, for example, a radio link failure procedure (RLF (Radio Link Failure) procedure) or a beam failure procedure (Beam Failure or Beam Recovery). Also, terminal 100 may transmit a RACH for resynchronization.

[0220] The HARQ-feedback may also be referred to as HARQ-ACK or ACK / NACK.

[0221] The embodiments of the present disclosure have been described above.

[0222] Although the above-described embodiments have been described using an NTN environment (e.g., a satellite communication environment) as an example, the present disclosure is not limited thereto. The present disclosure may be applied to other communication environments (e.g., an LTE and / or NR terrestrial cellular environment).

[0223] In the above-described embodiments, examples have been described in which GNSS such as GPS (i.e., position detection using satellite signals) is used. However, position detection using terrestrial cellular base stations, WiFi signals and / or Bluetooth (registered trademark) signals, position detection using an acceleration sensor, or a combination of these may also be performed. Furthermore, the position information may include altitude information in addition to latitude and longitude. Furthermore, it may be a value in a separately defined coordinate system. Altitude information may also be acquired from a barometric pressure sensor, etc.

[0224] In each of the above-described embodiments, an example has been shown in which a terminal notifies a base station of at least one of a TA value and location information, but the timing of notification (trigger for notification) may differ from that in the above-described embodiments. For example, the trigger for notification may be based on another index such as the amount of change in channel quality, instead of the amount of change in the TA value or location. For example, RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), SINR (Signal to Interference plus Noise Ratio), etc. may be used as channel quality. The index used and the threshold for the amount of change may be configured by the base station.

[0225] Also, the base station may instruct which information to notify, such as the TA value or location information.

[0226] Cell-specific TA offset and K offset,cell For example, the difference from the value notified by the cell parameter (for example, a value corresponding to the RTT near the center of the cell) may be notified. By notifying the difference, the amount of information to be notified can be reduced.

[0227] In each of the above-described embodiments, the TA command 1, which is controlled at a fine granularity, may use the TA command of Rel15 NR without changing the granularity and range. By using the granularity and range without changing them, the amount of change in the implementation between the terminal and the base station can be reduced. In addition, the granularity and range of the TA command 2 may be notified by the base station using an SIB or the like. This allows the notification of the TA command 2 to be realized with an appropriate number of bits (for example, the minimum number of bits) depending on the cell size, satellite altitude, etc., and reduces notification overhead. In addition, K offset YaK adj,UE The same applies to the granularity and range of

[0228] The TA command 1 may be expressed as a relative value to the TA command 1 transmitted at the immediately preceding transmission timing, or as a control value relative to the TA value transmitted at the immediately preceding transmission timing. In this case, N in Equation (1) TA The value used is the cumulative value of the TA command 1 received so far. The TA command 2 may be expressed as a relative value from the TA command 2 sent at the previous transmission timing, or as a control value for the TA value sent at the previous transmission timing. In this case, M in equation (2) coarse The value used is the cumulative value of the TA command 2 received so far.

[0229] Cell-specific TA offset and / or K offset,cell may be a value for each beam associated with the SSB. In this case, the amount of information to be notified may be reduced by notifying the difference from the value notified on a cell-by-cell basis.

[0230] Signals and / or information broadcast from the base station may be transmitted using SSB and / or SIB, or may be transmitted in a manner that can be received by multiple terminals, for example, in a DCI format (DCI format 2_x, etc.) common to the group. Furthermore, when TA command 1 and / or TA command 2 are collectively notified to multiple terminals so that the same timing adjustment value is used for multiple terminals, TA command 1 and / or TA command 2 may be transmitted in a DCI format (DCI format 2_x, etc.) common to the group.

[0231] In addition, in each of the above-described embodiments, two types of timing adjustment values ​​with different granularities and ranges are used, but the same granularity and range may be used, or one of them may be different. Furthermore, three or more types of timing adjustment values ​​with different granularities and ranges may be used.

[0232] In each of the above-described embodiments, timing adjustment based on GNSS / ephemeris position information and timing adjustment by path tracking are performed autonomously by the terminal, rather than in response to a command from a base station. The base station detects the reception timing of a signal received from the terminal, but if the reception timing changes significantly within the averaging window during detection, the accuracy of reception timing detection may deteriorate. Therefore, the timing adjustment performed autonomously by the terminal may be configured to specify a minimum interval and / or a minimum timing change width, and the terminal may be configured to change the timing within the specified range. Furthermore, information regarding the minimum interval and / or minimum change width may be notified to the terminal from the base station.

[0233] Furthermore, in each of the above-described embodiments, the terminal may perform timing adjustment based on GNSS / ephemeris position information and timing adjustment by path tracking, triggered by an instruction from the base station.

[0234] Furthermore, a cell may be an area defined by the received power of SSB and / or CSI-RS transmitted by a base station (or satellite), or may be an area defined by a geographical location. Furthermore, the cell in the above embodiment may be replaced with a beam defined by SSB.

[0235] Satellite ephemeris information, which is information about the position of a satellite, may be broadcast in system information or the like, or may be stored in advance by a terminal (or a base station). Also, the terminal (or a base station) may update the satellite ephemeris information when communication is possible. Also, the terminal (or a base station) may identify the position of a satellite using other information.

[0236] In addition, in the above-mentioned embodiments, the case where location information can be used has been described, but for terminals without GNSS functionality and / or terminals that cannot acquire information about satellite locations, timing control may be performed in accordance with timing control information common to the cell broadcast from the base station instead of timing control based on location information. In this case, the base station may transmit timing control information corresponding to the amount of propagation delay near the center of the cell.

[0237] If the PUSCH is allocated by a configured grant, that is, if the PUSCH is not allocated by DCI, the slot timing of the PUSCH transmission is not adjusted with respect to the DCI reception timing, and therefore the terminal may transmit the PUSCH without using TA command 2.

[0238] The uses of the cell-specific TA offset, TA command 1, TA command 2, and the TA value notification from the terminal are not limited to those described above.

[0239] When there are multiple TA groups (TAGs) in a system using multiple cells, component carriers, or transmission / reception points, this TA control may be performed for each TA group. Also, some parameters such as cell-specific TA offsets may be common. Also, Koffset may be set for each TA group. Alternatively, since the delay difference between each component carrier (or cell) is small compared to the slot length, Koffset set for a PCell or SpCell may be used for other component carriers or cells (SCells). This reduces the amount of information to be reported.

[0240] Although the timing adjustment value based on the position information has been described as a timing adjustment value with fine granularity, it may be positioned as a timing adjustment value with coarse granularity in consideration of the accuracy of the position information, etc.

[0241] The base station may be referred to as a gNodeB or a gNB, and the terminal may be referred to as a UE.

[0242] The slot may be replaced with a time slot, a minislot, a frame, a subframe, or the like.

[0243] Furthermore, the notation "··· part" in each of the above-mentioned embodiments may be replaced with other notations such as "··· circuitry," "··· device," "··· unit," or "··· module."

[0244] In addition, in each of the above-described embodiments, the radio wave propagation speed is set to approximately 3×10 8 [m / s], but is not limited to this, for example, 2.99792××10 8 Numerical values ​​such as [m / s] may be used. The accuracy of the radio wave propagation speed may depend on the implementation.

[0245] (control signal) In the present disclosure, a downlink control signal (or downlink control information) related to an embodiment of the present disclosure may be, for example, a signal (or information) transmitted in a Physical Downlink Control Channel (PDCCH) of a physical layer, or a signal (or information) transmitted in a Medium Access Control Control Element (MAC CE) or Radio Resource Control (RRC) of a higher layer. Furthermore, the signal (or information) is not limited to being notified by a downlink control signal, but may be predefined in a specification (or standard) or preconfigured in a base station and a terminal.

[0246] In the present disclosure, an uplink control signal (or uplink control information) related to an embodiment of the present disclosure may be, for example, a signal (or information) transmitted in a PUCCH of a physical layer, or a signal (or information) transmitted in a MAC CE or RRC of a higher layer. Furthermore, the signal (or information) is not limited to being notified by an uplink control signal, but may be predefined in a specification (or standard), or may be preconfigured in a base station and a terminal. Furthermore, the uplink control signal may be replaced with, for example, uplink control information (UCI), 1st stage sidelink control information (SCI), or 2nd stage SCI.

[0247] (base station) In an embodiment of the present disclosure, the base station may be a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a parent device, a gateway, or the like. Furthermore, in sidelink communication, the base station may be replaced by a terminal. Furthermore, the base station may be replaced by a relay device that relays communication between an upper node and a terminal. Furthermore, the base station may be replaced by a roadside unit.

[0248] (Uplink / Downlink / Sidelink) An embodiment of the present disclosure may be applied to, for example, any of an uplink, a downlink, and a sidelink. For example, an embodiment of the present disclosure may be applied to a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), or a Physical Random Access Channel (PRACH) in the uplink, a Physical Downlink Shared Channel (PDSCH), a PDCCH, or a Physical Broadcast Channel (PBCH) in the downlink, or a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Control Channel (PSCCH), or a Physical Sidelink Broadcast Channel (PSBCH) in the sidelink.

[0249] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0250] (Data channel / Control channel) An embodiment of the present disclosure may be applied to, for example, either a data channel or a control channel. For example, the channel in an embodiment of the present disclosure may be replaced with any of the data channels PDSCH, PUSCH, and PSSCH, or the control channels PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0251] (reference signal) In one embodiment of the present disclosure, the reference signal is a signal known by both the base station and the mobile station, and may be referred to as a Reference Signal (RS) or a pilot signal. The reference signal may be any of a Demodulation Reference Signal (DMRS), a Channel State Information - Reference Signal (CSI-RS), a Tracking Reference Signal (TRS), a Phase Tracking Reference Signal (PTRS), a Cell-specific Reference Signal (CRS), or a Sounding Reference Signal (SRS).

[0252] (time interval) In an embodiment of the present disclosure, the unit of time resource is not limited to one or a combination of slots and symbols, but may be, for example, a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot subslot, a minislot, or a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or a Single Carrier-Frequency Division Multiplexing (SC-FDMA) symbol, or another time resource unit. Furthermore, the number of symbols included in one slot is not limited to the number of symbols exemplified in the above-mentioned embodiment, and may be another number of symbols.

[0253] (frequency band) An embodiment of the present disclosure may be applied to either a licensed band or an unlicensed band.

[0254] (communication) An embodiment of the present disclosure may be applied to any of communication between a base station and a terminal (Uu link communication), communication between terminals (Sidelink communication), and Vehicle to Everything (V2X) communication. For example, the channel in an embodiment of the present disclosure may be replaced with any of PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0255] An embodiment of the present disclosure may be applied to a terrestrial network, a non-terrestrial network (NTN) using a satellite or a high altitude pseudo satellite (HAPS), or a terrestrial network in which transmission delay is large compared to the symbol length or slot length, such as a network with a large cell size or an ultra-wideband transmission network.

[0256] (antenna port) In one embodiment of the present disclosure, an antenna port refers to a logical antenna (antenna group) consisting of one or more physical antennas. For example, an antenna port does not necessarily refer to a single physical antenna, but may refer to an array antenna consisting of multiple antennas. For example, the number of physical antennas that an antenna port is composed of is not specified, and the antenna port may be specified as the smallest unit by which a terminal station can transmit a reference signal. Furthermore, an antenna port may also be specified as the smallest unit for multiplying a weighting factor of a precoding vector.

[0257] <5G NR system architecture and protocol stack> 3GPP is working on the next release of fifth-generation cellular technology (also known as 5G), which includes the development of New Radio Access Technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for the prototyping and commercial deployment of 5G NR compliant devices (e.g., smartphones).

[0258] For example, the system architecture assumes a Next Generation - Radio Access Network (NG-RAN) with gNBs. The gNBs provide UE-side termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other via an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) via a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity that performs AMF) via an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity that performs UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 14 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0259] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the Packet Data Convergence Protocol (PDCP) sublayer (see, for example, TS 38.300, section 6.4), the Radio Link Control (RLC) sublayer (see, for example, TS 38.300, section 6.3), and the Medium Access Control (MAC) sublayer (see, for example, TS 38.300, section 6.2), which are terminated on the network side at the gNB. A new Access Stratum (AS) sublayer (Service Data Adaptation Protocol (SDAP)) has also been introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack has also been defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is given in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in clauses 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0260] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0261] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), the Physical Uplink Shared Channel (PUSCH), and the Physical Uplink Control Channel (PUCCH) as uplink physical channels, and the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Broadcast Channel (PBCH) as downlink physical channels.

[0262] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communication (mMTC), which have diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in the downlink and 10 Gbps in the uplink) and effective (user-experienced) data rates that are approximately three times higher than those offered by IMT-Advanced. On the other hand, URLLC imposes stricter requirements for ultra-low latency (0.5 ms user-plane latency for UL and DL, respectively) and high reliability (1-10-5 within 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments). 2 ), wide coverage in adverse environments, and extremely long battery life (15 years) for low-cost devices may be desired.

[0263] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. Subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. Similar to LTE systems, the term "resource element" can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0264] In the new radio system 5G-NR, a resource grid of subcarriers and OFDM symbols is defined for each numerology and each carrier in the uplink and downlink. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0265] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 15 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0266] For example, the gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, encryption, and integrity protection of data; - AMF selection at UE attach time if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data towards UPF; - Routing of control plane information towards AMF; - Setting up and tearing down connections; - scheduling and sending of paging messages; - Scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, Maintenance (OAM) Function); - Configuring measurements and measurement reporting for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Network slicing support; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Sharing of radio access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0267] The Access and Mobility Management Function (AMF) hosts the following main functions: - Ability to terminate Non-Access Stratum (NAS) signaling; - NAS signaling security; - Access Stratum (AS) security control; - 3GPP Core Network (CN) inter-node signaling for mobility between access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Managing the registration area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization, including checking roaming privileges; - Mobility management control (subscription and policy); - Network slicing support; - Selection of Session Management Function (SMF).

[0268] Additionally, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and policy rule enforcement for the user plane part; - Traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - Branching Point for supporting multi-homed PDU session; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping to the QoS flow of the SDF); - Downlink packet buffering and trigger function for downlink data notification.

[0269] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Enforcement of control part policies and QoS; - Notification of downlink data.

[0270] <Procedures for RRC connection setup and reconfiguration> Figure 16 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).

[0271] RRC is a higher layer signaling protocol used to configure the UE and the gNB. With this transition, the AMF prepares UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message. The gNB then sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures the UE to set up a Signaling Radio Bearer 2 (SRB2) and a Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration steps are omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0272] Therefore, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes: control circuitry that, in operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that, in operation, transmits an initial context setup message to the gNodeB via the NG connection so that a signaling radio bearer between the gNodeB and a user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling that includes a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. Then, the UE performs uplink transmission or downlink reception based on the resource allocation configuration.

[0273] <IMT usage scenarios from 2020 onwards> Figure 17 shows some use cases for 5G NR. The 3rd Generation Partnership Project New Radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 17 shows some example use scenarios envisioned for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0274] URLLC use cases have stringent performance requirements, such as throughput, latency, and availability. URLLC use cases are envisioned as one of the enabling technologies for future applications, such as wireless control of industrial production or manufacturing processes, remote medical surgery, automated power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the uplink (UL) and 0.5 ms on the downlink (DL). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size at a user plane latency of 1 ms.

[0275] From a physical layer perspective, reliability can be improved in many possible ways. Current reliability improvement room includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and developed. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0276] Additionally, technology enhancements targeted by NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means that a transmission with previously allocated resources is stopped and the allocated resources are used for another transmission with a later requested lower latency / higher priority requirement. Thus, a previously allowed transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0277] The use case for massive machine-type communication (mMTC) is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to latency. These devices are required to be low cost and have very long battery life. From an NR perspective, using very narrow bandwidth portions is one solution that saves power and allows for long battery life from the UE perspective.

[0278] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, for example for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0279] For NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution: high reliability (up to 10-6 level), high availability, packet sizes up to 256 bytes, and time synchronization down to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the 0.5 ms to 1 ms range (e.g., 0.5 ms latency on the targeted user plane)).

[0280] Furthermore, for NR URLLC, several technical enhancements may be available from the perspective of the physical layer. These technical enhancements include enhancements to the PDCCH (Physical Downlink Control Channel) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. Also, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. In addition, there may be enhancements to the PUSCH related to mini-slot level hopping, and enhancements to retransmission / repetition. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0281] <QoS Control> The QoS (Quality of Service) model of 5G is based on QoS flows, and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flow) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flow). Therefore, at the NAS level, a QoS flow is the finest granularity QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header via the NG-U interface.

[0282] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for each PDU session, e.g., as shown above with reference to Figure 16. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and the 5GC associate UL packets and DL packets with QoS flows, while AS-level mapping rules in the UE and the NG-RAN associate UL QoS flows and DL QoS flows with DRBs.

[0283] Figure 18 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services, as illustrated in Figure 17) interacts with the 3GPP core network to provide services. For example, it accesses a Network Exposure Function (NEF) to support applications that affect traffic routing, or interacts with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on the operator's deployment, Application Functions that are considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions that are not authorized by the operator to directly access Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0284] Figure 18 further illustrates further functional units of the 5G architecture, namely, Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0285] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0286] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0287] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0288] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0289] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a wireless transceiver and processing / control circuitry. The wireless transceiver may include a receiver and a transmitter, or both functions. The wireless transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0290] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0291] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0292] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0293] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0294] A terminal according to one embodiment of the present disclosure includes a control circuit that controls uplink transmission timing using either a first offset or a second offset shorter than the first offset based on information related to a control signal for scheduling, and a transmission circuit that performs uplink transmission based on the control of the uplink transmission timing.

[0295] In one embodiment of the present disclosure, the information indicates a format of the control signal, and the control circuit uses the first offset when the format is DCI format 0_0 or DCI format 1_0.

[0296] In one embodiment of the present disclosure, the information indicates a search space to be used for transmitting the control signal, and the control circuit uses the first offset when the search space is a search space common to multiple terminals.

[0297] In one embodiment of the present disclosure, the information indicates a resource used to transmit the control signal, and the control circuit uses the first offset when the resource is a resource common to multiple terminals.

[0298] In one embodiment of the present disclosure, the information indicates a scheduling method by the control signal, and the control circuit uses the first offset when the scheduling method is semi-persistent scheduling.

[0299] In one embodiment of the present disclosure, the information indicates a retransmission process number notified by the control signal, and the control circuit selects either the first offset or the second offset according to the retransmission process number.

[0300] In one embodiment of the present disclosure, the control circuit selects the first offset when the retransmission process number is 0.

[0301] In one embodiment of the present disclosure, the wireless communication device includes a receiving circuit configured to receive information about the second offset through a retransmission process in which retransmission control is enabled.

[0302] In one embodiment of the present disclosure, the wireless communication device includes a receiving circuit that receives information about the second offset through a retransmission process in which retransmission control is disabled.

[0303] A base station according to one embodiment of the present disclosure includes a control circuit that controls uplink reception timing using either a first offset or a second offset shorter than the first offset based on information related to a control signal for scheduling, and a receiving circuit that performs uplink reception based on the control of the uplink reception timing.

[0304] In a transmission method according to one embodiment of the present disclosure, a terminal controls uplink transmission timing using either a first offset or a second offset shorter than the first offset based on information regarding a control signal for scheduling, and performs uplink transmission based on the control of the uplink transmission timing.

[0305] In a receiving method according to one embodiment of the present disclosure, a base station controls uplink reception timing using either a first offset or a second offset shorter than the first offset based on information regarding a control signal for scheduling, and performs uplink reception based on the control of the uplink reception timing.

[0306] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2020-177279, filed on October 22, 2020, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0307] One aspect of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0308] 100 devices 101 PRACH generation section 102,206 Data Generation Unit 103 Location information acquisition unit 104 Timing adjustment unit 105,208 Radio transmitter 106,201 antennas 107,202 Radio receiver 108 Demodulation and Decoding Unit 109,209 Control unit 200 base stations 203 Data receiving processing unit 204 PRACH detection unit 205 Timing control information generator 207 Data transmission processing unit

Claims

1. a control circuit configured to control uplink transmission timing using one of a first offset and a second offset based on information relating to a control signal used for scheduling; a transmitter that performs uplink transmission based on the uplink transmission timing; Equipped with the first offset is a cell-specific offset, and the second offset is an offset based on the cell-specific offset and a terminal-specific offset; the information about the control signal is a Radio Network Temporary Identifier (RNTI) of control information about downlink data transmission, When scheduled by downlink control information using an RNTI different from a C-RNTI, the uplink transmission timing is controlled based on the first offset. Terminal.

2. the first offset is used for uplink transmission scheduled by an UL grant in an RA response; The terminal according to claim 1 .

3. The uplink transmission timing is a transmission timing of a response signal to a downlink data transmission. The terminal according to claim 1 .

4. The first offset is used for a response signal to a PDSCH including message 4. The terminal according to claim 1 .

5. The first offset is used for a response signal to a PDSCH transmitted in the fourth step of a four-step random access procedure. The terminal according to claim 1 .

6. a control circuit configured to control uplink transmission timing using one of a first offset and a second offset based on information relating to a control signal used for scheduling; a receiver configured to receive uplink transmissions based on the uplink transmission timing; Equipped with the first offset is a cell-specific offset, and the second offset is an offset based on the cell-specific offset and a terminal-specific offset; the information about the control signal is a Radio Network Temporary Identifier (RNTI) of control information about downlink data transmission; When scheduled by downlink control information using an RNTI different from a C-RNTI, the uplink transmission timing is controlled based on the first offset. Base station.

7. the first offset is used for uplink transmission scheduled by an UL grant in an RA response; The base station of claim 6.

8. The uplink transmission timing is a transmission timing of a response signal to a downlink data transmission. The base station of claim 6.

9. The first offset is used for a response signal to a PDSCH including message 4. The base station of claim 6.

10. The first offset is used for a response signal to a PDSCH transmitted in the fourth step of a four-step random access procedure. The base station of claim 6.

11. controlling uplink transmission timing using one of the first offset and the second offset based on information about a control signal used for scheduling; performing uplink transmission based on the uplink transmission timing; the first offset is a cell-specific offset, and the second offset is an offset based on the cell-specific offset and a terminal-specific offset; the information about the control signal is a Radio Network Temporary Identifier (RNTI) of control information about downlink data transmission; When scheduled by downlink control information using an RNTI different from a C-RNTI, the uplink transmission timing is controlled based on the first offset. Sending method.

12. the first offset is used for uplink transmission scheduled by an UL grant in an RA response; The transmission method according to claim 11.

13. The uplink transmission timing is a transmission timing of a response signal to a downlink data transmission. The transmission method according to claim 11.

14. controlling uplink transmission timing using one of the first offset and the second offset based on information about a control signal used for scheduling; receiving an uplink transmission based on the uplink transmission timing; the first offset is a cell-specific offset, and the second offset is an offset based on the cell-specific offset and a terminal-specific offset; the information about the control signal is a Radio Network Temporary Identifier (RNTI) of control information about downlink data transmission; When scheduled by downlink control information using an RNTI different from a C-RNTI, the uplink transmission timing is controlled based on the first offset. Receiving method.

15. the first offset is used for uplink transmission scheduled by an UL grant in an RA response; 15. The receiving method according to claim 14.

16. The uplink transmission timing is a transmission timing of a response signal to a downlink data transmission.

15. The receiving method according to claim 14.

17. controlling uplink transmission timing using one of a first offset and a second offset based on information about a control signal used for scheduling; performing uplink transmission based on the uplink transmission timing; Control the the first offset is a cell-specific offset, and the second offset is an offset based on the cell-specific offset and a terminal-specific offset; the information about the control signal is a Radio Network Temporary Identifier (RNTI) of control information about downlink data transmission; When scheduled by downlink control information using an RNTI different from a C-RNTI, the uplink transmission timing is controlled based on the first offset. Integrated circuit.

18. controlling uplink transmission timing using one of a first offset and a second offset based on information about a control signal used for scheduling; receiving an uplink transmission based on the uplink transmission timing; Control the the first offset is a cell-specific offset, and the second offset is an offset based on the cell-specific offset and a terminal-specific offset; the information about the control signal is a Radio Network Temporary Identifier (RNTI) of control information about downlink data transmission; When scheduled by downlink control information using an RNTI different from a C-RNTI, the uplink transmission timing is controlled based on the first offset. Integrated circuit.

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