Terminal, communication method, and integrated circuit

Abstract

To improve transmission efficiency in unlicensed bands.SOLUTION: A terminal includes a receiving circuit that receives control information regarding a cyclic prefix (CP) length from a base station, and a control circuit that controls uplink transmission based on the CP length. The CP length differs when information indicating a channel occupation time for the terminal is a first value and when it is a second value different from the first value.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] The 3rd Generation Partnership Project (3GPP) has completed the physical layer specifications for Release 16 NR (New Radio access technology) as a functional extension of 5th Generation mobile communication systems (5G). NR supports enhanced mobile broadband (eMBB) to meet the requirements of high speed and large capacity, as well as functions that realize ultra-reliable and low latency communication (URLLC) (see, for example, non-patent documents 1-5). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 38.211 V16.2.0, "NR; Physical channels and modulation (Release 16)," June 2020 [Non-patent document 2] 3GPP TS 38.212 V16.2.0, "NR; Multiplexing and channel coding (Release 16)," June 2020 [Non-patent document 3] 3GPP TS 38.213 V16.2.0, "NR; Physical layer procedure for control (Release 16)," June 2020 [Non-patent document 4] 3GPP TS 38.214 V16.2.0, "NR; Physical layer procedures for data (Release 16)," June 2020 [Non-Patent Document 5] 3GPP TS 38.331 V16.1.0, "NR; Radio Resource Control (RRC) protocol specification (Release 16)", July 2020 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is room for further consideration regarding communication methods in unlicensed bands.

[0005] Non-limiting examples of the present disclosure contribute to providing a base station, a terminal, and a communication method that can improve transmission efficiency in unlicensed bands. [Means for solving the problem]

[0006] A base station according to one embodiment of the present disclosure includes a control circuit that determines a cyclic prefix (CP) length in coordination between a terminal and a base station, and a transmission circuit that transmits control information regarding the determined CP length to the terminal.

[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. [Effects of the Invention]

[0008] According to an embodiment of the present disclosure, transmission efficiency in unlicensed bands can be improved.

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

[0010] [Figure 1] An example of channel access using Frame Based Equipment (FBE) [Figure 2] An example of a CP extension for multiple transmission timings [Figure 3] Figure showing an example of the amount of CP extension for gap adjustment [Figure 4] Block diagram showing an example of the configuration of a portion of a base station [Figure 5] Block diagram showing an example of the configuration of a part of a terminal [Figure 6] Block diagram showing an example of the configuration of a base station [Figure 7] Block diagram showing an example of a terminal configuration [Figure 8] A sequence diagram showing an example of the operation of a base station and a terminal. [Figure 9] FIG. 10 is a diagram showing an example of COT acquisition control in FBE according to the first embodiment; [Figure 10] FIG. 10 shows an example of setting the amount of CP extension according to the second embodiment. [Figure 11] FIG. 10 shows an example of setting the amount of CP extension according to the second embodiment. [Figure 12] FIG. 10 shows an example of setting the amount of CP extension according to the third embodiment. [Figure 13] FIG. 10 shows an example of setting the amount of CP extension according to the third embodiment. [Figure 14] FIG. 13 shows an example of setting the amount of CP extension according to the fourth embodiment. [Figure 15] Diagram of an example architecture of a 3GPP NR system [Figure 16] Schematic diagram showing the functional separation between NG-RAN (Next Generation - Radio Access Network) and 5GC (5th Generation Core) [Figure 17] Sequence diagram of the Radio Resource Control (RRC) connection setup / reconfiguration procedure [Figure 18] Schematic diagram showing usage scenarios for enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Figure 19] 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] [Unlicensed frequency bands] In Release 16 NR, for example, the introduction of NR-Unlicensed (also called NR-U) will be considered, which will enable communication based on the NR radio access method in unlicensed frequency bands (also called unlicensed bands).

[0013] In an unlicensed frequency band, for example, before transmitting, each device performs carrier sensing (also called Listen Before Talk (LBT)) to check whether other systems or terminals are using the wireless channel.

[0014] In addition, in Release 17 NR, extensions are being considered to operate, for example, Ultra Reliable and Low Latency Communications (URLLC) services in unlicensed frequency bands. One of the extensions is, for example, support for operation (e.g., UE-initiated COT) in which a terminal (also referred to as User Equipment (UE)) acquires channel occupancy time (e.g., COT) in Frame based equipment (FBE), which is one of the channel access methods. Note that FBE is also referred to as semi-static channel occupancy.

[0015] However, the scheduling method for UE-initiated COT has not been fully studied.

[0016] Fig. 1 is a diagram showing an example of channel access using FBE. In FBE of Release 16 NR-U, for example, as shown in Fig. 1, a base station (also referred to as a gNB, for example) may acquire a COT by performing an LBT (e.g., a Category 2 LBT) at the beginning of a period called a Fixed Frame Period (FFP). A terminal may acquire a COT by performing a Category 2 or Category 1 LBT within the base station's COT (also referred to as a gNB COT, for example).

[0017] Load Based Equipment (LBE), which is a channel access method different from FBE, can attempt to acquire the COT at any time. On the other hand, LBE may perform Category 4 LBT, which can set a longer LBT period than Category 1 or Category 2.

[0018] In this way, FBE can acquire the COT during a shorter LBT period than LBE. On the other hand, FBE provides an "Idle period" during which neither the base station nor the terminal can transmit (for example, during which the COT cannot be acquired), as shown in FIG.

[0019] [Configured grant transmission] This section describes configured grant transmission (e.g., configured grant transmission in licensed frequency bands) supported in Release 15 NR.

[0020] Configured grant transmission of uplink data (for example, PUSCH: Physical Uplink Shared Channel) includes, for example, "Configured grant type 1 transmission" and "Configured grant type 2 transmission."

[0021] In configured grant type 1 transmission, information such as a coding and modulation scheme (MCS), radio resource allocation (e.g., allocation of at least one of time resources and frequency resources), transmission timing, and the number of Hybrid Automatic Repeat Request (HARQ) processes (e.g., referred to as configured grant configuration information or CG configuration information) may be configured (in other words, notified or instructed) in the terminal by a terminal-specific higher layer signal. For example, when uplink data is generated, the terminal may transmit uplink data (e.g., PUSCH) based on the CG configuration information such as the pre-configured MCS and radio resources, without a UL grant (e.g., dynamic uplink data scheduling information) from the base station via a downlink control channel (e.g., PDCCH: Physical Downlink Control Channel).

[0022] Note that the higher layer signal may also be called, for example, a Radio Resource Control (RRC) signal, higher layer signaling, or higher layer parameter.

[0023] Furthermore, in Configured grant type 2 transmission, the Configured grant transmission is activated or released by, for example, a PDCCH from a base station. In Configured grant type 2 transmission, information such as the transmission timing and the number of HARQ processes may be configured by a terminal-specific higher layer signal, as in Configure grant type 1 transmission. On the other hand, in Configured grant type 2 transmission, information such as MCS and radio resource allocation information may be configured by Downlink Control Information (DCI) for Activation. For example, when uplink data is generated, the terminal may transmit uplink data (e.g., PUSCH) using CG configuration information such as the MCS and radio resources configured by the higher layer signal and the DCI for Activation semi-permanently (in other words, statically or semi-statically) (in other words, without a UL grant or UL grant-free).

[0024] In Release 15 NR, for example, a UL grant is used for retransmission control of a Configured grant transmission. For example, the UL grant may control the MCS and radio resource allocation information of uplink data for retransmission.

[0025] Furthermore, as a non-limiting example, the HARQ process number (or HARQ process ID) used in the transmission of the Configured grant may be uniquely determined from the slot number for transmitting the PUSCH (in other words, the transmission timing of the PUSCH). For example, the PUSCH transmitted in the transmission of the Configured grant may be treated in the same way as a signal transmitted for the first time, and the Redundancy Version (RV) may be 0.

[0026] [Configured grant transmission in unlicensed frequency bands] In Configured grant transmission in NR-U (NR in unlicensed frequency bands), some of the parameters (e.g., parameters related to retransmission control) used for decoding PUSCH, such as the HARQ process number, New Data Indicator (NDI), and RV, may be notified from the terminal to the base station by uplink control information for Configured grant transmission (e.g., called CG-UCI: Configured grant Uplink Control Information).

[0027] The CG-UCI may be transmitted at the same transmission timing (e.g., the same slot) as the PUSCH (also referred to as a CG-PUSCH) by using, for example, part of the radio resources allocated to the PUSCH. In other words, the CG-UCI may be multiplexed with the CG-PUSCH.

[0028] Here, the reason why the HARQ process number is explicitly notified using the CG-UCI in NR-U is as follows. For example, in NR-U, the PUSCH is not necessarily transmitted depending on the result of the LBT. For this reason, for example, in a method of determining the HARQ process number in association with the transmission timing of the PUSCH, such as in a licensed frequency band, there is a possibility that the HARQ process cannot be flexibly used depending on whether the PUSCH is actually transmitted or not. Therefore, the HARQ process number can be notified using the CG-UCI transmitted together with the CG-PUSCH, for example.

[0029] Furthermore, in NR-U, for example, upon receiving a NACK or timer expiration, a terminal supports an operation of retransmitting without a UL grant using radio resources set for a Configured grant. Therefore, for example, information indicating the initial transmission or retransmission status (e.g., NDI) and an RV to be applied to the PUSCH at the time of retransmission may be transmitted by CG-UCI.

[0030] In NR-U, for example, HARQ-ACK feedback for CG-PUSCH may be explicitly notified from the base station to the terminal by information called Downlink Feedback Indicator (DFI). For CG-PUSCH, for example, a HARQ process number is notified by CG-UCI. For this reason, for example, if the base station fails to receive CG-UCI, the base station may not be able to identify which HARQ process data was transmitted from, and may not be able to specify the HARQ process and instruct retransmission of the PUSCH. Therefore, for example, the base station may notify (in other words, feed back) HARQ-ACK feedback information for all HARQ processes. Furthermore, for example, the base station may collectively feed back HARQ-ACK feedback information for multiple PUSCHs to the terminal, thereby reducing overhead due to LBT and improving the efficiency of retransmission control.

[0031] In the retransmission control using the DFI, the MCS and radio resource allocation of the PUSCH for retransmission may be the same as those in the initial transmission. Furthermore, the DFI may be transmitted, for example, in the PDCCH. Furthermore, the DFI may include other parameters such as a transmission power control (TPC) command in addition to the HARQ-ACK.

[0032] [CP extension in CG-PUSCH] In CG-PUSCH transmission, for example, even if a transmission resource is assigned to a terminal, if the terminal does not have transmission data, PUSCH transmission is not performed. If PUSCH transmission is not performed, the resource assigned to the terminal is not used, and therefore resource utilization efficiency may be reduced.

[0033] Therefore, methods have been considered for allocating multiple terminals to the same CG resource and sharing the resource. When multiple terminals share resources, for example, if multiple terminals transmit on the shared resource simultaneously, collisions may occur, and the base station may not be able to correctly receive the signals from each terminal. Therefore, to avoid collisions, a mechanism has been introduced that uses, for example, the "CP extension" to set different transmission start timings for each terminal.

[0034] In the following, the CP extension used in the mechanism for setting different transmission start timings for each terminal will be referred to as the "CP extension for multiple transmission timings."

[0035] Fig. 2 shows an example of a CP extension for multiple transmission timings. The example shown in Fig. 2 shows the CP extension when starting transmission of a PUSCH (e.g., a useful symbol) at Symbol N. Also, in Fig. 2, as an example, the subcarrier spacing (SCS) is 15 kHz, and T shown in Fig. 2 may correspond to one symbol. As shown in Fig. 2, by setting a different CP extension amount (also called extension amount, CP extension length, or CP length) such as "T-16 us", "T-25 us", ..., "T-61 us", or "0 us" for each terminal, the transmission start timing may differ between terminals.

[0036] For example, a case will be described in which there is another terminal (e.g., terminal B) whose transmission start timing (e.g., a smaller extension amount than terminal A) is set later than the transmission start timing of a certain terminal (e.g., terminal A). In this case, if terminal A starts transmission before terminal B, terminal B will perform carrier sensing (e.g., LBT) and the channel will become busy, so it will not start transmission.

[0037] In this way, in the CP extension for multiple transmission timings, by setting different CP extension amounts between terminals, it is possible to suppress collisions of transmissions between terminals (in other words, occurrence of interference).

[0038] [CP extension in Dynamic Grant (DG)-PUSCH] In channel access in unlicensed bands, depending on the type of LBT (e.g., category), the gap (e.g., period of no transmission) from the previous transmission may be set to a specified length (or less than the specified length). For example, the gap from the previous transmission may be set to 16 us or 25 us.

[0039] Therefore, in the DG-PUSCH, for example, a CP extension amount for adjusting the gap with the previous transmission may be set using a UL grant.

[0040] In the following, the CP extension used to adjust the gap with the previous transmission will be referred to as the "CP extension for gap adjustment."

[0041] In the gap adjustment CP extension, the CP extension amount may be set (for example, joint encoding) together with the Channel Access Type (also called LBT Type) and the Channel access priority type (CAPC) in DCI format 0_1, for example.

[0042] FIG. 3 is a diagram showing an example of a CP extension amount (or candidate CP extension amounts) that can be set in the CP extension for gap adjustment. In FIG. 3, C1 is a value set based on the subcarrier spacing (SCS), and C2 and C3 are values ​​set by higher layer signaling. TA indicates timing alignment. The transmission timing of the PUSCH in the terminal may be set earlier by TA than the reception timing of the terminal to match the transmission and reception timing of the base station. On the other hand, because gap adjustment is performed based on the transmission and reception timing of the terminal (for example, to adjust the period from reception to transmission by the terminal), the CP extension for gap adjustment may include a TA to subtract the influence of the TA. In this way, the CP extension for gap adjustment may include a candidate CP extension amount from which the influence of the TA has been subtracted (in other words, a CP extension amount calculated based on the TA). However, for example, when transmitting following uplink transmission, the TA is not subtracted during gap adjustment, so all candidate CP extension amounts do not need to be calculated based on the TA.

[0043] For example, before transmitting the PUSCH, the terminal may perform CP extension in response to the notification of the CP extension for gap adjustment.

[0044] [UE-initiated COT scheduling] When UE-initiated COT is scheduled semi-statically (in other words, when the FFP from which the terminal acquires COT is assigned semi-statically), the transmission delay time of the base station (or the terminal) may increase. For example, when COT acquisition (in other words, transmission start) is set at the beginning of a certain FFP for terminal A and terminal A does not have transmission data, even if another terminal B (or base station) has transmission data (however, terminal B does not have COT acquisition set in the FFP), terminal A can transmit but terminal B cannot transmit, so the delay time of terminal B may increase.

[0045] In addition, in FBE, COT acquisition is possible at the beginning of the FFP, and the timing for COT acquisition does not need to be set at a timing different from the beginning of the FFP (see, for example, ETSI EN 301 893). Therefore, even if there is no transmission data at the beginning of the FFP, if transmission may occur in the middle of the FFP at the terminal, it is assumed that COT acquisition will be performed at the beginning of the FFP.

[0046] In this way, a UE-initiated COT scheduling method is expected for a terminal having data to acquire a COT based on the timing of COT acquisition being the beginning of an FFP (for example, a constraint on COT acquisition).

[0047] Therefore, in one embodiment of the present disclosure, a method for improving transmission efficiency when UE-initiated COT scheduling is performed in an unlicensed frequency band will be described.

[0048] (Embodiment 1) [Communication System Overview] A communication system according to an embodiment of the present disclosure may include, for example, a base station 100 (e.g., gNB) shown in Figures 4 and 6, and a terminal 200 (e.g., UE) shown in Figures 5 and 7. There may be a plurality of base stations 100 and a plurality of terminals 200 in the communication system.

[0049] 4 is a block diagram showing a configuration example of a portion of base station 100 according to an embodiment of the present disclosure. In base station 100 shown in FIG. 4, scheduling unit 104 (e.g., corresponding to a control circuit) determines a CP length (e.g., a CP extension amount) coordinated between terminal 200 and base station 100. Transmitting unit 109 (e.g., corresponding to a transmitting circuit) transmits control information (e.g., CP extension setting information) related to the determined CP length to terminal 200.

[0050] Fig. 5 is a block diagram showing a configuration example of a portion of terminal 200 according to one embodiment of the present disclosure. In terminal 200 shown in Fig. 5, receiver 201 (e.g., corresponding to a receiver circuit) receives control information (e.g., CP extension setting information) related to the CP length coordinated between terminal 200 and base station 100. Transmission controller 204 (e.g., corresponding to a control circuit) controls uplink transmission (e.g., COT acquisition timing or transmission start timing) based on the CP length.

[0051] [Base station configuration] 6 is a block diagram showing an example configuration of a base station 100 according to an embodiment of the present disclosure. In FIG. 6, the base station 100 includes a receiving unit 101, a demodulating and decoding unit 102, a carrier sensing unit 103, a scheduling unit 104, a control information holding unit 105, a data and control information generating unit 106, an encoding and modulating unit 107, a cyclic prefix (CP) adding unit 108, and a transmitting unit 109.

[0052] The receiving unit 101 performs receiving processing such as down-conversion or A / D conversion on a received signal received via an antenna, and outputs the received signal after receiving processing to the demodulation and decoding unit 102 and the carrier sense unit 103. The received signal may include, for example, a signal transmitted from the terminal 200 (e.g., an uplink signal) or a signal of another system.

[0053] The demodulation and decoding unit 102 demodulates and decodes the received signal (for example, an uplink signal) input from the receiving unit 101 , and outputs the decoding result to the scheduling unit 104 .

[0054] The carrier sense unit 103 may perform carrier sensing (e.g., LBT) based on, for example, a received signal input from the receiving unit 101. For example, the carrier sense unit 103 may determine whether the channel state is "busy" or "idle" (in other words, whether the channel is available for use) based on the received signal input from the receiving unit 101. The carrier sense unit 103 outputs information indicating the determined channel state to the scheduling unit 104.

[0055] The scheduling unit 104, for example, determines CP extension setting information (which may include, for example, the CP extension amount), Configured grant (CG) setting information, or FBE setting information (which may include, for example, the FFP period or timing) for the terminal 200, and outputs the determined CP extension setting information, CG setting information, or FBE setting information to the control information holding unit 105.

[0056] Furthermore, the scheduling unit 104 may instruct the data and control information generating unit 106 to generate data or control information, for example, based on the decoding result input from the demodulation and decoding unit 102. Furthermore, when transmitting signaling information including, for example, CP extension setting information, CG setting information, or FBE setting information, the scheduling unit 104 may instruct the data and control information generating unit 106 to generate the signaling information. Furthermore, the scheduling unit 104 may output, for example, information regarding the amount of CP extension during downlink transmission to the CP adding unit 108. Furthermore, the scheduling unit 104 may determine whether or not to perform transmission, for example, based on information indicating the channel state input from the carrier sensing unit 103, and output a transmission instruction to the transmitting unit 109 based on the determination result.

[0057] The control information storage unit 105 stores control information such as CP extension setting information or CG setting information for each terminal 200. For example, the control information storage unit 105 may output the stored information to each component of the base station 100 (for example, the scheduling unit 104) as needed.

[0058] The data and control information generating unit 106 generates data or control information, for example, in accordance with an instruction from the scheduling unit 104, and outputs a signal including the generated data or control information to the coding and modulation unit 107. For example, the data and control information generating unit 106 may generate data including signaling information based on an instruction to generate signaling information input from the scheduling unit 104, and output the generated data to the coding and modulation unit 107.

[0059] Encoding and modulation section 107 encodes and modulates the signal inputted from data and control information generation section 106, for example, and outputs the modulated transmission signal (for example, a signal in the time domain) to CP addition section .

[0060] The CP adding unit 108 adds a CP to the time domain signal input from the encoding / modulation unit 107, for example, based on the CP extension amount input from the scheduling unit 104, and outputs the signal with the CP added to the transmitting unit 109.

[0061] Transmitting section 109 performs transmission processing such as D / A conversion, up-conversion, or amplification on the signal input from CP adding section 108. Furthermore, transmitting section 109 transmits the radio signal obtained by the transmission processing from an antenna to terminal 200 based on a transmission instruction from scheduling section 104, for example.

[0062] [Device configuration] 7 is a block diagram showing an example configuration of terminal 200 according to one embodiment of the present disclosure. In FIG. 7, terminal 200 includes receiving section 201, demodulating and decoding section 202, carrier sensing section 203, transmission control section 204, control information holding section 205, data and control information generating section 206, coding and modulating section 207, CP adding section 208, and transmitting section 209.

[0063] The receiving unit 201 performs receiving processing such as down-conversion or A / D conversion on a received signal received via an antenna, and outputs the received signal after receiving processing to the demodulation and decoding unit 202 and the carrier sense unit 203. The received signal may include, for example, a signal transmitted from the base station 100 (e.g., a downlink signal) or a signal of another system.

[0064] The demodulation and decoding unit 202 demodulates and decodes a received signal (e.g., a downlink signal) input from the receiving unit 201, and outputs the decoding result to the transmission control unit 204. The decoding result may include, for example, downlink control information (e.g., a UL grant, slot format information, or COT information).

[0065] Carrier sense unit 203 may perform carrier sensing (or LBT) based on, for example, a received signal input from receiving unit 201. For example, carrier sense unit 203 may determine whether the channel state is "busy" or "idle" (in other words, whether the channel is available or not) based on the received signal input from receiving unit 201. Carrier sense unit 203 outputs information indicating the determined channel state to transmission control unit 204.

[0066] The transmission control unit 204 outputs, for example, signaling information (e.g., CP extension setting information, CG setting information, or FBE setting information) included in the decoding result input from the demodulation and decoding unit 202 to the control information holding unit 205. Furthermore, the transmission control unit 204 may instruct the data and control information generation unit 206 to generate data or control information, for example, based on control information such as CG setting information input from the control information holding unit 205 or downlink control information input from the demodulation and decoding unit 202. Furthermore, the transmission control unit 204 may determine the amount of CP extension for uplink transmission, for example, based on the CP extension setting information, and output information regarding the amount of CP extension to the CP adding unit 208. Furthermore, the transmission control unit 204 may determine whether to perform transmission, for example, based on information indicating the channel state input from the carrier sense unit 203, and output a transmission instruction to the transmission unit 209 based on the determination result.

[0067] The control information holding unit 205 holds control information such as signaling information (e.g., CP extension setting information or CG setting information) input from the transmission control unit 204, and outputs the held information to each component unit (e.g., the transmission control unit 204) as necessary.

[0068] The data and control information generating unit 206 generates data or control information according to instructions from the transmission control unit 204 , for example, and outputs a signal including the generated data or control information to the encoding and modulation unit 207 .

[0069] Encoding and modulation section 207 encodes and modulates the signal inputted from data and control information generation section 206 , for example, and outputs the modulated transmission signal (for example, a signal in the time domain) to CP addition section 208 .

[0070] The CP adding unit 208 adds a CP to the time domain signal input from the encoding / modulation unit 207, for example, based on the CP extension amount input from the transmission control unit 204, and outputs the signal with the CP added to the transmission unit 209.

[0071] The transmitting unit 209 performs transmission processing such as D / A conversion, up-conversion, or amplification on the signal input from the CP adding unit 208. Furthermore, the transmitting unit 209 transmits the radio signal obtained by the transmission processing from the antenna to the base station 100 based on a transmission instruction from the transmission control unit 204, for example.

[0072] [Operations of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 having the above configuration will be described.

[0073] FIG. 6 is a sequence diagram showing an example of the operation of base station 100 and terminal 200. In FIG.

[0074] The base station 100, for example, determines a CP extension configuration for the terminal 200 (S101). The CP extension configuration may include information on the amount of CP extension (for example, CP length) to be configured for the terminal 200, for example.

[0075] Base station 100 transmits control information to terminal 200 (S102). The control information may include, for example, at least CP extension configuration information. The CP extension configuration information may be reported to terminal 200 by, for example, at least one of a higher layer signal (for example, an RRC signal) and a DCI. For example, the CP extension configuration information may be configured in terminal 200 by a higher layer signal, or may be dynamically reported to terminal 200 by a DCI. Alternatively, the CP extension configuration information may be configured in terminal 200 by a higher layer signal, and a DCI including a control value (or index) corresponding to one of the candidate CP extension amounts may be reported to terminal 200.

[0076] Terminal 200, for example, performs carrier sensing (e.g., LBT) (S103). Terminal 200 may configure a CP extension for the uplink signal based on, for example, CP extension configuration information. Terminal 200 may then perform carrier sensing at a transmission start timing according to the CP extension.

[0077] For example, when the result of carrier sensing for the channel is idle, the terminal 200 may transmit an uplink signal (S104).

[0078] [COT acquisition control method] A description will be given of an example of a method for controlling COT acquisition in base station 100 (e.g., scheduling unit 104). Terminal 200 (e.g., transmission control unit 204) may control COT acquisition and uplink transmission (e.g., PUSCH transmission) based on control by base station 100, for example.

[0079] In this embodiment, for example, the cycle and duration of the FFP may be common between base station 100 and terminal 200. Also, in this embodiment, for example, a period during which CP extension is possible may be set before the beginning of the FFP (for example, immediately before the beginning of the FFP). Note that the period during which CP extension is possible is not limited to a period before the beginning of the FFP, and may be, for example, a period after the beginning of the FFP (for example, immediately after the beginning of the FFP), or a period that includes the beginning of the FFP (for example, a period spanning multiple FFPs).

[0080] 9 is a diagram showing an example in which a CP extension setting period is set immediately before the beginning of the FFP. When the above-described CP extension setting period is set, the idle period may be set to, for example, a specified length or more (for example, 5% or more of the FFP, or 100 us or more).

[0081] For example, during a CP extension configurable period, base station 100 may set the CP extension amount for each terminal 200 that may transmit, and notify terminal 200 of CP extension configuration information indicating the CP extension amount. The transmission start timing for each terminal 200 may be determined according to the CP extension amount set by base station 100.

[0082] When transmitting, terminal 200 may wait until transmission start timing based on the CP extension amount instructed by base station 100, and may start transmission when the channel is idle as a result of carrier sense. For example, the terminal that acquires the COT in each FFP (for example, the terminal that acquires the COT first) may be terminal 200 that has started transmission. Note that, if multiplexed transmission in the frequency domain or spatial domain is possible, multiple terminals 200 may start transmission within an FFP. In other words, there may be multiple terminals 200 that acquire the COT in each FFP.

[0083] Furthermore, in a certain FFP, after terminal 200 has completed transmission, if there is time available for transmission remaining in the FFP excluding the idle period, base station 100 may perform downlink transmission after terminal 200 has completed transmission.

[0084] Also, for example, when base station 100 acquires COT and performs downlink transmission at the beginning of FFP, the CP extension amount and transmission start timing may be determined based on the priority of base station 100's transmission compared to terminal 200's transmission, or the transmission status of terminal 200.

[0085] For example, if base station 100 prioritizes transmission over terminal 200, base station 100 may set the CP extension amount for base station 100 to be larger than that for terminal 200. By setting this CP extension amount, for example, base station 100 can start transmission earlier than terminal 200, making it easier for base station 100 to acquire the COT and enabling transmission with higher priority than terminal 200.

[0086] Furthermore, for example, when none of the terminals 200 transmits at the beginning of a certain FFP (or when even the terminal 200 with the shortest CP extension set among the terminals 200 that can transmit in the FFP does not start transmission), the base station 100 may start transmission and acquire the COT. This makes it possible to suppress the occurrence of a situation in which none of the terminals 200 and the base station 100 transmits in the FFP (in other words, a situation in which the FFP is not used), and improves the transmission efficiency of the unlicensed frequency band.

[0087] In this way, base station 100 may determine the CP extension amount (e.g., the CP extension amount for multiple transmission timings) coordinated between terminal 200 and base station 100. Terminal 200 may also control uplink transmission based on, for example, CP extension setting information (e.g., the CP extension amount for multiple transmission timings) notified by base station 100.

[0088] For example, by setting the CP extension amount, priority can be assigned to COT acquisition by terminal 200 or base station 100, making it easier for terminal 200 (or base station 100) with a higher priority to acquire a COT, thereby reducing transmission delay. For example, by setting the CP extension amount, base station 100 can set a higher priority for transmission by base station 100 than for transmission by terminal 200. Therefore, base station 100 can dynamically perform COT acquisition and downlink transmission based on, for example, the priority of transmission by base station 100 and transmission by terminal 200, thereby improving scheduling flexibility.

[0089] Furthermore, when none of the terminals 200 transmit in a certain FFP based on the transmission status of the terminals 200, the base station 100 determines the transmission of the base station 100 (in other words, acquires the COT), thereby preventing the occurrence of a situation where the FFP is not used. Furthermore, for example, even when data occurs in the middle of the FFP in the base station 100 and the terminals 200 (in other words, at a timing different from the timing of the beginning of the FFP), transmission is possible, thereby reducing the transmission delay time.

[0090] In this way, for example, when the COT acquisition timing is the beginning of the FFP, even when UE-initiated COT is performed, it is possible to improve the efficiency of scheduling for base station 100 and terminal 200. Therefore, according to the present embodiment, it is possible to improve transmission efficiency when UE-initiated COT scheduling is performed in an unlicensed frequency band.

[0091] Note that multiple CP extension amounts may be set for one terminal 200. For example, different CP extension amounts may be set between FFPs (e.g., the CP extension amount may be changed periodically). By setting the CP extension amount, for example, a larger CP extension amount may be set in one FFP and a smaller CP extension amount may be set in another FFP. In this way, since the priority of COT acquisition for each terminal 200 differs between FFPs, fairness in the priority of COT acquisition among multiple terminals 200 can be improved. Also, for example, multiple CP extension amount candidates may be set for one terminal 200 in the same FFP, and one may be selected (e.g., randomly selected) from among the multiple candidates. This operation, for example, changes the priority of COT acquisition for one terminal 200, thereby improving fairness in the priority of COT acquisition among terminals 200.

[0092] Furthermore, the base station 100 may prioritize COT acquisition between the terminals 200 (or between the terminal 200 and the base station 100) by setting the data transmission timing, instead of setting the CP extension amount. For example, the base station 100 may set the data transmission timing to be set earlier for the terminal 200 or base station 100 with a higher priority. For example, the base station 100 may set the transmission timing of the terminal 200 with a higher priority to be one symbol earlier than the other terminals 200. This setting allows the terminal 200 or base station with a higher priority to perform transmission with a higher priority than the other terminals.

[0093] (Embodiment 2) In the configuration example of the base station and terminal according to this embodiment, for example, some functions may be different from those in the first embodiment, and other functions may be the same as those in the first embodiment.

[0094] As described above, for example, the CP extension in the DG-PUSCH is a gap adjustment CP extension used to adjust the gap length. Also, for example, the control method of embodiment 1 (e.g., a method of controlling the transmission priority of terminal 200 or base station 100 by setting multiple transmission start timings at the beginning of the FFP) may be applied to the DG-PUSCH. In other words, a CP extension for multiple transmission timings may be supported for the DG-PUSCH.

[0095] However, when transmitting a PUSCH within the COT of base station 100 (e.g., gNB COT), a CP extension for gap adjustment may be supported.

[0096] Therefore, in this embodiment, for example, a method of configuring both a CP extension for multiple transmission timings and a CP extension for gap adjustment for a DG-PUSCH will be described. Note that in this embodiment, the PUSCH is not limited to a DG-PUSCH and may be a CG-PUSCH.

[0097] In base station 100 (FIG. 6), for example, when determining CP extension configuration information (e.g., the amount of CP extension) for each terminal 200, scheduling section 104 may individually configure CP extension configuration information to be applied within a COT (e.g., a gNB COT) acquired by base station 100 and CP extension configuration information to be applied in a period different from the COT of base station 100 (e.g., the beginning of an FFP). Scheduling section 104, for example, outputs the determined CP extension configuration information to control information storage section 105. Furthermore, scheduling section 104 may schedule transmission of signaling information and PUSCH transmission of terminal 200, for example, using the CP extension configuration information.

[0098] In the terminal 200 (Fig. 7), for example, the transmission control unit 204 may determine whether the PUSCH to be transmitted is within the COT (e.g., gNB COT) of the base station 100 based on control information such as Configured grant setting information and FBE setting information input from the control information holding unit 205, or based on the decoding result input from the demodulation / decoding unit 202. The transmission control unit 204 may determine the amount of CP extension to be applied to the PUSCH based on the determination result and the CP extension setting information, and output information regarding the determined amount of CP extension to the CP addition unit 208.

[0099] [Operation examples of the base station 100 and the terminal 200] The operation examples in the base station 100 and the terminal 200 having the above configuration will be described.

[0100] In the present embodiment, for example, the combinations of a plurality of candidate CP extension amounts (e.g., candidate CP lengths) that can be notified by the CP extension setting information may be different for each type of COT. For example, the base station 100 may include any one of a plurality of combinations of different candidate CP lengths for each type of COT in the control information. Further, the terminal 200 may determine one CP extension amount from among the plurality of candidate CP lengths of the combination corresponding to the type of COT, for example, based on the control information notified from the base station 100.

[0101] The types of COT may include, for example, gNB COT and a period different from gNB COT.

[0102] For example, examples of the COT acquisition control method in the case where the PUSCH transmitted by the terminal 200 is "DG-PUSCH", the case of "type 1 CG PUSCH", and the case of "type 2 CG PUSCH" will be described. The terminal 200 may perform COT acquisition and PUSCH transmission, for example, based on the control information from the base station 100.

[0103] [Case of DG-PUSCH] For example, two types of tables may be set: a table that sets the CP extension amount to be applied within the COT (gNB COT) of base station 100 (e.g., an example of an association between an index and a CP extension amount for gap adjustment), and a table that sets the CP extension amount to be applied in a period different from the COT of base station 100 (e.g., an example of an association between an index and a CP extension amount for multiple transmission timings).

[0104] A table applied within the gNB COT (e.g., referred to as "Table 1") may be used, for example, to notify a CP extension for gap adjustment. Also, a table applied in a period different from the gNB COT (e.g., referred to as "Table 2") may be used, for example, to notify a CP extension for multiple transmission timings.

[0105] For example, Table 1 may or may not include other parameters such as channel access type and CAPC in addition to the CP extension amount for gap adjustment. Also, for example, Table 2 may or may not include parameters different from the CP extension amount for multiple transmission timings. For example, by reducing the number of parameter setting candidates in Table 2, the table size can be reduced.

[0106] Also, for example, a common index may be set in Table 1 and Table 2. In other words, base station 100 and terminal 200 may determine which of Table 1 and Table 2 to apply (or refer to) when acquiring the COT and transmitting the PUSCH, depending on the type of COT (or transmission timing).

[0107] For example, terminal 200 may determine which table to refer to based on whether the timing of transmitting the PUSCH is within the COT (gNB COT) of base station 100. Terminal 200 may determine whether the timing is within the gNB COT, for example, based on FBE configuration information and COT information (e.g., COT duration) included in downlink control information (e.g., DCI format 2_0). For example, when transmission is instructed at the beginning of the FFP based on the FBE configuration information, terminal 200 may determine that the period is different from the gNB COT and select Table 2. Furthermore, for example, terminal 200 may determine the duration of the COT based on the COT information, and if the timing of the instruction to transmit is within the duration of the COT, determine that the period is within the gNB COT and select Table 1.

[0108] The index to be referenced in the table may be notified, for example, from base station 100 to terminal 200. The index may be notified, for example, to terminal 200 using a UL grant. For example, terminal 200 may set one of multiple candidate CP extension lengths in the selected table using an index included in control information (for example, CP extension setting information) notified from base station 100.

[0109] FIG. 10 shows an example of Table 1 and Table 2 in which CP extensions are set.

[0110] 10 is a table applied, for example, within the COT of base station 100, and a CP extension for gap adjustment may be set in Table 1. Note that, although the CP extension amount is included in Table 1 in the example shown in Fig. 10, this is not limiting, and for example, an index of another table that defines the CP extension amount for gap adjustment (for example, an index of Table 5.3.1-1 in Non-Patent Document 1) may be included.

[0111] 10 may include, for example, a Channel Access Type and a CAPC in addition to the CP extension amount. As an example, the CP extension amount may be set (for example, joint encoding) together with the Channel Access Type and the CAPC in DCI format 0_1. Note that Table 1 does not necessarily need to include at least one of the Channel Access Type and the CAPC, and may include other parameters.

[0112] Table 2 shown in Fig. 10 is, for example, a table that is applied in a period different from the COT of base station 100, and a CP extension for multiple transmission timings may be set in it. Note that, although the CP extension amount is included in Table 2 in the example shown in Fig. 10, this is not limiting, and for example, an index of another table that defines the CP extension amount for multiple transmission timings (for example, an index of Table 5.3.1-2 in Non-Patent Document 1) may be included.

[0113] 10 may include, for example, CAPC in addition to the CP extension amount. As an example, the CP extension amount may be set together with CAPC (e.g., joint encoding). Note that Table 2 does not necessarily have to include CAPC, and may include other parameters.

[0114] For example, at least one candidate CP extension length included in Table 1 (e.g., candidate CP combination) corresponding to the COT (e.g., first type) of base station 100 may be based on Timing Alignment (TA) and Channel Access Type (or LBT category). On the other hand, the candidate CP extension length included in Table 2 corresponding to a period (e.g., second type) different from the COT of base station 100 does not need to be based on TA and Channel Access Type. Also, for example, the granularity of the CP extension length included in Table 2 may be finer than the granularity of the CP extension length included in Table 1.

[0115] In this way, in addition to the CP extension for gap adjustment, the CP extension for multiple transmission timings can be configured for the DG-PUSCH. This allows base station 100 to configure transmission of both the CG-PUSCH and the DG-PUSCH (for example, a CP extension for multiple transmission timings) when acquiring the COT at the beginning of the FFP (for example, a period different from the gNB COT), thereby improving the flexibility of scheduling in base station 100.

[0116] Furthermore, even when CG-PUSCH and DG-PUSCH coexist, for example, base station 100 may set priorities (for example, different CP extension amounts) for CG-PUSCH and DG-PUSCH and perform scheduling. This allows base station 100 to prioritize PUSCH transmission with a shorter delay setting, for example, regardless of CG-PUSCH and DG-PUSCH, thereby reducing the delay time.

[0117] Also, for example, regarding the setting of the CP extension amount of the CP extension for gap adjustment and the CP extension for multiple transmission timings, as shown in FIG. 10, when using two tables compared to using one table, the size of each table (in other words, the number of indexes) can be reduced, so the signaling overhead when notifying the index can be reduced.

[0118] Note that, for example, it is not limited to two tables according to the COT type as shown in FIG. 10, and a setting in which the CP extension amount for gap adjustment and the CP extension amount for multiple transmission timings are mixed in one table may be used. In this case, for example, when referring to the index of another table that defines the CP extension amount, it may be explicitly set (or defined) which CP extension (in other words, which another table) it is. FIG. 11 is a diagram showing an example including the CP extension amount for gap adjustment and the CP extension amount for multiple transmission timings in one table. In FIG. 11, for example, indexes in a plurality of tables (for example, Table 1 and Table 2) may be set.

[0119] Also, for example, the tables (or combinations of CP extensions for multiple transmission timings) applied in different periods from the gNB COT are not limited to one, and a plurality of them may be set. For example, the granularity of the CP extension amount for multiple transmission timings in each of the plurality of tables applied in different periods from the gNB COT may be different.

[0120] <In the case of type 1 CG PUSCH> In type 1 CG, for example, the CP extension applied within the COT of base station 100 (e.g., gNB COT), such as the CP extension for gap adjustment, and the CP extension applied during a period different from the COT of base station 100 (e.g., CP extension for multiple transmission timings) may be set semi-statically and individually for terminal 200.

[0121] Terminal 200 may determine, for example, the CP extension to be applied to type 1 CG PUSCH based on whether it is within the COT of base station 100.

[0122] Thus, different types of CP extensions can be set for type 1 CG-PUSCH. Thereby, for example, base station 100 can switch and use different CP extensions inside and outside the gNB COT in type 1 CG, improving the scheduling flexibility in base station 100.

[0123] Note that when CG transmission is performed during a period different from the COT of base station 100 (for example, at the beginning of FFP), in other words, when CG transmission is not performed within the COT of base station 100, if the CP extension is not used separately, one type of CP extension amount may be set.

[0124] <In the case of type 2 CG PUSCH> In type 2 CG, for example, since activation is performed by PDCCH (or DCI), a method using two tables corresponding to the COT type (for example, FIG. 10), similar to DG-PUSCH, may be applied.

[0125] For example, a table to be applied within the COT of base station 100 (for example, table 1 shown in FIG. 10) and a table to be applied during a period different from the COT of base station 100 (for example, table 2 shown in FIG. 10) may be set.

[0126] Terminal 200 may determine the table to refer to, for example, based on whether the timing of transmitting the CG-PUSCH is within the COT (gNB COT) of base station 100. Furthermore, an index corresponding to the table determined by terminal 200 may be configured (or notified) to terminal 200, for example, by an activation PDCCH. Furthermore, for example, an index configured in terminal 200 may be used until transmission of the CG-PUSCH is stopped by de-activation or until re-activation.

[0127] In this way, different types of CP extension can be configured for type 2 CG-PUSCH. This allows, for example, base station 100 to switch between the CP extension used within the gNB COT and that used outside the gNB COT for type 2 CG. Furthermore, base station 100 can dynamically configure the amount of CP extension for each terminal 200, for example, by using the activation PDCCH. This allows for improved scheduling flexibility in base station 100 for type 2 CG-PUSCH.

[0128] In Type 2 CG, different types of CP extensions may be set semi-statically, as in Type 1 CG. Also, when different CP extensions are not used, such as when CG transmission is performed in a period different from the COT of base station 100 (for example, at the beginning of FFP) (in other words, when CG transmission is not performed in the COT of base station 100), one type of CP extension amount may be set.

[0129] An example of a COT acquisition control method has been described above.

[0130] As described above, in the present embodiment, the combination (e.g., table) of multiple candidate CP extension amounts for the CP extension amount indicated by the CP extension configuration information may differ for each COT type. Base station 100 can control the CP extension for multiple transmission timings for both the DG-PUSCH and the CG-PUSCH, for example. In this way, base station 100 can reduce the delay of PUSCH transmission in terminal 200 by setting the CP extension amount for both the DG-PUSCH and the CG-PUSCH according to the type of PUSCH transmission (e.g., service type or delay request).

[0131] In addition, the control method for COT acquisition in this embodiment may be the control method for COT acquisition in embodiment 1 (for example, a method for controlling the transmission priority of terminal 200 or base station 100 by setting multiple transmission start timings at the beginning of the FFP), or another control method may be applied.

[0132] (Embodiment 3) In the configuration example of the base station and terminal according to this embodiment, for example, some functions may be different from those in the first embodiment, and other functions may be the same as those in the first embodiment.

[0133] [Time domain scheduling] When time domain scheduling is performed for DG-PUSCH, the transmission timing of PUSCH may be indicated to terminal 200, starting from the timing at which the UL grant is received.

[0134] For example, when a DG-PUSCH at the beginning of the next FFP is indicated (or scheduled) to a terminal, the scheduling may be further apart in time compared to scheduling within an FFP. For example, the period of an FFP may be up to 10 ms.

[0135] To cover scheduling that is distant in time, for example, there are methods of increasing the number of bits of a parameter for time domain scheduling (for example, a Time Domain Resource Assignment (TDRA) field in a UL grant) or methods of reducing the degree of freedom of scheduling. For example, a method of reducing the degree of freedom of scheduling is to increase candidates for scheduling that are distant in time instead of reducing candidates for scheduling that are closer in time.

[0136] [Behavior when COT acquisition fails] In terminal 200, for example, even if an attempt is made to acquire a COT at the beginning of an FFP for DG-PUSCH transmission, there is a possibility that the COT will not be acquired due to interference, etc. As described above, in FBE, a COT is not acquired at an intermediate timing different from the beginning of an FFP. Therefore, if terminal 200 fails to acquire a COT at the beginning of an FFP, it waits for rescheduling from base station 100 until at least the next FFP, which may increase the delay time.

[0137] Therefore, in this embodiment, a method for suppressing an increase in delay time in PUSCH transmission, for example, will be described.

[0138] In base station 100 (FIG. 6), scheduling section 104 may set COT acquisition setting information when determining CP extension setting information (for example, the amount of CP extension) for each terminal 200, for example.

[0139] The COT acquisition setting information may include, for example, information about time domain scheduling (for example, information different from the CP extension amount). The information about time domain scheduling may include, for example, at least one of information indicating the start timing of scheduling for terminal 200 (corresponding to "Next FFP" described later) and information indicating candidate timings of COT for terminal 200 (or retry timings for COT acquisition) (corresponding to "Re-attempt" described later).

[0140] Scheduling section 104 outputs, for example, the determined CP extension configuration information and COT acquisition configuration information to control information holding section 105. Furthermore, scheduling section 104 may schedule transmission of signaling information and PUSCH transmission of terminal 200, for example, by using the CP extension configuration information and the COT acquisition configuration information.

[0141] In terminal 200 (FIG. 7), transmission control section 204 may determine the transmission timing of the PUSCH based on, for example, control information such as configured grant setting information and FBE setting information input from control information storage section 205, or downlink control information (for example, CP extension setting information) and COT acquisition setting information input from demodulation and decoding section 202, and instruct data and control information generation section 206 to generate data or control information.

[0142] [Example of Operation of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 having the above configuration will be described.

[0143] For example, a description will be given of an example of a COT acquisition control method in base station 100 (for example, scheduling unit 104). Terminal 200 (for example, transmission control unit 204) may control COT acquisition and uplink transmission (for example, PUSCH transmission) based on control by base station 100, for example.

[0144] <Control method 1> In control method 1, for example, signaling for notifying information indicating the start timing of scheduling in the time domain for terminal 200 (for example, "Next FFP") may be added as an example of COT acquisition setting information.

[0145] For example, the timing at which the UL grant is received can be the starting point for scheduling in the time domain of the DG-PUSCH. On the other hand, in control method 1, for example, when "Next FFP" is notified to terminal 200, base station 100 may perform time domain scheduling of the DG-PUSCH starting from the beginning of an FFP corresponding to the Next FFP (for example, an FFP after the timing at which the UL grant is received).

[0146] For example, the FFP corresponding to the Next FFP may be the FFP immediately following the current FFP. Note that the current FFP may be the FFP at the timing when the UL grant is received, and the next FFP may be the FFP in the next cycle following the current FFP.

[0147] Below, we will explain an example of a Next FFP notification. Example 1: For example, the "Next FFP" may be notified to the terminal 200 by a one-bit flag.

[0148] For example, a one-bit flag corresponding to Next FFP may set the starting point of time domain scheduling for terminal 200. As an example, Next FFP="0" may mean that the starting point is the UL grant, and Next FFP="1" may mean that the starting point is the beginning of the next FFP at the timing when the UL grant is received.

[0149] The Next FFP (1-bit flag) may be notified (jointly encoded) to terminal 200 together with the CP extension amount (e.g., CP extension setting information), or may be notified to terminal 200 individually in a field of the UL grant.

[0150] 12 is a diagram showing an example in which the Next FFP is notified together with the CP extension amount (and CAPC). For example, the table shown in FIG. 12 (e.g., an example of the association between indexes, CP extension amounts, CAPC, and Next FFPs) may be set in advance from base station 100 to terminal 200. Note that the table shown in FIG. 12 is only an example, and for example, the parameters included in the table may not include CAPC, and may include other parameters different from CAPC.

[0151] In this way, by notifying terminal 200 of "Next FFP", base station 100 can perform scheduling starting from, for example, the beginning of the FFP next to the FFP at the timing when the UL grant is received. The time domain scheduling parameters (for example, TDRA) for terminal 200 may be the same as the parameters starting from, for example, the timing when the UL grant is received. This reduces the signaling overhead of the time domain scheduling parameters (for example, TDRA) and improves the degree of freedom in scheduling in the time domain.

[0152] The starting point of time domain scheduling notified to terminal 200 by Next FFP is not limited to the FFP next to the FFP for which the UL grant was received, but may be any FFP after the FFP for which the UL grant was received.

[0153] Example 2: For example, the "Next FFP" may be notified to the terminal 200 by an M-bit field.

[0154] For example, the starting point of scheduling in the time domain may be set for terminal 200 by an M-bit field corresponding to Next FFP. For example, Next FFP may indicate how many FFPs after the timing of receiving the UL grant are to be set as the starting point of scheduling in the time domain. For example, Next FFP="0" may indicate that the UL grant is the starting point, and Next FFP="m" may indicate that the start point is the beginning of the FFP m times after the timing of receiving the UL grant. Here, m may represent, for example, a value indicated in the M-bit field.

[0155] Next FFP (e.g., an M-bit field) may be signaled (jointly encoded) together with the CP extension amount (e.g., CP extension configuration information), or may be signaled separately in a UL grant field. For example, when Next FFP is signaled together with the CP extension amount, the table shown in FIG. 12 may be configured in advance by base station 100 in terminal 200, as in Example 1.

[0156] In this way, by notifying terminal 200 of "Next FFP" in an M-bit field, base station 100 can, for example, perform scheduling starting from the first FFP in the future or from more FFPs than in example 1. Furthermore, the time domain scheduling parameters (for example, TDRA) for terminal 200 may be the same as the parameters starting from the timing of receiving a UL grant, for example. This reduces the signaling overhead of the time domain scheduling parameters (for example, TDRA) and improves the flexibility of scheduling.

[0157] <Control method 2> In control method 2, for example, as an example of COT acquisition setting information, signaling may be added that notifies information indicating a retry of COT acquisition when terminal 200 fails to acquire a COT (for example, "Re-attempt").

[0158] For example, when a retry is instructed, if the terminal 200 fails to acquire a COT in a scheduled FFP, the terminal 200 may retry acquiring a COT in an FFP corresponding to "Re-attempt."

[0159] For example, the FFP corresponding to the re-attempt may be the FFP next to the current FFP. Note that the current FFP may be the FFP at the timing when the UL grant is received, and the next FFP may be the FFP in the next cycle after the current FFP.

[0160] An example of a re-attempt notification will be described below.

[0161] Example 1: For example, a one-bit flag may be used to notify the terminal 200 of a retry of COT acquisition (Re-attempt).

[0162] For example, a one-bit flag corresponding to Re-attempt may instruct terminal 200 whether to retry COT acquisition when COT acquisition fails. As an example, Re-attempt="0" may mean that COT acquisition will not be retried even if COT acquisition fails, and Re-attempt="1" may mean that COT acquisition will be retried in the next FFP when COT acquisition fails.

[0163] Furthermore, for example, if COT acquisition fails during a retry in the next FFP, whether or not to retry COT acquisition, or the number of retries, may be set or defined in advance. For example, the number of retries may be one or multiple.

[0164] Furthermore, the CP extension amount may be changed when retrying COT acquisition. For example, by increasing the CP extension amount when retrying, the priority of transmission to terminal 200 may be set high. Increasing the priority increases the possibility of COT acquisition, thereby reducing delay time. Alternatively, for example, by decreasing the CP extension amount when retrying, the priority of transmission to terminal 200 may be set low. By decreasing the priority, for example, between multiple terminals 200 (or base stations), directly scheduled transmission may be given priority over transmission retried by re-attempt. Note that the change in the CP extension amount when retrying may be set or defined in advance.

[0165] Re-attempt (1-bit flag) may be notified (jointly encoded) to terminal 200 together with the CP extension amount (e.g., CP extension setting information), or may be notified to terminal 200 individually in a field of the UL grant.

[0166] Fig. 13 is a diagram showing an example in which a re-attempt is notified together with the CP extension amount (and CAPC). For example, the table shown in Fig. 13 (e.g., indexes and associations between the CP extension amount, CAPC, and re-attempt) may be set in advance from base station 100 to terminal 200. Note that the table shown in Fig. 13 is only an example, and for example, the parameters included in the table may not include CAPC, and may include other parameters different from CAPC.

[0167] In this way, by notifying terminal 200 of an instruction (Re-attempt) regarding retrying COT acquisition, even if terminal 200 fails to acquire COT for an FFP scheduled by base station 100, it may be possible to perform uplink transmission without waiting for scheduling from base station 100 by retrying COT acquisition for the next FFP, thereby reducing delay time.

[0168] The timing of retrying COT acquisition notified to terminal 200 by Re-attempt is not limited to the FFP next to the FFP for which the UL grant was received, but may be any FFP after the FFP for which the UL grant was received.

[0169] Example 2: For example, the M-bit field may notify the terminal 200 of an instruction regarding a retry of COT acquisition (for example, Re-attempt).

[0170] For example, the M-bit field corresponding to Re-attempt may instruct the terminal 200 on the conditions for retrying COT acquisition when COT acquisition has failed.

[0171] For example, the M-bit field may indicate the number of retries to be performed to terminal 200. By indicating the number of retries, base station 100 can dynamically set (for example, change) the number of retries based on, for example, the state of terminal 200 in the cell (for example, whether or not there is terminal 200 having high-priority data), thereby realizing a reduction in delay time and an improvement in scheduling flexibility.

[0172] Furthermore, for example, the M bit field may instruct (or specify) a condition for retry to terminal 200, such as "retry if UL symbol" or "retry if either UL symbol or Flexible symbol." By instructing the condition for retry, base station 100 can instruct terminal 200 to retry acquiring COT at a timing that satisfies a condition (for example, symbol type), thereby improving the flexibility of scheduling of base station 100.

[0173] Furthermore, for example, the M bit field may also be used to notify the setting (e.g., increase or decrease) of the CP extension amount at the time of retry. This allows, for example, the CP extension amount at the time of COT acquisition attempt (e.g., including retry), to be dynamically set, thereby reducing delay time and improving the scheduling flexibility of base station 100.

[0174] Furthermore, Re-attempt (an M-bit field) may be notified (jointly encoded) to terminal 200 together with the CP extension amount (e.g., CP extension configuration information), or may be notified individually in a UL grant field to terminal 200. For example, when Re-attempt is notified together with the CP extension amount, for example, as in Example 1, the table shown in FIG. 13 may be configured in advance by base station 100 in terminal 200.

[0175] In this way, by notifying terminal 200 of "Re-attempt" in the M bit field, it becomes possible to conditionally instruct a retry of COT acquisition, which, in addition to the effect of Example 1, improves the flexibility of scheduling for base station 100.

[0176] Control method 1 and control method 2 have been described above.

[0177] It is also possible to apply a combination of control method 1 and control method 2. For example, when terminal 200 fails to acquire a COT in an FFP instructed to be transmitted by "Next FFP," "Re-attempt" can be used to instruct whether to retry acquiring a COT in the next FFP. This can reduce delay time and improve the flexibility of scheduling.

[0178] In addition, the control method for COT acquisition in this embodiment may be the control method for COT acquisition in embodiment 1 (for example, a method for controlling the transmission priority of terminal 200 or base station 100 by setting multiple transmission start timings at the beginning of the FFP), or another control method may be applied.

[0179] (Fourth embodiment) [Release 16 URLLC priority setting] As an extension to the URLLC functionality of Release 16, a function to define or set the priority of a terminal's transmission by "priority (High or Low)" is supported. This function can be used to determine (or judge) the transmission to be prioritized when multiple transmissions are triggered in the terminal. For example, the priority of PUSCH can be dynamically set by UL grant or semi-statically set.

[0180] In this embodiment, a method for controlling CP extension configuration based on the priority of terminal transmission (or data, channel, or service type) will be described.

[0181] In the configuration example of the base station and terminal according to this embodiment, for example, some functions may be different from those in the first embodiment, and other functions may be the same as those in the first embodiment.

[0182] In base station 100 (FIG. 6), scheduling section 104 may configure multiple pieces of CP extension configuration information corresponding to multiple priorities, for example, when determining CP extension configuration information (for example, the amount of CP extension) for each terminal 200. Scheduling section 104 may output the determined CP extension configuration information to control information storage section 105. Furthermore, scheduling section 104 may schedule transmission of signaling information and PUSCH transmission of terminal 200, for example, using this CP extension configuration information.

[0183] In terminal 200 (FIG. 7), transmission control section 204 may determine the amount of CP extension to be applied to the PUSCH by referring to CP extension setting information corresponding to the priority of the PUSCH to be transmitted, based on, for example, configured grant setting information input from control information holding section 205 or the decoding result input from demodulation and decoding section 202. Transmission control section 204 outputs information related to the determined amount of CP extension to CP adding section 208, for example.

[0184] [Example of Operation of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 having the above configuration will be described.

[0185] In this embodiment, for example, the combination of multiple candidate CP extension lengths (for example, candidate CP lengths) that can be notified by the CP extension configuration information may differ for each transmission priority of terminal 200.

[0186] For example, base station 100 may include in the control information one of a plurality of candidate CP lengths in different combinations for each transmission priority of terminal 200. Furthermore, terminal 200 may determine one CP extension length from a plurality of candidate CP lengths in combinations corresponding to the transmission priority of terminal 200, for example, based on the control information notified from base station 100.

[0187] The transmission priority of the terminal 200 may include, for example, "high" and "low." Note that the transmission priority of the terminal 200 is not limited to two types, and may be three or more types.

[0188] For example, an example of a COT acquisition control method will be described when the PUSCH transmitted by terminal 200 is a "DG-PUSCH," a "type 1 CG PUSCH," and a "type 2 CG PUSCH." Terminal 200 may perform COT acquisition and PUSCH transmission based on control information from base station 100, for example.

[0189] <In the case of DG-PUSCH> For example, a table for notifying a plurality of CP extension amounts based on priority may be set. The table for notifying the CP extension amount based on priority may be set in advance by the base station 100 for the terminal 200, or may be defined in the standard.

[0190] Here, it is assumed that for high-priority transmissions, for example, a larger CP extension amount is set in order to make it easier to obtain the COT. Therefore, for example, the table corresponding to a high priority may be set to include candidates with a larger CP extension amount compared to the table corresponding to a low priority.

[0191] For example, the terminal 200 may determine the table to be referred to during PUSCH transmission based on the priority notified by the UL grant. Also, for example, even when there is no priority notification, the terminal 200 may implicitly determine the table to be referred to during PUSCH transmission based on other parameters that can determine the priority. Other parameters that can determine the priority include, for example, the DCI format or an identifier used by the terminal 200 (e.g., Radio Network Temporary Identifier (RNTI)).

[0192] For example, when there are two types of priorities, high and low, two types of tables for setting the CP extension amount may be set. The terminal 200 may determine the table to be referred to during PUSCH transmission based on, for example, the notification of the UL grant (e.g., priority) instructing PUSCH transmission.

[0193] FIG. 14 is a diagram showing an example of a table that sets the CP extension amounts corresponding to low priority and high priority (for example, an example of the association between indexes and CP extension amounts).

[0194] The high priority table shown in FIG. 14 may include, for example, a CP extension amount (e.g., “T-16 us”, “T-25 us”, or “T-341 us”) that is larger than the CP extension amount (e.g., “T-43 us”, “T-52 us”, or “T-61 us”) in the low priority table.

[0195] The CP extension amounts included in the high priority table and the low priority table are not limited to the example shown in Fig. 14, and some CP extension amounts may be included in the high priority table and the low priority table in a duplicated manner. Also, the table shown in Fig. 14 includes, for example, Channel Access Type and CAPC in addition to the CP extension amount, but is not limited to this, and for example, at least one of Channel Access Type and CAPC may not be included, and other parameters may be included.

[0196] In this way, by setting or defining multiple tables corresponding to the transmission priority of terminal 200 for DG-PUSCH and switching the table that terminal 200 refers to depending on the priority, terminal 200 can transmit PUSCH (e.g., obtain COT) with a CP extension amount according to the DG-PUSCH transmission priority.

[0197] Also, for example, compared with the case where the CP extension amounts corresponding to a plurality of priorities are set in one table, since the CP extension amounts are set in a plurality of tables corresponding to a plurality of priorities, the number of candidates for the CP extension amount included in each table (in other words, the number of indexes) can be reduced, and the signaling overhead for notifying the indexes can be reduced.

[0198] <In the case of type 1 CG-PUSCH> In type 1 CG, the transmission priority of the terminal 200 may be set semi-statically, for example. Also, for example, the priorities of the upper layer data included in the physical layer data (for example, the priorities of the logical channels) may dynamically differ.

[0199] Therefore, for example, a plurality of tables corresponding to the priorities of the logical channels may be set for the CP extension amount. The terminal 200 may determine the table to be referred to based on any of the priorities of the upper layer data included in the physical layer data, for example. For example, the terminal 200 may dynamically switch the CP extension by determining the table to be referred to based on the most prioritized logical channel. Note that the determination of table reference is not limited to the highest priority and may be other priorities.

[0200] In this way, for type 1 CG-PUSCH, by switching the CP extension according to the priority of the logical channel, it becomes possible to support dynamic control of the priority even in type 1 CG operating by semi-static setting, and the delay time of the data to be transmitted with higher priority can be reduced.

[0201] <In the case of type 2 CG-PUSCH> In type 2 CG, for example, the priority may be set for each activation using the priority field included in the activation PDCCH.

[0202] Therefore, for example, similar to DG-PUSCH, multiple tables corresponding to multiple priorities may be set for the CP extension amount.

[0203] Terminal 200 may determine, for example, the table to be referenced when transmitting a CG-PUSCH and the amount of CP extension corresponding to the notified index in the table, based on the priority and table index notified by the activation PDCCH.

[0204] In this way, for type 2 CG-PUSCH, terminal 200 determines the CP extension amount based on the priority and index notified by the activation PDCCH, thereby allowing the CP extension amount to be set flexibly (for each activation or reactivation) compared to when the CP extension is determined semi-statically.

[0205] Furthermore, for example, compared to when CP extension amounts corresponding to multiple priorities are set in one table, CP extension amounts are set in multiple tables corresponding to multiple priorities, so the number of CP extension amount candidates included in each table (in other words, the number of indexes) can be reduced, and the signaling overhead for notifying indexes can be reduced.

[0206] An example of a COT acquisition control method has been described above.

[0207] As described above, in the present embodiment, the combination (e.g., table) of multiple candidate CP extension amounts for the CP extension amount notified by the CP extension configuration information may differ for each transmission priority of terminal 200. Base station 100 can reduce delay in PUSCH transmission in terminal 200 by configuring a CP extension for multiple transmission timings for both DG-PUSCH and CG-PUSCH, for example, based on the priority of PUSCH transmission.

[0208] In the present embodiment, for example, the priority of transmission within terminal 200 has been described, but the present invention is not limited to this, and the priority may be, for example, the priority between a plurality of terminals 200 (or base stations 100).

[0209] Furthermore, the control method for COT acquisition in this embodiment may be the control method for COT acquisition in embodiment 1 (for example, a method for controlling the transmission priority of terminal 200 or base station 100 by setting multiple transmission start timings at the beginning of the FFP), or another control method may be applied.

[0210] An embodiment of the present disclosure has been described above.

[0211] (Other embodiments) Furthermore, the above embodiments may be applied in combination.

[0212] In the above-described embodiments, the uplink signal is not limited to an uplink data channel such as a PUSCH, a DG-PUSCH, or a CG-PUSCH, but may be another signal or channel. For example, the present invention may be applied to a Physical Uplink Control Channel (PUCCH) or a Sounding Reference Signal (SRS). For example, since the transmission of a PUCCH or an SRS may be instructed by a DL assignment (e.g., scheduling information of dynamic downlink data) rather than a UL grant, the UL grant in the above-described embodiments may be replaced with a DL assignment.

[0213] (control signal) In one embodiment of the present disclosure, the downlink control signal (or downlink control information) may be, for example, a signal (or information) transmitted in a Physical Downlink Control Channel (PDCCH) of the physical layer, or a signal (or information) transmitted in a Medium Access Control (MAC) or Radio Resource Control (RRC) of a higher layer. Furthermore, the signal (or information) is not limited to being notified by a downlink control signal, but may be predefined in a specification (or standard) or may be preconfigured in a base station and a terminal.

[0214] In one embodiment of the present disclosure, the uplink control signal (or uplink control information) may be, for example, a signal (or information) transmitted in a PDCCH of the physical layer, or a signal (or information) transmitted in a MAC or RRC of a higher layer. Furthermore, the signal (or information) is not limited to being notified by an uplink control signal, but may be predefined in a specification (or standard), or may be preconfigured in a base station and a terminal. Furthermore, the uplink control signal may be replaced with, for example, uplink control information (UCI), 1st stage sidelink control information (SCI), or 2nd stage SCI.

[0215] (base station) In an embodiment of the present disclosure, the base station may be a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a parent device, a gateway, etc. In addition, in sidelink communication, a terminal may be used instead of the base station. In addition, a relay device that relays communication between an upper node and a terminal may be used instead of the base station.

[0216] (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.

[0217] 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.

[0218] (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.

[0219] (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).

[0220] (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.

[0221] (frequency band) An embodiment of the present disclosure may be applied to either a licensed band or an unlicensed band.

[0222] (communication) An embodiment of the present disclosure may be applied to any of communication between a base station and a terminal, communication between terminals (sidelink communication, Uu link communication), and Vehicle to Everything (V2X) communication. For example, the channel in an embodiment of the present disclosure may be replaced with any of PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0223] 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.

[0224] (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.

[0225] <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).

[0226] 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 15 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0227] 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.

[0228] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0229] 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.

[0230] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (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 approximately three times higher than those offered by IMT-Advanced. Meanwhile, URLLC imposes stricter requirements for ultra-low latency (0.5 ms user-plane latency for both UL and DL) and high reliability (1-10-5 within 1 ms). Finally, mMTC may require preferably high connection density (1,000,000 devices / km2 in urban environments), wide coverage in adverse environments, and extremely long battery life (15 years) for low-cost devices.

[0231] 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.

[0232] 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).

[0233] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 16 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.

[0234] 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.

[0235] 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).

[0236] 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); - Buffer for downlink packets and trigger function for downlink data notification.

[0237] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - Allocation and management of IP addresses 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.

[0238] <Procedures for RRC connection setup and reconfiguration> Figure 17 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).

[0239] 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.

[0240] 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.

[0241] <IMT usage scenarios from 2020 onwards> Figure 18 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 18 shows some example use scenarios envisioned for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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)).

[0248] Furthermore, for NR URLLC, several technical enhancements are possible 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. Additionally, enhancements to the PUSCH related to mini-slot level hopping, and enhancements to retransmission / repetition may be possible. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0249] <QoS Control> The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header over the NG-U interface.

[0250] 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 17. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and the 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and the NG-RAN associate UL and DL QoS flows with DRBs.

[0251] Figure 19 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 18) 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.

[0252] Figure 19 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.

[0253] 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.

[0254] 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.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0260] 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.

[0261] 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.

[0262] A terminal according to one embodiment of the present disclosure includes a control circuit that determines a cyclic prefix (CP) length in coordination between the terminal and a base station, and a transmission circuit that transmits control information regarding the determined CP length to the terminal.

[0263] In one embodiment of the present disclosure, the control circuit includes, in the control information, any one of a plurality of candidate CP lengths in one of different combinations for each type of channel occupation time.

[0264] In one embodiment of the present disclosure, at least one of the candidate CP lengths included in the combination corresponding to the first type is based on Timing Alignment (TA), and the candidate CP lengths included in the combination corresponding to the second type are not based on the TA.

[0265] In one embodiment of the present disclosure, at least one of the candidate CP lengths included in the combination corresponding to the first type is based on a carrier sense category, and the candidate CP lengths included in the combination corresponding to the second type are not based on the category.

[0266] In one embodiment of the present disclosure, the transmission circuit transmits other information related to time domain scheduling, different from the CP length.

[0267] In one embodiment of the present disclosure, the other information includes information indicating a start timing of the scheduling for the terminal.

[0268] In one embodiment of the present disclosure, the other information includes information indicating candidate timings of channel occupation time for the terminal.

[0269] In one embodiment of the present disclosure, the control circuit includes in the control information any one of a plurality of candidate CP lengths, which are different combinations for each priority for the terminal or channel.

[0270] A terminal according to one embodiment of the present disclosure includes a receiving circuit that receives control information regarding a cyclic prefix (CP) length coordinated between the terminal and a base station, and a control circuit that controls uplink transmission based on the CP length.

[0271] In a communication method according to one embodiment of the present disclosure, a base station determines a cyclic prefix (CP) length coordinated between a terminal and the base station, and transmits control information regarding the determined CP length to the terminal.

[0272] In a communication method according to one embodiment of the present disclosure, a terminal receives control information regarding a cyclic prefix (CP) length coordinated between the terminal and a base station, and controls uplink transmission based on the CP length.

[0273] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2020-134799, filed on August 7, 2020, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0274] One embodiment of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0275] 100 base stations 101,201 Receiver 102,202 Demodulation and decoding section 103,203 Career Sense Department 104 Scheduling Department 105,205 Control information storage unit 106,206 Data and control information generation unit 107,207 Encoding and Modulation Section 108,208 CP addition part 109,209 Transmitter 200 devices 204 Transmission control section

Claims

1. a receiving circuit for receiving control information relating to a cyclic prefix (CP) length from a base station; a control circuit that controls uplink transmission based on the CP length; Equipped with The CP length is different when the information indicating the channel occupation time for the terminal is a first value and when the information is a second value different from the first value. Terminal.

2. Information regarding different CP lengths is set for each type of the channel occupation time. The terminal according to claim 1 .

3. The CP length corresponding to the first type is determined based on Timing Alignment (TA), The CP length corresponding to the second type is not based on the TA. The terminal according to claim 2.

4. The CP length corresponding to the first type is determined based on a carrier sense category, The CP length corresponding to the second type is not based on the category. The terminal according to claim 2.

5. the receiving circuit receives an index associated with a table used to set the CP length; The terminal according to claim 1 .

6. the receiving circuit receives information indicating a start timing of scheduling for the terminal; The terminal according to claim 1 .

7. the receiving circuit receives information indicating candidate timings for channel occupation time for the terminal; The terminal according to claim 1 .

8. Information regarding different CP lengths is set for each priority level for transmission from the terminal. The terminal according to claim 1 .

9. The control information is notified in Radio Resource Control (RRC). The terminal according to claim 1 .

10. The control information is notified to each terminal. The terminal according to claim 1 .

11. The CP length is different when the channel occupation time for the terminal is a first length and when the channel occupation time for the terminal is a second length different from the first length. The terminal according to claim 1 .

12. The CP length varies depending on the subcarrier spacing. The terminal according to claim 1 .

13. The same CP length can be set when the channel occupation time for the terminal is a first length and when the channel occupation time for the terminal is a second length different from the first length. The terminal according to claim 1.

14. the transmission of the terminal is a sidelink transmission; The terminal according to claim 1.

15. The terminal is receiving control information regarding a cyclic prefix (CP) length from a base station; Controlling uplink transmission based on the CP length; The CP length is different when the information indicating the channel occupation time for the terminal is a first value and when the information is a second value different from the first value. Communication method.

16. a receiving circuit for receiving control information relating to a cyclic prefix (CP) length from a base station; a control circuit that controls uplink transmission based on the CP length; Equipped with The CP length is different when the information indicating the channel occupation time for the terminal is a first value and when the information is a second value different from the first value. Integrated circuit.

Images