WO2024237113A1 - Communication device, base station, and communication method - Google Patents

Abstract

A communication device (100) comprises: a control unit (120) that executes first switching control in which an orthogonal frequency division multiplexing (OFDM) scheme for uplink transmission is switched on the basis of first switching information which is notified through a radio resource control (RRC) layer, and second switching control in which the OFDM scheme for the uplink transmission is switched on the basis of second switching information which is notified through a layer that is lower than the RRC layer; and a reception unit (112) that receives, from a base station (200) and separately from first MCS table information indicating a modulation and coding scheme (MCS) index table which is applied to the uplink transmission using the OFDM scheme based on the first switching control, second MCS table information indicating the MCS index table which is applied to the uplink transmission using the OFDM scheme based on the second switching control.

Description

Communication device, base station, and communication method CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims the benefit of priority to patent application serial number 2023-079487, filed May 12, 2023, the entire contents of which are incorporated herein by reference.

This disclosure relates to a communication device, a base station, and a communication method used in a mobile communication system.

In 3GPP (registered trademark, the same applies below) (3rd Generation Partnership Project), a standardization project for mobile communication systems, orthogonal frequency division multiplexing (OFDM) using a cyclic prefix (CP) (hereinafter referred to as "CP-OFDM") or discrete Fourier transform spreading (DFT spreading) OFDM (hereinafter referred to as "DFT-s-OFDM") can be applied as the waveform of the uplink signal. DFT-s-OFDM is CP-OFDM to which a function for performing DFT spreading (hereinafter referred to as "transform precoder") is applied. Therefore, depending on whether or not a transform precoder is applied, it is possible to switch between the waveforms of DFT-s-OFDM or CP-OFDM to be used (i.e., the OFDM method). The communication device switches the OFDM method for uplink transmission based on switching information (specifically, "transformPrecoder") notified in the radio resource control (RRC) layer.

The communication device also determines the modulation and coding scheme (MCS) to be applied to uplink transmission (e.g., physical uplink shared channel (PUSCH) transmission) in the OFDM scheme after the switch. Here, if multiple MCS index tables for determining the MCS are specified, the communication device can receive MCS table information indicating the MCS index table (e.g., "mcs-Table", "mcs-TableTransformPrecoder", etc.) from the base station. Based on the received MCS table information, the communication device determines the MCS index table to be applied to the uplink transmission from among the multiple MCS index tables.

In recent years, dynamic switching has been studied in which switching information notified at the RRC layer is notified at a layer lower than the RRC layer (for example, see Non-Patent Document 1). Since notification at a lower layer reduces processing delays in communication devices, it is possible to switch the OFDM method for uplink transmission at an appropriate timing according to the situation, enabling flexible control of uplink transmission.

3GPP contribution “R1-2302575”

The communication device according to the first aspect includes a control unit (120) that executes a first switching control for switching an orthogonal frequency division multiplexing (OFDM) scheme for uplink transmission based on first switching information notified in a radio resource control (RRC) layer, and a second switching control for switching the OFDM scheme for the uplink transmission based on second switching information notified in a layer lower than the RRC layer, and a receiving unit (112) that receives from a base station (200) second MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from first MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control.

The base station according to the second aspect is a base station (200) that communicates with a communication device (100) that executes a first switching control for switching an orthogonal frequency division multiplexing (OFDM) scheme for uplink transmission based on first switching information notified in a radio resource control (RRC) layer, and a second switching control for switching the OFDM scheme for the uplink transmission based on second switching information notified in a layer lower than the RRC layer. The base station includes a transmission unit (211) that transmits to the communication device second MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, in addition to first MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control.

The communication method according to the third aspect is a communication method executed by a communication device (100). The communication method includes a step of executing a first switching control for switching an orthogonal frequency division multiplexing (OFDM) scheme for uplink transmission based on first switching information notified in a radio resource control (RRC) layer, and a second switching control for switching the OFDM scheme for the uplink transmission based on second switching information notified in a layer lower than the RRC layer, and a step of receiving, from a base station (200), second MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control.

The objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
FIG. 1 is a diagram showing a configuration of a mobile communication system according to an embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a protocol stack according to the embodiment. FIG. 3 is a diagram for explaining application of a transform precoder. FIG. 4 is a diagram showing a configuration of a UE according to the embodiment. FIG. 5 is a diagram showing a configuration of a base station according to the embodiment. FIG. 6 is a sequence diagram (part 1) for explaining the operation example 1 according to the embodiment. FIG. 7 is a diagram for explaining an operation example 1 according to the embodiment. FIG. 8 is a sequence diagram (part 2) for explaining the operation example 1 according to the embodiment. FIG. 9 is a sequence diagram (part 3) for explaining the operation example 1 according to the embodiment. FIG. 10 is a sequence diagram for explaining an operation example 2 according to the embodiment. FIG. 11 is a sequence diagram for explaining an operation example 3 according to the embodiment.

The mobile communication system according to the embodiment will be described with reference to the drawings. In the drawings, the same or similar parts are denoted by the same or similar reference numerals.

However, existing 3GPP technical specifications do not provide a specific mechanism for dynamically switching OFDM schemes by notifying switching information at layers lower than the RRC layer. This raises concerns that uplink transmissions cannot be flexibly controlled using OFDM schemes based on switching information notified at lower layers.

Therefore, one of the objectives of this disclosure is to provide a communication device, base station, and communication method that enable flexible control of uplink transmission using OFDM based on switching information notified in a lower layer.

(System Configuration)
First, the configuration of a mobile communication system 1 according to the present embodiment will be described with reference to Fig. 1. The mobile communication system 1 is, for example, a system conforming to the 3GPP Technical Specification (TS). In the following, the mobile communication system 1 will be described using a 3GPP standard 5th Generation System (5G system), i.e., a mobile communication system based on NR (New Radio) as an example.

The mobile communication system 1 has a network 10 and a user equipment (UE) 100 that communicates with the network 10. The network 10 includes a 5G radio access network, NG-RAN (Next Generation Radio Access Network) 20, and a 5G core network, 5GC (5G Core Network) 30.

UE100 is a communication device that communicates via base station 200. UE100 may be a device used by a user. UE100 is a mobile device such as a mobile phone terminal such as a smartphone, a tablet terminal, a notebook PC, a communication module, or a communication card. UE100 may be a vehicle (e.g., a car, a train, etc.) or a device provided therein. UE100 may be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device provided therein. UE100 may be a sensor or a device provided therein. Note that UE100 may be called a terminal, terminal device, mobile station, mobile terminal, mobile device, mobile unit, subscriber station, subscriber terminal, subscriber device, subscriber unit, wireless station, wireless terminal, wireless device, wireless unit, remote station, remote terminal, remote device, or remote unit. Also, UE100 is an example of a terminal, and the terminal may include factory equipment, etc.

NG-RAN20 includes multiple base stations 200. Each base station 200 manages at least one cell. A cell constitutes the smallest unit of a communication area. One cell belongs to one frequency (carrier frequency). The term "cell" may refer to a wireless communication resource, and may also refer to a communication target of UE100. Each base station 200 can perform wireless communication with UE100 located in its own cell. The base station 200 communicates with UE100 using a protocol stack of the RAN. Details of the protocol stack will be described later. In addition, the base station 200 is connected to other base stations 200 (which may be referred to as adjacent base stations) via an Xn interface. The base station 200 communicates with adjacent base stations via an Xn interface. In addition, the base station 200 provides NR user plane and control plane protocol terminations toward the UE100, and is connected to the 5GC30 via an NG interface. Such an NR base station 200 may be referred to as a gNodeB (gNB).

The 5GC30 includes a core network device 300. The core network device 300 includes, for example, an AMF (Access and Mobility Management Function) and/or a UPF (User Plane Function). The AMF manages the mobility of the UE 100. The UPF provides functions specialized for U-plane processing. The AMF and the UPF are connected to the base station 200 via an NG interface.

(Example of protocol stack configuration)
Next, an example of the configuration of a protocol stack according to this embodiment will be described with reference to FIG.

The protocol for the wireless section between UE100 and base station 200 includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and an RRC layer.

The PHY layer performs encoding/decoding, modulation/demodulation, antenna mapping/demapping, and resource mapping/demapping. Data and control information are transmitted between the PHY layer of UE 100 and the PHY layer of base station 200 via a physical channel.

The MAC layer performs data priority control, retransmission processing using Hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of UE100 and the MAC layer of base station 200 via a transport channel. The MAC layer of base station 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resources to be allocated to UE100.

The RLC layer uses the functions of the MAC layer and PHY layer to transmit data to the RLC layer on the receiving side. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the base station 200 via logical channels.

The PDCP layer performs header compression/decompression, and encryption/decryption.

The SDAP (Service Data Adaptation Protocol) layer may be provided as a layer above the PDCP layer. The SDAP (Service Data Adaptation Protocol) layer maps IP flows, which are the units by which the core network performs QoS (Quality of Service) control, to radio bearers, which are the units by which the AS (Access Stratum) performs QoS control.

The RRC layer controls logical channels, transport channels, and physical channels in response to the establishment, re-establishment, and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of UE100 and the RRC layer of base station 200. When there is an RRC connection between the RRC of UE100 and the RRC of base station 200, UE100 is in an RRC connected state. When there is no RRC connection between the RRC of UE100 and the RRC of base station 200, UE100 is in an RRC idle state. When the RRC connection between the RRC of UE100 and the RRC of base station 200 is suspended, UE100 is in an RRC inactive state.

The NAS layer, which is located above the RRC layer in UE100, performs session management and mobility management for UE100. NAS signaling is transmitted between the NAS layer of UE100 and the NAS layer of the core network device 300.

In addition, UE100 has an application layer and the like in addition to the radio interface protocol.

(Radio Frame Structure)
In a 5G system, downlink transmission and uplink transmission are configured within a radio frame of 10 ms duration. For example, a radio frame is configured with 10 subframes. For example, one subframe may be 1 ms. Also, one subframe may be configured with one or more slots. For example, the number of symbols that constitute one slot is 14 in a normal CP (Cyclic Prefix) and 12 in an extended CP. Also, the number of slots that constitute one subframe changes depending on the set subcarrier interval. For example, for a normal CP, when the subcarrier interval is set to 15 kHz, the number of slots per subframe is 1 (i.e., 14 symbols), when the subcarrier interval is set to 30 kHz, the number of slots per subframe is 2 (i.e., 28 symbols), when the subcarrier interval is set to 60 kHz, the number of slots per subframe is 4 (i.e., 56 symbols), and when the subcarrier interval is set to 120 kHz, the number of slots per subframe is 8 (i.e., 128 symbols). Also, when the subcarrier interval is set to 60 kHz for an extended CP, the number of slots per subframe is 4 (i.e., 48 symbols). That is, the number of slots constituting one subframe is determined based on the subcarrier interval set by the base station 200. Also, the number of symbols constituting one subframe is determined based on the subcarrier interval set by the base station 200. That is, the number of symbols constituting a 1 ms subframe is determined based on the subcarrier interval set by the base station 200, and the length (length in the time direction) of each symbol changes.

(Waveform)
With reference to FIG. 3, a waveform in the mobile communication system 1 according to the embodiment will be described. The waveform of a signal transmitted and received in the mobile communication system 1 may be cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) or discrete Fourier transform spreading-orthogonal frequency division multiplexing (DFT-s-OFDM). In the mobile communication system 1 based on the 5G system, the downlink transmission waveform may be ODFM using a cyclic prefix (CP). The uplink transmission waveform may be ODFM using a CP with a transform precoding function that performs DFT spreading, which may be disabled or enabled. In operation with shared spectrum channel access in FR (Frequency Range) 1, the subcarrier mapping of the uplink transmission waveform may be mapped to subcarriers in one or more physical resource block (PRB) interlaces.

For example, either CP-OFDM or DFT-s-OFDM may be used for uplink signals such as the physical uplink shared channel (PUSCH) and/or phase tracking reference signals (PTRS). On the other hand, CP-OFDM may be used for downlink signals such as the physical downlink shared channel (PDSCH). In addition, CP-OFDM may be used for signals used for direct communication between UEs 100, such as sidelink signals (e.g., physical sidelink shared channel (PSSCH)).

CP-OFDM has the advantage of being resistant to multipath interference because it is a multicarrier waveform, but has the disadvantage of increasing the peak-to-average power ratio (PAPR). In addition, because CP-OFDM is a multicarrier waveform, it can frequency-division multiplex a transmission data sequence and a reference signal (RS) on different subcarriers of the same symbol. In addition, the transmission band of a CP-OFDM transmission signal is not limited to a continuous frequency band (e.g., one or more continuous physical resource blocks (PRBs)), but may be composed of a discontinuous frequency band (e.g., multiple discontinuous PRBs), so there are fewer scheduling constraints compared to DFT-s-OFDM. For this reason, for example, in cells where the load is higher than a certain level, frequency utilization efficiency can be improved by using CP-OFDM.

DFT-s-OFDM is a single carrier waveform, so it can reduce the PAPR more than CP-OFDM. Therefore, it is possible to use power close to the maximum rated power, and a higher modulation method and/or a higher coding rate. As a result, it is possible to reduce the power consumption and/or the cost of the UE 100. It also becomes easier to ensure a coverage area. On the other hand, in DFT-s-OFDM, the transmission data sequence and RS of a certain UE 100 are time-division multiplexed to different symbols. That is, the transmission data sequence and RS of a certain UE 100 are not frequency-division multiplexed to different subcarriers of the same symbol, which is different from CP-OFDM. In addition, the transmission band of the transmission signal of DFT-s-OFDM is limited to a continuous frequency band (for example, one or more continuous PRBs).

As shown in FIG. 3A, DFT-s-OFDM differs from CP-OFDM shown in FIG. 5B in that it has a transform precoder. DFT-s-OFDM is CP-OFDM to which a transform precoder is applied. The transform precoder may be a function that performs DFT spreading. The transform precoder may be referred to as transform precoding, DFT precoder, DFT precoding, etc.

In DFT-s-OFDM, the encoded and modulated transmission data sequence or RS is input to an M-point DFT and transformed from the time domain to the frequency domain. The output from the DFT is mapped to M subcarriers and input to an N-point Inverse Fast Fourier Transform (IFFT) and transformed from the frequency domain to the time domain. Note that the DFT may be replaced by a Fast Fourier Transform (FFT), and the IFFT may be replaced by an Inverse Discrete Fourier Transform (IDFT). When N>M, input information to the IFFT that is not used is set to zero. N may be equal to the number of subcarriers corresponding to a given frequency bandwidth (e.g., bandwidth portion (BWP) or cell bandwidth). M may be the number of subcarriers corresponding to the transmission bandwidth. This results in the output of the IFFT being a signal with small instantaneous power fluctuations and a bandwidth that depends on M. The output from the IFFT is parallel to serial (P/S) converted and a CP is added. The CP is also called a guard interval (GI). In this way, in DFT-s-OFDM, a signal having the characteristics of a single carrier is generated and transmitted in one symbol. The CP may be inserted before P/S conversion of the output from the IFFT.

In CP-OFDM, the transmitted data sequence and/or RS after encoding and modulation is mapped to a number of subcarriers equal to the transmission bandwidth and input to the IFFT. Unused input information to the IFFT is set to zero. The output from the IFFT is P/S converted and a CP is inserted. In this way, since CP-OFDM uses multiple carriers, the RS and the transmitted data sequence can be frequency division multiplexed. Of course, the transmitted data sequence can also be transmitted without frequency division multiplexing with the RS.

As described above, there is a trade-off between the characteristics of DFT-s-OFDM and CP-OFDM, so DFT-s-OFDM and CP-OFDM can be switched depending on various parameters (e.g., cell load, scheduling situation, antenna state, etc.). In the mobile communication system 1, the UE 100 switches the OFDM method for uplink transmission based on switching information notified at the RRC layer (specifically, "transformPrecoder"). In recent years, dynamic switching has been studied in which the switching information notified at the RRC layer is notified at a layer lower than the RRC layer. Since notification at a lower layer reduces processing delays in the communication device, the OFDM method for uplink transmission can be switched at an appropriate timing according to the situation, enabling flexible control of uplink transmission.

However, existing 3GPP technical specifications do not provide a specific mechanism for dynamically switching OFDM schemes by notifying switching information at layers lower than the RRC layer. This raises concerns that uplink transmissions cannot be flexibly controlled using OFDM schemes based on switching information notified at lower layers.

For example, the UE 100 determines the modulation and coding scheme (MCS) to be applied to uplink transmission (e.g., physical uplink shared channel (PUSCH) transmission) in the OFDM scheme after switching. Here, multiple MCS index tables for determining the MCS may be specified. In this case, the communication device can receive MCS table information (e.g., "mcs-Table", "mcs-TableTransformPrecoder", etc.) indicating which MCS index table to use for uplink transmission from the base station. Based on the received MCS table information, the communication device determines the MCS index table to be applied to the uplink transmission from among the multiple MCS index tables. However, as described above, since there is no specific mechanism for dynamically switching the OFDM scheme by notification of switching information in a lower layer, there is a concern that the UE 100 cannot determine an appropriate MCS index table. Therefore, in one embodiment described later, an operation for enabling flexible control of uplink transmission in the OFDM scheme based on switching information notified in a lower layer will be described.

The MCS index table has a plurality of MCS indexes and items associated with each MCS index. For example, the MCS index table has an MCS index (MCS Index I _MCS ), a modulation order (Modulation Order Qm) representing the amount of information carried per symbol, a target code rate (Target code Rate R x [1024]) representing the coding rate of transmission data, and/or a spectral efficiency (Spectral efficiency) representing the amount of information per unit bandwidth. The modulation order may simply be referred to as a modulation scheme. Also, each of the MCS indexes of the plurality of MCS index tables may be associated with a different modulation order (i.e., modulation scheme), target code rate, and/or spectral efficiency ("qam256", "qam64LowSE"). For example, each of the multiple MCS index tables may be referred to as an “MCS index table corresponding to qam256” and an “MCS index table corresponding to qam64LowSE.” The MCS index table may be referred to as an MCS table.

As described below, the MCS index may be indicated using information included in a DCI format (e.g., DCI format 0_0, DCI format 0_1, and/or DCI format 0_2) used for scheduling the PUSCH. The field of information used to determine the MCS index may also be referred to as the MCS field. For example, the UE 100 may determine the MCS index based on a value set in the MCS field included in the DCI format used for scheduling the PUSCH. The UE 100 may also apply a modulation order, target code rate, and/or spectral efficiency corresponding to the determined MCS index to the uplink transmission based on an MCS table.

(Switching information notified by RRC layer)
The switching information notified in the RRC layer will be described. The switching information is included in a radio resource control (RRC) message notified in the RRC layer. The switching information corresponds to transform precoder information described later. The transform precoder information sets the enable or disable of transform precoding in the UE 100. Therefore, the UE 100 determines whether or not to apply a transform precoder to uplink transmission using the transform precoder information, thereby switching which waveform of DFT-s-OFDM or CP-OFDM to use (i.e., the OFDM method).

The switching information may be included in the configuration information regarding the transform precoder. The configuration information regarding the transform precoder that includes the switching information may be, for example, at least one of the following pieces of information:

First, the configuration information for the transform precoder may be configuration information (e.g., PUSCH-config) for configuring communication device-specific physical uplink shared channel (PUSCH) parameters applicable to a specific bandwidth portion (BWP). PUSCH-config is included in information (e.g., BWP-UplinkDedicated) used for configuring UE-specific parameters of one uplink BWP. PUSCH transmission is scheduled using a downlink control information (DCI) format (i.e., the DCI format used for scheduling PUSCH) with a cyclic redundancy check (CRC) (CRC parity bits) scrambled by the cell radio network temporary identifier (C-RNTI).

Using transform precoder information (specifically, transformPrecoder), which is a parameter included in PUSCH-config, UE100 is configured to enable or disable transform precoding for PUSCH transmission. The transform precoder information (transformPrecoder) is used for UE-specific selection of a transform precoder for PUSCH. If the transform precoder information (transformPrecoder) field does not exist, UE100 applies the value of the "msg3-transformPrecoder" field. Note that "msg3-transformPrecoder" is included in RACH-ConfigCommon.

Secondly, the configuration information for the transform precoder may be configuration information (e.g., ConfiguredGrantConfig) for configuring uplink transmission without dynamic grant. ConfiguredGrantConfig may be used to configure uplink transmission without dynamic grant according to two possible schemes. The actual uplink grant may be configured via RRC or provided via the Physical Downlink Control Channel (PDCCH) (destined to the Configured Scheduling-Radio Network Temporary Identifier (CS-RNTI)).

Specifically, the two types of transmissions without dynamic grants are CG (Configured Grant) Type 1 PUSCH transmission and CG Type 2 PUSCH transmission. In CG Type 1 PUSCH transmission, the uplink grant is provided via RRC. The uplink grant is stored as a configured uplink grant. On the other hand, in CG Type 2 PUSCH transmission, the uplink grant is provided by PDCCH. That is, the uplink grant is transmitted on PDCCH, used for scheduling PUSCH, and provided by DCI format with CS-RNTI. The uplink grant is stored or cleared as a configured uplink grant based on L1 signaling indicating activation or deactivation of the configured uplink grant. CG type 1 PUSCH transmission and CG type 2 PUSCH transmission are configured by RRC for the serving cell per BWP.

UE100 stores the provided uplink grant and considers the stored uplink grant to have occurred at a predetermined timing. The predetermined timing may be, for example, a timing according to a period and/or offset set using an RRC message. UE100 performs PUSCH transmission at the predetermined timing.

ConfiguredGrantConfig is included in BWP-UplinkDedicated, which is used to set UE-specific parameters for one uplink BWP. ConfiguredGrantConfig includes transform precoder information (specifically, transformPrecoder). Using the transform precoder information (transformPrecoder), which is a parameter included in ConfiguredGrantConfig, the enable or disable of transform precoding for CG type 1 PUSCH transmission/CG type 2 PUSCH transmission is set in UE100. Therefore, the transform precoder information (transformPrecoder) enables or disables the transform precoder for type 1 and type 2. If the transform precoder information (transformPrecoder) field does not exist, the UE 100 enables or disables transform precoding according to the "msg3-transformPrecoder" field in the RACH-ConfigCommon described below.

Thirdly, the configuration information regarding the transform precoder may be configuration information (e.g., RACH-ConfigCommon) for specifying cell-specific random access (RA) parameters. RACH-ConfigCommon is used to specify cell-specific RA parameters. RACH-ConfigCommon may be configuration information regarding a random access procedure. RACH-ConfigCommon is included in information (e.g., BWP-UplinkCommon) used to configure cell-specific parameters (i.e., common parameters) of one uplink BWP. RACH-ConfigCommon includes transform precoder information (msg3-transformPrecoder). msg3-transformPrecoder enables the transform precoder for Msg. 3 transmission. If the msg3-transformPrecoder field is not present, the UE 100 disables the transform precoder. Therefore, the enable (or disable) of transform precoding for PUSCH transmission for Msg. 3 (UL-SCH of Msg. 3) in the random access procedure is set in the UE 100 using the transform precoder information (msg3-transformPrecoder), which is a parameter included in the RACH-ConfigCommon.

Note that Msg. 3 PUSCH transmission is scheduled in a random access (RA) response grant or in a DCI format with a CRC scrambled by a temporary C-RNTI (TC-RNTI) (i.e., the DCI format used for PUSCH scheduling). The RA response grant is included in Msg. 2 (i.e., the random access response). The RA response grant is transmitted as a MAC payload for the RA response.

Fourthly, the configuration information regarding the transform precoder may be configuration information (e.g., MsgA-PUSCH-Config) for specifying the allocation of a physical uplink shared channel (PUSCH) for message A in a two-step RA type procedure. MsgA-PUSCH-Config is used to specify the allocation of a PUSCH for message A in a two-step RA type procedure. MsgA-PUSCH-Config may be configuration information regarding a random access procedure. MsgA-PUSCH-Config includes transform precoder information (msgA-TransformPrecoder). msgA-TransformPrecoder enables or disables the transform precoder for transmitting MsgA. Using the transform precoder information (msgA-TransformPrecoder), which is a parameter included in MsgA-PUSCH-Config, the enable or disable of transform precoding for PUSCH transmission for Msg. A (specifically, the UL-SCH of Msg. A) in the random access procedure is set in UE 100.

Note that Msg. A PUSCH transmission is performed using the PUSCH resources set by the parameters (e.g., MsgA-PUSCH-Resource) included in MsgA-PUSCH-Config. MsgA-PUSCH-Resource is included in BWP-UplinkCommon, which is used to set cell-specific parameters (common parameters) for one uplink BWP.

UE Procedure for Applying Transform Precoding on PUSCH
A UE procedure for applying transform precoding on PUSCH is described.

UE100 may apply enable/disable of transform precoding according to transform precoder information (specifically, parameter: msg3-transformPrecoder) to a PUSCH transmission scheduled by an uplink grant (UL grant) in a random access (RA) response (i.e., RA response permission) or a PUSCH transmission scheduled by DCI format 0_0 CRC scrambled by a TC-RNTI (Temporary C-RNTI).

UE100 may apply transform precoding enabled/disabled to PDCCH transmissions CRC scrambled by CS-RNTI, C-RNTI, or MCS-C-RNTI with NDI=1, or PUSCH transmissions scheduled by in the following cases (i) and (ii).

(i) If DCI format 0_0 is received (i.e., PUSCH transmission is scheduled by DCI format 0_0), UE100 may apply enable/disable of transform precoding according to the parameter: msg3-transformPrecoder.

(ii) If DCI format 0_0 is not received (i.e., if the PUSCH transmission is scheduled by DCI format 0_1/0_2), (a) if the parameter transformPrecoder included in the PUSCH-Config is set, the UE100 may apply enable/disable of transform precoding in accordance with the parameter transformPrecoder included in the push-Config. (ii) If DCI format 0_0 is not received, (b) if the parameter: transformPrecoder included in PUSCH-Config is not set, UE100 may apply the enable/disable of transform precoding according to the parameter: msg3-transformPrecoder.

As described above, whether or not to apply a transform precoder, i.e., switching between the OFDM scheme (specifically, between DFT-s-OFDM and CP-OFDM), is performed by RRC signaling. Note that whether or not to apply a transform precoder may also be rephrased as whether or not to enable a transform precoder, or whether or not to activate it, etc.

(UE Configuration)
A configuration of the UE 100 according to the embodiment will be described with reference to Fig. 4. The UE 100 includes a communication unit 110 and a control unit 120.

The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving radio signals to and from the base station 200. The communication unit 110 has at least one transmitting unit 111 and at least one receiving unit 112. The transmitting unit 111 and the receiving unit 112 may be configured to include multiple antennas and RF circuits. The antenna converts a signal into radio waves and radiates the radio waves into space. The antenna also receives radio waves in space and converts the radio waves into a signal. The RF circuit performs analog processing of the signal transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

The control unit 120 performs various controls in the UE 100. The control unit 120 controls communication with the base station 200 via the communication unit 110. The operations of the UE 100 described above and below may be operations under the control of the control unit 120. The control unit 120 may include at least one processor capable of executing programs and a memory for storing the programs. The processor may execute programs to perform the operations of the control unit 120. The control unit 120 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of the RAN protocol stack. The memory stores the programs executed by the processor, parameters related to the programs, and data related to the programs. The memory may include at least one of ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access Memory), and flash memory. All or a portion of the memory may be contained within the processor.

In the UE 100 configured in this manner, the control unit 120 executes a first switching control in which the OFDM scheme for uplink transmission is switched based on first switching information notified at the RRC layer, and a second switching control in which the OFDM scheme for uplink transmission is switched based on second switching information notified at a layer lower than the RRC layer. The receiving unit 112 receives from the base station 200 second MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, in addition to first MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control. This allows the UE 100 to change the MCS index table to be applied to the uplink transmission between the first switching control and the second switching control, thereby allowing for flexible control of the uplink transmission.

(Base Station Configuration)
The configuration of the base station 200 according to the embodiment will be described with reference to Fig. 5. The base station 200 includes a communication unit 210, a network communication unit 220, and a control unit 230.

The communication unit 210, for example, receives a radio signal from the UE 100 and transmits a radio signal to the UE 100. The communication unit 210 has at least one transmission unit 211 and at least one reception unit 212. The transmission unit 211 and the reception unit 212 may be configured to include an RF circuit. The RF circuit performs analog processing of the signal transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

The network communication unit 220 transmits and receives signals to the network. For example, the network communication unit 220 receives signals from adjacent base stations connected via an Xn interface, which is an interface between base stations, and transmits signals to the adjacent base stations. The network communication unit 220 also receives signals from a core network device 300 connected via an NG interface, and transmits signals to the core network device 300.

The control unit 230 performs various controls in the base station 200. For example, the control unit 230 controls communication with the UE 100 via the communication unit 210. The control unit 230 also controls communication with a node (for example, an adjacent base station, a core network device 300) via the network communication unit 220. The operations of the base station 200 described above and below may be operations under the control of the control unit 230. The control unit 230 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute a program to perform the operation of the control unit 230. The control unit 230 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of the RAN protocol stack. The memory stores the program executed by the processor, parameters related to the program, and data related to the program. All or a part of the memory may be included in the processor.

In the base station 200 configured in this manner, the transmitter 211 transmits to the UE 100 second MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from the first MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control. This allows the UE 100 to change the MCS index table to be applied to the uplink transmission between the first switching control and the second switching control, thereby enabling the UE 100 to flexibly control the uplink transmission.

(Operation example 1)
Referring to FIG. 6, a first operation example of the mobile communication system 1 will be described.

Step S101:
The transmitting unit 111 of the UE 100 may transmit capability information indicating the capability of the UE 100 to the base station 200. The receiving unit 212 of the base station 200 may receive the capability information from the UE 100. Furthermore, the transmitting unit 111 of the UE 100 may transmit, for example, a UE capability information message (UECapabilityInformation) including the capability information to the base station 200. The receiving unit 212 of the base station 200 may receive the UE capability information message from the UE 100.

The capability information may be, for example, a capability indicating whether it is possible to determine an MCS index table based on second MCS table information described below. The capability information may be a capability indicating whether it is possible to receive second switching information in a lower layer. That is, the capability information may include information indicating whether dynamic waveform switching is supported. Furthermore, the capability information may include information indicating the supported OFDM method. For example, the capability information may include information indicating whether the CP-OFDM method is supported and/or information indicating whether the DFT-s-OFDM method is supported.

The control unit 120 of the UE 100 may include in the capability information information indicating whether or not dynamic waveform switching is supported only when, for example, the capability information includes information indicating support for the CP-OFDM method and information indicating support for the DFT-s-OFDM method. Also, the control unit 120 of the UE 100 may include in the capability information information indicating whether or not an MCS index table based on the second MCS table information is supported only when, for example, the capability information includes information indicating support for dynamic waveform switching. Here, when the UE 100 supports dynamic waveform switching, it may be specified in the specifications, etc., that the UE 100 always supports an MCS index table based on the second MCS table information.

Step S102:
The transmitting unit 211 of the base station 200 may transmit an RRC message including the following information to the UE 100. The receiving unit 112 of the UE 100 may receive the RRC message from the base station 200.

The control unit 230 of the base station 200 may include the first switching information in an RRC message. The first switching information is switching information notified in the RRC layer. The first switching information may be transform precoder information indicating (or indicating or setting) the enablement or disablement of transform precoding. As shown in E10 of FIG. 7, the control unit 230 may include, for example, "transformPrecoder" as the first switching information in the setting information (e.g., PUSCH-Config). The receiving unit 112 of the UE 100 receives the first switching information from the base station 200 by an RRC message.

The control unit 230 may include the first MCS table information in the RRC message. The first MCS table information indicates an MCS index table to be applied to uplink transmission by the OFDM method based on the first switching control described below. The first MCS table information may include information indicating an MCS index table to be applied to uplink transmission by the OFDM method to which a transform precoder is applied. In other words, the first MCS table information may include information indicating which MCS table the UE 100 uses for uplink transmission involving a transform precoder. Such information is appropriately referred to as first TP present information.

The first MCS table information may also include information indicating an MCS index table to be applied to uplink transmission using the OFDM method without applying a transform precoder. That is, the first MCS table information may include information indicating which MCS table UE 100 uses for uplink transmission without a transform precoder. Such information is appropriately referred to as first no-TP information.

For example, the control unit 120 of the UE 100 may determine which of the multiple MCS tables to use for uplink transmission with a transform precoder based on the first MCS table information. The control unit 120 of the UE 100 may also apply a modulation order, a target code rate, and/or a spectral efficiency corresponding to the MCS index to the uplink transmission (i.e., uplink transmission with a transform precoder) based on the determined MCS table. The control unit 120 of the UE 100 may also determine which of the multiple MCS tables to use for uplink transmission without a transform precoder based on the first MCS table information. The control unit 120 of the UE 100 may also apply a modulation order, a target code rate, and/or a spectral efficiency corresponding to the MCS index to the uplink transmission (i.e., uplink transmission without a transform precoder) based on the determined MCS table.

The first TP presence information may indicate, for example, an MCS table to be used for uplink transmission involving transform precoding (e.g., PUSCH). The first TP presence information may include, for example, information indicating the MCS index table applied to DCI format 0_0 and DCI format 0_1 (which may be referred to as "mcs-TableTransformPrecoder") as shown in E11 of FIG. 7, and information indicating the MCS index table applied to DCI format 0_2 (which may be referred to as "mcs-TableTransformPrecoderDCI-0-2-r16") as shown in E12 of FIG. 7.

The first no-TP information may, for example, indicate an MCS table to be used for uplink transmission (e.g., PUSCH) without transform precoding. The first no-TP information may, for example, include information indicating an MCS index table applied to DCI format 0_0 and DCI format 0_1 (which may be referred to as "mcs-Table") as shown in E11 of FIG. 7, and information indicating an MCS index table applied to DCI format 0_2 (which may be referred to as "mcs-TableDCI-0-2-r16") as shown in E12 of FIG. 7.

The information indicating the MCS index table applied to the above-mentioned DCI format 0_0 and DCI format 0_1 ("mcs-Table", "mcs-TableTransformPrecoder"; hereinafter, sometimes referred to as MCS-0-0&1 information) may indicate the MCS index table applied to the uplink transmission (PUSCH) scheduled using DCI format 0_0 and/or DCI format 0_1. The information indicating the MCS index table applied to the above-mentioned DCI format 0_2 ("mcs-TableDCI-0-2-r16", "mcs-TableTransformPrecoderDCI-0-2-r16"; hereinafter, sometimes referred to as first MCS-0-2 information) may indicate the MCS index table applied to the uplink transmission (PUSCH) scheduled using DCI format 0_2.

The control unit 230 may include second MCS table information in the RRC message. The second MCS table information indicates an MCS index table to be applied to uplink transmission by the OFDM method based on the second switching control described below. The second MCS table information may have information indicating an MCS index table to be applied to uplink transmission by the OFDM method to which a transform precoder is applied. In other words, the second MCS table information may include information indicating which MCS table the UE 100 uses for uplink transmission involving a transform precoder. Such information is appropriately referred to as second TP present information.

The second MCS table information may include information indicating an MCS index table to be applied to uplink transmission using the OFDM method without applying a transform precoder. That is, the second MCS table information may include information indicating which MCS table the UE 100 uses for uplink transmission without a transform precoder. Such information is appropriately referred to as second no-TP information.

For example, the control unit 120 of the UE 100 may determine which of the multiple MCS tables to use for uplink transmission with a transform precoder based on the second MCS table information. The control unit 120 of the UE 100 may also apply a modulation order, a target code rate, and/or a spectral efficiency corresponding to the MCS index to uplink transmission (i.e., uplink transmission with a transform precoder) based on the determined MCS table. The control unit 120 of the UE 100 may also determine which of the multiple MCS tables to use for uplink transmission without a transform precoder based on the second MCS table information. The control unit 120 of the UE 100 may also apply a modulation order, a target code rate, and/or a spectral efficiency corresponding to the MCS index to uplink transmission (i.e., uplink transmission without a transform precoder) based on the determined MCS table.

The second TP presence information may, for example, indicate an MCS table to be used for uplink transmission involving transform precoding (e.g., PUSCH). The second TP presence information may, for example, include information indicating an MCS index table that is not applied to DCI format 0_0 but is applied to DCI format 0_1 (which may be referred to as "mcs-TableTransformPrecoderDCI-0-1-DWS-r18") as shown in E21 of FIG. 7, and information indicating an MCS index table that is applied to DCI format 0_2 (which may be referred to as "mcs-TableTransformPrecoderDCI-0-2-DWS-r18") as shown in E22 of FIG. 7.

The second no-TP information may, for example, indicate an MCS table to be used for uplink transmission (e.g., PUSCH) without transform precoding. The second no-TP information may, for example, include information indicating an MCS index table that is not applied to DCI format 0_0 but is applied to DCI format 0_1 (which may be referred to as "mcs-TableDCI-0-1-DWS-r18") as shown in E21 of FIG. 7, and information indicating an MCS index table that is applied to DCI format 0_2 (which may be referred to as "mcs-TableDCI-0-2-DWS-r18") as shown in E22 of FIG. 7.

The information indicating the MCS index table applied to the above-mentioned DCI format 0_1 ("mcs-TableDCI-0-1-DWS-r18", "mcs-TableTransformPrecoderDCI-0-1-DWS-r18"; hereinafter, sometimes referred to as MCS-0-1 information) may indicate the MCS index table applied to uplink transmission scheduled using DCI format 0_1. The information indicating the MCS index table applied to the above-mentioned DCI format 0_2 ("mcs-TableTransformPrecoderDCI-0-1-DWS-r18", "mcs-TableTransformPrecoderDCI-0-2-DWS-r18"; hereinafter, sometimes referred to as second MCS-0-2 information) may indicate the MCS index table applied to uplink transmission scheduled using DCI format 0_2.

As described above, the receiving unit 112 of the UE 100 receives the second MCS table information separately from the first MCS table information. Note that the control unit 230 may include the first MCS table information and the second MCS table information in the same RRC message, or may include them in different RRC messages. Thus, the receiving unit 112 of the UE 100 may receive the first MCS table information and the second MCS table information in the same RRC message. The receiving unit 112 of the UE 100 may receive an RRC message including the second MCS table information separately from the RRC message including the first MCS table information.

The control unit 230 may include in the RRC message notification information indicating whether or not the second switching information is notified in the lower layer. Thus, the receiving unit 112 of the UE 100 may receive the notification information from the base station 200. The notification information may be, for example, information indicating that the second switching information is notified in the lower layer, or the notification information may be, for example, information indicating that the second switching information is notified in the lower layer. When the notification information is not included in the RRC message, it may be indicated that the second switching information is notified in the lower layer. When the notification information is not included in the RRC message, it may be indicated that the second switching information is not notified in the lower layer.

The notification information may indicate that the second switching information is included in the DCI format. In this case, the notification information may indicate that the second switching information is notified in the lower layer. The notification information may indicate that the second switching information is not included in the DCI format. In this case, the notification information may indicate that the second switching information is not notified in the lower layer. The notification information may indicate that the second switching information is included in a predetermined DCI format. The notification information may indicate, for example, that the second switching information is included in DCI format 0_1 and/or DCI format 0_2. The notification information may indicate that the second switching information is not included in a predetermined DCI format. The notification information may indicate, for example, that the second switching information is not included in DCI format 0_1 and/or DCI format 0_2. Therefore, the notification information may be a common setting for whether or not the second switching information is included for a plurality of DCI formats, or may be a setting for whether or not the second switching information is included for each of the plurality of DCI formats independently. In addition, whether or not the second switching information is included may be based on whether or not a field to which the second switching information is mapped exists.

The control unit 230 of the base station 200 may determine whether to transmit the second MCS table information to the UE 100 based on the capability information from the UE 100. If the capability information indicates that (a) it is possible to determine an MCS index table based on the second MCS table information, and/or (b) it is possible to receive the second switching information in a lower layer, the control unit 230 may decide to transmit the second MCS table information to the UE 100 and include the second MCS table information in the RRC message. If the capability information indicates that (a) it is not possible to determine an MCS index table based on the second MCS table information, and/or (b) it is not possible to receive the second switching information in a lower layer, the control unit 230 may decide not to transmit the second MCS table information to the UE 100 and perform control not to include the second MCS table information in the RRC message.

Step S103:
The transmitting unit 211 of the base station 200 notifies the UE 100 of the second switching information (i.e., a value set in the field of the second switching information) in a layer lower than the RRC layer. In this embodiment, the transmitting unit 211 transmits DCI including the second switching information to the UE 100. Therefore, the transmitting unit 211 can transmit the second switching information by a physical layer (i.e., L1 signaling). For example, the transmitting unit 211 may transmit the DCI including the second switching information on a PDCCH. The receiving unit 112 of the UE 100 receives the DCI including the second switching information (i.e., a value set in the field of the second switching information) from the base station 200.

The second switching information is switching information notified by a lower layer. The second switching information indicates (or indicates or sets) whether or not to apply a transform precoder. For example, the second switching information may be information for indicating whether or not to apply a transform precoder to the corresponding PUSCH transmission. That is, the TP information may be information for indicating whether the transform precoder is enabled or disabled. For example, by setting "0" or "1" in the field of the second switching information, it may be indicated that the transform precoder is applied to the uplink transmission (e.g., the transform precoder is enabled). Also, by setting "0" or "1" in the field of the second switching information, it may be indicated that the transform precoder is not applied to the uplink transmission (e.g., the transform precoder is disabled).

The DCI including the second switching information may be a (predetermined) DCI format including the second switching information. The DCI indicating whether or not to apply a transform precoder may be the second switching information. The DCI format including the second switching information may be, for example, a DCI format used for scheduling the PUSCH. The DCI format including the second switching information may be, for example, DCI format 0_1 and/or DCI format 0_2. DCI format 0_0 may be a DCI format including the second switching information, or may not be a DCI format including the second switching information. The DCI format including the second switching information may be another DCI format used for scheduling uplink transmission. For example, the second switching information included in the DCI format (a value set in the field of the second switching information) may be applied to the PUSCH transmission scheduled using the DCI format. That is, the second switching information included in the DCI format may be applied only to the PUSCH transmission corresponding to the DCI format.

The DCI format including the second switching information may be a DCI format in which a field (hereinafter referred to as a specific field) to which the second switching information is mapped is set. Therefore, the presence or absence of the second switching information may be specified by the presence or absence of the specific field. The specific field may be a one-bit information field or a multi-bit information field. Therefore, the second switching information may be one-bit or multi-bit information. For example, when scheduling a PUSCH in one or more serving cells using one DCI format, the number of bits of the specific field may be determined based on the number of serving cells (e.g., UL serving cells) set for one DCI format. That is, the control unit 230 of the base station 200 may schedule one or more PUSCHs in one or more serving cells using one DCI format. Here, for example, the transmission unit 211 of the base station 200 may transmit an RRC message including information used to determine one or more serving cells (e.g., the number of serving cells) to which one or more PUSCHs are scheduled. In addition, the control unit 120 of the UE 100 may determine the number of bits of the field of the second switching information included in one DCI format based on information used to determine one or more serving cells (e.g., the number of serving cells) to which one or more PUSCHs are scheduled. For example, when three PUSCHs in three serving cells are scheduled using one DCI format, the control unit 120 of the UE 100 may determine the number of bits of the field of the second switching information included in the one DCI format as 3 bits. This makes it possible to apply the value of the field of the second switching information to each of the uplink transmissions in each of the multiple serving cells.

Note that DCI format 0_0 may be used for scheduling the PUSCH in one cell. DCI format 0_1 may be used for scheduling one or more PUSCHs in one cell, or for indicating CG downlink feedback information (CG-DFI) to UE 100. DCI format 0_2 may be used for scheduling the PUSCH in one cell. Here, CRC parity bits scrambled by C-RNTI, CS-RNTI, and/or MCS-C-RNTI may be added to DCI format 0_0, DCI format 0_1, and/or DCI format 0_2. That is, CRC parity bits scrambled by C-RNTI, CS-RNTI, and/or MCS-C-RNTI may be added to the DCI format including the second switching information.

Further, the transmission unit 211 of the base station 200 may transmit to the UE 100 an RRC message including configuration information for monitoring a PDCCH for a DCI (or DCI format) including the second switching information. The configuration information may include information for setting a control resource set (e.g., CORESET(s)) for monitoring a PDCCH for a DCI (or DCI format) including the second switching information, and/or information for setting a search space set (Search Space Set(s)) for monitoring a PDCCH for a DCI (or DCI format) including the second switching information. The control unit 120 of the UE 100 may determine that the DCI received in the set control resource set and/or search space set includes the second switching information. For example, the search space set includes a UE-specific search space set (also referred to as a USS set) and/or a common search space set (also referred to as a CSS set). The CSS set may include a Type 3 PDCCH CSS. In addition, the information for configuring the search space set may include information indicating that the search space set is either a USS set or a CSS set.

The information for setting the search space set may include information indicating that, when the search space set is indicated as a CSS set, the PDCCH for DCI format 0_0 is to be monitored in the search space set. The information for setting the search space set may also include information indicating that, when the search space set is indicated as a USS set, the PDCCH for DCI format 0_0 is to be monitored in the search space set. That is, the control unit 120 of the UE 100 may monitor the PDCCH for DCI format 0_0 in the configured CSS set. The control unit 120 of the UE 100 may monitor the PDCCH for DCI format 0_0 in the configured USS set.

In addition, the information for setting the search space set may include information indicating that, when the search space set is indicated as a USS set, the PDCCH for DCI format 0_1 is monitored in the search space set. That is, the control unit 120 of the UE 100 may monitor the PDCCH for DCI format 0_1 in the set USS set. In addition, the information for setting the search space set may include information indicating that, when the search space set is indicated as a USS set, the PDCCH for DCI format 0_2 is monitored in the search space set. That is, the control unit 120 of the UE 100 may monitor the PDCCH for DCI format 0_2 in the set USS set. The control unit 120 of the UE 100 may monitor the PDCCH for DCI format 0_1 and the PDCCH for DCI format 0_2 in different USS sets. For example, the control unit 120 of the UE 100 may monitor the PDCCH for DCI format 0_1 and the PDCCH for DCI format 0_2 in each of the configured USS sets, and detect DCI format 0_1 and DCI format 0_2 that include the second switching information.

The control unit 230 of the base station 200 may determine whether to transmit the second switching information to the UE 100 based on the capability information from the UE 100. If the capability information indicates that (a) it is possible to determine an MCS index table based on the second MCS table information, and/or (b) it is possible to receive the second switching information in a lower layer, the control unit 230 may determine to transmit the second switching information to the UE 100 and, for example, include the second switching information in the DCI. If the capability information indicates that (a) it is not possible to determine an MCS index table based on the second MCS table information, and/or (b) it is not possible to receive the second switching information in a lower layer, the control unit 230 may determine not to transmit the second MCS table information to the UE 100 and, for example, perform control not to include the second switching information in the DCI.

Step S104:
The control unit 120 of the UE 100 performs a notification determination of the second switching information. That is, the control unit 120 determines whether or not the second switching information is notified in a lower layer. The control unit 120 may determine whether or not the second switching information is included in the DCI (DCI format). In addition, the control unit 120 may determine whether or not the DCI (DCI format) includes a field (i.e., a specific field) to which the second switching information is mapped. Each time the control unit 120 receives the DCI (DCI format), it may determine whether or not the second switching information is included in the received DCI format. Note that the control unit 120 may determine whether or not the second switching information is included in the DCI format before step S103 (i.e., before receiving the DCI format).

The control unit 120 may determine whether the second switching information is notified in the lower layer by at least one of the following methods:

First, the control unit 120 determines whether or not the second switching information is notified in the lower layer based on the notification information. For example, when the notification information indicates that the second switching information is notified in the lower layer, the control unit 120 may determine that the second switching information is notified in the lower layer. On the other hand, when the notification information indicates that the second switching information is not notified in the lower layer, the control unit 120 may determine that the second switching information is not notified in the lower layer. In addition, as shown in step S102, the control unit 120 may determine whether or not the second switching information is notified in the lower layer depending on what is indicated by the notification information. For example, when the notification information is included in the RRC message, the control unit 120 may determine that the second switching information is included in the DCI format (e.g., DCI format 0_1 and/or DCI format 0_2). As described above, the notification information may be set commonly to multiple DCI formats (e.g., DCI format 0_1 and DCI format 0_2). Furthermore, the notification information may be set for each of a plurality of DCI formats (e.g., DCI format 0_1 and DCI format 0_2). Furthermore, the notification information may be set for each of one or a plurality of uplink BWPs. Furthermore, if the notification information is not included in the RRC message, the control unit 120 may determine that the second switching information is not included in the DCI format (e.g., DCI format 0_1 and/or DCI format 0_2). That is, the control unit 120 may determine whether the second switching information is included in the DCI format received after the setting, based on the reception of the notification information.

Secondly, the control unit 120 determines whether or not the second switching information is notified in the lower layer based on the second MCS table information. For example, when the control unit 120 receives the second MCS table information, it may determine that the second switching information is notified in the lower layer. On the other hand, when the control unit 120 does not receive the second MCS table information, it may determine that the second switching information is not notified in the lower layer. For example, when the RRC message includes the second MCS table information, the control unit 120 may determine that the second switching information is included in the DCI format (e.g., DCI format 0_1 and/or DCI format 0_2). Furthermore, when the RRC message does not include the second MCS table information, the control unit 120 may determine that the second switching information is not included in the DCI format (e.g., DCI format 0_1 and/or DCI format 0_2). In this way, the second MCS table information may be used as information equivalent to the above-mentioned notification information. Note that the second MCS table information may be included in the notification information.

In addition, when the control unit 120 receives second MCS table information corresponding to a predetermined DCI format from the base station 200, the control unit 120 may determine that the second switching information is included in the predetermined DCI format. For example, when the control unit 120 receives second MCS table information (i.e., MCS-0-1 information) corresponding to DCI format 0_1, the control unit 120 may determine that the second switching information is included in DCI format 0_1. When the control unit 120 receives second MCS table information (i.e., second MCS-0-2 information) corresponding to DCI format 0_2, the control unit 120 may determine that the second switching information is included in DCI format 0_2. On the other hand, when the control unit 120 does not receive second MCS table information corresponding to a predetermined DCI format from the base station 200, the control unit 120 may determine that the second switching information is not included in the predetermined DCI format. For example, when the control unit 120 does not receive MCS-0-1 information, the control unit 120 may determine that the second switching information is not included in DCI format 0_1. When the control unit 120 does not receive the second MCS-0-2 information, the control unit 120 may determine that the second switching information is not included in the DCI format 0_2. For example, when the RRC message includes the second MCS table information corresponding to the DCI format 0_1, the control unit 120 may determine that the second switching information is included in the DCI format 0_1. Also, when the RRC message does not include the second MCS table information corresponding to the DCI format 0_1, the control unit 120 may determine that the second switching information is not included in the DCI format 0_1. Also, when the RRC message includes the second MCS table information corresponding to the DCI format 0_2, the control unit 120 may determine that the second switching information is included in the DCI format 0_2. Also, when the RRC message does not include the second MCS table information corresponding to the DCI format 0_2, the control unit 120 may determine that the second switching information is not included in the DCI format 0_2. Hereinafter, when UE100 (or control unit 120 of UE100) receives information, it may refer to a case where the information is included in the RRC message. Also, when UE100 (or control unit 120 of UE100) does not receive information, it may refer to a case where the information is not included in the RRC message.

Thirdly, the control unit 120 determines whether or not the second switching information is notified in the lower layer based on the first MCS table information. For example, when the control unit 120 receives the first MCS table information, it may determine that the second switching information is notified (or may be notified) in the lower layer. On the other hand, when the control unit 120 does not receive the first MCS table information, it may determine that the second switching information is not notified (i.e., there is no possibility of it being notified) in the lower layer. For example, when the RRC message includes the first MCS table information corresponding to DCI format 0_1, the control unit 120 may determine that the second switching information is included in DCI format 0_1. Also, when the RRC message does not include the first MCS table information corresponding to DCI format 0_1, the control unit 120 may determine that the second switching information is not included in DCI format 0_1. Furthermore, when the RRC message includes the first MCS table information corresponding to the DCI format 0_2, the control unit 120 may determine that the second switching information is included in the DCI format 0_2. Furthermore, when the RRC message does not include the first MCS table information corresponding to the DCI format 0_2, the control unit 120 may determine that the second switching information is not included in the DCI format 0_2. In this manner, the first MCS table information may be used as information equivalent to the above-mentioned notification information. Note that the first MCS table information may be included in the notification information.

In addition, when the control unit 120 receives first MCS table information corresponding to a predetermined DCI format from the base station 200, the control unit 120 may determine that the second switching information is included (or may be included) in the predetermined DCI format. For example, when the control unit 120 receives first MCS table information corresponding to DCI format 0_1 (i.e., MCS-0-0&1 information), the control unit 120 may determine that the second switching information is included in DCI format 0_1. When the control unit 120 receives first MCS table information corresponding to DCI format 0_2 (i.e., first MCS-0-2 information), the control unit 120 may determine that the second switching information is included in DCI format 0_2. On the other hand, when the control unit 120 does not receive first MCS table information corresponding to a predetermined DCI format from the base station 200, the control unit 120 may determine that the second switching information is not included in the predetermined DCI format. For example, when the control unit 120 does not receive MCS-0-0&1 information, the control unit 120 may determine that the second switching information is not included in DCI format 0_1. If the control unit 120 has not received the first MCS-0-2 information, it may determine that the second switching information is not included in the DCI format 0_2.

Fourthly, the control unit 120 determines whether or not the second switching information is notified in the lower layer based on the first switching information. That is, the first switching information may be included in the notification information. For example, when the control unit 120 receives the first switching information, it may determine that the second switching information is notified (or there is a possibility that it is notified) in the lower layer. On the other hand, when the control unit 120 does not receive the first switching information, it may determine that the second switching information is not notified (i.e. there is no possibility that it is notified) in the lower layer. For example, when the RRC message includes the first switching information, the control unit 120 may determine that the DCI format includes the second switching information. Also, when the RRC message does not include the first switching information, the control unit 120 may determine that the DCI format does not include the second switching information.

The above-mentioned methods may be combined. For example, as shown below (see FIG. 8), the control unit 120 may perform a notification determination of the second switching information.

Step S111:
The control unit 120 determines whether or not the first switching information has been received. If the control unit 120 has received the first switching information, the control unit 120 executes the process of step S112. On the other hand, if the control unit 120 has not received the first switching information, the control unit 120 executes the process of step S114.

Step S112:
The control unit 120 determines whether or not the second MCS table information has been received. If the control unit 120 has received the second MCS table information, the control unit 120 executes the process of step S113. On the other hand, if the control unit 120 has not received the second MCS table information, the control unit 120 executes the process of step S114.

Alternatively, when the control unit 120 receives second MCS table information corresponding to a specific DCI format from the base station 200, the control unit 120 may execute the process of step S113 for the specific DCI format. On the other hand, when the control unit 120 does not receive second MCS table information corresponding to a specific DCI format from the base station 200, the control unit 120 may execute the process of step S114 for the specific DCI format even if the control unit 120 has received second MCS table information corresponding to another DCI format.

Step S113:
The control unit 120 determines that the second switching information is notified in the lower layer. For example, the control unit 120 may determine that the second switching information is included in the DCI format. The control unit 120 may also determine that the second switching information is included in a predetermined DCI format corresponding to the received second MCS table information.

Step S114:
The control unit 120 determines that the second switching information is not notified in the lower layer. For example, the control unit 120 may determine that the second switching information is not included in the DCI format. In this way, when the control unit 120 has not received the first switching information from the base station 200, the control unit 120 may determine that the second switching information is not notified in the lower layer (see step S111). Also, when the control unit 120 has not received the second MCS table information from the base station 200, the control unit 120 may determine that the second switching information is not notified in the lower layer (see step S112). Note that the control unit 120 may determine that the second switching information is not notified in a predetermined DCI format corresponding to the second MCS table information that has not been received.

After determining the notification method in this manner, UE100 may perform the process of step S105 in FIG. 6 as shown below.

Step S105:
The control unit 120 performs OFDM scheme switching control. Specifically, the control unit 120 can execute either a first switching control in which the OFDM scheme for uplink transmission is switched based on first switching information notified in the RRC layer, or a second switching control in which the OFDM scheme for uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer, as the OFDM scheme switching control. The control unit 120 can execute the first switching control when the first switching information is received, and execute the second switching control when the second switching information is received.

When the transform precoder is enabled based on the first switching information and/or the second switching information, the control unit 120 determines to apply the transform precoder to the uplink transmission. That is, the control unit 120 determines to use a DFT-s-OFDM waveform for the uplink transmission. For example, when the uplink transmission is performed using a CP-OFDM waveform, the control unit 120 switches the OFDM scheme from CP-OFDM to DFT-s-OFDM.

On the other hand, if the transform precoder is disabled by the first switching information and/or the second switching information, the control unit 120 decides not to apply the transform precoder to the uplink transmission. That is, the control unit 120 decides to use a CP-OFDM waveform for the uplink transmission. In this case, if the control unit 120 has been performing uplink transmission using a DFT-s-OFDM waveform, it switches the OFDM scheme from DFT-s-OFDM to CP-OFDM.

The control unit 120 also determines (selects) the MCS index table. The control unit 120 determines the MCS index table based on the first MCS table information and/or the second MCS table information. For example, when the control unit 120 receives second switching information, it may determine the MCS index table as shown in FIG. 9.

Step S121:
The control unit 120 determines whether the received DCI format is DCI format 0_0. If the control unit 120 receives DCI format 0_0, the control unit 120 executes the process of step S125. On the other hand, if the control unit 120 does not receive DCI format 0_0, the control unit 120 executes the process of step S122.

Step S122:
The control unit 120 determines whether the received DCI format is DCI format 0_1. If the control unit 120 receives DCI format 0_1, the control unit 120 executes the process of step S123. On the other hand, if the control unit 120 does not receive DCI format 0_1, the control unit 120 executes the process of step S126.

Step S123:
The control unit 120 judges whether or not the MCS-0-1 information has been received. If the control unit 120 has received the MCS-0-1 information, the control unit 120 executes the process of step S124. On the other hand, if the control unit 120 has not received the MCS-0-1 information, the control unit 120 executes the process of step S125.

Step S124:
The control unit 120 determines the MCS index table based on the MCS-0-1 information. Therefore, when the second switching information is notified in the DCI format 0_1 in the lower layer, the control unit 120 determines the MCS table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the MCS-0-1 information. For example, when the second switching information (e.g., a value set in the field of the second switching information) indicates the enablement of transform precoding, the control unit 120 determines the MCS index table indicated by the second TP presence information (e.g., "mcs-TableTransformPrecoderDCI-0-1-DWS-r18") in the MCS-0-1 information as the MCS index table to be applied to the uplink transmission. On the other hand, when the second switching information (e.g., a value set in a field of the second switching information) indicates the disablement of transform precoding, the control unit 120 determines the MCS index table indicated by the second TP-free information in the MCS-0-1 information (e.g., "mcs-TableDCI-0-1-DWS-r18") as the MCS index table to be applied to the uplink transmission.

Step S125:
The control unit 120 determines the MCS index table based on the first MCS table information. For example, when the second switching information is notified in the DCI format 0_1 in the lower layer, the control unit 120 determines the MCS table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information. When the second switching information (e.g., a value set in the field of the second switching information) indicates the enablement of transform precoding, the control unit 120 determines the MCS index table indicated by the first TP presence information (e.g., "mcs-TableTransformPrecoder") in the first MCS table information as the MCS index table to be applied to the uplink transmission. On the other hand, when the second switching information (e.g., a value set in a field of the second switching information) indicates the disablement of transform precoding, the control unit 120 determines the MCS index table indicated by the first TP-free information (e.g., “mcs-Table”) in the first MCS table information as the MCS index table to be applied to the uplink transmission.

Furthermore, when uplink transmission (i.e., PUSCH) is scheduled using DCI format 0_0, the control unit 120 may determine the MCS index table to be applied to the uplink transmission based on the first MCS table information. That is, when uplink transmission (i.e., PUSCH) is scheduled using DCI format 0_0, the control unit 120 may determine the MCS index table to be applied to the uplink transmission based on the first MCS table information, regardless of whether the second MCS table information is received. For example, the control unit 120 determines the MCS index table indicated by the first TP present information or the first TP absent information as the MCS index table to be applied to the uplink transmission based on the enablement or disablement of transform precoding indicated by the first switching information. Furthermore, the control unit 120 determines the MCS index table indicated by the first TP present information or the first TP absent information as the MCS index table to be applied to the uplink transmission, based on whether the second switching information (the value set in the field of the second switching information) included in the DCI format 0_0 indicates the enablement of transform precoding.

Step S126:
The control unit 120 determines whether the received DCI format is DCI format 0_2. When the control unit 120 receives DCI format 0_2, the control unit 120 executes the process of step S126. On the other hand, when the control unit 120 does not receive DCI format 0_2, the control unit 120 may end this flow. Alternatively, when another DCI format is defined as a DCI format used for scheduling uplink transmission (e.g., PUSCH), the control unit 120 may determine whether the received DCI format is the other defined DCI format. When the other defined DCI format may include the second switching information, the control unit 120 may execute the same process as step S123 or S127.

Step S127:
The control unit 120 judges whether or not the second MCS-0-2 information has been received. If the control unit 120 has received the second MCS-0-2 information, the control unit 120 executes the process of step S128. On the other hand, if the control unit 120 has not received the second MCS-0-2 information, the control unit 120 executes the process of step S129.

Step S128:
The control unit 120 determines the MCS index table based on the second MCS-0-2 information. For example, when the second switching information is notified in the DCI format 0_1 in the lower layer, the control unit 120 determines the MCS table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the second MCS-0-2 information. For example, when the second switching information (e.g., a value set in the field of the second switching information) included in the DCI format 0_2 indicates the enablement of transform precoding, the control unit 120 determines the MCS index table indicated by the second TP presence information (e.g., "mcs-TableTransformPrecoderDCI-0-2-DWS-r18") in the second MCS-0-2 information as the MCS index table to be applied to the uplink transmission. On the other hand, when the second switching information included in DCI format 0_2 (e.g., a value set in a field of the second switching information) indicates the disablement of transform precoding, the control unit 120 determines the MCS index table indicated by the second TP-free information in the first MCS table information (e.g., "mcs-TableDCI-0-2-DWS-r18") as the MCS index table to be applied to the uplink transmission.

Step S129:
The control unit 120 determines the MCS index table based on the first MCS-0-2 information. For example, when the second switching information (e.g., a value set in the field of the second switching information) included in the DCI format 0_2 indicates the enablement of transform precoding, the control unit 120 determines the MCS index table indicated by the first TP present information (e.g., "mcs-TableTransformPrecoderDCI-0-2-r16") in the first MCS-0-2 information as the MCS index table to be applied to the uplink transmission. On the other hand, when the second switching information (e.g., a value set in the field of the second switching information) included in the DCI format 0_2 indicates the disablement of transform precoding, the control unit 120 determines the MCS index table indicated by the first TP absent information (e.g., "mcs-TableDCI-0-2-r16") in the first MCS table information as the MCS index table to be applied to the uplink transmission.

As shown in the above-mentioned cases of NO in step S123 and NO in step S127, when the control unit 120 of the UE 100 has not received the second MCS table information, the control unit 120 may determine the MCS index table based on the first MCS table information. In other words, when the control unit 120 of the UE 100 has received the first MCS table information but has not received the second MCS table information, the control unit 120 may determine the MCS index table based on the first MCS table information.

The control unit 120 determines the MCS (e.g., modulation order, target code rate, and/or spectral efficiency) based on the determined MCS index table. The UE 100 may then perform the process of step S106 in FIG. 6 as follows:

When the control unit 120 receives DCI format 0_1 that does not include second switching information, the control unit 120 may determine the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information, regardless of whether the control unit 120 has received second MCS table information.

Step S106:
The transmitter 111 of the UE 100 performs uplink transmission in an active BWP among the set uplink BWPs. The transmitter 111 may transmit an uplink signal (e.g., PUSCH) to the base station 200. The transmitter 111 performs uplink transmission by applying an MCS (e.g., modulation order, target code rate, and/or spectral efficiency) determined based on the determined MCS index table. The receiver 212 of the base station 200 may receive an uplink signal from the UE 100. Note that, when the control unit 120 determines to apply a transform precoder (i.e., when the enablement of the transform precoder is instructed (or set)), the transmitter 111 transmits an uplink signal to which the transform precoder is applied. When the control unit 120 determines not to apply a transform precoder, the transmitter 111 transmits an uplink signal to which the transform precoder is not applied.

As described above, the control unit 120 of the UE 100 executes a first switching control in which the OFDM scheme for uplink transmission is switched based on the first switching information notified at the RRC layer, and a second switching control in which the OFDM scheme for uplink transmission is switched based on the second switching information notified at a layer lower than the RRC layer. The transmission unit 211 of the base station 200 transmits to the UE 100 second MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from the first MCS table information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control. The reception unit 112 of the UE 100 receives the second MCS table information from the base station 200 separately from the first MCS table information. This allows the UE 100 to change the MCS index table to be applied to the uplink transmission between the first switching control and the second switching control, thereby allowing for flexible control of the uplink transmission.

The second MCS table information may include information indicating an MCS index table to be applied to uplink transmission by the OFDM scheme to which a transform precoder is applied, and information indicating an MCS index table to be applied to uplink transmission by the OFDM scheme to which a transform precoder is not applied. This allows the UE 100 to change the MCS index table to be applied to uplink transmission between the OFDM scheme to which a transform precoder is applied and the OFDM scheme to which a transform precoder is not applied when switching the OFDM scheme based on the second switching control. As a result, uplink transmission can be flexibly controlled.

The second MCS table information may also include MCS-0-1 information indicating an MCS index table that is not applied to DCI format 0_0 but is applied to DCI format 0_1. When second switching information is included in DCI format 0_1 in a lower layer, the control unit 120 may determine an MCS table to be applied to uplink transmission scheduled using DCI format 0_1 based on the MCS-0-1 information. Here, the first MCS table information "mcs-Table" and/or "mcs-TableTransformPrecoder" may indicate an MCS index table to be applied to both DCI format 0_0 and DCI format 0_1. On the other hand, since the MCS-0-1 information indicates an MCS index table that is not applied to DCI format 0_0 but is applied to DCI format 0_1, the MCS index table that is applied to uplink transmission by the OFDM method based on the second switching control can be changed between when uplink transmission is scheduled using DCI format 0_0 and when uplink transmission is scheduled using DCI format 0_1. As a result, uplink transmission can be flexibly controlled.

Furthermore, when the second switching information is included in the DCI format 0_1, if the control unit 120 has not received MCS-0-1 information, the control unit 120 may determine the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information. This allows the UE 100 to determine an appropriate MCS even if it has not received MCS-0-1 information. Furthermore, when the base station 200 performs control to apply the same MCS in the first switching control and the second switching control, for example, it can omit the transmission of MCS-0-1 information, thereby making it possible to conserve radio resources.

Furthermore, when the control unit 120 receives DCI format 0_1 that does not include second switching information, the control unit 120 may determine the MCS index table to be applied to uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information, regardless of whether the second MCS table information has been received. This allows the UE 100 to determine the MCS index table based on the first MCS table information even when the UE 100 has received the second MCS table information, and allows the UE 100 to flexibly control uplink transmission.

Furthermore, when the control unit 120 receives DCI format 0_0, it may determine the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_0 based on the first MCS table information, regardless of whether or not the second MCS table information has been received. This allows the control unit 120 to omit the process of selecting (determining) which MCS table information to base the determination on when DCI format 0_0 is received. In particular, when the second switching information cannot be included in DCI format 0_0 (i.e., it cannot be set), the control unit 120 can omit the above process, thereby reducing the processing load on the UE 100.

The second MCS table information may also include second MCS-0-2 information indicating an MCS index table to be applied to downlink control information (DCI) format 0_2. When second switching information is notified in DCI format 0_2 in a lower layer, the control unit 120 may determine an MCS index table to be applied to uplink transmission scheduled using the DCI format 0_2 based on the second MCS-0-2 information. This makes it possible to change the MCS index table to be applied to uplink transmission between an OFDM scheme to which a transform precoder is applied and an OFDM scheme to which a transform precoder is not applied when uplink transmission is scheduled using DCI format 0_2. As a result, uplink transmission can be flexibly controlled.

The control unit 120 may also determine whether or not the second switching information is notified in the lower layer based on notification information indicating whether or not the second switching information is notified in the lower layer. This explicitly indicates whether or not the second switching information is notified, so that the UE 100 can accurately determine whether or not the second switching information is notified.

Furthermore, if the control unit 120 has not received the second MCS table information from the base station 200, the control unit 120 may determine that the second switching information is not notified in the lower layer. This allows the control unit 120 to determine that the second switching information is not notified in the lower layer even if notification information is not received, making it possible to save radio resources.

Furthermore, if the control unit 120 has not received the first switching information from the base station 200, the control unit 120 may determine that the second switching information is not notified in the lower layer. This allows the control unit 120 to determine that the switching information is not notified in the lower layer when the switching information is not notified in the RRC layer. As a result, the control unit 120 can omit determining each time whether or not the second switching information is notified when signaling is received in the lower layer, thereby reducing the processing load of the UE 100.

As described above, since the MCS index table applied to the uplink transmission can be changed according to the DCI format used to schedule the uplink transmission, the uplink transmission can be flexibly controlled. For example, when the uplink transmission is scheduled using DCI format 0_0 that does not include the second switching information, the MCS index table may be determined based on the first MCS table information. That is, the first switching control may be applied to the uplink transmission scheduled using DCI format 0_0. Also, when the uplink transmission is scheduled using DCI format 0_1 and/or DCI format 0_2 that include the second switching information, the MCS index table may be determined based on the second MCS table information. That is, since the MCS index table can be changed according to the DCI format used to schedule the uplink transmission, the MCS index table suitable for the uplink transmission can be determined.

(Operation example 2)
With reference to Fig. 10, an operation example 2 of the mobile communication system 1 will be described. The description of the same parts as the above operation examples will be omitted. This operation example is an example of the operation of the UE 100 that determines the MCS index table. This operation example can be applied to the case where the second MCS-0-2 information is not specified in the mobile communication system 1, for example.

Steps S221 to S226:
This is the same as steps S121 to S126.

Step S227:
The control unit 120 determines the MCS index table based on the first MCS-0-2 information, similarly to step S129. Therefore, regardless of whether the second switching information is included in the DCI format 0_2 in the lower layer, the control unit 120 may determine the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_2 based on the first MCS-0-2 information. As a result, the control unit 120 can uniformly determine the MCS index table based on the first MCS-0-2 information regardless of whether the control unit 120 receives the first switching information or the second switching information, thereby reducing the processing load of the UE 100.

(Operation example 3)
With reference to Fig. 11, an operation example 3 of the mobile communication system 1 will be described. The same parts as those in the above operation examples will not be described. In this operation example, an example of a method for determining whether or not to execute switching control in a BWP after switching based on the second switching information when the UE 100 receives second switching information in a BWP before switching will be described.

After receiving DCI (DCI format) including the second switching information and a BWP indicator indicating a BWP (e.g., an uplink BWP) (e.g., after step S103 described above), the receiver 112 of the UE 100 may perform the following operations.

Step S301:
The control unit 120 of the UE 100 determines whether the BWP is switched. If the BWP indicator included in the DCI indicates a currently inactive BWP, the control unit 120 determines that the BWP is switched. In this case, the control unit 120 executes the process of step S302. On the other hand, if the BWP indicator included in the DCI indicates a currently active BWP, the control unit 120 determines that the BWP is not switched. In this case, the control unit 120 executes the process of step S304. Therefore, the BWP indicator included in the DCI (DCI format) may be used to indicate the BWP (e.g., the index of the BWP) in which the uplink transmission (PUSCH transmission) scheduled using the DCI (DCI format) is performed. Here, the BWP indicated by the BWP indicator may also be referred to as the switched BWP.

Step S302:
The control unit 120 determines whether or not the DCI in the switched BWP includes the second switching information. The control unit 120 may determine whether or not the DCI for each BWP (e.g., each uplink BWP) includes the second switching information based on information set for each BWP (e.g., each uplink BWP). The set information may set whether or not dynamic waveform switching (DWS) is possible for each of a plurality of uplink BWPs.

The configured information may be included in the configuration information (e.g., PUSCH-config) for each of the multiple uplink BWPs. The configured information may be, for example, second MCS table information. For example, when the second MCS table information is configured for the uplink BWP after the switching, the control unit 120 may determine that the DCI for the uplink BWP after the switching includes the second switching information. When the second MCS table information is not configured for the uplink BWP after the switching, the control unit 120 may determine that the DCI for the uplink BWP after the switching does not include the second switching information.

The control unit 120 may also perform a determination similar to that of step S104 described above for the configuration information that sets each uplink BWP. Therefore, the control unit 120 may determine whether or not the second switching information is notified in the lower layer for each uplink BWP.

If the control unit 120 determines that the DCI for the BWP after the switch does not include the second switching information, it executes the process of step S303. On the other hand, if the control unit 120 determines that the DCI for the BWP after the switch includes the second switching information, it executes the process of step S304.

Step S303:
The control unit 120 ignores the second switching information (or the value of the specific field). The control unit 120 may consider that the DCI does not include the second switching information (or the value of the specific field). That is, the control unit 120 may consider that the DCI (DCI format) does not include the second switching information (or the specific field) and perform detection (decoding, blind decoding) of the DCI (DCI format). Therefore, for example, when the control unit 120 receives the first switching information, the control unit 120 performs switching control (i.e., the first switching control) based on the first switching information, not the second switching information. In the BWP after switching, the control unit 120 performs uplink transmission by the OFDM scheme based on the first switching control.

Step S304:
The control unit 120 performs switching control based on the second switching information. Therefore, the control unit 120 performs switching control (i.e., second switching control) based on, for example, the second switching information. The control unit 120 performs uplink transmission by the OFDM scheme based on the second switching control in the BWP after switching. The control unit 120 can execute the same operation as in step S105 described above.

As described above, the receiver 112 may receive DCI including the second switching information and the BWP indicator. The controller 120 may determine the OFDM method for uplink transmission in the BWP indicated by the BWP indicator based on the second switching information. This allows the UE 100 to receive information for determining the OFDM method for uplink transmission in the BWP after the switch in the BWP before the switch, and to flexibly control the uplink transmission in the BWP after the switch.

If the control unit 120 determines that the second switching information is notified in a lower layer in the BWP indicated by the BWP indicator, it may determine the OFDM method for uplink transmission in the BWP indicated by the BWP indicator based on the second switching information, and if it determines that the second switching information is not notified in a lower layer in the BWP indicated by the BWP indicator, it may ignore the second switching information. This allows the UE 100 to apply or not apply the second switching information received in the BWP before switching to the BWP after switching, thereby allowing flexibly controlling uplink transmission in the BWP after switching.

Other Embodiments
In the above-described embodiment, when the control unit 120 of the UE 100 determines that the second switching information has been notified in a lower layer, for example, the control unit 120 may determine (or assume) that (a) the second switching information is included in the DCI (or DCI format), (b) the DCI (or DCI format) has a field (i.e., a specific field) to which the second switching information is mapped, (c) the DCI (or DCI format) has a value set in the specific field, and/or (d) the DCI (or DCI format) includes a value set in the specific field. In addition, the control unit 120 may determine (or assume) that the second switching information has been notified in a lower layer in at least any of the above cases (a) to (c).

Similarly, when the control unit 120 of the UE 100 determines that the second switching information has not been notified in the lower layer, it may determine (or assume) that (a) the second switching information is not included in the DCI (or DCI format), (b) the DCI (or DCI format) does not have a field (i.e., a specific field) to which the second switching information is mapped, (c) the DCI (or DCI format) does not have a value set in the field of the second switching information, and/or (d) the DCI (or DCI format) does not include a value set in the specific field. Furthermore, the control unit 120 may determine (or assume) that the second switching information has not been notified in the lower layer in at least any of the above cases (a) to (c).

In the above embodiment, the lower layer is described by taking the physical layer as an example, but this is not limited to this. For example, the second switching information may be notified in the MAC layer as the lower layer. The second switching information may be included in the MAC CE.

In the above embodiment, the predetermined operation is executed based on the reception of the predetermined information (e.g., second switching information, second MCS table information, etc.), but this is not limited to this. After the reception of the predetermined information, the predetermined operation may be executed based on the predetermined information being configured or set in the UE 100.

In the above embodiment, the PUSCH has been described as an example, but this is not limiting. Similar operations may be performed for other uplink signals (e.g., PTRS, etc.) or other signals (e.g., sidelink signals, etc.).

In the above embodiment, a mobile communication system based on NR has been described as an example of the mobile communication system 1. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system that complies with the TS of either LTE (Long Term Evolution) or another generation system of the 3GPP standard (e.g., the sixth generation). The base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination toward the UE 100 in LTE. The mobile communication system 1 may be a system that complies with the TS of a standard other than the 3GPP standard. The base station 200 may be an IAB (Integrated Access and Backhaul) donor or an IAB node.

In the above embodiment, a mobile communication system based on NR has been described as an example of the mobile communication system 1. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system that complies with the TS of either LTE or another generation system of the 3GPP standard (e.g., the 6th generation). The base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination toward the UE 100 in LTE. The mobile communication system 1 may be a system that complies with the TS of a standard other than the 3GPP standard.

The steps in the operations of the above-described embodiments do not necessarily have to be executed in chronological order according to the order depicted in the flow diagram or sequence diagram. For example, the steps in the operations may be executed in an order different from that depicted in the flow diagram or sequence diagram, or may be executed in parallel. Some of the steps in the operations may be deleted, and additional steps may be added to the process. Furthermore, each of the above-described operation flows is not limited to being executed separately and independently, but can be executed by combining two or more operation flows. For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow.

A program may be provided that causes a computer to execute each process performed by the UE 100 or the base station 200. The program may be recorded in a computer-readable medium. Using the computer-readable medium, it is possible to install the program in the computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM (Compact Disk Read Only Memory) or a DVD-ROM (Digital Versatile Disk Read Only Memory). In addition, circuits that execute each process performed by the UE 100 or the base station 200 may be integrated, and at least a part of the UE 100 or the base station 200 may be configured as a semiconductor integrated circuit (chip set, SoC (System On Chip)).

In the above embodiment, "transmit" may mean performing processing of at least one layer in a protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or wired. Alternatively, "transmit" may mean a combination of performing processing of at least one layer and physically transmitting a signal wirelessly or wired. Similarly, "receive" may mean performing processing of at least one layer in a protocol stack used for reception, or may mean physically receiving a signal wirelessly or wired. Alternatively, "receive" may mean a combination of performing processing of at least one layer and physically receiving a signal wirelessly or wired. Similarly, "obtain/acquire" may mean obtaining information from stored information, obtaining information from information received from other nodes, or obtaining the information by generating the information. Similarly, the terms "based on" and "depending on/in response to" do not mean "based only on" or "only in response to," unless expressly stated otherwise. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "in response to" means both "only in response to" and "at least in part on." Similarly, "include" and "comprise" do not mean including only the recited items, but may include only the recited items or may include additional items in addition to the recited items. Similarly, in this disclosure, "or" does not mean an exclusive or, but does mean a logical or. Furthermore, any reference to elements using designations such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and second element does not imply that only two elements may be employed therein, or that the first element must precede the second element in some manner. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles are intended to include the plural unless the context clearly indicates otherwise.

Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

(Additional Note)
The following additional features relate to the above-described embodiment.

(Appendix 1)
a control unit that executes first switching control in which an Orthogonal Frequency Division Multiplexing (OFDM) scheme for uplink transmission is switched based on first switching information notified in a radio resource control (RRC) layer, and second switching control in which the OFDM scheme for the uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer;
a receiving unit that receives, from a base station, second MCS table information indicating a modulation and coding scheme (MCS) index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control.
Communications equipment.

(Appendix 2)
The communication device according to claim 1, wherein the second MCS table information includes information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme to which a transform precoder is applied, and information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme to which a transform precoder is not applied.

(Appendix 3)
The second MCS table information includes MCS-0-1 information indicating the MCS index table that is not applied to a DCI format 0_0 but is applied to the DCI format 0_1,
The control unit determines, when the second switching information is included in the DCI format 0_1 in the lower layer, the MCS table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the MCS-0-1 information. The communication device according to claim 1 or 2.

(Appendix 4)
The communication device described in Supplementary Note 3, wherein when the second switching information is included in the DCI format 0_1 in the lower layer, if the control unit has not received the MCS-0-1 information, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information.

(Appendix 5)
When the control unit receives a DCI format 0_1 that does not include the second switching information, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information, regardless of whether the second MCS table information has been received.

(Appendix 6)
When the control unit receives DCI format 0_0, it determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_0 based on the first MCS table information, regardless of whether the second MCS table information is received.

(Appendix 7)
The second MCS table information includes second MCS-0-2 information indicating the MCS index table applied to a DCI format 0_2;
The control unit determines, when the second switching information is included in the DCI format 0_2 in the lower layer, the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_2 based on the second MCS-0-2 information. The communication device described in any one of Supplementary Notes 1 to 6.

(Appendix 8)
The first MCS table information includes first MCS-0-2 information indicating the MCS index table applied to a downlink control information (DCI) format 0_2;
The control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_2 based on the first MCS-0-2 information, regardless of whether the second switching information is included in the DCI format 0_2 in the lower layer.

(Appendix 9)
The communication device according to any one of Supplementary Notes 1 to 8, wherein the control unit determines whether or not the second switching information is notified in the lower layer based on notification information indicating whether or not the second switching information is notified in the lower layer.

(Appendix 10)
The communication device according to any one of Supplementary Note 1 to 9, wherein the controller determines that the second switching information is not notified in the lower layer when the second MCS table information is not received from the base station.

(Appendix 11)
The communication device according to any one of Supplementary claims 1 to 10, wherein the control unit determines that the second switching information is not notified in the lower layer when the first switching information is not received from the base station.

(Appendix 12)
The receiving unit receives downlink control information (DCI) including the second switching information and a BWP indicator indicating a bandwidth portion (BWP);
The communication device according to any one of Supplementary Note 1 to 11, wherein the controller determines the OFDM scheme of the uplink transmission in the BWP indicated by the BWP indicator based on the second switching information.

(Appendix 13)
The control unit is
When it is determined that the second switching information is notified in the lower layer in the BWP indicated by the BWP indicator, determining the OFDM scheme of the uplink transmission in the BWP indicated by the BWP indicator based on the second switching information;
The communication device according to claim 12, wherein the second switching information is ignored when it is determined that the second switching information is not notified in the lower layer in the BWP indicated by the BWP indicator.

(Appendix 14)
A base station communicating with a communication device that executes a first switching control in which an Orthogonal Frequency Division Multiplexing (OFDM) scheme for uplink transmission is switched based on first switching information notified in a radio resource control (RRC) layer, and a second switching control in which the OFDM scheme for the uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer,
a transmitter configured to transmit, to the communication device, second MCS table information indicating a modulation and coding scheme (MCS) index table to be applied to the uplink transmission using the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission using the OFDM scheme based on the first switching control.
Base station.

(Appendix 15)
1. A communication method performed in a communication device, comprising:
Executing a first switching control in which an Orthogonal Frequency Division Multiplexing (OFDM) scheme for uplink transmission is switched based on first switching information notified in a radio resource control (RRC) layer, and a second switching control in which the OFDM scheme for the uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer;
receiving, from a base station, second MCS table information indicating an MCS index table to be applied to the uplink transmission using the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission using the OFDM scheme based on the first switching control;
Communication methods.

Claims (15)

a control unit (120) that executes a first switching control in which an Orthogonal Frequency Division Multiplexing (OFDM) scheme for uplink transmission is switched based on first switching information notified in a radio resource control (RRC) layer, and a second switching control in which the OFDM scheme for the uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer;
and a receiving unit (112) that receives, from a base station (200), second MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control.
Communications equipment. 2. The communication device according to claim 1, wherein the second MCS table information includes information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme to which a transform precoder is applied, and information indicating the MCS index table to be applied to the uplink transmission by the OFDM scheme to which a transform precoder is not applied. The second MCS table information includes MCS-0-1 information indicating the MCS index table that is not applied to a DCI format 0_0 but is applied to the DCI format 0_1,
3. The communication device according to claim 1, wherein when the second switching information is included in the DCI format 0_1 in the lower layer, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the MCS-0-1 information. 4. The communication device according to claim 3, wherein, when the second switching information is included in the DCI format 0_1 in the lower layer, if the control unit has not received the MCS-0-1 information, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information. 4. The communication device according to claim 3, wherein when the control unit receives a DCI format 0_1 that does not include the second switching information, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_1 based on the first MCS table information, regardless of whether the second MCS table information has been received. 3. The communication device according to claim 1, wherein when the control unit receives DCI format 0_0, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_0 based on the first MCS table information, regardless of whether the second MCS table information has been received. The second MCS table information includes second MCS-0-2 information indicating the MCS index table applied to a downlink control information (DCI) format 0_2;
3. The communication device according to claim 1, wherein when the second switching information is included in the DCI format 0_2 in the lower layer, the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_2 based on the second MCS-0-2 information. The first MCS table information includes first MCS-0-2 information indicating the MCS index table applied to a downlink control information (DCI) format 0_2;
The communication device according to claim 1 or 2, wherein the control unit determines the MCS index table to be applied to the uplink transmission scheduled using the DCI format 0_2 based on the first MCS-0-2 information, regardless of whether the second switching information is included in the DCI format 0_2 in the lower layer. The communication device according to claim 1 , wherein the control unit determines whether or not the second switching information is notified in the lower layer based on notification information indicating whether or not the second switching information is notified in the lower layer. The communication device according to claim 1 , wherein the control unit determines that the second switching information is not notified in the lower layer when the second MCS table information is not received from the base station. The communication device according to claim 1 , wherein the control unit determines that the second switching information is not notified in the lower layer when the first switching information is not received from the base station. The receiving unit receives downlink control information (DCI) including the second switching information and a BWP indicator indicating a bandwidth portion (BWP);
The communication device according to claim 1 , wherein the control unit determines the OFDM scheme of the uplink transmission in the BWP indicated by the BWP indicator based on the second switching information. The control unit is
When it is determined that the second switching information is notified in the lower layer in the BWP indicated by the BWP indicator, determining the OFDM scheme of the uplink transmission in the BWP indicated by the BWP indicator based on the second switching information;
The communication device according to claim 12 , wherein the second switching information is ignored when it is determined that the second switching information is not notified in the lower layer in the BWP indicated by the BWP indicator. A base station (200) that communicates with a communication device (100) that executes a first switching control in which an orthogonal frequency division multiplexing (OFDM) scheme for uplink transmission is switched based on first switching information notified in a radio resource control (RRC) layer, and a second switching control in which the OFDM scheme for the uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer,
a transmitter (211) for transmitting, to the communication device, second MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control.
Base station. A communication method performed in a communication device (100), comprising:
Executing a first switching control in which an Orthogonal Frequency Division Multiplexing (OFDM) scheme for uplink transmission is switched based on first switching information notified in a radio resource control (RRC) layer, and a second switching control in which the OFDM scheme for the uplink transmission is switched based on second switching information notified in a layer lower than the RRC layer;
receiving, from a base station (200), second MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the second switching control, separately from first MCS table information indicating an MCS index table to be applied to the uplink transmission by the OFDM scheme based on the first switching control;
Communication methods.

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