Base station device, radio communication device, radio communication method, and program

Abstract

[Problem] To provide a base station device, a terminal device, and a radio communication system that can perform efficient communication while satisfying a request of low PAPR. [Solution] A base station device according to the present disclosure comprises a control unit that provides notification about first information in which a signal waveform to be used in downlink communication with a terminal device, that is, a first signal waveform or a second signal waveform is associated with at least one of time information, frequency information, and space information, and performs the downlink communication using the used signal waveform on the basis of the first information.

Description

Base station device, wireless communication device, wireless communication method and program

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

[0002] Radio access methods and radio networks for cellular mobile communications (hereinafter also referred to as "Long Term Evolution (LTE)," "LTE-Advanced (LTE-A)," "LTE-Advanced Pro (LTE-A Pro)," "New Radio (NR)," "New Radio Access Technology (NRAT)," "Evolved Universal Terrestrial Radio Access (EUTRA)," or "Further EUTRA (FEUTRA)") are being studied by the 3rd Generation Partnership Project (3GPP). In the following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, and NR includes NRAT and FEUTRA. In LTE, a base station device (base station) is also referred to as an eNodeB (evolved NodeB). In NR, a base station device is also referred to as a gNodeB. In LTE and NR, a terminal device (mobile station, mobile station device, terminal) is also referred to as a UE (User Equipment). LTE and NR are cellular communication systems in which areas covered by base station devices are arranged in the form of multiple cells. A single base station device may manage multiple cells.

[0003] NR is a next-generation radio access technology (RAT) that is different from LTE. NR is an access technology that can support various use cases, including eMBB (Enhanced mobile broadband), mMTC (Massive machine-type communications), and URLLC (Ultra reliable and low latency communications). NR standardization was carried out with the aim of creating a technical framework that supports the usage scenarios, requirements, and deployment scenarios of those use cases.

[0004] In recent years, there has been a demand for support of high-frequency bands such as millimeter waves and terahertz waves, as well as for lower-cost base stations, and this has led to a demand for a reduction in the Peak-To-Average-Power Ratio (PAPR) in the downlink. Furthermore, small satellites (e.g., Cube-sats, micro-satellites, etc.), which are being considered as a type of mobile satellite, are inferior to conventional satellites in terms of power or antenna gain, and therefore do not have high-performance amplifiers (power amplifiers), making it difficult to meet the low-PAPR requirement. Patent Document 1 (JP-A-2005-102626) describes a technology related to a downlink communication waveform during initial access as a prior art related to meeting the low-PAPR requirement.

[0005] International Publication No. 2023 / 095708

[0006] As mentioned above, in order to solve the problem of difficulty in meeting the requirement for low PAPR due to the cost reduction of base stations, etc., it is necessary to consider means for carrying out communications more efficiently.

[0007] The present disclosure proposes a base station apparatus, a terminal apparatus, a wireless communication method, and a program that enable efficient communication while satisfying the requirement for low PAPR.

[0008] The base station device of the present disclosure includes a control unit that notifies first information that associates a signal waveform to be used in downlink communication with a terminal device, from among a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information, and performs the downlink communication using the signal waveform to be used based on the first information.

[0009] 1 is a diagram showing an example of an overview of a terrestrial network and a non-terrestrial network. A diagram showing an example of an overview of a geostationary satellite and a low-earth orbit satellite. A diagram showing an example of a cell constituted by low-earth orbit satellites. A diagram for explaining an overview of a communication system according to an embodiment of the present disclosure. A diagram showing an example of an NR frame configuration as a radio frame configuration. A diagram showing signal processing on a transmitting side and a receiving side during 5G NR downlink or uplink transmission. A block diagram of a base station device according to an embodiment of the present disclosure. A block diagram of a radio transmitting unit in the base station device. A block diagram of a first signal waveform transmitting unit in the base station device. A block diagram of a second signal waveform transmitting unit in the base station device. A block diagram of a terminal device according to an embodiment of the present disclosure. A block diagram of a radio receiving unit in the terminal device. A block diagram of a first signal waveform receiving unit in the terminal device. A block diagram of a second signal waveform receiving unit in the terminal device. A diagram showing an example of setting CP-OFDM / DFT-S-OFDM according to slots. A diagram showing an example of DRX / DTX operation in a terminal device. A diagram showing, in a table, an example of setting a signal waveform according to slots. FIG. 1 is a table showing an example of setting a signal waveform according to a Symbol. FIG. 2 is a table showing an example of setting a flexible waveform. FIG. 3 is a table showing another example of setting a flexible waveform. FIG. 4 is a table showing an example of setting a signal waveform according to a slot for each terminal. FIG. 5 is a table showing an example of a procedure for notifying information specifying a signal waveform according to time information. FIG. 6 is an example of setting CP-OFDM / DFT-S-OFDM according to frequency. FIG. 7 is an example of a frequency at which DFT-S-OFDM or CP-OFDM is set that changes over time. FIG. 8 is an example of a procedure for notifying information specifying a signal waveform according to frequency information. FIG. 9 is an example of setting CP-OFDM or DFT-S-OFDM in a cell for each space. FIG. 10 is an example of a procedure for notifying information specifying a signal waveform according to spatial information. FIG. 11 is an example of a procedure for notifying information specifying a signal waveform according to spatial information. FIG. 12 is an example of a procedure for notifying information specifying a signal waveform according to a channel. FIG. 13 is an example of a procedure for notifying information specifying a signal waveform according to a channel. 10 is a diagram showing an example of a procedure for notifying a plurality of terminal devices of information specifying a signal waveform according to at least one of time, frequency, space, and channel, or any combination thereof.a signal waveform specifying means for specifying a signal waveform corresponding to at least one of time, frequency, space, and channel, or any combination thereof, to a plurality of terminal devices; a signal waveform specifying means for specifying a signal waveform corresponding to at least one of time, frequency, space, and channel, or any combination thereof ...

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In one or more embodiments shown in the present disclosure, elements included in each embodiment can be combined with each other, and the combined result also forms part of the embodiment shown in the present disclosure.

[0011] As described in the Background Art section, in recent years, support for high frequency bands such as millimeter waves and terahertz waves and the reduction in the cost of base stations have led to a demand for a reduction in the Peak-To-Average-Power Ratio (PAPR) in the downlink. In addition, small satellites (which may also be called cube-sats or micro-satellites, for example) that are being considered as a type of mobile satellite are inferior to conventional satellites in terms of power and antenna gain, and therefore do not have high-performance amplifiers (power amps), making it difficult to reduce the PAPR.

[0012] Transmission methods using single-carrier signals (single-carrier transmission methods) are effective in reducing PAPR. An example of a single-carrier transmission method is DFT (Discrete Fourier Transform)-Spread-OFDM (Orthogonal Frequency Division Multiplexing). On the other hand, transmission methods using multi-carrier signals (multi-carrier transmission methods) are effective in multiple-layer transmission (MIMO transmission) that enables large-capacity communication. An example of a multi-carrier transmission method is CP-OFDM (Cyclic Prefix-OFDM).

[0013] Considering cost reduction and coverage expansion of base stations, it is possible to introduce DFT-S-OFDM, which has a low PAPR, in the downlink. When DFT-S-OFDM is introduced in the downlink, CP-OFDM and DFT-S-OFDM signal waveforms (communication methods) will coexist, so it is necessary for the terminal device and the base station to agree on which signal waveform to use.

[0014] The present disclosure proposes a technique for solving this problem and efficiently performing communications that meet the requirement of low PAPR.

[0015] First, prior knowledge related to the embodiment of the present disclosure will be described below.

[0016] <Terrestrial Network and Non-Terrestrial Network> Figure 1 shows an example of an overview of a terrestrial network and a non-terrestrial network. In cellular mobile communications, a cell (macrocell 17, microcell, femtocell 18, or small cell) is formed by a base station device 1 (e.g., eNodeB (eNB), gNodeB (gNB), RAN node (including EUTRAN and NGRAN)) installed on the ground or a relay device 3, and a wireless network is formed by multiple cells. The base station device 1 or the relay device 3 may be referred to as a terrestrial station device. The wireless network formed and provided by the terrestrial station device is referred to as a terrestrial network 4.

[0017] On the other hand, due to the need to reduce the cost of base station equipment and to provide coverage to areas where radio waves from base stations are difficult to reach, wireless networks consisting of communication devices floating in the air, such as satellites orbiting the Earth (satellite base station equipment, satellite relay station equipment, space stations), aircraft (aerial vehicles), and drones, are being considered. A wireless network consisting of communication devices other than terrestrial stations is called a non-terrestrial network (NTN).

[0018] Examples of communication devices other than ground stations include satellite devices and aviation station devices. Satellite devices are devices, such as artificial satellites, that have wireless communication capabilities and float outside the atmosphere. Satellite devices in this embodiment include low-earth orbiting (LEO) satellites 12, medium-earth orbiting (MEO) satellites, geostationary earth orbiting (GEO) satellites 11, and highly elliptical orbiting (HEO) satellites. Aviation station devices 13 are devices, such as aircraft and balloons, that have wireless communication capabilities and float within the atmosphere. The aviation station device 13 in this embodiment includes an airborne platform 19, specifically, for example, an unmanned aerial system (UAS), a tethered unmanned aerial system (TAS), a lighter than air UAS (LTA), a heavier than air UAS (HTA), and a high altitude UAS platform (HAP). Note that communication devices other than ground stations may also be referred to as eNodeB (eNB), gNodeB (gNB), or RAN node (including EUTRAN and NGRAN) from the perspective of 3GPP-based cellular mobile communications.

[0019] The satellite devices 11 and 12 and the aircraft station device 13 are connected to a terrestrial network (core network, e.g., EPC or 5GC) via relay stations 3 installed on Earth. The core network 15 is connected to a wide area network such as the Internet 16. Hereinafter, the relay stations 3 may be referred to as earth stations (very small aperture terminals, gateways, control earth stations, or hub stations). Terminal devices 2 (UE: User Equipment) compatible with non-terrestrial networks communicate with these satellite devices 11 and 12 and / or the aircraft station device 13. Terminal devices (earth terminal devices) compatible with non-terrestrial networks may include mobile phones, smartphones, automobiles, buses, trains, airplanes, M2M (Machine to Machine) / IoT (Internet of Things) devices, relay stations that relay satellite communications, and base stations that receive satellite communications.

[0020] <Satellite communications> Satellite communications refers to wireless communication between satellite equipment and terminal devices. Satellite equipment is mainly divided into geostationary satellites and low-earth orbit satellites.

[0021] FIG. 2 shows an example of an overview of a geostationary satellite 11 and a low-earth orbit satellite 12. The geostationary satellite 11 is located at an altitude of approximately 35,786 km and revolves around the Earth at the same speed as the Earth's rotation. The geostationary satellite 11 has a relative velocity of almost zero with respect to a terrestrial terminal device 2, and is observed by the terrestrial terminal device 2 as if it were stationary. The low-earth orbit satellite 12 is generally located at an altitude between 100 km and 2,000 km and orbits at a lower altitude than other satellites. Unlike the geostationary satellite 11, the low-earth orbit satellite 12 has a relative velocity with respect to the terrestrial terminal device 2, and is observed by the terrestrial terminal device 2 as if it were moving.

[0022] Figure 3 shows an example of a cell made up of low-orbit satellites 12. Satellites orbiting in low orbit have a predetermined directivity toward the ground and communicate with terrestrial terminal devices. Low-orbit satellites 12 move at a constant speed. If a low-orbit satellite 12 has difficulty providing satellite communications to terrestrial terminal devices, satellite communications will be provided to the terrestrial terminal devices from a subsequent low-orbit satellite (neighbor satellite station) (this is assumed to be connected mobility).

[0023] As mentioned above, medium-earth orbit satellites and low-earth orbit satellites 12 move in orbit at extremely high speeds. For example, a low-earth orbit satellite at an altitude of 600 km moves in orbit at a speed of 7.6 km / s. Low-earth orbit satellites 12 form cells (or beams) on the ground with a radius of several tens to several hundreds of kilometers. However, because the cells formed on the ground move in accordance with the movement of the satellite, handover may be necessary even if the terrestrial terminal device is not moving. For example, assuming a case in which the diameter of a cell formed on the ground is 50 km and the terrestrial terminal device is not moving, handover occurs in approximately 6 to 7 seconds. Note that the numerical values ​​shown in the figure are merely examples and are not limited to these values.

[0024] Non-terrestrial networks are expected to provide the following services: - Service extension to terminal devices (mainly IoT devices / MTC, public safety / critical communications) in areas that cannot be covered by terrestrial networks (e.g., outside cell coverage) - Service reliability and resilience to reduce service vulnerability to physical attacks or natural disasters - Service connection and provision to aircraft terminals (e.g., Aerial UE(s)) such as airplane passengers and drones - Service connection and provision to mobile terminals such as ships and trains - Provision of highly efficient multicast / broadcast services such as A / V content, group communications, IoT broadcast services, software downloads, and emergency messages - Traffic offloading of communications between terrestrial and non-terrestrial networks

[0025] In the following description, the base station device may include not only terrestrial base station devices but also non-terrestrial base station devices that operate as communication devices, such as satellites, drones, balloons, and airplanes.

[0026] In the following description, when specific examples are given and specific values ​​are used, the values ​​are not limited to those examples, and other values ​​may be used.

[0027] The resource described in the following description represents at least one of a frequency, a time, a resource element (including REG, CCE, and CORESET), a resource block, a bandwidth part (BWP), a component carrier, a symbol, a sub-symbol, a slot, a mini-slot, a subslot, a subframe, a frame, a PRACH occasion, an occasion, a code, a multi-access physical resource, a multi-access signature, and a subcarrier spacing (numerology).

[0028] In the following explanation, an example will be given in which CP-OFDM is used as the multi-carrier scheme and DFT-S-OFDM is used as the single-carrier scheme, but other schemes can be similarly applied as long as they are multi-carrier or single-carrier communications. DFT-S-OFDM may be interpreted as a scheme that applies transform precoding, and CP-OFDM as a scheme that does not apply transform precoding.

[0029] The following describes examples of the advantages and disadvantages of CP-OFDM and DFT-S-OFDM. One advantage of CP-OFDM is that it is highly compatible with multi-layer MIMO, enabling high-speed, large-capacity communications. On the other hand, one disadvantage of CP-OFDM is that its PAPR is higher than that of DFT-S-OFDM, requiring a high-performance power amplifier. One advantage of DFT-S-OFDM is that its PAPR can be lowered compared to CP-OFDM, eliminating the need for a high-performance power amplifier. On the other hand, one disadvantage of DFT-S-OFDM is that its communication performance may deteriorate when multi-layer MIMO is used.

[0030] <Overview of communication system> Fig. 4 is a diagram for explaining an overview of a communication system according to an embodiment of the present disclosure. The communication system in Fig. 4 includes a base station device 1 and multiple terminal devices 2A and 2B. Hereinafter, when there is no need to particularly distinguish between the terminal devices 2A and 2B, they will be referred to as terminal device 2, and the terminal device 2 may refer to either the terminal device 2A or 2B.

[0031] The base station device 1 determines a signal waveform to be used for downlink communication with the terminal device 2. For example, the base station device 1 determines either a single-carrier signal or a multi-carrier signal for downlink communication. Examples of multi-carrier signals include OFDM signals and CP-OFDM signals. Examples of single-carrier signals include DFT-S-OFDM signals (SC-FDMA signals), SC-QAM signals, and single carrier with zero padding / unique word.

[0032] The base station apparatus 1 determines, for example, a signal waveform to be used for each terminal apparatus 2 and notifies the terminal apparatus 2 of information regarding the determined signal waveform. The base station apparatus 1 performs downlink communication with the terminal apparatus 2 using the notified signal waveform. As an example, the base station apparatus 1 determines a single-carrier signal for downlink communication that strictly requires a low PAPR, and determines a signal waveform other than a single-carrier signal (here, a multi-carrier signal) for downlink communication that loosely requires a low PAPR. In this way, the base station apparatus 1 can achieve a low PAPR and improve the efficiency of the entire system.

[0033] In the example of Fig. 4, the base station apparatus 1 selects a multicarrier signal to perform downlink communication S1 for terminal apparatus 2A located near the center of cell C. This is because the required transmission power for terminal apparatus 2A located near the center of cell C is smaller than that at the cell edge, making it easier to ensure the required transmission power even if the PAPR is high. Furthermore, the base station apparatus 1 selects a single-carrier signal to perform downlink communication S2 for terminal apparatus 2B located near the edge of cell C. This is because greater transmission power is required to perform downlink communication for terminal apparatus 2B located near the cell edge, and a low PAPR is required.

[0034] Although an example has been described in which the base station device 1 determines the signal waveform depending on the position of the terminal device 2 in the cell C, the method of determining the signal waveform by the base station device 1 is not limited to this.

[0035] <Radio Frame Structure> An example of a radio frame structure of a communication system according to this embodiment will be described. Fig. 5 shows an example of an NR frame structure as a radio frame structure. A radio frame has a time interval of 10 ms and includes two half frames, each with a time interval of 5 ms. Each half frame includes five subframes. One subframe includes one or more slots. One slot includes 14 symbols in the case of a normal CP and 12 symbols in the case of an extended CP.

[0036] <OFDM Transmission and DFT-S-OFDM Transmission> An example of the operation of transmitting a signal from a transmitting device to a receiving device using OFDM transmission or DFT-S (Spread)-OFDM transmission, which are used in 5G NR and the like, will be described.

[0037] 6 shows an example of signal processing on the transmitting side and receiving side during 5G NR downlink or uplink transmission. More specifically, FIG. 6 shows an example of physical layer signal processing performed in each of a transmitting device and a receiving device when performing downlink or uplink transmission. During downlink, the transmitting device is a base station device 1, and the receiving device is a terminal device 2. During uplink, the transmitting device is a terminal device 2, and the receiving device is a base station device 1.

[0038] In a transmitting device, error correction parity bits are added to a transmission signal sequence by error correction coding (S101), and bits corresponding to the number of bits corresponding to the transmission resource and modulation scheme are extracted from the coded bit sequence by rate matching (S102). Interleaving (S103) and scrambling (S104) are applied to the bit sequence including the extracted bits, and the bit sequence is mapped to a complex signal point by modulation processing (S105). In the case of transmission using multiple layers (MIMO transmission), complex signal points are mapped to each layer (S106). Here, when DFT-S-OFDM transmission is performed (i.e., when a single-carrier signal is transmitted), transform precoding, for example, DFT processing, is performed (S107). The term "transform precoding" is an example, and other names for DFT processing may also be used. When OFDM transmission is performed (i.e., when a multi-carrier signal is transmitted), transform precoding is omitted. Precoding for beamforming (i.e., setting of transmission weights) is performed (S108), and resource mapping is performed on the precoded signal (S109). The resource-mapped signal is converted into a time-domain signal by OFDM processing (IDFT, IFFT, etc.), and the converted signal is transmitted.

[0039] The receiving device converts the received signal into a frequency domain signal using OFDM processing (DFT, FFT, etc.) (S111), performs resource demapping on the converted signal, and compensates for distortion due to radio wave propagation using frequency equalization processing (S113). If the signal is transmitted from the transmitting device using DFT-S-OFDM transmission, the distortion-compensated signal is further subjected to transform de-precoding, for example, IDFT processing. If the signal is transmitted from the transmitting device using OFDM transmission, IDFT processing is omitted. Thereafter, the signal mapped to multiple layers is returned (S115), and soft decision values ​​for each bit are obtained from the complex signal point (S116), followed by descrambling (S117), deinterleaving (S118), de-rate matching (S119), and error correction decoding (S120).

[0040] <Configuration Example of Base Station Device> Fig. 7 is a block diagram of a base station device 1 according to an embodiment of the present disclosure. The base station device 1 includes an upper layer processing unit 101, a control unit 103, a receiving unit 105, a transmitting unit 107, and an antenna 109. The control unit 103 is a first control unit that controls the base station device 1. The operation of the base station device 1 may be realized by causing a computer (including a processor such as a CPU (Central Processing Unit)) to execute a program, or may be realized by hardware including a dedicated circuit, or may be realized by a combination of these.

[0041] The base station device 1 may support one or more RATs (Radio Access Technologies). For example, the base station device 1 may support both LTE and NR. In this case, some or all of the units included in the base station device 1 may be configured individually according to the RAT. For example, the receiving unit 105 and the transmitting unit 107 may be configured individually for LTE and NR. Furthermore, in an NR cell, some or all of the units included in the base station device 1 may be configured individually according to a parameter set related to a transmission signal. For example, in a certain NR cell, the radio receiving unit 1057 and the radio transmitting unit 1077 may be configured individually according to a parameter set related to a transmission signal.

[0042] The upper layer processing unit 101 outputs downlink data (transport blocks) to the control unit 103. The upper layer processing unit 101 performs processing of the Medium Access Control (MAC) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Radio Resource Control (RRC) layer. The upper layer processing unit 101 also generates control information for controlling the receiving unit 105 and the transmitting unit 107, and outputs the generated control information to the control unit 103.

[0043] The upper layer processing unit 101 performs processing and management related to RAT control, radio resource control, subframe configuration, scheduling control, and / or CSI (Channel State Information) reporting control. The processing and management in the upper layer processing unit 101 is performed for each terminal device or commonly for all terminal devices connected to a base station device. The processing and management in the upper layer processing unit 101 may be performed individually depending on the RAT. For example, the upper layer processing unit 101 performs processing and management in LTE and processing and management in NR separately.

[0044] In the RAT control in the upper layer processing unit 101, management related to the RAT is performed. For example, in the RAT control, management related to LTE and / or management related to NR is performed. The management related to NR includes setting and processing of parameter sets related to transmission signals in NR cells.

[0045] The radio resource control in the upper layer processing unit 101 manages configuration information in the own device. The radio resource control in the upper layer processing unit 101 generates and / or manages downlink data (transport blocks), system information, RRC messages (RRC parameters), and / or MAC control elements (CEs).

[0046] The subframe configuration in the upper layer processing unit 101 manages subframe configuration, subframe pattern configuration, uplink / downlink configuration, uplink reference UL-DL configuration, and / or downlink reference UL-DL configuration. Note that the subframe configuration in the upper layer processing unit 101 is also referred to as base station subframe configuration. Furthermore, the subframe configuration in the upper layer processing unit 101 can be determined based on the uplink traffic volume and the downlink traffic volume. Furthermore, the subframe configuration in the upper layer processing unit 101 can be determined based on the scheduling result of the scheduling control in the upper layer processing unit 101.

[0047] The scheduling control in the upper layer processing unit 101 determines the frequency and subframe to which the physical channel is assigned, the coding rate, modulation scheme, and transmission power of the physical channel, etc., based on the channel state information received from the terminal device and the propagation path estimate or channel quality input from the channel measurement unit 1059. For example, the control unit 103 generates control information (DCI format) based on the scheduling result of the scheduling control in the upper layer processing unit 101.

[0048] The CSI reporting control in the upper layer processing unit 101 controls the CSI reporting of the terminal device 2. For example, the setting related to the CSI reference resource to be assumed for calculating the CSI in the terminal device 2 is controlled.

[0049] The control unit 103 controls the receiving unit 105 and the transmitting unit 107 based on control information from the upper layer processing unit 101. The control unit 103 generates control information for the upper layer processing unit 101 and outputs it to the upper layer processing unit 101. The control unit 103 receives a decoded signal from the decoding unit 1051 and a channel estimation result from the channel measurement unit 1059. The control unit 103 outputs a signal to be coded to the coding unit 1071. The control unit 103 is used to control all or part of the base station apparatus 1.

[0050] The control unit 103 determines a signal waveform (hereinafter also referred to as a usage signal waveform) to be used for downlink communication with the terminal device 2, from among a single-carrier signal and a multi-carrier signal. The control unit 103 controls the transmission unit 107 to notify the terminal device 2 of information regarding the usage signal waveform using a predetermined signal waveform (for example, a single-carrier signal). The control unit 103 also controls the transmission unit 107 to perform downlink communication with the terminal device 2 using the notified usage signal waveform.

[0051] The receiving unit 105 receives a signal transmitted from the terminal device 2 via the antenna 109 under the control of the control unit 103, and further performs reception processing such as separation, demodulation, and decoding, and outputs the processed information to the control unit 103. The reception processing in the receiving unit 105 is performed based on a predetermined setting or a setting notified to the terminal device 2 by the base station device 1. The receiving unit 105 includes a decoding unit 1051, a demodulation unit 1053, a demultiplexing unit 1055, a radio receiving unit 1057, and a channel measurement unit 1059.

[0052] The radio receiving unit 1057 performs the following operations on the uplink signal received via the antenna 109: conversion to an intermediate frequency (down-conversion), removal of unnecessary frequency components, control of the amplification level to maintain an appropriate signal level, quadrature demodulation based on the in-phase and quadrature components of the received signal, conversion from an analog signal to a digital signal, removal of the guard interval (GI), and / or extraction of a frequency domain signal using a fast Fourier transform (FFT).

[0053] The demultiplexing unit 1055 separates an uplink channel such as a PUCCH (Physical Uplink Control Channel) or a PUSCH (Physical Uplink Shared Channel) and / or an uplink reference signal from the signal input from the radio receiving unit 1057. The demultiplexing unit 1055 outputs the uplink reference signal to the channel measurement unit 1059. The demultiplexing unit 1055 performs propagation path compensation for the uplink channel based on the propagation path estimate input from the channel measurement unit 1059.

[0054] The demodulation unit 1053 demodulates the received signal using a modulation method such as BPSK (Binary Phase Shift Keying), π / 2BPSK, QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64QAM, 256QAM, etc. The demodulation unit 1053 also separates and demodulates the MIMO-multiplexed uplink channel.

[0055] The decoding unit 1051 performs decoding processing on the coded bits of the demodulated uplink channel. The decoded uplink data and / or uplink control information is output to the control unit 103. The decoding unit 1051 performs decoding processing on the PUSCH for each transport block.

[0056] The channel measurement unit 1059 measures a propagation path estimate and / or channel quality from the uplink reference signal input from the demultiplexing unit 1055, and outputs the results to the demultiplexing unit 1055 and / or the control unit 103. For example, the channel measurement unit 1059 measures a propagation path estimate for performing propagation path compensation for the PUCCH or PUSCH using an Uplink Demodulation Reference Signal (UL-DMRS), and measures the channel quality in the uplink using an SRS (Sounding Reference Signal).

[0057] The transmitter 107 performs transmission processing such as coding, modulation, and multiplexing on the downlink control information and downlink data input from the upper layer processing unit 101 under control of the control unit 103. For example, the transmitter 107 generates and multiplexes a PHICH (Physical Hybrid ARQ Indicator Channel), a PDCCH (Physical Downlink Control Channel), an EPDCCH (Enhanced PDCCH), a PDSCH (Physical Downlink Shared Channel), and a downlink reference signal to generate a transmission signal. Note that the transmission processing in the transmitter 107 is performed based on a predefined setting, a setting notified to the terminal device 2 by the base station device 1, or a setting notified via a PDCCH or EPDCCH transmitted in the same subframe. The transmitter 107 includes a coding unit 1071, a modulation unit 1073, a multiplexing unit 1075, a radio transmission unit 1077, and a downlink reference signal generation unit 1079.

[0058] The coding unit 1071 encodes the HARQ indicator (HARQ-ACK), downlink control information, and downlink data input from the control unit 103 using a coding method such as block coding, convolutional coding, or turbo coding. The modulation unit 1073 modulates the coded bits input from the coding unit 1071 using a modulation method such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, or 256QAM. The downlink reference signal generation unit 1079 generates a downlink reference signal based on a physical cell identification (PCI), RRC parameters set in the terminal device 2, and the like.

[0059] The multiplexing unit 1075 multiplexes the modulation symbols of each channel with the downlink reference signal and arranges the multiplexed symbols in predetermined resource elements.

[0060] The radio transmitting unit 1077 performs processes on the signal from the multiplexing unit 1075, such as signal transformation using at least the latter of DFT and IDFT, addition of a guard interval, generation of a baseband digital signal, conversion to an analog signal, quadrature modulation, conversion from an intermediate frequency signal to a high frequency signal (up-conversion), removal of unnecessary frequency components, and power amplification, to generate a transmission signal. The transmission signal output by the radio transmitting unit 1077 is transmitted from the antenna 109.

[0061] The radio transmitting unit 1077 can support multiple signal waveforms (downlink signal waveforms) in the downlink. Details of the radio transmitting unit 1077 in the base station device 1 that supports both the first signal waveform and the second signal waveform will be described using Figures 8 to 10. In the following description, it is assumed that the first signal waveform includes a multi-carrier signal and the second signal waveform includes a single-carrier signal, but a case where the first signal waveform includes a single-carrier signal and the second signal waveform includes a multi-carrier signal is also not excluded.

[0062] 8 is a block diagram of wireless transmission section 1077. Wireless transmission section 1077 includes signal waveform switching section 401, first signal waveform transmission section 403, and second signal waveform transmission section 405.

[0063] The signal waveform switching unit 401 (signal waveform control unit) determines whether to use a first signal waveform or a second signal waveform in downlink communication depending on the conditions or circumstances, and switches the output destination of the signal input from the multiplexing unit 1075 depending on the result of the determination. When the first signal waveform is used, the output destination is the first signal waveform transmission unit 403, and downlink transmission processing is performed by the first signal waveform transmission unit 403. When the second signal waveform is used, the output destination is the second signal waveform transmission unit 405, and downlink transmission processing is performed by the second signal waveform transmission unit 405. The conditions or circumstances for switching in the signal waveform switching unit 401 will be described later. In FIG. 8, the first signal waveform transmission unit 403 and the second signal waveform transmission unit 405 are depicted as separate processing units, but they may also be configured as a single processing unit and have their transmission processing switched between.

[0064] 9 is a block diagram of the first signal waveform transmitter 403. The first signal waveform transmitter 403 performs transmission processing on a multicarrier signal as a signal waveform for downlink communication, in this case, a downlink channel and signal transmitted by CP-OFDM. The first signal waveform transmitter 403 includes an S / P (Serial / Parallel) unit 4031, an IDFT (Inverse Discrete Fourier Transform) unit 4033, a P / S (Parallel / Serial) unit 4035, and a CP insertion unit 4037.

[0065] The S / P unit 4031 converts the input serial signal into a parallel signal of size M. The size M is determined depending on the size of the frequency domain resource used for downlink communication. The parallel signals of size M are input to the IDFT unit 4033 so as to correspond to a predetermined frequency domain.

[0066] The IDFT unit 4033 performs an inverse Fourier transform process on the parallel signals of size N. If the size N is an exponent of 2, the Fourier transform process may be an inverse fast Fourier transform (IFFT) process. The P / S unit 4035 converts the parallel signals of size N into serial signals. The CP insertion unit 4037 inserts a CP into each OFDM symbol.

[0067] FIG. 10 is a block diagram of the second signal waveform transmitter 405. The second signal waveform transmitter 405 performs transmission processing on a single-carrier signal as a signal waveform for downlink communication, in this case, a downlink channel and signal transmitted using SC-FDMA. The second signal waveform transmitter 405 uses DFT-Spread-OFDM for transmission processing. The second signal waveform transmitter 405 includes a DFT unit 4051, an IDFT (Inverse Discrete Fourier Transform) unit 4053, a P / S unit 4055, and a CP insertion unit 4057. The DFT unit 4051 performs a Fourier transform (DFT) on the input serial signal to generate parallel signals of size M. The size M is determined depending on the size of the frequency domain resource used for downlink communication. The parallel signals of size M are input to the IDFT unit 4053 so as to correspond to a predetermined frequency domain. The IDFT unit 4053 performs an inverse Fourier transform on the parallel signals of size N. If the size N is an exponent of 2, the inverse Fourier transform processing may be an IFFT (Inverse Fast Fourier Transform) processing. The P / S unit 4055 converts the parallel signal of size N into a serial signal. The CP insertion unit 4057 inserts a CP for each SC-FDMA symbol or each DFT-Spread-OFDM symbol.

[0068] Fig. 11 is a block diagram of a terminal device 2 according to an embodiment of the present disclosure. The terminal device 2 in Fig. 11 includes an upper layer processing unit 201, a control unit 203, a receiving unit 205, a transmitting unit 207, and an antenna 209. The control unit 203 is a second control unit that controls the terminal device 2. The operation of the terminal device 2 may be realized by causing a computer (including a processor such as a CPU (Central Processing Unit)) to execute a program, or may be realized by hardware including a dedicated circuit, or may be realized by a combination of these.

[0069] The terminal device 2 may support one or more RATs (Radio Access Technologies). For example, the terminal device 2 may support both LTE and NR. In this case, some or all of the units included in the terminal device 2 may be configured individually according to the RAT. For example, the receiving unit 205 and the transmitting unit 207 are configured individually for LTE and NR. Furthermore, in an NR cell, some or all of the units included in the terminal device 2 shown in FIG. 11 may be configured individually according to a parameter set related to a transmission signal. For example, in a certain NR cell, the radio receiving unit 2057 and the radio transmitting unit 2077 may be configured individually according to a parameter set related to a transmission signal.

[0070] Upper layer processing unit 201 outputs uplink data (transport blocks) to control unit 203. Upper layer processing unit 201 processes the Medium Access Control (MAC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Radio Resource Control (RRC) layer. Upper layer processing unit 201 also generates control information for controlling receiving unit 205 and transmitting unit 207, and outputs the control information to control unit 203.

[0071] The upper layer processing unit 201 performs processing and management related to RAT control, radio resource control, subframe configuration, scheduling control, and / or CSI reporting control. The processing and management in the upper layer processing unit 201 are performed based on predefined settings and / or settings based on control information configured or notified from the base station device 1. For example, the control information from the base station device 1 includes RRC parameters, MAC control elements, or DCI. The processing and management in the upper layer processing unit 201 may also be performed separately depending on the RAT. For example, the upper layer processing unit 201 performs processing and management in LTE and processing and management in NR separately.

[0072] In the RAT control in the upper layer processing unit 201, management related to the RAT is performed. For example, in the RAT control, management related to LTE and / or management related to NR is performed. The management related to NR includes setting and processing of parameter sets related to transmission signals in NR cells.

[0073] The radio resource control in the upper layer processing unit 201 manages configuration information in the own device. The radio resource control in the upper layer processing unit 201 generates and / or manages uplink data (transport blocks), system information, RRC messages (RRC parameters), and / or MAC control elements (CEs).

[0074] The upper layer processing unit 201 manages subframe configurations in the base station device 1 and / or a base station device different from the base station device 1. The subframe configurations include uplink or downlink configurations for the subframes, subframe pattern configurations, uplink / downlink configurations, uplink reference UL-DL configurations, and / or downlink reference UL-DL configurations. The subframe configurations in the upper layer processing unit 201 are also referred to as terminal device subframe configurations.

[0075] In the scheduling control in the upper layer processing unit 201, control information for controlling the scheduling of the receiving unit 205 and the transmitting unit 207 is generated based on DCI (scheduling information) from the base station device 1.

[0076] The CSI reporting control in the upper layer processing unit 201 controls the reporting of CSI to the base station apparatus 1. For example, the CSI reporting control controls the setting of CSI reference resources to be assumed for calculating CSI in the channel measurement unit 2059. The CSI reporting control controls the resources (timing) used to report CSI based on DCI and / or RRC parameters.

[0077] The control unit 203 controls the receiving unit 205 and the transmitting unit 207 based on control information from the upper layer processing unit 201. The control unit 203 generates control information for the upper layer processing unit 201 and outputs it to the upper layer processing unit 201. The control unit 203 receives the decoded signal from the decoding unit 2051 and the channel estimation result from the channel measurement unit 2059. The control unit 203 outputs the signal to be coded to the coding unit 2071. The control unit 203 may also be used to control all or part of the terminal device 2.

[0078] The control unit 203 acquires information regarding a signal waveform (used signal waveform) to be used for downlink communication with the base station apparatus 1, from the base station apparatus 1 via the receiving unit 205. The information regarding the used signal waveform may be transmitted in association with a predetermined signal. The predetermined signal may be transmitted using a predetermined signal waveform from a single-carrier signal or a multi-carrier signal. The control unit 203 controls the receiving unit 205 to perform downlink communication with the base station apparatus 1 using reception processing for the used signal waveform.

[0079] The receiving unit 205 receives signals transmitted from the base station device 1 via the antenna 209 under the control of the control unit 203, and further performs reception processing such as separation, demodulation, and decoding, and outputs the processed information to the control unit 203. The reception processing in the receiving unit 205 is performed based on a predetermined setting or a notification or setting from the base station device 1. The receiving unit 205 is configured to include a decoding unit 2051, a demodulating unit 2053, a demultiplexing unit 2055, a radio receiving unit 2057, and a channel measuring unit 2059.

[0080] The radio receiving unit 2057 performs the following operations on the uplink signal received via the antenna 209: conversion to an intermediate frequency (down-conversion), removal of unnecessary frequency components, control of the amplification level to maintain an appropriate signal level, quadrature demodulation based on the in-phase and quadrature components of the received signal, conversion from an analog signal to a digital signal, removal of the guard interval (GI), and / or extraction of the frequency domain signal using a fast Fourier transform (FFT).

[0081] The radio receiving unit 2057 can support multiple downlink signal waveforms (first signal waveform and second signal waveform). Details of the radio receiving unit 2057 in the terminal device 2 that supports both the first signal waveform and the second signal waveform will be described using Figures 12 to 14.

[0082] 12 is a block diagram of the wireless receiving section 2057. The wireless receiving section 2057 includes a signal waveform switching section 301, a first signal waveform receiving section 303, and a second signal waveform receiving section 305.

[0083] The signal waveform switching unit 301 (signal waveform control unit) determines whether the received downlink communication signal will have a first signal waveform or a second signal waveform depending on the conditions or circumstances, and switches the output destination of the signal depending on the result of the determination. When the downlink communication signal has the first signal waveform, the downlink communication signal is received and processed by the first signal waveform receiving unit 303. The reception processing performed by the first signal waveform receiving unit 303 is reception processing for the first signal waveform. When the downlink communication signal has the second signal waveform, the downlink communication signal is received and processed by the second signal waveform receiving unit 305. The reception processing performed by the second signal waveform receiving unit 305 is reception processing for the second signal waveform. The conditions or circumstances for switching in the signal waveform switching unit 301 will be described later. In FIG. 12, the first signal waveform receiving unit 303 and the second signal waveform receiving unit 305 are depicted as separate processing units, but they may be a single processing unit, with only part of the reception processing being switched.

[0084] 13 is a block diagram of the first signal waveform receiver 303. The first signal waveform receiver 303 performs reception processing on a multicarrier signal as a signal waveform for downlink communication, in this case, a downlink channel and signal transmitted by CP-OFDM. The first signal waveform receiver 303 includes a CP remover 3031, an S / P unit 3033, a DFT (Discrete Fourier Transform) unit 3035, and a P / S unit 3037.

[0085] The CP removal unit 3031 removes a cyclic prefix (CP) from the received downlink communication signal. The S / P unit 3033 converts the input serial signal into a parallel signal of size N. The DFT unit 3035 performs a Fourier transform process on the parallel signals of size N and outputs parallel signals of size N. If the size N is an exponent of 2, the Fourier transform process may be a fast Fourier transform (FFT) process. The P / S unit 3037 converts the input parallel signals of size M into a serial signal. The size M is determined depending on the size of the frequency domain resource used for downlink communication. The IDFT 3037 receives as input the downlink communication signal transmitted by the base station device 1 that performs transmission processing.

[0086] 14 is a block diagram of the second signal waveform receiver 305. The second signal waveform receiver 305 performs reception processing on a single-carrier signal as a signal waveform for downlink communication, in this case, a downlink channel and signal transmitted by SC-FDMA. The second signal waveform receiver 305 includes a CP remover 3051, an S / P unit 3053, a DFT (Discrete Fourier Transform) unit 3055, and an IDFT (Inverse Discrete Fourier Transform) unit 3057.

[0087] The CP removal unit 3051 removes a CP (Cyclic Prefix) from the received downlink communication signal and outputs a serial signal. The S / P unit 3053 converts the input serial signal into a parallel signal of size N. The DFT unit 3055 performs a Fourier transform process on the parallel signals of size N. If the size N is an exponent of 2, the Fourier transform process may be an FFT (Fast Fourier Transform) process. The IDFT unit 3057 performs an inverse Fourier transform process on the input signal of size M. The size M is determined depending on the size of the frequency domain resource used for downlink communication. The IDFT 3057 receives as input a downlink communication signal transmitted by the base station device 1 that performs transmission processing.

[0088] 11 separates downlink channels such as PHICH, PDCCH, EPDCCH, or PDSCH, downlink synchronization signals, and / or downlink reference signals from the signals input from the radio receiving unit 2057. The demultiplexing unit 2055 outputs the downlink reference signals to the channel measuring unit 2059. The demultiplexing unit 2055 performs propagation path compensation for the downlink channels based on the propagation path estimates input from the channel measuring unit 2059.

[0089] The demodulation unit 2053 demodulates the received signal using a modulation method such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, 256QAM, etc. for the modulation symbols of the downlink channel. The demodulation unit 2053 separates and demodulates the MIMO-multiplexed downlink channels.

[0090] The decoding unit 2051 performs decoding processing on the coded bits of the demodulated downlink channel. The decoded downlink data and / or downlink control information is output to the control unit 203. The decoding unit 2051 performs decoding processing on the PDSCH for each transport block.

[0091] The channel measurement unit 2059 measures a propagation path estimate and / or channel quality from the downlink reference signal input from the demultiplexing unit 2055, and outputs the results to the demultiplexing unit 2055 and / or the control unit 203. The downlink reference signal used for measurement by the channel measurement unit 2059 may be determined based on at least a transmission mode set by an RRC parameter and / or other RRC parameters. For example, DL-DMRS is used to measure a propagation path estimate for performing propagation path compensation for a PDSCH or an EPDCCH. CRS is used to measure a propagation path estimate for performing propagation path compensation for a PDCCH or a PDSCH and / or a downlink channel for reporting CSI. CSI-RS is used to measure a downlink channel for reporting CSI. The channel measurement unit 2059 calculates RSRP (Reference Signal Received Power) and / or RSRQ (Reference Signal Received Quality) based on the CRS, CSI-RS, or detected signal, and outputs the results to the upper layer processing unit 201.

[0092] The transmitter 207 performs transmission processing such as coding, modulation, and multiplexing on the uplink control information and uplink data input from the upper layer processing unit 201 under control of the control unit 203. For example, the transmitter 207 generates and multiplexes an uplink channel such as a PUSCH or a PUCCH and / or an uplink reference signal to generate a transmission signal. The transmission processing in the transmitter 207 is performed based on a predefined setting or a setting or notification from the base station device 1. The transmitter 207 includes a coding unit 2071, a modulation unit 2073, a multiplexing unit 2075, a radio transmission unit 2077, and an uplink reference signal generation unit 2079.

[0093] The coding unit 2071 encodes the HARQ indicator (HARQ-ACK), uplink control information, and uplink data input from the control unit 203 using a coding method such as block coding, convolutional coding, or turbo coding. The modulation unit 2073 modulates the coded bits input from the coding unit 2071 using a modulation method such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, or 256QAM. The uplink reference signal generation unit 2079 generates an uplink reference signal based on RRC parameters set in the terminal device 2, etc.

[0094] The multiplexing unit 2075 multiplexes the modulation symbols of each channel with the uplink reference signal and arranges them in predetermined resource elements.

[0095] The radio transmitting unit 2077 performs processes on the signal from the multiplexing unit 2075, such as converting it to a time domain signal using DFT or IFFT, adding a guard interval, generating a baseband digital signal, converting it to an analog signal, quadrature modulation, converting an intermediate frequency signal to a high frequency signal (up-converting), removing unnecessary frequency components, and amplifying its power, to generate a transmission signal. The transmission signal output by the radio transmitting unit 2077 is transmitted from the antenna 209.

[0096] In the above-described configuration, the signal waveform transmitted from the base station device 1 can be switched, but a configuration may be added that can switch the signal waveform of the signal transmitted by the terminal device 2. In this case, the terminal device 2 may be provided with a radio transmission unit configuration similar to that of the base station device 1 (see FIG. 8), and the base station device 1 may be provided with a radio reception unit configuration similar to that of the terminal device 2 (see FIG. 12).

[0097] One feature of an embodiment of the present disclosure is that a base station device 1 notifies a terminal device 2 of first information associating a signal waveform to be used, from a first signal waveform and a second signal waveform, with at least one of time information, frequency information, spatial information, and channel information, and performs downlink communication using the notified signal waveform. The first information may be transmitted in association with a predetermined signal. Various types of predetermined signals are possible, such as a synchronization signal. The base station device 1 performs downlink communication (downlink signal transmission) with the terminal device 2 using a signal waveform to be used based on the notified first information. The terminal device 2 receives the downlink communication signal using reception processing for the signal waveform indicated in the first information notified by the base station device 1.

[0098] The information specifying the signal waveform according to the time information includes at least one or more of the following information: - Information indicating the time resource (information indicating the symbol, information indicating the slot, information indicating the subframe, information indicating the radio frame, etc.) - Information indicating the signal waveform according to the time resource

[0099] The information specifying the signal waveform according to the frequency information includes at least one or more of the following information: - Information indicating the frequency resource - Subcarrier - Resource block - Component carrier - Bandwidth part (BWP) - Information indicating the signal waveform according to the frequency resource

[0100] The information specifying the signal waveform according to the spatial information includes at least one or more of the following information: - Information indicating the spatial resource - Beam ID - Cell ID (e.g., Physical Cell ID) - Information indicating the signal waveform according to the spatial resource

[0101] The information specifying the signal waveform according to the channel information includes at least one or more of the following information: - Information indicating the channel: - Logical channel - BCCH, PCCH, CCCH, DCCH, DTCH, etc. - Transport channel - BCH, DL-SCH, UL-SCH, PCH, etc. - Physical channel - PBCH, PDCCH, PUCCH, PSCCH, PDSCH, PUSCH, PSSCH, PRACH, etc. - Information indicating the signal waveform according to the channel information

[0102] The details of this embodiment will be described below.

[0103] (Embodiment 1) CP-OFDM (a signal waveform or communication method to which transform precoding is not applied) and DFT-S-OFDM (a signal waveform or communication method to which transform precoding is applied) are set according to time information (such as symbol, slot, subframe, frame, and radio frame). FIG. 15 shows an example of setting CP-OFDM / DFT-S-OFDM according to slots. With this setting, when a base station device performs communication using multiple layers using MIMO, it can perform communication using CP-OFDM during the time set for CP-OFDM, and can perform communication with extended coverage using DFT-S-OFDM during other times. For example, a terminal device located at the cell edge that cannot communicate using CP-OFDM can transition to a sleep state and stop communication during the time set for CP-OFDM (discontinuous reception (DRX) / discontinuous transmission (DTX)). FIG. 16 shows an example of a terminal device performing DRX / DTX operations.

[0104] The setting contents may be notified as semi-static information or may be notified implicitly. An example of implicit notification is a method of linking setting information related to DFT-S-OFDM or CP-ODFM to a slot for transmitting a Synchronization Signal Block (SSB).

[0105] An example of information notified from the base station device to the terminal device will be described in detail below.

[0106] 17 is a table showing an example of setting a signal waveform according to slots. DFT-S-OFDM or CP-ODFM is set for each slot.

[0107] 18 is a table showing an example of setting a signal waveform according to a symbol. DFT-S-OFDM or CP-ODFM is set for each symbol.

[0108] Fig. 19 shows an example of setting a Flexible Waveform in the form of a table. DFT-S-OFDM, CP-ODFM, or Flexible is set on a slot-by-slot basis. Flexible is a period in which a signal waveform is set arbitrarily, and for Flexible slots, the PDSCH signal waveform may be determined by dynamic notification such as DCI, or a default signal waveform may be used. Alternatively, nothing may be transmitted.

[0109] 20 is a table showing another example in which the Flexible Waveform is set. DFT-S-OFDM, CP-ODFM, or Flexible is set in units of symbols. Flexible is a period in which a signal waveform is set arbitrarily, and in the Flexible slot, the PDSCH signal waveform may be determined by dynamic notification of a control signal such as DCI, or a default signal waveform may be used. Alternatively, nothing may be transmitted.

[0110] 21 is a table showing an example of how signal waveforms are set for each terminal according to slots. A reserved waveform slot is a slot to which a predetermined signal waveform is applied. The predetermined signal waveform is DFT-S-OFDM or CP-OFDM.

[0111] Information such as frame format / slot format in the case of DFT-S-OFDM / CP-OFDM may be included in system information, RRC signaling, DCI, etc. (see TS38.331, TS38.212).

[0112] An example of when information such as Frame format / Slot format is included in ServingCellConfigCommon is shown below.

[0113] 22 shows an example of a procedure for notifying information (first information) specifying a signal waveform according to time information. The information specifying a signal waveform according to time information includes at least one or more of the following information: - Information indicating a time resource - Information indicating a symbol - Information indicating a slot - Information indicating a subframe - Information indicating a radio frame - Information indicating a signal waveform according to a time resource The control unit 103 of the base station device determines the signal waveform (usage signal waveform) to be applied to the terminal device as a first signal waveform or a second signal waveform according to the time information (e.g., slot, symbol, subframe, or radio frame), and transmits information (first information) indicating the determined use signal waveform to the terminal device for the period or time indicated by the time information (S201). Thereafter, the control unit 103 of the base station device determines the signal waveform to be transmitted to the terminal device based on the first information, and the first signal waveform transmission unit 403 of the base station device transmits using the first signal waveform if the signal waveform is determined to be the first signal waveform. When the second signal waveform is determined to be the signal waveform, the second signal waveform transmitter 405 of the base station device transmits using the second signal waveform. Based on the first information received from the base station device, the terminal device performs reception processing of the signal waveform from the base station device at the time specified in the first information (S202). More specifically, based on the first information, the first signal waveform receiver 303 of the terminal device receives the first signal waveform transmitted from the base station device and performs reception processing of the first signal waveform. Based on the first information, the second signal waveform receiver 305 of the terminal device receives the second signal waveform transmitted from the base station device and performs reception processing of the second signal waveform.

[0114] The first information may include information specifying a first signal waveform or a second signal waveform as a use signal waveform for time information other than the predetermined time information. In this case, the use signal waveform for the predetermined time information may be predetermined to be the first signal waveform or the second signal waveform (see "Reserved" in FIG. 21). Alternatively, with regard to the use signal waveform for the predetermined time information, the base station device may dynamically change it to the first signal waveform or the second signal waveform by transmitting a control signal to the terminal device, or may not transmit any signal during the time of the predetermined time information (see the explanation of "Flexible" in FIG. 19 or FIG. 20).

[0115] Second Embodiment CP-OFDM and DFT-S-OFDM are set according to frequency information (subcarrier, resource block, component carrier, band width part (BWP), etc.).

[0116] 23A and 23B show examples of setting CP-OFDM / DFT-S-OFDM according to frequency.

[0117] With the above settings, when communicating using multiple layers using MIMO, the base station device communicates using the frequency set for CP-OFDM, and at other frequencies it can communicate with expanded coverage using DFT-S-OFDM.

[0118] The terminal device performs reception processing according to CP-OFDM at the frequency set for CP-OFDM, and performs reception processing according to DFT-S-OFDM at the frequency set for DFT-S-OFDM. DFT-S-OFDM or CP-OFDM may be set in a divided form across multiple distant frequencies (see FIG. 23(B)).

[0119] The frequency at which DFT-S-OFDM or CP-OFDM is set may vary over time. Figure 24 shows an example in which the frequency at which DFT-S-OFDM or CP-OFDM is set varies over time.

[0120] The time variation of the frequencies at which the DFT-S-OFDM and CP-OFDM are configured may be set based on semi-static or dynamic configuration, such as semi-static configuration based on RRC signaling or dynamic configuration based on DCI.

[0121] FIG. 25 shows an example of a procedure for notifying information (first information) specifying a signal waveform according to frequency information. The information specifying a signal waveform according to frequency information includes at least one or more of the following information: - Information indicating frequency resources - Subcarriers - Resource blocks - Component carriers - Bandwidth portion (BWP) - Information indicating a signal waveform according to frequency resources The control unit 103 of the base station device determines the signal waveform (used signal waveform) to be applied to the terminal device as a first signal waveform or a second signal waveform according to the frequency information, and transmits information indicating the determined signal waveform for the frequency indicated by the frequency information to the terminal device (S211). The first information is, for example, information specifying a different usable signal waveform for each frequency. Thereafter, the control unit 103 of the base station device determines a transmission signal waveform to be transmitted to the terminal device based on the first information, and the first signal waveform transmission unit 403 of the base station device transmits using the first signal waveform if the signal waveform is determined to be the first signal waveform. When the second signal waveform is determined as the transmission signal waveform, the second signal waveform transmitter 405 of the base station device transmits using the second signal waveform. Based on information (first information) received from the base station device, the terminal device performs reception processing of the signal waveform from the base station device at the frequency specified in the first information (S212). More specifically, based on the first information, the first signal waveform receiver 303 of the terminal device receives the first signal waveform transmitted from the base station device and performs reception processing of the first signal waveform. Based on the first information, the second signal waveform receiver 305 of the terminal device receives the second signal waveform transmitted from the base station device and performs reception processing of the second signal waveform.

[0122] (Embodiment 3) CP-OFDM and DFT-S-OFDM are set according to spatial information (beam ID, physical cell ID, etc.).

[0123] FIG. 26A shows an example of setting CP-OFDM or DFT-S-OFDM in a cell for each physical cell ID (PCI).

[0124] FIG. 26B shows an example of setting CP-OFDM and DFT-S-OFDM according to the Beam ID.

[0125] 26(A) or 26(B), when the base station device performs communication using multiple layers using MIMO, it communicates in the area set for CP-OFDM (the cell of the corresponding PCI or the area to which the corresponding beam is applied), and in other areas it becomes possible to perform communication with extended coverage using DFT-S-OFDM. The terminal device performs reception processing using CP-OFDM in the area set for CP-OFDM, and performs reception processing using DFT-S-OFDM in the area set for DFT-S-OFDM.

[0126] When multiple Beam IDs are set in the same PCI cell, a different signal waveform may be applied to each Beam ID. That is, the signal waveform set for the Beam ID may be applied with priority over the signal waveform set for the PCI cell.

[0127] 27 shows an example of a procedure for notifying information (first information) that specifies a signal waveform according to spatial information. The information that specifies a signal waveform according to spatial information includes at least one or more of the following information: - Information indicating a spatial resource - Beam ID - Cell ID (e.g., Physical Cell ID) - Information indicating a signal waveform according to a spatial resource The control unit 103 of the base station device determines the signal waveform (signal waveform to be used) to be applied to the terminal device to a first signal waveform or a second signal waveform according to the space (e.g., area, beam) used by the terminal device, and transmits information (first information) that indicates the determined signal waveform to the terminal device (S221). The first information may be, as spatial information, information that specifies a signal waveform to be used according to the area in which the terminal device is located, or information that specifies a signal waveform to be used according to the beam used by the terminal device. Thereafter, the control unit 103 of the base station device determines a signal waveform of data to be transmitted to the terminal device based on the first information, and the first signal waveform transmission unit 403 of the base station device generates the first signal waveform and transmits using the first signal waveform when the transmission signal waveform is determined to be the first signal waveform. The second signal waveform transmission unit 405 of the base station device generates the second signal waveform and transmits using the second signal waveform when the transmission signal waveform is determined to be the second signal waveform. The terminal device performs reception processing of the signal waveform from the base station device based on the information (first information) received from the base station device (S222). More specifically, the first signal waveform reception unit 303 of the terminal device receives the first signal waveform transmitted from the base station device based on the first information and performs reception processing of the first signal waveform. The second signal waveform reception unit 305 of the terminal device receives the second signal waveform transmitted from the base station device based on the first information and performs reception processing of the second signal waveform.

[0128] (Fourth embodiment) Regardless of the settings made in the above-described first to third embodiments, either DFT-S-OFDM or CP-OFDM may be fixedly applied to the PDCCH.

[0129] Figures 28(A) and 28(B) show an example in which DFT-S-OFDM is fixedly applied to PDCCH, regardless of the DFT-S-OFDM / CP-OFDM settings made in the above-mentioned first to third embodiments.

[0130] For example, by fixedly setting DFT-S-OFDM for PDCCH, it becomes possible to transmit PDCCH to the entire coverage area regardless of the DFT-S-OFDM / CP-OFDM setting performed in the above-mentioned embodiments 1 to 3.

[0131] 29 shows an example of a procedure for notifying information (first information) specifying a signal waveform according to channel information. The information specifying a signal waveform according to channel information includes at least one or more of the following information: - Information indicating a channel: - Logical channel - BCCH, PCCH, CCCH, DCCH, DTCH, etc. - Transport channel - BCH, DL-SCH, UL-SCH, PCH, etc. - Physical channel - PBCH, PDCCH, PUCCH, PSCCH, PDSCH, PUSCH, PSSCH, PRACH, etc. - Information indicating a signal waveform according to channel information The control unit 103 of the base station apparatus determines a first signal waveform or a second signal waveform as the signal waveform to be applied to the terminal apparatus (signal waveform to be used) according to a channel (e.g., physical channel) to be transmitted to the terminal apparatus, and transmits information (first information) indicating the determined signal waveform to the terminal apparatus (S231). Thereafter, the control unit 103 of the base station device determines a signal waveform of data to be transmitted to the terminal device based on the first information, and the first signal waveform transmission unit 403 of the base station device transmits using the first signal waveform if the transmission signal waveform is determined to be the first signal waveform. The second signal waveform transmission unit 405 of the base station device transmits using the second signal waveform if the transmission signal waveform is determined to be the second signal waveform. The terminal device performs reception processing of the signal waveform from the base station for the channel specified in the first information based on the information (first information) received from the base station device (S232). More specifically, the first signal waveform reception unit 303 of the terminal device receives the first signal waveform transmitted from the base station device based on the first information and performs reception processing of the first signal waveform. The second signal waveform reception unit 305 of the terminal device receives the second signal waveform transmitted from the base station device based on the first information and performs reception processing of the second signal waveform.

[0132] The first information may be channel information, and may specify the same signal waveform to be used for a channel transmitted to the entire coverage to multiple or all terminal devices within the coverage. The channel transmitted in common to the entire coverage may be the PDCCH or the PBCH described in embodiment 5. Note that the signal waveform may be determined in advance depending on the channel, and in this case, a configuration is possible in which notification of the first information from the base station device to the terminal device is omitted.

[0133] (Embodiment 5) Either DFT-S-OFDM or CP-OFDM may be fixedly applied to the PBCH (or SSB) regardless of the settings made in the above-described embodiments 1 to 3.

[0134] FIG. 30 shows an example in which DFT-S-OFDM is fixedly applied to the PBCH, regardless of the DFT-S-OFDM / CP-OFDM settings made in the above-described first to third embodiments.

[0135] For example, by fixedly setting DFT-S-OFDM for PDCCH, it becomes possible to transmit PBCH simultaneously to the entire coverage area regardless of the DFT-S-OFDM / CP-OFDM setting performed in the above-mentioned embodiments 1 to 3.

[0136] The procedure example in the fifth embodiment is the same as that in the fourth embodiment, and therefore the explanation will be omitted.

[0137] At this time, the symbols for transmitting the PBCH may include other physical channels (e.g., PDSCH), etc. At this time, the other physical channels may follow the DFT-S-OFDM / CP-OFDM settings performed in the above-described first to third embodiments, or may be transmitted using the same transmission method as the PBCH.

[0138] (Embodiment 6) An example of notification of first information related to the present disclosure will be described.

[0139] (1) First information regarding a cell-specific frame format / slot format setting / frequency setting / space setting according to a signal waveform is transmitted to a terminal device. This first information may be transmitted as information that can be recognized even when the terminal device is in an RRC-Idle state (e.g., system information).

[0140] (2) First information regarding UE-specific frame format / slot format setting / frequency setting / spatial setting according to a signal waveform is transmitted to the terminal device. This first information may be transmitted, for example, in information (e.g., RRC signaling) notified in the RRC-Connected state during initial connection.

[0141] (3) Dynamically transmit first information related to frame format / slot format setting / frequency setting / spatial setting according to a signal waveform. This first information may be transmitted using, for example, UE-Group DCI (e.g., format 2_x in 5G NR) or UE-specific DCI (e.g., format 1_x in 5G NR).

[0142] When a default signal waveform is set in the terminal device and it is necessary to switch the signal waveform, first information for switching may be transmitted to the terminal device. The first information may be configured to switch to one of CP-OFDM and DFT-S-OFDM based on the other. The notification method may be any of the notification methods (1) to (3) above. The above example of notification of the first information may be applied to control information including the first information.

[0143] 31 shows an example of a procedure for notifying a plurality of terminal devices of information (first information) that designates a signal waveform (signal waveform to be used) corresponding to at least one of time information, frequency information, spatial information, and channel information, or any combination thereof, as a first signal waveform or a second signal waveform. The control unit 103 of the base station device determines, for each terminal device, a signal waveform to be applied according to a combination of time, frequency, space, and transmission channel, and transmits information (first information) indicating the determined signal waveform to each of the plurality of terminal devices (S241_A to S241_X). That is, the control unit 103 of the base station device generates different first information for each of the plurality of terminal devices and notifies each of the plurality of terminal devices of the first information. Thereafter, the control unit 103 of the base station device determines, for each terminal device, a transmission signal waveform to be transmitted to the terminal device based on the first information. When the first signal waveform is determined as the signal waveform of the data, the first signal waveform transmission unit 403 of the base station device transmits using the first signal waveform. When the second signal waveform is determined as the transmission signal waveform, the second signal waveform transmitter 405 of the base station device transmits using the second signal waveform. Each terminal device performs reception processing of the signal waveform from the base station based on information (first information) received from the base station device (S242_A to S242_X). More specifically, the first signal waveform receiver 303 of each terminal device receives the first signal waveform transmitted from the base station device based on the first information and performs reception processing of the first signal waveform. The second signal waveform receiver 305 of each terminal device receives the second signal waveform transmitted from the base station device based on the first information and performs reception processing of the second signal waveform.

[0144] 32 shows an example of a procedure for notifying a plurality of terminal devices of information (first information) that designates a signal waveform (signal waveform in use) corresponding to at least one of time information, frequency information, spatial information, and channel information, or any combination thereof, as a first signal waveform or a second signal waveform. The control unit 103 of the base station device determines a signal waveform to be applied to a plurality of terminal devices belonging to a cell according to a combination of time, frequency, space, and transmission channel, and transmits information (first information) indicating the determined signal waveform to the plurality of terminal devices (S243). That is, the control unit 103 of the base station device generates first information common to a plurality of terminal devices and notifies the plurality of terminal devices of the common first information. In the example of FIG. 32, the first information is transmitted by broadcast, but it may also be transmitted to each terminal device by unicast. Thereafter, the control unit 103 of the base station device determines, in the multiple terminal devices, a signal waveform to be transmitted to the terminal device based on the first information, and the first signal waveform transmission unit 403 of the base station device generates the first signal waveform and transmits using the first signal waveform when the signal waveform is determined to be the first signal waveform. The second signal waveform transmission unit 405 of the base station device generates the second signal waveform and transmits using the second signal waveform when the signal waveform is determined to be the second signal waveform. The multiple terminal devices perform reception processing of the signal waveform from the base station based on the information (first information) received from the base station device (S244A, S244_X). More specifically, the first signal waveform reception unit 303 of the multiple terminal devices receives the first signal waveform transmitted from the base station device based on the first information and performs reception processing of the first signal waveform. The second signal waveform receiving units 305 of the plurality of terminal devices receive the second signal waveform transmitted from the base station device based on the first information, and perform reception processing of the second signal waveform.

[0145] (Embodiment 7) Measurement-related processing related to the present disclosure will be described.

[0146] (1) When signal waveforms are different, the RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), and SINR (Signal to Interference plus Noise Ratio) measured for each signal waveform are likely to be different. Therefore, different measurement means are required for each signal waveform. The base station device may transmit an independent SSB for each signal waveform. For example, it may transmit a PSS, SSS, PBCH, or SSB for CP-OFDM and a PSS, SSS, PBCH, or SSB for DFT-S-OFDM. The base station device transmits a different CSI-RS for each signal waveform, and the terminal device measures RSRP, RSRQ, RSSI, SINR, etc. In this case, the PSS, SSS, PBCH, or SSB may be the same signal waveform rather than being independent for each signal waveform.

[0147] (2) Measurement Report The base station apparatus may cause the terminal apparatus to perform a measurement report for each signal waveform. Here, the terminal apparatus may report (transmit) the measurement results for each signal waveform independently, or may report (transmit) the measurement results for multiple signal waveforms together. Examples of information to be reported in the measurement report are shown below. SS-RSRP CSI-RSRP SS-RSRQ CSI-RSRQ SS-SINR CSI-SINR

[0148] (3) Measurement Period of Terminal Device <Periodic> The terminal device performs measurement at a predetermined timing. The period may be a combination of multiple periods. Alternatively, the terminal device may perform measurement continuously.

[0149] <Aperiodic (Event Trigger)> The terminal device performs measurement at the timing when it receives a measurement execution request from the base station device.

[0150] The terminal device detects a measurement execution trigger that has been notified or determined in advance, and performs measurement when the trigger occurs. Examples of triggers are shown below: - When a predetermined time has arrived - When the reception quality has fallen below a certain level - When the moving speed of the terminal device has increased - When the terminal device has started to move

[0151] (4) Measurement Report Period of Terminal Device <Periodic> The terminal device transmits measurement results to the base station device at predetermined timing.

[0152] <Aperiodic (Event Trigger)> The terminal device transmits the measurement result at the timing when it receives a request to notify the measurement result from the base station device.

[0153] The terminal device detects a measurement execution trigger that has been notified or determined in advance, and transmits the measurement results when the trigger is activated. Examples of triggers are as follows: - When the communication quality (e.g., RSRP) of the measured signal waveform exceeds a threshold; - When the communication quality (e.g., RSRP) of the measured signal waveform falls below a threshold; - When the communication quality (e.g., RSRP) of the current signal waveform falls above or below an offset from the communication quality (e.g., RSRP) of the other signal waveform; - When the communication quality (e.g., RSRP) of the current signal waveform becomes better or worse than the communication quality (e.g., RSRP) of the other signal waveform; - When the communication quality (e.g., RSRP) of the current signal waveform becomes worse than a first threshold and the communication quality (e.g., RSRP) of the other signal waveform becomes better than a second threshold. - In addition to the measurement reports related to the above signal waveforms, the following measurement reports may also be included. ...When the communication quality (e.g., RSRP) of the neighboring cell becomes more than an offset compared to the communication quality (e.g., RSRP) of the cell to which the terminal device belongs. ...When the communication quality (e.g., RSRP) of the neighboring cell becomes a cell with better reception quality than the communication quality (e.g., RSRP) of the cell to which the terminal device belongs. ...When the communication quality (e.g., RSRP) of the cell to which the terminal device belongs becomes worse than a first threshold, and the communication quality (e.g., RSRP) of the neighboring cell becomes better than a second threshold. ...When the quality of the reference signal (e.g., CSI-RS) resource becomes better than a threshold. ...When the quality of the reference signal (e.g., CSI-RS) resource becomes better than the reference signal to be compared by more than an offset. ...When the moving speed of the terminal becomes more than a threshold. ...When the moving speed of the terminal becomes less than a threshold.

[0154] FIG. 33 shows an example of a procedure for performing measurements for each signal waveform. The control unit 103 of the base station device determines measurement conditions (e.g., trigger conditions, conditions for performing a measurement report) for measuring communication quality for each signal waveform, and notifies the terminal device of information indicating the determined measurement conditions (third information) (S251). The control unit 203 of the terminal device periodically or aperiodically measures communication quality for each signal waveform in accordance with the measurement conditions indicated in the information received from the base station (S252). The control unit 203 of the terminal device transmits a measurement report including the measurement results to the base station device (S253). The control unit 103 of the base station device acquires the measurement results of communication quality measured for each signal waveform in accordance with the measurement conditions from the terminal device. By acquiring the measurement results for each signal waveform, communication can be controlled for each signal waveform, enabling efficient communication.

[0155] (Embodiment 8) A default signal waveform may be determined, and the terminal device may determine whether to apply a different signal waveform based on information about a predetermined signal received from a base station device. Specific examples are given below.

[0156] (1) When the default signal waveform is multicarrier transmission (CP-OFDM), if it is determined that a signal waveform needs to be switched based on information about a specific signal received from a base station device, the signal waveform is switched to another signal waveform, such as single-carrier transmission (DFT-S-OFDM). For example, if no information about the signal waveform is received from the base station device, the default signal waveform is used, and if information about a different signal waveform is received from the base station device, the signal waveform is switched to another signal waveform.

[0157] (2) A default signal waveform is used for predetermined processing, and a signal waveform other than the default signal waveform is switched to for processing other than the predetermined processing. Examples of predetermined processing include the following: Synchronization signal transmission / reception processing: Transmission and reception processing of synchronization signals such as PSS, SSS, and TSS. Random access transmission / reception processing (processing related to initial access): Transmission and reception processing of Message 2, Message 4, and Message B. Control signal transmission / reception processing: Transmission and reception processing of PDCCH. Reference signal transmission / reception processing Transmission and reception processing of system information (MIB, SIB, etc.)

[0158] In the above (1) or (2), the default signal waveform may be either a signal waveform to which transform precoding is applied (e.g., DFT-Spread-OFDM transmission) or a signal waveform to which transform precoding is not applied (e.g., OFDM transmission).

[0159] FIG. 34 shows an example of a procedure for transmitting a notification of switching from a predetermined default signal waveform to a terminal device and applying the other signal waveform to the terminal device. The terminal device MP control unit controls reception processing of signals received from a base station device to be performed using the predetermined default signal waveform (S261). Note that the target to which the default signal waveform is applied may be identified by one or any combination of the above-mentioned time information, frequency information, spatial information, and channel information. The control unit 103 of the base station device determines to switch the signal waveform of the terminal device to the other signal waveform and transmits information (first information) instructing the terminal device to switch to the other signal waveform (S262). The control unit 203 of the terminal device switches the applied signal waveform to the other signal waveform in accordance with the information received from the base station (S263).

[0160] FIG. 35 shows an example of a procedure for notifying a terminal device of a default signal waveform to apply the default signal waveform, and then transmitting a notification of switching from the default signal waveform to the terminal device to apply the other signal waveform to the terminal device. The control unit 103 of the base station device transmits information (first information) instructing the terminal device to use the default signal waveform (S271), and the terminal device controls the base station device to perform signal waveform reception processing using the default signal waveform indicated in the information received from the base station (S272). Note that the target to which the default signal waveform is applied may be identified by one or any combination of the aforementioned time information, frequency information, spatial information, and channel information. The control unit 103 of the base station device determines to switch the terminal device's signal waveform to another signal waveform and transmits information (second information) instructing the terminal device to switch to the other signal waveform (S273). The second information associates the signal waveform to be used after switching with at least one of time information, frequency information, and spatial information. The control unit 203 of the terminal device switches the signal waveform to be applied to another signal waveform in accordance with the information received from the base station (S274).

[0161] (Embodiment 9) The relationship between downlink signal waveforms and uplink signal waveforms will be described.

[0162] (1) If the downlink is a single-carrier system (e.g., DFT-S-OFDM), the uplink is also configured to be a single-carrier system (e.g., DFT-S-OFDM). When the downlink is configured to be a single-carrier system (e.g., DFT-S-OFDM), the terminal device assumes that only a single-carrier system (e.g., DFT-S-OFDM) is configured for the uplink. In other words, when the downlink is configured to be a single-carrier system (e.g., DFT-S-OFDM), it is assumed that a multi-carrier system (e.g., CP-OFDM) is not configured for the uplink. For example, when considering coverage such as cell edge, it is possible to use a single-carrier system (e.g., DFT-S-OFDM) for both links.

[0163] (2) If the downlink is a multicarrier system (e.g., CP-OFDM), the uplink is also configured to be a multicarrier system (e.g., CP-OFDM). When the downlink is configured to be a multicarrier system (e.g., CP-OFDM), the terminal device assumes that only a multicarrier system (e.g., CP-OFDM) is configured for the uplink. In other words, when the downlink is configured to be a multicarrier system (e.g., CP-OFDM), it is assumed that a single-carrier system (e.g., DFT-S-OFDM) is not configured for the uplink. For example, in the case of coverage where a multicarrier system (e.g., CP-OFDM) is available for communication on the downlink, it is conceivable to use a multicarrier system (e.g., CP-OFDM) on both links.

[0164] (3) If the downlink is a multicarrier scheme (e.g., CP-OFDM), the uplink is set to either a multicarrier scheme (e.g., CP-OFDM) or a single-carrier scheme (e.g., DFT-S-OFDM), or both. If the downlink is set to a multicarrier scheme (e.g., CP-OFDM), the terminal device assumes that the uplink is set to either a multicarrier scheme (e.g., CP-OFDM) or a single-carrier scheme (e.g., DFT-S-OFDM), or both.

[0165] (4) If the uplink is a single-carrier system (e.g., DFT-S-OFDM), the downlink is also configured to be a single-carrier system (e.g., DFT-S-OFDM). When the uplink is configured to be a single-carrier system (e.g., DFT-S-OFDM), the terminal device assumes that only a single-carrier system (e.g., DFT-S-OFDM) is configured for the downlink. In other words, when the uplink is configured to be a single-carrier system (e.g., DFT-S-OFDM), it is assumed that a multi-carrier system (e.g., CP-OFDM) is not configured for the downlink. For example, when considering coverage such as cell edge, it is possible to use a single-carrier system (e.g., DFT-S-OFDM) for both links.

[0166] (5) If the uplink is a multicarrier system (e.g., CP-OFDM), the downlink is also configured to be a multicarrier system (e.g., CP-OFDM). When the uplink is configured to be a multicarrier system (e.g., CP-OFDM), the terminal device assumes that only a multicarrier system (e.g., CP-OFDM) is configured for the downlink. In other words, when the uplink is configured to be a multicarrier system (e.g., CP-OFDM), it is assumed that a single-carrier system (e.g., DFT-S-OFDM) is not configured for the downlink. For example, in the case of coverage where a multicarrier system (e.g., CP-OFDM) is available for communication on the downlink, it is conceivable to use a multicarrier system (e.g., CP-OFDM) on both links.

[0167] (6) If the uplink is a multicarrier scheme (e.g., CP-OFDM), the downlink is set to either a multicarrier scheme (e.g., CP-OFDM) or a single-carrier scheme (e.g., DFT-S-OFDM), or both. For example, if the uplink is set to a multicarrier scheme (e.g., CP-OFDM), the terminal device assumes that the downlink is set to either a multicarrier scheme (e.g., CP-OFDM) or a single-carrier scheme (e.g., DFT-S-OFDM), or both.

[0168] (Embodiment 10) Examples of signal waveforms other than those described above are described below.

[0169] <Example of Single-Carrier Signal Waveform> The single-carrier method (or DFT-S-OFDM) in the above explanation may be interpreted as any of the following, but is not limited to these, and is similarly applicable to any method that uses a single-carrier signal waveform. DFT-S-OFDM (Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing) Constant envelope SC-QAM (Single Carrier-Quadrature Amplitude Modulation) SC-FDE (single-carrier modulation with frequency domain equalization) SC-FDM (Single Carrier-Frequency Division Multiplex) Zero-tail SC-FDM

[0170] <Examples of Multi-Carrier Signal Waveforms> The multi-carrier method (or CP-OFDM) in the above explanation may be interpreted as any of the following, but is not limited to these and can be similarly applied to any method that uses a multi-carrier signal waveform. CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) CP-OFDM with WOLA (Cyclic Prefix - Orthogonal Frequency Division Multiplexing with Weighted Overlap and Add) UFMC (Universal Filter Multi Carrier) FBMC (Filter-Bank Multi Carrier) GFDM (Generalized Frequency Division Multiplexing)

[0171] As described above, according to this embodiment of the transcription, when both CP-OFDM and DFT-S-OFDM signal waveforms coexist in the downlink, the terminal device and the base station can agree on which signal waveform to use, so that both signal waveforms can be used depending on the situation, and it becomes possible to efficiently carry out communications that meet the requirements for low PAPR.

[0172] The above-described embodiment shows an example for realizing the present disclosure, and the present disclosure can be implemented in various other forms. For example, various modifications, substitutions, omissions, or combinations thereof are possible without departing from the spirit of the present disclosure. Such modifications, substitutions, omissions, etc. are also included within the scope of the present disclosure, as well as within the scope of the inventions described in the claims and their equivalents.

[0173] Furthermore, the effects of the present disclosure described in this specification are merely examples, and other effects may also be present.

[0174] The present disclosure may also have the following configurations: [Item 1] A base station apparatus comprising: a control unit that notifies first information associating a signal waveform to be used in downlink communication with a terminal device, of a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information, and performs the downlink communication using the signal waveform to be used based on the first information. [Item 2] The base station apparatus according to Item 1, comprising: a first signal waveform transmission unit that generates the first signal waveform and transmits the first signal waveform; and a second signal waveform transmission unit that generates the second signal waveform and transmits the second signal waveform, wherein the second signal waveform transmission unit generates the second signal waveform using transform precoding, and the first signal waveform transmission unit generates the first signal waveform without using transform precoding. [Item 3] The base station device according to Item 2, wherein the control unit determines a signal waveform to be transmitted to the terminal device based on the first information, the first signal waveform transmission unit performs transmission using the first signal waveform when the control unit has determined the signal waveform to be the first signal waveform, and the second signal waveform transmission unit performs transmission using the second signal waveform when the control unit has determined the signal waveform to be the second signal waveform. [Item 4] The base station device according to any one of Items 1 to 3, wherein the first information specifies the use signal waveform in units of symbols, slots, subframes, or radio frames as the time information. [Item 5] The base station device according to Item 4, wherein the first information includes information specifying the use signal waveform only for symbols, slots, subframes, or radio frames other than predetermined symbols, slots, subframes, or radio frames among a plurality of symbols, a plurality of slots, a plurality of subframes, or a plurality of radio frames. [Item 6] The base station device according to Item 5, wherein the control unit uses a default signal waveform of the first signal waveform or the second signal waveform as the use signal waveform of the predetermined symbol, slot, subframe, or radio frame.[Item 7] The base station device according to item 5, wherein the control unit dynamically changes the use signal waveform to the first signal waveform or the second signal waveform for the predetermined symbol, slot, subframe, or radio frame by transmitting a control signal to the terminal device. [Item 8] The base station device according to any one of items 1 to 7, wherein the first information specifies the use signal waveform that differs for each frequency. [Item 9] The base station device according to any one of items 1 to 8, wherein the first information specifies the use signal waveform as the spatial information depending on an area in which the terminal device is located. [Item 10] The base station device according to any one of items 1 to 9, wherein the first information specifies the use signal waveform as the spatial information depending on a beam used by the terminal device. [Item 11] The base station device according to any one of items 1 to 10, wherein the first information associates the use signal waveform with channel information, and specifies the same use signal waveform commonly to a plurality of the terminal devices for channels transmitting over an entire coverage area. [Item 12] The base station device according to Item 11, wherein the channel transmitted commonly to the entire coverage area includes a PBCH or a PDCCH. [Item 13] The base station device according to any one of Items 1 to 12, wherein the control unit generates different first information for each of the plurality of terminal devices and notifies the plurality of terminal devices of the first information. [Item 14] The base station device according to any one of Items 1 to 13, wherein the terminal device uses a default signal waveform that is predetermined for at least one of the time information, the frequency information, and the spatial information, the default signal waveform being one of the first signal waveform and the second signal waveform, and when switching the default signal waveform to the first signal waveform or the second signal waveform, the control unit notifies the terminal device of the first information instructing the switching of the signal waveform.[Item 15] The base station device according to any one of items 1 to 14, wherein the control unit notifies the terminal device of the first information as information specifying a predetermined default signal waveform for at least one of the time information, the frequency information, and the spatial information, and when switching the default signal waveform to the first signal waveform or the second signal waveform, the control unit notifies the terminal device of second information instructing the switching of the signal waveform, and the second information associates the used signal waveform after switching with at least one of the time information, the frequency information, and the spatial information. [Item 16] The base station device according to any one of items 1 to 15, wherein the control unit notifies the terminal device of third information specifying measurement conditions for communication quality for each of the first signal waveform and the second signal waveform. [Item 17] The base station device according to item 16, wherein the control unit acquires from the terminal device measurement results of communication quality measured according to the measurement conditions for each of the first signal waveform and the second signal waveform. [Item 18] A terminal device comprising: a control unit that acquires first information that associates a signal waveform to be used in downlink communication with a base station device, of a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information, and performs the downlink communication using the used signal waveform based on the first information. [Item 19] The terminal device according to Item 18 comprises: a first signal waveform receiving unit that receives the first signal waveform transmitted from the base station device based on the first information and performs reception processing of the first signal waveform, and a second signal waveform receiving unit that receives the second signal waveform transmitted from the base station device based on the first information and performs reception processing of the second signal waveform, wherein the first signal waveform is a signal generated using transform precoding, and the second signal waveform is a signal generated without using transform precoding. [Item 20] A wireless communication method comprising: notifying first information that associates a signal waveform to be used in downlink communication with a terminal device, from among a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information; and performing the downlink communication using the signal waveform to be used based on the first information.[Item 21] A wireless communication method comprising: acquiring first information associating a signal waveform from among a first signal waveform and a second signal waveform to be used in downlink communication with a base station device with at least one of time information, frequency information, and spatial information, and performing the downlink communication using the used signal waveform based on the first information. [Item 22] A program causing a computer to execute the steps of: notifying a terminal device of first information associating a signal waveform from among a first signal waveform and a second signal waveform to be used in downlink communication with the base station device with at least one of time information, frequency information, and spatial information, and performing the downlink communication using the used signal waveform based on the first information. [Item 23] A program causing a computer to execute the steps of: acquiring first information associating a signal waveform from among a first signal waveform and a second signal waveform to be used in downlink communication with a base station device with at least one of time information, frequency information, and spatial information, and performing the downlink communication using the used signal waveform based on the first information.

[0175] REFERENCE SIGNS LIST 1 Base station device 2 Terminal device 2A Terminal device 2B Terminal device 3 Relay device (relay station) 4 Terrestrial network 11 Geostationary satellite 12 Low-earth orbit satellite 13 Aviation station device 15 Core network 16 Internet 17 Macrocell 18 Femtocell 19 Airborne platform 101 Upper layer processing unit 103 Control unit 105 Receiving unit 107 Transmitting unit 109 Antenna 201 Upper layer processing unit 203 Control unit 205 Receiving unit 207 Transmitting unit 209 Antenna 301 Signal waveform switching unit 303 First signal waveform receiving unit 305 Second signal waveform receiving unit 401 Signal waveform switching unit 403 First signal waveform transmitting unit 405 Second signal waveform transmitting unit 1051 Decoding unit 1053 Demodulation unit 1055 Demultiplexing unit 1057 Radio receiving unit 1059 Channel measurement unit 1071 Encoding unit 1073 Modulation unit 1075 Multiplexing unit 1077 Radio transmitting unit 1079 Link reference signal generation unit 2051 Decoding unit 2053 Demodulation unit 2055 Demultiplexing unit 2057 Radio receiving unit 2059 Channel measurement unit 2071 Encoding unit 2073 Modulation unit 2075 Multiplexing unit 2077 Radio transmitting unit 2079 Link reference signal generation unit 3031 CP removal unit 3033 S / P unit 3035 DFT unit 3037 P / S unit 3051 CP removal unit 3053 S / P unit 3055 DFT unit 3057 IDFT unit 4031 S / P unit 4033 IDFT section 4035 P / S section 4037 CP insertion section 4051 DFT section 4053 IDFT section 4055 P / S section 4057 CP insertion section

Claims

1. A base station device comprising: a control unit that notifies first information that associates a signal waveform to be used in downlink communication with a terminal device, from among a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information; and performs the downlink communication using the signal waveform to be used based on the first information.

2. The base station device according to claim 1, comprising: a first signal waveform transmission unit that generates the first signal waveform and transmits the first signal waveform; and a second signal waveform transmission unit that generates the second signal waveform and transmits the second signal waveform, wherein the second signal waveform transmission unit generates the second signal waveform using transform precoding, and the first signal waveform transmission unit generates the first signal waveform without using transform precoding.

3. The base station device according to claim 2, wherein the control unit determines a signal waveform to be transmitted to the terminal device based on the first information, the first signal waveform transmission unit transmits using the first signal waveform when the control unit determines the signal waveform to be the first signal waveform, and the second signal waveform transmission unit transmits using the second signal waveform when the control unit determines the signal waveform to be the second signal waveform.

4. The base station device according to claim 1, wherein the first information specifies the signal waveform to be used in units of symbols, slots, subframes or radio frames as the time information.

5. The base station device according to claim 4, wherein the first information includes information specifying the signal waveform to be used only for symbols, slots, subframes or radio frames other than predetermined symbols, slots, subframes or radio frames among a plurality of symbols, a plurality of slots, a plurality of subframes or a plurality of radio frames.

6. The base station device according to claim 5, wherein the control unit uses a default signal waveform of either the first signal waveform or the second signal waveform as the signal waveform to be used for the predetermined symbol, slot, subframe, or radio frame.

7. The base station device according to claim 5, wherein the control unit dynamically changes the signal waveform used to the first signal waveform or the second signal waveform for the predetermined symbol, slot, subframe or radio frame by transmitting a control signal to the terminal device.

8. The base station device according to claim 1, wherein the first information specifies the signal waveform to be used, which differs for each frequency.

9. The base station device according to claim 1, wherein the first information specifies the signal waveform to be used as the spatial information depending on the area in which the terminal device is located.

10. The base station device according to claim 1, wherein the first information specifies the signal waveform to be used as the spatial information depending on the beam to be used by the terminal device.

11. The base station device according to claim 1, wherein the first information associates the signal waveform to be used with channel information, and the same signal waveform to be used is designated in common to multiple terminal devices for channels transmitting over the entire coverage area.

12. The base station apparatus according to claim 11, wherein the channel commonly transmitted throughout the entire coverage area includes a PBCH or a PDCCH.

13. The base station device according to claim 1, wherein the control unit generates different first information for each of the plurality of terminal devices and notifies the plurality of terminal devices of the first information, respectively.

14. The base station device of claim 1, wherein the terminal device uses a predetermined default signal waveform for at least one of the time information, the frequency information, and the spatial information, the default signal waveform being one of the first signal waveform and the second signal waveform, and the control unit notifies the terminal device of the first information instructing the switching of the signal waveform when the default signal waveform is switched to the first signal waveform or the second signal waveform.

15. The base station device of claim 1, wherein the control unit notifies the terminal device of the first information as information specifying a predetermined default signal waveform for at least one of the time information, the frequency information, and the spatial information; and when the control unit switches the default signal waveform to the first signal waveform or the second signal waveform, the control unit notifies the terminal device of second information instructing the switching of the signal waveform, and the second information associates the signal waveform to be used after the switching with at least one of the time information, the frequency information, and the spatial information.

16. The base station device according to claim 1, wherein the control unit notifies the terminal device of third information specifying measurement conditions for communication quality for each of the first signal waveform and the second signal waveform.

17. The base station device according to claim 16, wherein the control unit acquires from the terminal device measurement results of communication quality measured in accordance with the measurement conditions for each of the first signal waveform and the second signal waveform.

18. A terminal device having a control unit that acquires first information that associates a signal waveform to be used in downlink communication with a base station device, from among a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information, and performs the downlink communication using the signal waveform to be used based on the first information.

19. A terminal device as described in claim 18, comprising: a first signal waveform receiving unit that receives the first signal waveform transmitted from the base station device based on the first information and performs reception processing of the first signal waveform; and a second signal waveform receiving unit that receives the second signal waveform transmitted from the base station device based on the first information and performs reception processing of the second signal waveform, wherein the first signal waveform is a signal generated using transform precoding, and the second signal waveform is a signal generated without using transform precoding.

20. A wireless communication method comprising: notifying a terminal device of first information associating a signal waveform to be used in downlink communication with the terminal device, from among a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information; and performing the downlink communication using the signal waveform to be used based on the first information.

21. A wireless communication method comprising: acquiring first information that associates a signal waveform, out of a first signal waveform and a second signal waveform, to be used in downlink communication with a base station device with at least one of time information, frequency information, and spatial information; and performing the downlink communication using the signal waveform to be used based on the first information.

22. A program causing a computer to execute the steps of: notifying a terminal device of first information associating a signal waveform to be used in downlink communications with the terminal device, from among a first signal waveform and a second signal waveform, with at least one of time information, frequency information, and spatial information; and performing the downlink communications with the signal waveform to be used based on the first information.

23. A program causing a computer to execute the steps of: acquiring first information that associates a signal waveform, out of a first signal waveform and a second signal waveform, to be used in downlink communications with a base station device with at least one of time information, frequency information, and spatial information; and performing the downlink communications using the signal waveform to be used based on the first information.

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