Terminal device, base station equipment, and communication method

Abstract

A terminal device (2) according to the present disclosure includes a control unit (203). The control unit (203) acquires information about a used signal waveform among a plurality of signal waveforms including a single carrier signal from a base station device (1), the used signal waveform being used for downlink communication with the base station device (1), the information being transmitted by using a predetermined signal waveform among the plurality of signal waveforms. Based on the information, the control unit (203) performs downlink communication with the base station device (1) by using the used signal waveform.

Description

Technical Field

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

[0002] The radio access system and radio network for cellular mobile communications (hereinafter also referred to as "Long Term Evolution (LTE)", "LTE-Advanced (LTE-A)", "LTE-Advanced Pro (LTE-APro)", "New Radio (NR)", "New Radio Access Technology (NRAT)", "Evolved Universal Terrestrial Radio Access (EUTRA)", or "Further EUTRA (FEUTRA)") are discussed in the Third Generation Partnership Project (3GPP). Note that in the following description, LTE includes LTE-A, LTE-APro, and EUTRA, and NR includes NRAT and FEUTRA. In LTE and NR, the base station apparatus (base station) is also referred to as an evolved Node B (eNodeB) in LTE and as a gNodeB in NR, and the terminal device (mobile station, mobile station apparatus, or terminal) is also referred to as a user equipment (UE). LTE and NR are cellular communication systems in which multiple areas covered by base station apparatuses are arranged in the form of cells. Note that a single base station apparatus can manage multiple cells.

[0003] As the next-generation radio access method for LTE, NR is a radio access technology (RAT) distinct from LTE. NR is an access technology configured to support a variety of use cases, including enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). NR is being studied to address the usage scenarios, requirements, and deployment scenarios for these use cases.

[0004] In NR, in response to the demand for wider frequency bands, research is underway to utilize high-frequency bands, known as millimeter waves, from 52.6 GHz to 110 GHz. The use of millimeter waves is being investigated for various use cases, such as high-data-rate eMBB, mobile data traffic offload, and vertical industry factory applications. For example, Non-Patent Document 1 discloses research on the use of millimeter waves within 3GPP.

[0005] Citation List

[0006] Non-patent literature

[0007] Non-Patent Document 1: 3GPP TR 38.807 V0.2.0 "3rd GeneRATion Partnership Project; Technical Specification Group Radio Access Network; Study oN Requirements for NR beyond 52.6 GHz (Release 16)", June 2019. Summary of the Invention

[0008] Technical issues

[0009] Millimeter-wave transmissions require signal waveforms with low peak-to-average power ratios (PAPRs), particularly in areas with high transmission power, due to nonlinearities in power amplifiers (PAs). However, the cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) used for downlink communications in LTE and NR suffers from high PAPRs and struggles to meet the low PAPR requirements of millimeter-wave transmissions.

[0010] Therefore, the present disclosure proposes a mechanism that can meet the PAPR requirement in downlink communication.

[0011] Solution to the problem

[0012] According to the present disclosure, a terminal device is provided. The terminal device includes a control unit. The control unit obtains information about a used signal waveform among multiple signal waveforms including a single carrier signal from a base station device, the used signal waveform being used for downlink communication with the base station device, the information being transmitted using a predetermined signal waveform among the multiple signal waveforms. Based on the information, the control unit performs downlink communication with the base station device using the used signal waveform. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a diagram for illustrating an overview of a communication system according to an embodiment of the present disclosure.

[0014] Figure 2 is a block diagram illustrating a configuration example of a base station device according to an embodiment of the present disclosure.

[0015] Figure 3 is a block diagram illustrating a configuration example of a radio transmitter.

[0016] Figure 4 is a block diagram illustrating a configuration example of a first signal waveform transmitting unit.

[0017] Figure 5 is a block diagram illustrating a configuration example of a second signal waveform transmitting unit.

[0018] Figure 6 is a block diagram illustrating a configuration example of a terminal device according to an embodiment of the present disclosure.

[0019] Figure 7 is a block diagram illustrating a configuration example of a radio receiver.

[0020] Figure 8 is a block diagram illustrating a configuration example of a first signal waveform receiving unit.

[0021] Figure 9 is a block diagram illustrating a configuration example of a second signal waveform receiving unit.

[0022] Figure 10 is a diagram illustrating an example of setting of component carriers according to an embodiment of the present disclosure.

[0023] Figure 11 is a diagram illustrating an example of setting of component carriers according to an embodiment of the present disclosure.

[0024] Figure 12 It is an explanatory diagram illustrating an example of the NR frame structure.

[0025] Figure 13 is a diagram illustrating the positional relationship between a base station apparatus and a terminal device.

[0026] Figure 14 is a sequence diagram illustrating an example of communication processing according to an embodiment of the present disclosure.

[0027] Figure 15 1 is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology of the present disclosure is applied.

[0028] Figure 16 is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology of the present disclosure is applicable.

[0029] Figure 17 This is a block diagram illustrating an example of a schematic configuration of a smartphone to which the technology according to the present disclosure is applied.

[0030] Figure 18 This is a block diagram illustrating an example of a schematic configuration of a car navigation device to which the technology according to the present disclosure is applied. DETAILED DESCRIPTION

[0031] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that in the specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and repeated description of these components will be omitted.

[0032] In addition, in some cases, in this specification and the accompanying drawings, multiple components with substantially the same functional configuration will be distinguished by assigning the same reference numeral followed by a different letter. For example, when necessary, multiple components with substantially the same functional configuration will be distinguished, such as terminal device 2A and terminal device 2B. However, in cases where it is not necessary to specifically distinguish multiple components with substantially the same functional configuration, the components are simply represented by the same reference numeral. For example, when it is not necessary to specifically distinguish terminal device 2A from terminal device 2B, the terminal device is simply referred to as terminal device 2.

[0033] Note that the description will be given in the following order.

[0034] 1. Introduction

[0035] 2. Examples

[0036] 2.1. Overview of the communication system

[0037] 2.2. Communication system composition

[0038] 2.2.1. Base station equipment configuration example

[0039] 2.2.2. Terminal device configuration example

[0040] 2.3. Communication system processing

[0041] 2.3.1. Communication Processing

[0042] 2.3.2. Signal waveform switching processing of base station equipment

[0043] 2.3.3. Notification Processing Using Signal Waveforms

[0044] 2.3.4. Communication processing according to the signal waveform used

[0045] 3. Application Examples

[0046] 3.1. Application Examples of Base Stations

[0047] 3.2. Application examples of terminal devices

[0048] 4. Other embodiments

[0049] 5. Additional Notes

[0050] 1. Introduction

[0051] In recent years, due to the growing mix of wireless systems in wireless environments and the growth and diversification of wirelessly transmitted content, the depletion of radio resources (frequencies) that can be allocated to wireless systems has become a problem. In such circumstances, in order to obtain available radio wave resources, consideration has been given to operations using millimeter waves, which are frequency bands that are easier to secure, and in particular, operations using millimeter waves, which are frequency bands between 52.6 GHz and 110 GHz.

[0052] Examples of use cases for millimeter wave communications include the following use cases.

[0053] High data rate eMBB

[0054] Mobile data traffic offloading

[0055] Short-range high data rate D2D communication

[0056] Vertical industry factory applications

[0057] Broadband distribution network

[0058] Integrated Access Backhaul (IAB)

[0059] Factory Automation / Industrial IoT (IIoT)

[0060] Augmented reality / virtual reality headsets and other high-end wearable devices

[0061] Intelligent Transportation Systems (ITS) and V2X

[0062] Data center inter-rack connectivity

[0063] Smart grid automation

[0064] Radar / positioning

[0065] Thus, in millimeter-wave communications, due to the nonlinearity of power amplifiers (PAs), signal waveforms with low peak-to-average power ratios (PAPRs) are required. In particular, downlink communications, where signals are transmitted from base stations to terminal devices, involve high-power communications such as multicast communications. Consequently, downlink communications using millimeter waves are often affected by the nonlinearity of power amplifiers, necessitating signal waveforms with low PAPRs.

[0066] A single-carrier signal is known as a signal having a low PAPR signal waveform. Using a single-carrier signal for millimeter-wave wireless communication can achieve a low PAPR.

[0067] On the other hand, from the perspective of frequency utilization efficiency and compatibility with FR1 / FR2, it is desirable to use multi-carrier signals for downlink communications in the millimeter wave band. For example, multi-carrier signals have the following advantages over single-carrier signals.

[0068] Easy to separate from multipath

[0069] Easy to digitally precode for each frequency

[0070] Easy to allocate resources non-continuously on the frequency axis

[0071] In particular, ease of separation from multipath affects the number of multiplexes in MIMO. Easier separation of multicarrier signals and multipaths allows for an increased number of multiplexes in MIMO compared to single carrier signals.

[0072] Base station devices are connected to a plurality of terminal devices, and therefore, frequency utilization efficiency needs to be improved even in the millimeter wave band. As described above, in downlink communication in the millimeter wave band, low PAPR and improvement in efficiency of the entire system are required.

[0073] <2. Example>

[0074] <2.1. Overview of Communication System>

[0075] Therefore, in the technology of the present disclosure, one of a plurality of signal waveforms including a single carrier signal is used for downlink communication to achieve low PAPR and improved efficiency of the entire system. Figure 1 An overview of the technology disclosed herein will be described.

[0076] Figure 1 1 is a diagram for illustrating an overview of a communication system according to an embodiment of the present disclosure. Figure 1 As shown in the diagram, the communication system according to the present embodiment includes a base station apparatus 1 and a plurality of terminal devices 2A and 2B.

[0077] Base station apparatus 1 determines a signal waveform to be used for downlink communication with each terminal device 2 from a plurality of signal waveforms including a single carrier signal. For example, base station apparatus 1 determines to use a single carrier signal or a multi-carrier signal for downlink communication.

[0078] Here, the multi-carrier signal is, for example, CP-OFDM. In addition, examples of single-carrier signals include DFT-S-OFDM, SC-QAM, single carrier with zero padding / unique word, etc.

[0079] For example, base station apparatus 1 determines a signal waveform to be used for each terminal device 2 and notifies terminal device 2 of information about the determined signal waveform. Base station apparatus 1 performs downlink communication with terminal device 2 by using the signal waveform notified by base station apparatus 1.

[0080] exist Figure 1 In the example shown in FIG, base station apparatus 1 selects a multi-carrier signal and performs downlink communication S1 with terminal apparatus 2A located near the center of cell C. Furthermore, base station apparatus 1 selects a single-carrier signal and performs downlink communication S2 with terminal apparatus 2B located near the edge of cell C.

[0081] In order to perform downlink communication with terminal device 2B located near the cell edge, a larger transmission power is required, which requires a lower PAPR. On the other hand, the transmission power required for terminal device 2A located near the center of cell C is less than the transmission power required for terminal device 2B located near the cell edge. Therefore, even if the PAPR is high, it is easy to ensure the required transmission power.

[0082] Then, the base station apparatus 1 selects a multi-carrier signal for the terminal device 2A located near the center of the cell C, and selects a single-carrier signal for the terminal device 2B located near the edge of the cell C.

[0083] As described above, base station apparatus 1 allocates a single-carrier signal to downlink communications where a low PAPR is strictly required, while allocating a signal waveform other than the single-carrier signal (here, a multi-carrier signal) to downlink communications where a low PAPR is less strictly required. Thus, base station apparatus 1 can achieve a low PAPR and improve overall system efficiency.

[0084] Note that although the base station apparatus 1 is described here as determining the signal waveform according to the position of the terminal device 2 in the cell C, the method by which the base station apparatus 1 determines the signal waveform is not limited thereto. Details of the method by which the base station apparatus 1 determines the signal waveform will be described later.

[0085] <2.2. Example of Communication System Configuration>

[0086] An example of the configuration of a communication system according to an embodiment of the present disclosure will be described. As described above, the communication system according to the present embodiment includes the base station device 1 and the terminal device 2.

[0087] <2.2.1. Example of Base Station Equipment Configuration>

[0088] Figure 2 1 is a block diagram illustrating a configuration example of a base station device 1 according to an embodiment of the present disclosure. Figure 2As shown in the diagram, 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 a transmitting / receiving antenna 109 .

[0089] The base station device 1 can be configured to support one or more radio access technologies (RATs). For example, the base station device 1 is configured to support both LTE and NR. In this configuration, some or all units included in the base station device 1 can be configured separately according to the RAT. For example, the receiving unit 105 and the transmitting unit 107 can be configured separately according to LTE and NR. In addition, in the NR cell, the units included in Figure 2 Some or all units in the base station device 1 shown in the figure can be individually configured according to parameter sets related to transmitted signals. For example, in a certain NR cell, the radio receiver 1057 and the radio transmitter 1077 can be individually configured according to parameter sets related to transmitted signals.

[0090] (Upper layer processing unit)

[0091] The higher-layer processing unit 101 outputs downlink data (transport blocks) to the control unit 103. The higher-layer processing unit 101 performs processing at 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. Furthermore, the higher-layer processing unit 101 generates control information for controlling the receiving unit 105 and the transmitting unit 107, and outputs this control information to the control unit 103.

[0092] The upper layer processing unit 101 performs processing and management related to RAT control, radio resource control, subframe setting, scheduling control and / or CSI report control. The processing and management in the upper layer processing unit 101 are performed for each terminal device, or are performed collectively for the terminal devices connected to the base station device. The processing and management in the upper layer processing unit 101 can be performed only by the upper layer processing unit 101, or can be obtained from an upper layer node or other base station device. In addition, the processing and management in the upper layer processing unit 101 can be performed separately according to the RAT. For example, the upper layer processing unit 101 separately performs processing and management according to LTE and processing and management according to NR.

[0093] The upper layer processing unit 101 performs RAT-related management in RAT control. For example, RAT control includes management related to LTE and / or management related to NR. Management related to NR includes setting and processing parameter sets related to transmission signals in NR cells.

[0094] The radio resource control in the higher layer processing unit 101 manages the configuration information in the base station device. The radio resource control in the higher layer processing unit 101 generates and / or manages downlink data (transport blocks), system information, RRC messages (RRC parameters), and / or MAC control elements (CEs).

[0095] In the subframe setting in the upper layer processing unit 101, the subframe setting, subframe mode setting, uplink downlink setting, uplink reference UL-DL setting, and / or downlink reference UL-DL setting are managed. Note that the subframe setting in the upper layer processing unit 101 is also called the base station subframe setting. In addition, the subframe setting in the upper layer processing unit 101 can be determined based on the uplink traffic and downlink traffic. In addition, the subframe setting 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.

[0096] In scheduling control in the higher layer processing unit 101, the frequency and subframe to which the physical channel is allocated, the coding rate, modulation scheme, and transmit power of the physical channel are determined based on the received channel state information, the estimated value of the propagation channel input from the channel measurement unit 1059, the channel quality, and the like. For example, the control unit 103 generates control information (DCI format) based on the scheduling results of the scheduling control in the higher layer processing unit 101.

[0097] In the CSI reporting control of the higher layer processing unit 101, the CSI report from each terminal apparatus 2 is controlled. For example, the setting related to the CSI reference resource assumed to be used for the calculation of the CSI in the terminal apparatus 2 is controlled.

[0098] (Control Unit)

[0099] Control unit 103 controls receiving unit 105 and transmitting unit 107 based on control information from higher-layer processing unit 101. Control unit 103 generates control information for higher-layer processing unit 101 and outputs the control information to higher-layer processing unit 101. Control unit 103 receives input of a decoded signal from decoding unit 1051 and input of a channel estimation result from channel measurement unit 1059. Control unit 103 outputs a signal to be encoded to encoding unit 1071. Control unit 103 is also configured to control all or part of base station device 1.

[0100] In addition, the control unit 103 determines the signal waveform (hereinafter also referred to as the use signal waveform) to be used for downlink communication with each terminal device 2 from the single carrier signal and the multi-carrier signal. The control unit 103 controls the transmission unit 107 to notify the terminal device 2 of information related to the use signal waveform by using a predetermined signal waveform (e.g., a single carrier signal). In addition, the control unit 103 controls the transmission unit 107 to perform downlink communication with the terminal device 2 by using the notified use signal waveform. Note that the processing performed by the control unit 103 will be described in detail later.

[0101] (Receiving Unit)

[0102] Under the control of the control unit 103, the receiving unit 105 receives the signal transmitted from the terminal device 2 via the transmission / reception antenna 109, performs reception processing such as separation, demodulation, and decoding, and outputs the information subjected to the reception processing to the control unit 103. Note that the reception processing in the receiving unit 105 is performed based on predefined settings or settings notified by the base station apparatus 1 to the terminal device 2. The receiving unit 105 includes a decoding unit 1051, a demodulation unit 1053, a demultiplexing unit 1055, a radio receiver 1057, and a channel measurement unit 1059.

[0103] (Radio Receiver)

[0104] The radio receiver 1057 performs conversion to an intermediate frequency (down conversion), removal of unnecessary frequency components, control of the amplification level to maintain an appropriate signal level, orthogonal demodulation based on the in-phase component and the orthogonal component of the received signal, conversion from an analog signal to a digital signal, removal of a guard interval (GI), and / or extraction of a frequency domain signal by fast Fourier transform (FFT) on the uplink signal received via the transmit / receive antenna 109.

[0105] (Demultiplexing unit)

[0106] The demultiplexing unit 1055 separates an uplink channel such as the PUCCH or PUSCH and / or an uplink reference signal from the signal input from the radio receiver 1057. The demultiplexing unit 1055 outputs the uplink reference signal to the channel measurement unit 1059. The demultiplexing unit 1055 compensates for the propagation channel of the uplink channel based on the estimated propagation channel value input from the channel measurement unit 1059.

[0107] (Demodulation Unit)

[0108] The demodulation unit 1053 demodulates the modulation symbols from the uplink channel using a modulation scheme such as binary phase shift keying (BPSK), π / 2 BPSK, quadrature phase shift keying (QPSK), quadrature amplitude modulation (16QAM), 64QAM, or 256QAM to demodulate the received signal. The demodulation unit 1053 separates and demodulates the uplink channels multiplexed in MIMO.

[0109] (Decoding unit)

[0110] The decoding unit 1051 decodes the coded bits demodulated in the uplink channel. The decoded uplink data and uplink control information are output to the control unit 103. The decoding unit 1051 decodes the PUSCH for each transport block.

[0111] (Channel Measurement Unit)

[0112] The channel measurement unit 1059 measures an estimated value of a propagation channel and / or channel quality based on the uplink reference signal input from the demultiplexing unit 1055, and outputs the estimated value and / or channel quality to the demultiplexing unit 1055 and / or the control unit 103. For example, the channel measurement unit 1059 measures an estimated value of a propagation channel for propagation channel compensation for a PUCCH or a PUSCH by using a UL-DMRS, and measures channel quality in the uplink by using an SRS.

[0113] (Sending Unit)

[0114] Under the control of the control unit 103, the transmission unit 107 performs transmission processing such as coding, modulation, and multiplexing on the downlink control information and downlink data input from the higher layer processing unit 101. For example, the transmission unit 107 multiplexes the generated PHICH, PDCCH, EPDCCH, PDSCH, and downlink reference signal to generate a transmission signal. Note that the transmission processing in the transmission unit 107 is performed based on predefined settings, settings notified by the base station device 1 to the terminal device 2, or settings notified via the PDCCH or EPDCCH transmitted in the same subframe. The transmission unit 107 includes a coding unit 1071, a modulation unit 1073, a multiplexing unit 1075, a radio transmitter 1077, and a downlink reference signal generation unit 1079.

[0115] (coding unit)

[0116] The coding unit 1071 encodes the HARQ indication (HARQ-ACK), downlink control information, and downlink data input from the control unit 103 using a predetermined 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 predetermined 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 the physical cell identity (PCI), the RRC parameters set in the terminal device 2, and the like.

[0117] (Multiplexing Unit)

[0118] The multiplexing unit 1075 multiplexes the modulation symbols and downlink reference signals in the respective channels and arranges the modulation symbols and downlink reference signals in predetermined resource elements.

[0119] (Radio transmitter)

[0120] The radio transmitter 1077 processes the signal from the multiplexing unit 1075, such as by converting the signal into the time domain through inverse fast Fourier transform (IFFT), adding a guard interval, generating a baseband digital signal, converting it into an analog signal, performing orthogonal modulation, converting the intermediate frequency signal into a high frequency signal (up-conversion), removing unnecessary frequency components, and amplifying the power, thereby generating a transmission signal. The transmission signal output from the radio transmitter 1077 is transmitted from the transmission / reception antenna 109.

[0121] Here, the radio transmitter 1077 according to the present embodiment is configured to support a plurality of downlink signal waveforms. The radio transmitter 1077 in the base station apparatus 1 supporting both the first signal waveform (multi-carrier signal) and the second signal waveform (single carrier signal) will be referred to as Figures 3-5 Detailed description.

[0122] Figure 3 2 is a block diagram illustrating a configuration example of the radio transmitter 1077. The radio transmitter 2077 includes a signal waveform switching unit 401, a first signal waveform transmitting unit 403, and a second signal waveform transmitting unit 405.

[0123] The signal waveform switching unit 401 is configured to switch the signal waveform in the downlink communication for transmission between a first signal waveform and a second signal waveform according to predetermined conditions or conditions. In the case where the downlink communication for transmission uses the first signal waveform, the downlink communication is transmitted and processed by the first signal waveform transmitting unit 403. In the case where the downlink communication for transmission uses the second signal waveform, the downlink communication is transmitted and processed by the second signal waveform transmitting unit 405. The switching conditions and conditions in the signal waveform switching unit 401 will be described later. Note that the signal waveform switching unit is also referred to as a signal waveform control unit. In addition, Figure 3 , the first signal waveform transmitting unit 403 and the second signal waveform transmitting unit 405 are illustrated as different processing units, however, the first and second signal waveform transmitting units 403 and 405 may be configured as one processing unit so that only a portion of the transmission process is switched.

[0124] Figure 4 4 is a block diagram illustrating an example configuration of the first signal waveform transmitting unit 403. The first signal waveform transmitting unit 403 transmits a downlink channel and signal to be transmitted using CP-OFDM as a signal waveform for uplink communication. The first signal waveform transmitting unit 403 includes an S / P unit 4031, an inverse discrete Fourier transform (IDFT) unit 4033, a P / S unit 4035, and a CP insertion unit 4037.

[0125] The S / P unit 4031 converts the input serial signal into a parallel signal of size M. Here, the size M is determined by the size of the resources in the frequency domain used for downlink communication. The parallel signal of size M is input to the IDFT unit 4033 so as to correspond to the predetermined frequency domain.

[0126] The IDFT unit 4033 performs inverse Fourier transform processing on the parallel signal of size N. Here, in the Fourier transform processing, when the size N is a power of 2, an inverse fast Fourier transform (IFFT) processing can be performed. The P / S unit 4035 converts the parallel signal of size N into a serial signal. The CP insertion unit 4037 inserts a predetermined CP for each OFDM symbol.

[0127] Figure 52 is a block diagram illustrating an example configuration of the second signal waveform transmitting unit 405. The second signal waveform transmitting unit 405 transmits a downlink channel and signal to be transmitted using, for example, SC-FDMA as a signal waveform for downlink communication. The second signal waveform transmitting unit 405 includes a DFT unit 4051, an inverse discrete Fourier transform (IDFT) unit 4053, a P / S unit 4055, and a CP insertion unit 4057. The DFT unit 4051 performs DFT conversion on parallel signals of size M. Here, the size M is determined based on the size of the resources in the frequency domain 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. Here, in the Fourier transform process, when the size N is a power of 2, an inverse fast Fourier transform (IFFT) process can be performed. The P / S unit 4055 converts the parallel signals of size N into a serial signal. The CP inserting unit 4057 inserts a predetermined CP for each SC-FDMA symbol.

[0128] <2.2.2. Example of terminal device configuration>

[0129] Figure 6 1 is a block diagram illustrating a configuration example of each terminal device 2 according to an embodiment of the present disclosure. Figure 6 As shown in the diagram, the terminal device 2 includes an upper layer processing unit 201, a control unit 203, a receiving unit 205, a transmitting unit 207 and a transmitting / receiving antenna 209.

[0130] The terminal device 2 is configured to support one or more radio access technologies (RATs). For example, the terminal device 2 is configured to support both LTE and NR. In this configuration, some or all units included in the terminal device 2 can be configured separately according to the RAT. For example, the receiving unit 205 and the transmitting unit 207 are configured separately according to LTE and NR. In addition, in the NR cell, the units included in Figure 6 Some or all of the units in the terminal device 2 shown in the diagram may be individually configured according to a parameter set related to the transmitted signal. For example, in a certain NR cell, the radio receiver 2057 and the radio transmitter 2077 may be individually configured according to a parameter set related to the transmitted signal.

[0131] (Upper layer processing unit)

[0132] The higher-layer processing unit 201 outputs uplink data (transport blocks) to the control unit 203. The higher-layer processing unit 201 performs processing at the medium access control (MAC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, and radio resource control (RRC) layer. Furthermore, the higher-layer processing unit 201 generates control information for controlling the receiving unit 205 and the transmitting unit 207, and outputs the control information to the control unit 203.

[0133] The upper layer processing unit 201 performs processing and management related to RAT control, radio resource control, subframe setting, 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 set or notified by the base station device 1. For example, the control information from the base station device 1 includes RRC parameters, MAC control elements, or DCI. In addition, the processing and management in the upper layer processing unit 201 can be performed separately according to the RAT. For example, the upper layer processing unit 201 separately performs processing and management according to LTE and processing and management according to NR.

[0134] In the RAT control in the upper layer processing unit 201, RAT-related management is performed. For example, in the RAT control, management related to LTE and / or management related to NR is performed. Management related to NR includes setting and processing parameter sets related to transmission signals in NR cells.

[0135] The radio resource control in the upper layer processing unit 201 manages the configuration information in the terminal 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).

[0136] The subframe configuration in the higher-layer processing unit 201 manages the subframe configuration in base station apparatus 1 and / or base station apparatuses other than base station apparatus 1. The subframe configuration includes uplink or downlink configuration for a subframe, subframe mode configuration, uplink-downlink configuration, uplink reference UL-DL configuration, and / or downlink reference UL-DL configuration. Note that the subframe configuration in the higher-layer processing unit 201 is also referred to as a terminal subframe configuration.

[0137] In the scheduling control in the higher layer processing unit 201 , control information used for control related to scheduling of the reception unit 205 and the transmission unit 207 is generated based on DCI (scheduling information) from the base station device 1 .

[0138] In the CSI reporting control in the higher layer processing unit 201, control is performed related to CSI reporting to the base station device 1. For example, in the CSI reporting control, settings related to the CSI reference resources assumed to be used for CSI calculation in the channel measurement unit 2059 are controlled. In the CSI reporting control, the resources (timing) for reporting CSI are controlled based on DCI and / or RRC parameters.

[0139] (Control Unit)

[0140] The control unit 203 controls the receiving unit 205 and the transmitting unit 207 based on the control information from the higher layer processing unit 201. The control unit 203 generates control information for the higher layer processing unit 201 and outputs the control information to the higher layer processing unit 201. The control unit 203 receives an input of a decoded signal from the decoding unit 2051 and an input of a channel estimation result from the channel measurement unit 2059. The control unit 203 outputs a signal to be encoded to the encoding unit 2071. In addition, the control unit 203 can be used to control the entire terminal device 2 or a portion thereof.

[0141] In addition, the control unit 203 obtains information about the signal waveform (i.e., single-carrier signal or multi-carrier signal) used for downlink communication with the base station device 1 from the base station device 1 via the receiving unit 205. Note that the information about the signal waveform is information transmitted using a predetermined signal waveform (e.g., single-carrier signal). The control unit 203 controls the receiving unit 205 and performs downlink communication with the base station device 1 using the signal waveform.

[0142] (Receiving Unit)

[0143] Under the control of the control unit 203, the receiving unit 205 receives the signal transmitted from the base station device 1 via the transmission / reception antenna 209, performs reception processing such as separation, demodulation, and decoding, and outputs the information subjected to the reception processing to the control unit 203. Note that the reception processing in the receiving unit 205 is performed based on predefined settings or notification or settings from the base station device 1. The receiving unit 205 includes a decoding unit 2051, a demodulation unit 2053, a demultiplexing unit 2055, a radio receiver 2057, and a channel measurement unit 2059.

[0144] (Radio Receiver)

[0145] The radio receiver 2057 performs conversion to an intermediate frequency (down conversion) on the uplink signal received via the transmit / receive antenna 209, removal of unnecessary frequency components, control of the amplification level to maintain an appropriate signal level, orthogonal demodulation based on the in-phase component and the orthogonal component of the received signal, conversion from an analog signal to a digital signal, removal of a guard interval (GI), and / or extraction of a frequency domain signal by fast Fourier transform (FFT).

[0146] Here, the radio receiver 2057 according to the present embodiment is configured to support a plurality of uplink signal waveforms. The radio receiver 2057 in the terminal device 2 supporting both the first signal waveform (multi-carrier signal) and the second signal waveform (single carrier signal) will refer to Figures 7-9 Detailed description.

[0147] Figure 7 2057 is a block diagram illustrating a configuration example of the radio receiver 2057. The radio receiver 2057 includes a signal waveform switching unit 301, a first signal waveform receiving unit 303, and a second signal waveform receiving unit 305.

[0148] The signal waveform switching unit 301 is configured to switch according to predetermined conditions or conditions, depending on whether the received downlink communication uses the first signal waveform or the second signal waveform. In the case where the received downlink communication uses the first signal waveform, the downlink communication is received and processed by the first signal waveform receiving unit 303. In the case where the received downlink communication uses the second signal waveform, the downlink communication is received and processed by the second signal waveform receiving unit 305. The switching conditions and conditions in the signal waveform switching unit 301 will be described later. Note that the signal waveform switching unit is also referred to as a signal waveform control unit. In addition, Figure 7 , the first signal waveform receiving unit 303 and the second signal waveform receiving unit 305 are illustrated as different processing units, however, the first and second signal waveform receiving units 303 and 305 may be configured as one processing unit so that only a portion of the receiving process is switched.

[0149] Figure 8 1 is a block diagram illustrating an example configuration of the first signal waveform receiving unit 303. The first signal waveform receiving unit 303 performs reception processing on a downlink channel and signal transmitted using CP-OFDM, which is a signal waveform for downlink communication. The first signal waveform receiving unit 303 includes a CP removal unit 3031, an S / P unit 3033, a discrete Fourier transform (DFT) unit 3035, and a P / S unit 3037.

[0150] The CP removal unit 3031 removes the cyclic prefix (CP) added to the received downlink communication. The S / P unit 3033 converts the input serial signal into a parallel signal of size N. The DFT unit 3035 performs Fourier transform processing. Here, in the Fourier transform processing, when the size N is a power of 2, a fast Fourier transform (FFT) processing can be performed. The P / S unit 3037 converts the input parallel signal of size M into a serial signal. Here, the downlink communication signal sent by the terminal device 2 that performs reception processing is input to the P / S unit 3037. In addition, the size M is determined depending on the size of the resource in the frequency domain used for downlink communication.

[0151] Figure 9 2 is a block diagram illustrating an example configuration of the second signal waveform receiving unit 305. The second signal waveform receiving unit 305 receives a downlink channel and signal transmitted using, for example, SC-FDMA, as a signal waveform for downlink communication. The second signal waveform receiving unit 305 includes a CP removal unit 3051, an S / P unit 3053, a discrete Fourier transform (DFT) unit 3055, and an inverse discrete Fourier transform (IDFT) unit 3057.

[0152] The CP removal unit 3051 removes the cyclic prefix (CP) added to the received downlink communication. The S / P unit 3053 converts the input serial signal into a parallel signal of size N. The DFT unit 3055 performs Fourier transform processing. Here, in the Fourier transform processing, when the size N is a power of 2, a fast Fourier transform (FFT) processing can be performed. The IDFT unit 3057 performs inverse Fourier transform processing on the input signal of size M. Here, the downlink communication signal transmitted by the terminal device 2 performing the reception processing is input to the IDFT unit 3057. In addition, the size M is determined depending on the size of the resource in the frequency domain used for downlink communication.

[0153] (Demultiplexing unit)

[0154] return Figure 6 The demultiplexing unit 2055 separates downlink channels such as PHICH, PDCCH, EPDCCH, or PDSCH, downlink synchronization signals, and / or downlink reference signals from the signal input from the radio receiver 2057. The demultiplexing unit 2055 outputs the downlink reference signals to the channel measurement unit 2059. The demultiplexing unit 2055 compensates for the propagation channel of the downlink channel based on the estimated propagation channel value input from the channel measurement unit 2059.

[0155] (Demodulation Unit)

[0156] The demodulation unit 2053 demodulates the modulation symbols from the downlink channel using a modulation scheme such as BPSK, π / 2BPSK, QPSK, 16QAM, 64QAM, or 256QAM to receive the signal. The demodulation unit 2053 separates and demodulates the downlink channel multiplexed in MIMO.

[0157] (Decoding unit)

[0158] The decoding unit 2051 decodes the coded bits demodulated in the downlink channel. The decoded downlink data and downlink control information are output to the control unit 203. The decoding unit 2051 decodes the PDSCH for each transport block.

[0159] (Channel Measurement Unit)

[0160] The channel measurement unit 2059 measures an estimated value of the propagation channel and / or the quality of the channel based on the downlink reference signal input from the demultiplexing unit 2055, and outputs the estimated value and / or the channel quality to the demultiplexing unit 2055 and / or the control unit 203. The downlink reference signal used by the channel measurement unit 2059 for measurement may be determined based on at least the transmission mode and / or other RRC parameters configured using RRC parameters. For example, the DL-DMRS measures an estimated value of the propagation channel used for propagation channel compensation for the PDSCH or EPDCCH. The CRS measures an estimated value of the propagation channel used for propagation channel compensation for the PDCCH or PDSCH and / or the channel in the downlink used for reporting CSI. The CSI-RS measures the channel in the downlink used for reporting CSI. The channel measurement unit 2059 calculates the reference signal received power (RSRP) and / or the reference signal received quality (RSRQ) based on the CRS, CSI-RS, or detection signal, and outputs the RSRP and / or RSRQ to the upper layer processing unit 201.

[0161] (Sending Unit)

[0162] Under the control of the control unit 203, the transmission unit 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. For example, the transmission unit 207 generates and multiplexes uplink channels such as PUSCH or PUCCH and / or uplink reference signals to generate a transmission signal. Note that the transmission processing in the transmission unit 207 is performed based on predefined settings or settings or notifications from the base station device 1. The transmission unit 207 includes a coding unit 2071, a modulation unit 2073, a multiplexing unit 2075, a radio transmitter 2077, and an uplink reference signal generation unit 2079.

[0163] (coding unit)

[0164] The coding unit 2071 encodes the HARQ indication (HARQ-ACK), uplink control information, and uplink data input from the control unit 203 using a predetermined 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 predetermined 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 the RRC parameters set in the terminal device 2, etc.

[0165] (Multiplexing Unit)

[0166] The multiplexing unit 2075 multiplexes the modulation symbols and uplink reference signals in each channel, and arranges the modulation symbols and downlink reference signals in predetermined resource elements.

[0167] (Radio transmitter)

[0168] The radio transmitter 2077 processes the signal from the multiplexing unit 2075, such as by converting the signal into the time domain through inverse fast Fourier transform (IFFT), adding a guard interval, generating a baseband digital signal, converting it into an analog signal, performing orthogonal modulation, converting the intermediate frequency signal into a high frequency signal (up-conversion), removing unnecessary frequency components, and amplifying the power, thereby generating a transmission signal. The transmission signal output from the radio transmitter 2077 is transmitted from the transmission / reception antenna 209.

[0169] <2.3. Communication System Processing>

[0170] Next, communication processing performed by the communication system according to the embodiment of the present disclosure will be described. As described above, the communication system according to the present embodiment performs downlink communication between the base station apparatus 1 and each terminal device 2 using one of a single carrier signal or a multi-carrier signal.

[0171] Here, an example of a radio access technique and a radio frame structure of the communication system according to the present embodiment will be described.

[0172] (Radio Access Technology)

[0173] As described above, in this embodiment, each of the base station device 1 and the terminal device 2 supports one or more radio access technologies (RATs). For example, RATs include LTE and NR. One RAT corresponds to one cell (component carrier). In other words, when multiple RATs are supported, RATs correspond to different cells. In this embodiment, a cell represents a combination of downlink resources, uplink resources, and / or side links. In addition, in the following description, a cell corresponding to LTE is referred to as an LTE cell, and a cell corresponding to NR is referred to as an NR cell.

[0174] The base station device 1 and the terminal device 2 are configured to support communication using a collection of one or more cells in the downlink, uplink, and / or sidelink. The collection of multiple cells is also referred to as carrier aggregation or dual connectivity. Carrier aggregation and dual connectivity will be described in detail later. In addition, each cell uses a predetermined frequency bandwidth. The maximum, minimum, and possible values ​​within the predetermined frequency bandwidth can be predefined.

[0175] Figure 10 1 is a diagram illustrating an example of setting a component carrier according to an embodiment of the present disclosure. Figure 10 In the example, 1 LTE cell and 2 NR cells are set. 1 LTE cell is set as the primary cell. 2 NR cells are set as the primary and secondary cells. 2 NR cells are aggregated together through carrier aggregation. In addition, LTE cells and NR cells are aggregated through dual connectivity. Note that LTE cells and NR cells can be aggregated together through carrier aggregation. Figure 1 In the example shown in FIG, , NR can be connected with the assistance of the LTE cell as the primary cell, thereby eliminating the need to support certain functions, such as functions for independent communication. Functions for independent communication include those required for initial connection.

[0176] Figure 11 1 is a diagram illustrating an example of setting a component carrier according to an embodiment of the present disclosure. Figure 11 In the example shown in Figure 2, two NR cells are configured. These two NR cells are configured as a primary cell and a secondary cell and are integrated through carrier aggregation. In this configuration, the NR cell supports independent communication functions, eliminating the need for assistance from an LTE cell. Note that these two NR cells can be aggregated using dual connectivity.

[0177] (Radio frame structure)

[0178] Next, as an example of a radio frame structure, an example of an NR frame structure will be described. Figure 12This diagram illustrates an example of an NR frame structure. A 10ms radio frame consists of two half-frames. A half-frame lasts 5ms. Each half-frame consists of five subframes. Furthermore, a subframe consists of one or more slots. A slot consists of 14 symbols for a normal CP and 12 symbols for an extended CP.

[0179] <2.3.1. Communication Processing>

[0180] Next, we will refer to Figure 14 A communication process performed in a communication system according to an embodiment of the present disclosure is described. Figure 14 is a sequence diagram illustrating an example of communication processing according to an embodiment of the present disclosure.

[0181] like Figure 14 As shown in the diagram, the base station device 1 first determines whether to switch the signal waveform (step S101). Then, when the signal waveform for downlink communication is switched, the base station device 1 determines the signal waveform to be used (step S102). Note that when the signal waveform is not switched, the base station device 1 performs downlink communication by using a predefined signal waveform.

[0182] Next, the base station apparatus 1 notifies the corresponding terminal device 2 of information (waveform information) on the determined usage signal waveform (step S103). Then, the base station apparatus 1 and the terminal device 2 perform downlink communication by using the usage signal waveform (step S104).

[0183] Hereinafter, the processing in each step will be described in detail.

[0184] <2.3.2. Signal Waveform Switching Processing of Base Station Equipment>

[0185] As described above, in the communication system according to this embodiment, downlink communication is performed by switching between a single carrier signal and a multi-carrier signal. In downlink communication, the base station device 1 selects one of the single carrier signal and the multi-carrier signal.

[0186] [Switch judgment]

[0187] First, as in Figure 14As illustrated in step S101 of , the base station device 1 determines whether to perform signal waveform switching processing. The base station device 1 determines whether to switch the signal waveform, for example, according to the capabilities of the base station device 1. The base station device 1 determines whether to switch the signal waveform, for example, according to the maximum transmission power of the base station device 1 or the presence or absence of transmission circuits corresponding to multiple signal waveforms. For example, in a case where the maximum transmission power of the base station device 1 is equal to or greater than a predetermined threshold value and the power amplifier can operate in a linear region even when a multi-carrier signal is transmitted, the base station device 1 performs downlink communication by using the multi-carrier signal without switching the signal waveform. Alternatively, in a case where the base station device 1 includes a transmission circuit corresponding to a single signal waveform, for example, in a case where the base station device 1 includes a transmission circuit corresponding only to a multi-carrier signal, the base station device 1 performs downlink communication by using the multi-carrier signal without switching the signal waveform.

[0188] Alternatively, base station device 1 may determine whether to switch signal waveforms based on the coverage or data throughput required for downlink communications. For example, if the required coverage is narrow, due to low transmit power, base station device 1 selects a multicarrier signal with high frequency utilization efficiency without switching the signal waveform. Similarly, if the required data throughput is high, base station device 1 selects a multicarrier signal with high frequency utilization efficiency without switching the signal waveform.

[0189] Furthermore, base station apparatus 1 determines whether to switch signal waveforms, for example, based on the capabilities of terminal apparatus 2 serving as the communication partner. In this case, base station apparatus 1 determines whether to switch signal waveforms for multiple terminal apparatuses 2. Base station apparatus 1 determines whether to switch signal waveforms, for example, based on whether terminal apparatus 2 has a receiving circuit compatible with multiple signal waveforms. For example, if terminal apparatus 2 has a receiving circuit compatible with a single signal waveform, such as a receiving circuit compatible only with multicarrier signals, base station apparatus 1 performs downlink communication using multicarrier signals without switching signal waveforms.

[0190] [Signal waveform switching target]

[0191] When the base station device 1 determines that a handover process is to be performed, the base station device 1 switches the signal waveform according to, for example, a physical channel or a frequency band. The base station device 1 switches the signal waveform for a predetermined physical channel or a predetermined frequency band. The objects for which the base station device 1 switches the signal waveform will be described below.

[0192] (Physical Channel)

[0193] The base station device 1 switches the signal waveform for a predetermined physical channel / signal, for example. The base station device 1 uses a signal waveform selected from, for example, a multi-carrier signal and a single-carrier signal for the physical channel / signal used for the transmission of data information (more specifically, PDSCH and / or PDSCH DMRS). On the other hand, for physical channels / signals other than the predetermined physical channels, for example, physical channels / signals used for the transmission of control information (more specifically, SSB, PDCCH and / or CSI-RS), a predetermined signal waveform is used. For example, the base station device 1 can use a single-carrier signal as the predetermined signal waveform to expand the coverage range, thereby more reliably transmitting the control information.

[0194] (Bandwidth part)

[0195] For example, when a contiguous subset of common resource blocks, called a bandwidth part (BWP), is defined, the signal waveform is switched for the predetermined BWP. For example, base station device 1 switches the signal waveform in BWPs other than the initial activation bandwidth, but transmits signals using the predetermined signal waveform in the initial activation bandwidth. In this case, base station device 1 uses the initial activation bandwidth, for example, to notify information about the signal waveform to be used in the other BWPs.

[0196] (Carrier Aggregation / Dual Connectivity)

[0197] As described above, when the communication system supports communication using carrier aggregation or dual connectivity, base station device 1 switches the signal waveform for a predetermined cell. For example, base station device 1 switches the signal waveform for transmission in a secondary cell (Scell) or a secondary cell group (SCG) including a secondary cell. On the other hand, in a primary cell (Pcell) or a primary cell group (MCG) including the primary cell, base station device 1 transmits signals using a predetermined signal waveform. In this case, base station device 1 notifies the user of the signal waveform to be used in the Scell ​​or SCG, for example, using the Pcell or MCG.

[0198] [Signal waveform selection]

[0199] Next, we will explain Figure 14 The selection criteria for selecting a signal waveform to be used when the base station apparatus 1 selects a signal waveform to be used for downlink communication in step S102 are used. The base station apparatus 1 switches the signal waveform according to the following selection criteria.

[0200] · Location of terminal device

[0201] Bandwidth or channel width

[0202] Length of time

[0203] Signal waveform used in uplink communication

[0204] Signal waveforms used in other wireless communication systems

[0205] (Location of terminal device)

[0206] Base station apparatus 1 selects a signal waveform to use based on the location of terminal device 2. For example, when base station apparatus 1 and terminal device 2 are farther apart, greater transmission power is required. To ensure greater transmission power using the power amplifier, a low PAPR is required. Therefore, when greater transmission power is required, base station apparatus 1 selects a single-carrier signal as the signal waveform to use. On the other hand, when base station apparatus 1 and terminal device 2 are closer together, transmission power can be lower. Consequently, the PAPR can be higher, and in this case, base station apparatus 1 selects a multi-carrier signal as the signal waveform to use.

[0207] Figure 13 is a diagram illustrating the positional relationship between the base station apparatus 1 and the terminal device 2. Figure 13 As shown in the diagram, when cell C is divided into two areas, cell edge C1 and cell center C2, base station apparatus 1 selects a single-carrier signal as the signal waveform to be used for downlink communication with terminal device 2B located at cell edge C1. Furthermore, base station apparatus 1 selects a multi-carrier signal as the signal waveform to be used for downlink communication with terminal device 2A located at cell center C2.

[0208] Base station apparatus 1 determines, for example, based on RSRP, whether terminal apparatus 2 is located at cell edge C1 or cell center C2. More specifically, when terminal apparatus 2 has an RSRP less than a predetermined threshold, base station apparatus 1 determines that the distance to terminal apparatus 2 is long, and terminal apparatus 2 is located at cell edge C1. On the other hand, when the RSRP of terminal apparatus 2 is equal to or greater than the predetermined threshold, base station apparatus 1 determines that the distance to terminal apparatus 2 is short, and terminal apparatus 2 is located at cell center C2.

[0209] Alternatively, the base station device 1 may determine the position of the terminal device 2 within the cell C based on the position information of the terminal device 2. For example, the base station device 1 determines whether the terminal device 2 is located at the cell edge C1 or the cell center C2 based on the position information obtained from the GPS or the like mounted on the terminal device 2.

[0210] (Bandwidth or channel width)

[0211] Alternatively, base station device 1 can select a signal waveform based on the bandwidth or channel width used for downlink communication. For example, the wider the frequency band, the lower the transmit power density. Therefore, if a single-carrier signal is selected, which can increase transmit power, transmit power density can be maintained even with wider frequency bands. On the other hand, if a multi-carrier signal with a high PAPR (which makes it difficult to increase transmit power) is selected, transmit power density decreases as the frequency band becomes wider. Therefore, it is preferable to use a multi-carrier signal in a narrower frequency band to ensure transmit power.

[0212] Then, base station device 1 selects a signal waveform according to the bandwidth or channel width used for downlink communication. Specifically, base station device 1 selects a single carrier signal when the bandwidth is equal to or greater than a predetermined width, and selects a multi-carrier signal when the bandwidth is less than a predetermined width.

[0213] (Duration)

[0214] Alternatively, base station device 1 can select a signal waveform according to the time length. For example, base station device 1 selects a single-carrier signal for a predetermined time length and selects a multi-carrier signal for other time lengths. In this way, base station device 1 can switch signal waveforms according to the time length.

[0215] More specifically, for example, the base station apparatus 1 switches the signal waveform for each time slot. For example, the base station apparatus 1 selects a single-carrier signal for a predetermined time slot and selects a multi-carrier signal for the other time slots.

[0216] Note that the time length (e.g., number of time slots) for which a single-carrier signal is selected may be the same as or different from the time length (e.g., number of time slots) for which a multi-carrier signal is selected. For example, the time length of downlink communication using a multi-carrier signal may be longer or shorter than the time length of downlink communication using a single-carrier signal. Alternatively, the multi-carrier signal and the single-carrier signal may be switched at the same periodic interval.

[0217] (Signal waveform used in uplink communication)

[0218] Base station device 1 selects a signal waveform to be used in accordance with the signal waveform to be used in uplink communication. In uplink communication, either a single-carrier signal or a multi-carrier signal is used. In this configuration, base station device 1 also uses the signal waveform to be used for uplink communication in downlink communication. This configuration enables, for example, the use of the same signal waveform for both uplink and downlink communication, and allows notification of the signal waveform to be used for both uplink and downlink communication simultaneously. Note that notification of information regarding the signal waveform to be used by base station device 1 will be described in detail later.

[0219] (Signal waveforms used in other wireless communication systems)

[0220] Base station device 1 selects a signal waveform based on the signal waveforms used by other wireless communication systems. For example, the 60 GHz frequency band is used not only for cellular communications but also for wireless communications in accordance with wireless LAN standards (e.g., IEEE 802.11ad, 11ay, etc.). When base station device 1 detects another wireless communication system communicating in the same frequency band, it selects the signal waveform used by the other wireless communication system as the signal waveform. For example, wireless communications in accordance with IEEE 802.11ad use a single-carrier signal. Upon detecting communication using a single-carrier signal, base station device 1 selects the single-carrier signal as the signal waveform.

[0221] As described above, communicating using the same signal waveform as other wireless communication systems allows other wireless communication systems to easily detect signals transmitted by base station device 1. Similarly, base station device 1 can also more easily detect signals transmitted and received to and from other wireless communication systems.

[0222] [Frequency of switching signal waveform]

[0223] The base station apparatus 1 switches the signal waveform in any one of three frequency modes, ie, a static mode, a semi-static mode, and a dynamic mode.

[0224] When switching the signal waveform in a static mode, base station apparatus 1 selects a signal waveform to be used once, notifies terminal apparatus 2 of the selected signal waveform, and then uses the notified signal waveform. In this case, base station apparatus 1 adds information about the selected signal waveform to be used, for example, to system information, thereby notifying terminal apparatus 2 of the information.

[0225] When switching the signal waveform in a semi-static mode, the base station apparatus 1 selects a signal waveform for use at predetermined periodic intervals and notifies the terminal device 2 of the selected signal waveform. In this case, the base station apparatus 1 adds information about the selected signal waveform for use to, for example, RRC signaling, thereby notifying the terminal device 2 of the information.

[0226] In the case of switching the signal waveform in a dynamic mode, the base station apparatus 1 selects a signal waveform to be used each time data information is transmitted, and notifies the terminal device 2 of the selected signal waveform. In this case, the base station apparatus 1 adds information about the selected signal waveform to be used to, for example, the PDCCH, thereby notifying the terminal device 2 of the information.

[0227] <2.3.3. Notification Processing Using Signal Waveform>

[0228] As in Figure 14As illustrated in step S103 of FIG, base station apparatus 1 that has switched the use signal waveform notifies terminal apparatus 2 of the selected use signal waveform. As a method of transmitting information on the use signal waveform to terminal apparatus 2 by base station apparatus 1, three methods are considered, namely, an explicit transmission method, an implicit transmission method, and a blind detection method of the use signal waveform used on the terminal apparatus 2 side.

[0229] [Explicit signaling]

[0230] First, description will be given of explicit transmission of information on a use signal waveform (hereinafter also referred to as waveform information) by base station apparatus 1. In this case, base station apparatus 1 transmits waveform information added to system information, RRC signaling, or DCI, for example.

[0231] (System Information)

[0232] System information is classified into a master information block (MIB) and a system information block (SIB).

[0233] Base station device 1 adds waveform information as system information to, for example, the MIB and transmits the waveform information. The waveform information is added to the MIB as, for example, a 1-bit parameter. The waveform information specifies the signal waveform of a single carrier signal or a multi-carrier signal by setting the 1-bit parameter to 1 or 0, for example.

[0234] More specifically, waveform information is added to a synchronization signal (SSB / PBCH block) such as the MIB and transmitted. In this case, base station device 1 transmits the SSB using a predetermined signal waveform (e.g., a single carrier signal) and transmits physical downlink channels / signals other than the SSB using a signal waveform specified in the waveform information. For example, base station device 1 transmits the PDCCH or PDSCH included in the SIB using the signal waveform specified in the waveform information.

[0235] Alternatively, the base station device 1 may add waveform information as system information to, for example, the SIB, and transmit the waveform information. In this case, the base station device 1 transmits the SSB, type0-PDCCH, and PDSCH scheduled by type0-PDCCH by using a predetermined signal waveform (e.g., a single carrier signal), and transmits other physical downlink channels / signals by using the signal waveform specified in the waveform information. As described above, transmitting the predetermined physical downlink channel / signal by using the predetermined signal waveform enables the terminal device 2 to receive the predetermined physical downlink channel / signal more reliably.

[0236] (RRC signaling)

[0237] Base station device 1 adds a parameter indicating waveform information to RRC signaling after RRC connection, for example, and transmits the parameter. Base station device 1 can then periodically notify waveform information.

[0238] (DCI)

[0239] Base station device 1 adds waveform information to the DCI of the PDCCH and transmits the waveform information. Base station device 1 notifies the waveform information by using a field included in the DCI. This allows base station device 1 to dynamically switch the signal waveform.

[0240] (other)

[0241] As described above, when base station apparatus 1 selects the same signal waveform as that used in uplink communication as the signal waveform for downlink communication, base station apparatus 1 can notify waveform information in conjunction with notification of the used signal waveform for uplink communication.

[0242] Specifically, the base station apparatus 1 notifies that the use signal waveform for uplink communication is the use signal waveform for downlink communication. In other words, the base station apparatus 1 collectively notifies information on the use signal waveforms for uplink communication and downlink communication as one piece of information.

[0243] As described above, for example, notification of waveform information added to DCI is transmitted using, for example, a single-carrier signal, which complicates the multiplexing of resources for single-carrier and multi-carrier signals. Therefore, it is desirable to transmit notification of waveform information as early as possible using, for example, system information such as the MIB. However, using system information to notify waveform information makes it difficult to dynamically allocate signal waveforms.

[0244] Thus, for example, when the base station device 1 adds waveform information to system information such as MIB and transmits the system information and then switches the used signal waveform, the waveform information after switching can be added to RRC signaling or DCI for transmission.

[0245] As described above, the base station apparatus 1 transmits waveform information a plurality of times, thereby making it possible to individually switch the use signal waveform used by the terminal equipment 2 while transmitting waveform information common to the cells.

[0246] [Implicit signaling]

[0247] Next, description will be given of implicit notification of waveform information by the base station apparatus 1. In this case, the base station apparatus 1 changes, for example, the configuration of the SSB and the configuration of the PDCCH according to the waveform of the used signal to notify each terminal device 2 of the waveform information.

[0248] (Composition of SSB)

[0249] For example, the correspondence relationship between the signal waveform and the configuration of the SSB is determined in advance, and the base station apparatus 1 transmits the SSB having the configuration corresponding to the selected usage signal waveform to notify the terminal device 2 of the waveform information.

[0250] More specifically, for example, a primary synchronization signal (PSS) and / or secondary synchronization signal (SSS) sequence is defined for each signal waveform, and base station device 1 transmits the PSS and / or SSS according to the defined sequence. When a PSS and / or SSS is detected, terminal device 2 determines the signal waveform corresponding to the detected PSS and / or SSS as the used signal waveform. In this way, base station device 1 is configured to notify waveform information by associating the signal waveform with the PSS and / or SSS sequence.

[0251] Alternatively, the base station device 1 can notify the waveform information through the resource allocation of the PSS / SSS / PBCH (SSB block). In this case, the resources of the PSS / SSS / PBCH (SSB block) are defined for each signal waveform. When the PSS / SSS / PBCH (SSB block) is detected, the terminal device 2 determines the signal waveform corresponding to the resource to which the detected PSS / SSS / PBCH (SSB block) is transmitted as the signal waveform to be used. In this way, the association between the signal waveform and the resource enables the base station device 1 to notify the waveform information.

[0252] (PDCCH Configuration)

[0253] For example, by associating the signal waveform with the CORESET or search space of the PDCCH, the type of DCI, the RNTI, etc., the base station device 1 can notify the terminal device 2 of the waveform information by sending the PDCCH.

[0254] For example, the signal waveform is associated with a CORESET, for example, associated with CORESET#0 and other CORESETs respectively. When the base station device 1 transmits CORESET#0 or other CORESETs, the terminal device 2 detects and uses the signal waveform.

[0255] Alternatively, the signal waveforms are associated with the common search space (CSS) and the UE-specific search space (USS) of the search space, and the base station apparatus 1 notifies the terminal device 2 of the signal waveform to be used depending on in which search interval the PDCCH is transmitted.

[0256] Alternatively, the signal waveform may be associated with the type of DCI, for example, fallback DCI and non-fallback DCI, respectively. In this case, when the base station apparatus 1 transmits fallback DCI or non-fallback DCI, the terminal device 2 detects the use signal waveform.

[0257] Alternatively, the signal waveform may be associated with the RNTI, for example, with the C-RNTI and other RNTIs, respectively. In this case, when the base station apparatus 1 transmits the C-RNTI or other RNTI, the terminal device 2 detects and uses the signal waveform.

[0258] [Blind Detection]

[0259] In addition to explicit or implicit transmission of waveform information by base station apparatus 1, as described above, a method of acquiring waveform information (blind detection) may be provided. In this method, terminal equipment 2 detects a signal transmitted by base station apparatus 1 using a signal waveform.

[0260] (PAPR-based detection)

[0261] As described above, a single carrier signal has a low PAPR, while a multi-carrier signal has a high PAPR. Therefore, for example, the terminal device 2 detects amplitude changes of the received signal to determine whether the signal waveform of the received signal indicates a single carrier signal or a multi-carrier signal.

[0262] Terminal device 2 blindly detects the state of the signal waveform of the symbols in downlink communication. More specifically, terminal device 2 detects changes in amplitude on the frequency axis (e.g., PAPR). When the detected change is below a predetermined threshold, terminal device 2 determines that the signal waveform used is a single-carrier signal, and when the detected change is equal to or above the predetermined threshold, terminal device 2 determines that the signal waveform used is a multi-carrier signal.

[0263] Thus, even if the base station apparatus 1 does not notify waveform information, the terminal device 2 can detect the use signal waveform.

[0264] (Detection based on frame structure)

[0265] In addition to detection based on PAPR, the base station apparatus 1 uses a single-carrier signal and a multi-carrier signal, resulting in a change in the frame structure, which enables the terminal device 2 to blindly detect the signal waveform.

[0266] In this configuration, the base station device 1 changes the frame format or symbol length of the radio frame, the CP composition of the radio frame, etc. for each signal waveform. For example, the base station device 1 changes the CP composition by using a single-carrier signal and a multi-carrier signal. More specifically, the base station device 1 changes the CP composition to, for example, zero padding or a unique word according to the signal waveform. Assuming that the CP composition is zero padding, the power of the portion corresponding to the CP of the radio frame becomes 0. On the other hand, assuming that the CP composition is a unique word, the power of the portion corresponding to the CP of the radio frame does not change to 0. Therefore, the terminal device 2 detects the signal waveform of the received signal by performing a threshold judgment on the power of the portion of the received signal corresponding to the CP.

[0267] In this way, base station apparatus 1 can also add waveform information to the transmission signal and transmit the transmission signal to terminal device 2 using the usage signal waveform. Here, base station apparatus 1 adds waveform information to the CP for transmission. Thus, even if base station apparatus 1 does not separately transmit waveform information, base station apparatus 1 and terminal device 2 can communicate using the usage signal waveform.

[0268] Note that in addition to the above-described CP configuration, base station device 1 can also change the symbol length according to, for example, the signal waveform being used. As described above, in a normal CP, one slot consists of 14 symbols, but the number of symbols in one slot can be changed, for example, according to the signal waveform. More specifically, for example, base station device 1 sets the number of symbols in one slot to 14 when communicating using a multicarrier signal, and sets the number of symbols in one slot to 28 when communicating using a single carrier signal, which is twice the number of symbols in multicarrier communication.

[0269] Alternatively, base station apparatus 1 can change the number of CP symbols, rather than the number of symbols in the time slot, according to the signal waveform. In this configuration, for example, base station apparatus 1 continuously transmits multiple CPs when using a single-carrier signal, and transmits a single CP when using a multi-carrier signal. In this way, base station apparatus 1 can change the number of CPs, i.e., the CP length, according to the signal waveform.

[0270] <2.3.4. Communication processing according to the signal waveform used>

[0271] When the information on the usage signal waveform is notified by the above method, the base station apparatus 1 performs downlink communication with the terminal device 2 using the usage signal waveform, such as Figure 14 Here, the communication processing performed by the base station apparatus 1 according to the use signal waveform will be explained.

[0272] [Resource Allocation]

[0273] Base station 1 changes the resource allocation method according to the signal waveform being used. For example, when communicating using a multi-carrier signal, base station 1 allocates the transmitted signal to resources discontinuously. Alternatively, when using a single-carrier signal, base station 1 allocates the transmitted signal to resources continuously.

[0274] As described above, when it is desired to transmit a signal with a low PAPR, base station device 1 selects a single carrier signal. By arranging the single carrier signals together on the frequency axis, the single carrier signals can be transmitted with a low PAPR. Therefore, when selecting a single carrier signal, base station device 1 selects non-contiguous allocation (resource allocation type 1) as the resource allocation method.

[0275] On the other hand, when a multicarrier signal is used for communication, base station apparatus 1 selects non-contiguous allocation (resource allocation type 0). Thus, base station apparatus 1 can transmit a signal using a portion having good characteristics on the frequency axis, thereby improving frequency utilization efficiency.

[0276] [Beamforming / Precoding]

[0277] When multiplexing and transmitting data signals on the same resource, as in MIMO, for example, base station apparatus 1 determines the number of layers (the amount of multiplexed data) according to the signal waveform. For example, when using a single-carrier signal, the number of layers is limited to two or fewer layers of vertically polarized waves and horizontally polarized waves. On the other hand, when using a multi-carrier signal, the number of layers is not particularly limited. Thus, base station apparatus 1 can transmit a multi-carrier signal by setting the number of layers to, for example, three or more.

[0278] Therefore, when using a single-carrier signal, base station apparatus 1 sets the number of MIMO layers to 2 or less, and when using a multi-carrier signal, sets the number of layers to 3 or more. Thus, base station apparatus 1 determines the number of MIMO layers according to the signal waveform.

[0279] As described above, the number of layers varies depending on the signal waveform, and thus, precoding and feedback from terminal device 2 (e.g., channel state information (CSI)) also vary depending on the signal waveform. For example, the rank indicator (RI) and precoding matrix indicator (PMI) included in the CSI have values ​​corresponding to the signal waveform.

[0280] [Modulation method]

[0281] Furthermore, base station device 1 determines the modulation scheme based on the signal waveform. For example, when a low PAPR is required, base station device 1 uses a single-carrier signal for downlink communication. Therefore, when using a single-carrier signal, base station device 1 selects a modulation scheme with a low PAPR. Examples of modulation schemes with a low PAPR include π / 2 BPSK.

[0282] On the other hand, when there are no problems even with a high PAPR, base station apparatus 1 uses a multi-carrier signal for downlink communication. Therefore, when using a multi-carrier signal, base station apparatus 1 selects a modulation method other than a modulation method with a low PAPR. For example, base station apparatus 1 selects a modulation method such as QPSK or 16QAM, which has higher transmission efficiency than BPSK, as the modulation method for the multi-carrier signal.

[0283] As described above, the base station device 1 determines the modulation method according to the signal waveform, thereby improving the transmission efficiency while satisfying the requirement for low PAPR.

[0284] As described above, in the communication processing according to this embodiment, base station apparatus 1 determines a signal waveform to be used for downlink communication from a plurality of signal waveforms including a single carrier signal. Base station apparatus 1 notifies terminal apparatus 2 of information (waveform information) regarding the determined signal waveform to be used. Terminal apparatus 2, having received the notification, performs downlink communication with base station apparatus 1 using the signal waveform to be used.

[0285] By selecting a single carrier signal by the base station device 1 , the requirement for low PAPR can be met, and by selecting a signal waveform other than the single carrier signal by the base station device 1 , the transmission efficiency of the entire system can be improved.

[0286] <3. Application Examples>

[0287] The technology disclosed herein is applicable to various products. For example, the base station device 1 can be implemented as any type of evolved node B (eNB), such as a macro eNB or a small eNB. A small eNB can be an eNB that covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB, or a home (fly) eNB. The base station device 1 can be implemented as other types of base stations, such as a Node B or a base transceiver station (BTS). The base station device 1 may include a main body (also referred to as a base station device) that controls wireless communications, and one or more remote radio heads (RRHs) that are located in different places from the main body. In addition, the various terminals described below can act as the base station device 1 by temporarily or permanently providing base station functions.

[0288] Furthermore, for example, the terminal device 2 may be implemented as a mobile terminal (such as a smartphone, a tablet personal computer (PC), a notebook PC, a portable game terminal, a portable / adapter-type mobile router, and a digital camera) and an in-vehicle terminal (such as a car navigation device). Furthermore, the terminal device 2 may be implemented as a terminal that performs machine-to-machine (M2M) communication (also known as a machine-type communication (MTC) terminal). Furthermore, the terminal device 2 may be a wireless communication module (e.g., an integrated circuit module including a bare chip) mounted on each of these terminals.

[0289] <3.1. Application Examples of Base Stations>

[0290] (First Application Example)

[0291] Figure 15 8 is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology of the present disclosure is applicable. The eNB 800 includes one or more antennas 810 and a base station device 820. Each antenna 810 and base station device 820 may be connected to each other via an RF cable.

[0292] Each antenna 810 includes a single or multiple antenna elements (for example, multiple antenna elements constituting a MIMO antenna) and is used to transmit and receive radio signals to and from the base station device 820. Figure 15 As shown in the diagram, the eNB 800 may include, for example, multiple antennas 810 corresponding to multiple frequency bands used by the eNB 800. Note that although Figure 15 The illustration illustrates an example in which the eNB 800 includes multiple antennas 810 ; however, the eNB 800 may include a single antenna 810 .

[0293] The base station device 820 includes a controller 821 , a memory 822 , a network interface 823 , and a wireless communication interface 825 .

[0294] The controller 821 can be, for example, a CPU or a DSP, and enables various functions of the upper layer of the base station device 820 to be executed. For example, the controller 821 generates data packets from the data in the signal processed by the wireless communication interface 825, and transmits the generated packets via the network interface 823. The controller 821 can generate packetized packets by packetizing data from multiple baseband processors and transmit the generated packetized packets. In addition, the controller 821 can have logical functions for performing controls such as radio resource control, radio bearer control, mobility management, admission control, or scheduling. In addition, the control can be performed in collaboration with surrounding eNBs or core network nodes. The memory 822 includes RAM and ROM, and stores programs executed by the controller 821, as well as various control data (for example, terminal lists, transmit power data, scheduling data, etc.).

[0295] The network interface 823 is a communication interface for connecting the base station device 820 to the core network 824. The controller 821 can communicate with the core network node or other eNB via the network interface 823. In this configuration, the eNB 800 and the core network node or other eNB can be connected to each other via a logical interface (e.g., an S1 interface or an X2 interface). The network interface 823 can be a wired communication interface or a wireless communication interface for wireless backhaul. When the network interface 823 is a wireless communication interface, the network interface 823 can use a higher frequency band for wireless communication than the frequency band used by the wireless communication interface 825.

[0296] The wireless communication interface 825 supports any cellular communication system, such as Long Term Evolution (LTE) or LTE-Advanced, and provides wireless connectivity to terminals located in the cell of the eNB 800 via each antenna 810. The wireless communication interface 825 may generally include a baseband (BB) processor 826, an RF circuit 827, and the like. The BB processor 826 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and may also perform various signal processing functions within each layer (e.g., Layer 1, Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP)). In place of the controller 821, the BB processor 826 may have some or all of the aforementioned logical functions. The BB processor 826 may include a module comprising a memory for storing communication control programs, a processor for executing the programs, and associated circuitry. The BB processor 826 may have functions that can be modified by updating the programs. Furthermore, the module may be a card or blade inserted into a slot of the base station device 820, or a chip mounted on the card or blade. On the other hand, the RF circuit 827 may include a mixer, a filter, an amplifier, etc., and transmits and receives radio signals via the antenna 810 .

[0297] The wireless communication interface 825 includes a plurality of BB processors 826, such as Figure 15 As shown in the diagram, the multiple BB processors 826 may correspond to multiple frequency bands used by the eNB 800. In addition, the wireless communication interface 825 includes multiple RF circuits 827, such as Figure 15 As shown in the diagram, the multiple RF circuits 827 may correspond to, for example, multiple antenna elements. Note that although Figure 15 826 and 827 , respectively. However, the wireless communication interface 825 may include a single BB processor 826 or a single RF circuit 827 .

[0298] (Second application example)

[0299] Figure 16 8 is a block diagram illustrating a second example of the schematic configuration of an eNB to which the techniques of the present disclosure are applicable. An eNB 830 includes one or more antennas 840, a base station 850, and an RRH 860. Each antenna 840 and RRH 860 can be interconnected via an RF cable. Alternatively, the base station 850 and RRH 860 can be interconnected via a high-speed line such as an optical fiber cable.

[0300] Each antenna 840 includes a single or multiple antenna elements (e.g., multiple antenna elements constituting a MIMO antenna) and is used for transmitting and receiving radio signals to and from the RRH 860. Figure 16As shown in the diagram, the eNB 830 may include, for example, multiple antennas 840 corresponding to the multiple frequency bands used by the eNB 830. Note that although Figure 16 The illustration illustrates an example in which the eNB 830 includes multiple antennas 840 ; however, the eNB 830 may include a single antenna 840 .

[0301] The base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857. The controller 851, the memory 852, and the network interface 853 are similar to those of the reference Figure 15 The controller 821, memory 822 and network interface 823 are configured as shown.

[0302] The wireless communication interface 855 supports any cellular communication system such as LTE and LTE-Advanced, and provides wireless connection with terminals located in the sector corresponding to the RRH 860 via the RRH 860 and each antenna 840. The wireless communication interface 855 may generally include a BB processor 856, etc. The BB processor 856 is similar to the reference 8 except that the BB processor 856 is connected to the RF circuit 864 of the RRH 860 via the connection interface 857. Figure 15 The wireless communication interface 855 includes multiple BB processors 856, such as Figure 16 As shown in the diagram, the multiple BB processors 856 may correspond to multiple frequency bands used by, for example, the eNB 830. Note that although Figure 16 , an example in which the wireless communication interface 855 includes a plurality of BB processors 856 is illustrated; however, the wireless communication interface 855 may include a single BB processor 856 .

[0303] The connection interface 857 is an interface for connecting the base station device 850 (wireless communication interface 855) to the RRH 860. The connection interface 857 may be a communication module for connecting the base station device 850 (wireless communication interface 855) and the RRH 860 for communication on a high-speed line.

[0304] In addition, the RRH 860 includes a connection interface 861 and a wireless communication interface 863 .

[0305] The connection interface 861 is an interface for connecting the RRH 860 (wireless communication interface 863) to the base station device 850. The connection interface 861 may be a communication module for communication on a high-speed line.

[0306] The wireless communication interface 863 transmits and receives radio signals via the respective antennas 840. The wireless communication interface 863 may generally include an RF circuit 864, etc. The RF circuit 864 may include a mixer, a filter, an amplifier, etc., and transmits and receives radio signals via the antenna 840. The wireless communication interface 863 includes a plurality of RF circuits 864, such as Figure 16 As shown in the diagram, the plurality of RF circuits 864 may correspond to, for example, a plurality of antenna elements. Note that although Figure 16 864 , an example is illustrated in which the wireless communication interface 863 includes a plurality of RF circuits 864 ; however, the wireless communication interface 863 may include a single RF circuit 864 .

[0307] Figure 15 and 16 The eNB 800, eNB 830, base station device 820 or base station device 850 shown in the diagram may correspond to the reference Figure 2 Base station device 1 as described above.

[0308] <3.2. Application Examples of Terminal Devices>

[0309] (First Application Example)

[0310] Figure 17 1 is a block diagram illustrating an example of a schematic configuration of a smartphone 900 to which the technology of the present disclosure is applicable. Smartphone 900 includes a processor 901, memory 902, storage device 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 912, one or more antenna switches 915, one or more antennas 916, bus 917, battery 918, and auxiliary controller 919.

[0311] The processor 901 may be, for example, a CPU or a system on a chip (SoC), and controls the functions of the application layer and other layers of the smartphone 900. The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901. The storage device 903 may include a storage medium such as a semiconductor memory or a hard disk. The external connection interface 904 is an interface for connecting an external device such as a memory card or a universal serial bus (USB) device to the smartphone 900.

[0312] The camera 906 includes, for example, an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) to generate a captured image. The sensor 907 may include, for example, a sensor group including a positioning sensor, a gyro sensor, a geomagnetic sensor, an acceleration sensor, and the like. The microphone 908 converts the voice input to the smartphone 900 into a voice signal. The input device 909 includes, for example, a touch sensor, a keypad, a keyboard, a button, or a switch that detects a touch on the screen of the display device 910, and receives an operation or information input from the user. The display device 910 includes a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays the output image of the smartphone 900. The speaker 911 converts the voice signal output from the smartphone 900 into voice.

[0313] The wireless communication interface 912 supports any cellular communication system such as LTE or LTE-Advanced and performs wireless communication. The wireless communication interface 912 may generally include a BB processor 913, an RF circuit 914, etc. The BB processor 913 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and perform various signal processing for wireless communication. On the other hand, the RF circuit 914 may include a mixer, a filter, an amplifier, etc., and transmit and receive radio signals via an antenna 916. The wireless communication interface 912 may be a single-chip module on which the BB processor 913 and the RF circuit 914 are integrated. The wireless communication interface 912 may include multiple BB processors 913 and multiple RF circuits 914, such as Figure 17 As shown in the figure. Note that although Figure 17 , an example in which the wireless communication interface 912 includes a plurality of BB processors 913 and a plurality of RF circuits 914 is illustrated; however, the wireless communication interface 912 may include a single BB processor 913 or a single RF circuit 914 .

[0314] In addition, in addition to the cellular communication system, the wireless communication interface 912 can also support other types of wireless communication systems, such as a near-field wireless communication system, a proximity wireless communication system, or a wireless local area network (LAN) system, and in this configuration, a BB processor 913 and an RF circuit 914 for each wireless communication system can be included.

[0315] The antenna switch 915 is configured to switch a connection destination of the antenna 916 between a plurality of circuits (eg, circuits for different wireless communication systems) included in the wireless communication interface 912 .

[0316] Each antenna 916 includes one or more antenna elements (e.g., multiple antenna elements forming a MIMO antenna) for transmitting and receiving radio signals to and from the wireless communication interface 912. The smartphone 900 may have multiple antennas 916, such as Figure 17 As shown in the figure. Note that although Figure 17 An example is illustrated in which the smartphone 900 includes multiple antennas 916 ; however, the smartphone 900 may include a single antenna 916 .

[0317] Furthermore, the smartphone 900 may include an antenna 916 for each wireless communication system. In this configuration, the antenna switch 915 can be omitted from the configuration of the smartphone 900.

[0318] The bus 917 interconnects the processor 901, the memory 902, the storage device 903, the external connection interface 904, the camera 906, the sensor 907, the microphone 908, the input device 909, the display device 910, the speaker 911, the wireless communication interface 912 and the auxiliary controller 919. The battery 918 is supplied to the battery 918 via a feeder line partially indicated by a dotted line in the figure. Figure 17 The auxiliary controller 919 enables the minimum necessary functions of the smartphone 900 to be performed, for example, in a sleep mode.

[0319] (Second application example)

[0320] Figure 18 1 is a block diagram illustrating an example of a schematic configuration of a car navigation device 920 to which the technology of the present disclosure is applicable. The car navigation device 920 includes a processor 921, a memory 922, a global positioning system (GPS) module 924, a sensor 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, a speaker 931, a wireless communication interface 933, one or more antenna switches 936, one or more antennas 937, and a battery 938.

[0321] The processor 921 may be, for example, a CPU or a SoC, and controls navigation functions and other functions of the car navigation device 920. The memory 922 includes a RAM and a ROM, and stores programs executed by the processor 921 and data.

[0322] The GPS module 924 uses GPS signals received from GPS satellites to measure the position (e.g., latitude, longitude, and altitude) of the car navigation device 920. The sensor 925 may include, for example, a sensor group including a gyro sensor, a geomagnetic sensor, a pressure sensor, and the like. The data interface 926 is connected to the in-vehicle network 941 via, for example, a terminal (not shown) and acquires data generated on the vehicle side, such as vehicle speed data.

[0323] The content player 927 plays back content stored in a storage medium (e.g., a CD or DVD) inserted into the storage medium interface 928. The input device 929 includes, for example, a touch sensor, button, or switch that detects a touch on the screen of the display device 930, and receives user operations or information input. The display device 930 has a screen such as an LCD or OLED display, and displays images of navigation functions or played back content. The speaker 931 outputs the sound of the navigation functions or played back content.

[0324] The wireless communication interface 933 supports any cellular communication system such as LTE or LTE-Advanced and performs wireless communication. The wireless communication interface 933 may generally include a BB processor 934, an RF circuit 935, etc. The BB processor 934 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and perform various signal processing for wireless communication. On the other hand, the RF circuit 935 may include a mixer, a filter, an amplifier, etc., and transmit and receive radio signals via an antenna 937. The wireless communication interface 933 may be a single-chip module on which the BB processor 934 and the RF circuit 935 are integrated. The wireless communication interface 933 may include multiple BB processors 934 and multiple RF circuits 935, such as Figure 18 As shown in the figure. Note that although Figure 18 , an example in which the wireless communication interface 933 includes a plurality of BB processors 934 and a plurality of RF circuits 935 is illustrated; however, the wireless communication interface 933 may include a single BB processor 934 or a single RF circuit 935 .

[0325] In addition, in addition to the cellular communication system, the wireless communication interface 933 can also support other types of wireless communication systems, such as a near-field wireless communication system, a proximity wireless communication system, or a wireless local area network (LAN) system, and in this configuration, a BB processor 934 and an RF circuit 935 for each wireless communication system can be included.

[0326] The antenna switch 936 is configured to switch a connection destination of the antenna 937 between a plurality of circuits (for example, circuits for different wireless communication systems) included in the wireless communication interface 933 .

[0327] Each antenna 937 includes one or more antenna elements (eg, multiple antenna elements constituting a MIMO antenna) and is used to transmit and receive radio signals to and from the wireless communication interface 933. The car navigation device 920 may have multiple antennas 937, such as Figure 18 As shown in the figure. Note that although Figure 18, an example in which the car navigation device 920 includes a plurality of antennas 937 is illustrated; however, the car navigation device 920 may include a single antenna 937 .

[0328] Furthermore, the car navigation device 920 may include an antenna 937 for each wireless communication system. In this configuration, the antenna switch 936 can be omitted from the configuration of the car navigation device 920.

[0329] The battery 938 is fed to the Figure 18 The respective components of the car navigation device 920 illustrated in the figure are supplied with power. In addition, the battery 938 accumulates the power supplied from the vehicle side.

[0330] Furthermore, the technology according to the present disclosure can be implemented as an in-vehicle system (or vehicle) 940 that includes one or more components of the aforementioned car navigation device 920 and further includes an in-vehicle network 941 and a vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data, such as vehicle speed, engine speed, or fault information, and outputs the generated data to the in-vehicle network 941.

[0331] <4. Other embodiments>

[0332] The processing according to the above-described embodiment can be performed in various forms other than those in the above-described embodiment.

[0333] In the above embodiment, the signal waveform used for downlink communication is switched primarily in cellular communication. However, the signal waveform used for downlink communication can also be switched in communications other than cellular communication. For example, when a wireless communication device onboard a satellite (hereinafter also referred to as a satellite station) transmits a signal to a wireless communication device on the ground (hereinafter also referred to as a ground station), the satellite station can switch the signal waveform.

[0334] Unlike cellular communications, satellite communications use microwaves rather than millimeter waves. However, in some cases, it's not possible to install high-performance power amplifiers in satellite stations. In such cases, a signal waveform with low PAPR may be required to ensure the power amplifier operates at high output to transmit signals to ground stations. Therefore, by switching signal waveforms using the techniques disclosed in this disclosure, transmission efficiency can be further improved while maintaining a low PAPR in satellite communications.

[0335] <5. Additional Notes>

[0336] While preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to these examples. It is apparent that those skilled in the art may make various changes and modifications within the scope of the technical concepts set forth in the claims, and it should be understood that such changes and modifications naturally fall within the technical scope of the present disclosure.

[0337] Among the processes described in the above embodiments, all or some of the processes described as being performed automatically may be performed manually, or all or some of the processes described as being performed manually may be performed automatically by known methods. Furthermore, unless otherwise specified, the processes, specific names, and information including various data and parameters illustrated in the above description or drawings may be appropriately modified. For example, the various information illustrated in the drawings is not limited to the information shown in the diagrams.

[0338] Furthermore, the components of the device are illustrated as functional concepts and are not necessarily required to be physically configured as shown. In other words, the specific distribution or integration of the various devices is not limited to that shown in the diagrams; all or some of the specific configurations can be configured by functionally or physically distributing or integrating them in appropriate units according to various loads or usage conditions.

[0339] Furthermore, the above-described embodiments and modifications may be appropriately combined within the scope consistent with the content of the processing. In addition, in the above-described embodiments, a microscope is described as an example of an image processing apparatus, but the image processing disclosed is also applicable to image capturing devices other than a microscope.

[0340] In addition, the effects described in this article are merely illustrative or exemplary, and not restrictive. In other words, together with the above effects, or in place of the above effects, other effects that are obvious to those skilled in the art based on the descriptions herein can be obtained according to the technology disclosed herein.

[0341] The present technology can also be configured as follows.

[0342] (1) A terminal device comprising

[0343] control unit,

[0344] the control unit acquires, from the base station apparatus, information on a used signal waveform among a plurality of signal waveforms including a single carrier signal, the used signal waveform being used for downlink communication with the base station apparatus, the information being transmitted by using a predetermined signal waveform among the plurality of signal waveforms, and

[0345] Based on the information, downlink communication is performed with the base station device by using the usage signal waveform.

[0346] (2) The terminal device according to (1), wherein

[0347] The information on the usage signal waveform is included in the system information.

[0348] (3) The terminal device according to (2), wherein

[0349] The control unit receives at least one of a synchronization signal block, a physical downlink control channel (PDCCH), or a physical downlink shared channel (PDSCH) scheduled by the PDCCH by using a predetermined signal waveform regardless of the use signal waveform.

[0350] (4) The terminal device according to (1), wherein

[0351] The information on the usage signal waveform is transmitted by using RRC signaling.

[0352] (5) The terminal device according to (1), wherein

[0353] The information related to the used signal waveform is included in a DCI field in the PDCCH.

[0354] (6) The terminal device according to (1), wherein

[0355] The usage signal waveform is a signal waveform used for uplink communication with a base station device.

[0356] (7) The terminal device according to (1), wherein

[0357] The plurality of signal waveforms correspond to a plurality of synchronization signal sequences respectively, and

[0358] The control unit determines the use signal waveform according to the received synchronization signal sequence.

[0359] (8) The terminal device according to (1), wherein

[0360] The control unit uses the use signal waveform for communication with the secondary cell group based on information on the use signal waveform acquired through communication with the primary cell group.

[0361] (9) A base station device comprising

[0362] control unit,

[0363] The control unit determines a use signal waveform to be used for downlink communication with the terminal device from a plurality of signal waveforms including a single carrier signal;

[0364] notifying information related to the used signal waveform by using a predetermined signal waveform among the plurality of signal waveforms; and

[0365] Downlink communication is performed with the terminal device by using the notified usage signal waveform.

[0366] (10) The base station device according to (9), wherein

[0367] The control unit determines the use signal waveform according to whether the terminal device is located at a cell center or a cell edge of a cell.

[0368] (11) The base station device according to (9), wherein

[0369] The plurality of signal waveforms also include multi-carrier signals, and

[0370] The predetermined signal waveform is a single carrier signal.

[0371] (12) The base station device according to (11), wherein

[0372] The control unit

[0373] allocating the multi-carrier signal non-contiguously to the resources; and

[0374] Single carrier signals are continuously allocated to resources.

[0375] (13) The base station device according to (9), wherein

[0376] When data signals to be transmitted to a plurality of the terminal devices are multiplexed on the same resource, the control unit determines the number of multiplexed data signals in accordance with the usage signal waveform.

[0377] (14) The base station device according to (9), wherein

[0378] The control unit determines a modulation method of a signal to be transmitted to the terminal device according to the usage signal waveform.

[0379] (15) A communication method comprising:

[0380] acquiring, from a base station device, information regarding a used signal waveform among a plurality of signal waveforms including a single carrier signal, the used signal waveform being used for downlink communication with the base station device, the information being transmitted by using a predetermined signal waveform among the plurality of signal waveforms, and

[0381] Based on the information, downlink communication is performed with the base station device by using the usage signal waveform.

[0382] (16) A communication method comprising:

[0383] determining, from a plurality of signal waveforms including a single carrier signal, a used signal waveform to be used for downlink communication with a terminal device;

[0384] notifying information related to the used signal waveform by using a predetermined signal waveform among the plurality of signal waveforms; and

[0385] Downlink communication is performed with the terminal device by using the notified usage signal waveform.

[0386] Reference Signs List

[0387] 1 Base station equipment

[0388] 101 Upper layer processing unit

[0389] 103 control unit

[0390] 105 receiving unit

[0391] 1051 decoding unit

[0392] 1053 Demodulation Unit

[0393] 1055 Demultiplexing Unit

[0394] 1057 Radio Receiver

[0395] 1059 Channel Measurement Unit

[0396] 107 Sending Unit

[0397] 1071 coding units

[0398] 1073 Modulation Unit

[0399] 1075 Multiplexing Unit

[0400] 1077 Radio Transmitter

[0401] 1079 Downlink Reference Signal Generation Unit

[0402] 109 Transmit / Receive Antenna

[0403] 2 Terminal devices

[0404] 201 Upper layer processing unit

[0405] 203 control unit

[0406] 205 receiving unit

[0407] 2051 decoding unit

[0408] 2053 Demodulation Unit

[0409] 2055 Demultiplexing Unit

[0410] 2057 Radio Receiver

[0411] 2059 Channel Measurement Unit

[0412] 207 Sending Unit

[0413] 2071 coding units

[0414] 2073 Modulation Unit

[0415] 2075 Multiplexing Unit

[0416] 2077 Radio Transmitter

[0417] 2079 Uplink Reference Signal Generation Unit

[0418] 209 Transmit / Receive Antenna

Claims

1. A terminal device, comprising: Control unit: acquiring, from a base station device, information regarding a used signal waveform among a plurality of signal waveforms including a single-carrier signal and a multi-carrier signal, the used signal waveform being used for downlink communication with the base station device, the information being transmitted by using a predetermined signal waveform among the plurality of signal waveforms, wherein when the bandwidth or channel width used for downlink communication is equal to or greater than a predetermined width, a single carrier signal is used as the signal waveform used, and when the bandwidth or channel width used for downlink communication is less than the predetermined width, a multi-carrier signal is used as the signal waveform used, or wherein when it is detected that another wireless communication system communicating in the same frequency band uses a single-carrier signal, the single-carrier signal is used as the signal waveform in use, and when it is detected that the other wireless communication system uses a multi-carrier signal, the multi-carrier signal is used as the signal waveform in use; and Based on the information, downlink communication is performed with the base station device by using the usage signal waveform.

2. The terminal device according to claim 1, wherein The information on the usage signal waveform is included in the system information.

3. The terminal device according to claim 2, wherein The control unit: At least one of a synchronization signal block, a physical downlink control channel (PDCCH), or a physical downlink shared channel (PDSCH) scheduled by the PDCCH is received by using a predetermined signal waveform regardless of the use signal waveform.

4. The terminal device according to claim 1, wherein The information on the usage signal waveform is transmitted by using RRC signaling.

5. The terminal device according to claim 1, wherein The information related to the used signal waveform is included in a DCI field in the PDCCH.

6. The terminal device according to claim 1, wherein The usage signal waveform is a signal waveform used for uplink communication with a base station device.

7. The terminal device according to claim 1, wherein The plurality of signal waveforms correspond to a plurality of synchronization signal sequences respectively, and The control unit: The use signal waveform is determined according to the received synchronization signal sequence.

8. The terminal device according to claim 1, wherein The control unit: The used signal waveform is used for communication with the secondary cell group based on information related to the used signal waveform acquired through communication with the primary cell group.

9. A base station device, comprising: Control unit: determining a signal waveform to be used for downlink communication with a terminal device from a plurality of signal waveforms including single-carrier signals and multi-carrier signals, wherein when the bandwidth or channel width for downlink communication is equal to or greater than a predetermined width, a single-carrier signal is determined to use a signal waveform, and when the bandwidth or channel width for downlink communication is less than the predetermined width, a multi-carrier signal is determined to use a signal waveform, or wherein when it is detected that another wireless communication system communicating in the same frequency band uses a single-carrier signal, the single-carrier signal is determined to be used as the signal waveform, and when it is detected that the other wireless communication system uses a multi-carrier signal, the multi-carrier signal is determined to be used as the signal waveform; notifying information related to the used signal waveform by using a predetermined signal waveform among the plurality of signal waveforms; and Downlink communication is performed with the terminal device by using the notified usage signal waveform.

10. The base station device according to claim 9, wherein The control unit: The signal waveform to be used is determined according to whether the terminal device is located at a cell center or a cell edge of a cell.

11. The base station device according to claim 9, wherein The predetermined signal waveform is a single carrier signal.

12. The base station device according to claim 9, wherein The control unit: allocating the multi-carrier signal non-contiguously to the resources; and Single carrier signals are continuously allocated to resources.

13. The base station device according to claim 9, wherein The control unit: When data signals to be transmitted to a plurality of terminal devices are multiplexed on the same resource, the number of multiplexed data signals is determined according to the usage signal waveform.

14. The base station device according to claim 9, wherein The control unit: A modulation method of a signal to be transmitted to the terminal device is determined according to the usage signal waveform.

15. A communication method, comprising: acquiring, from a base station device, information regarding a used signal waveform among a plurality of signal waveforms including a single-carrier signal and a multi-carrier signal, the used signal waveform being used for downlink communication with the base station device, the information being transmitted by using a predetermined signal waveform among the plurality of signal waveforms, wherein when the bandwidth or channel width used for downlink communication is equal to or greater than a predetermined width, a single carrier signal is used as the signal waveform used, and when the bandwidth or channel width used for downlink communication is less than the predetermined width, a multi-carrier signal is used as the signal waveform used, or wherein when it is detected that another wireless communication system communicating in the same frequency band uses a single-carrier signal, the single-carrier signal is used as the signal waveform in use, and when it is detected that the other wireless communication system uses a multi-carrier signal, the multi-carrier signal is used as the signal waveform in use; and Based on the information, downlink communication is performed with the base station device by using the usage signal waveform.

16. A communication method, comprising: determining a signal waveform to be used for downlink communication with a terminal device from a plurality of signal waveforms including single-carrier signals and multi-carrier signals, wherein when the bandwidth or channel width for downlink communication is equal to or greater than a predetermined width, a single-carrier signal is determined to use a signal waveform, and when the bandwidth or channel width for downlink communication is less than the predetermined width, a multi-carrier signal is determined to use a signal waveform, or wherein when it is detected that another wireless communication system communicating in the same frequency band uses a single-carrier signal, the single-carrier signal is determined to be used as the signal waveform, and when it is detected that the other wireless communication system uses a multi-carrier signal, the multi-carrier signal is determined to be used as the signal waveform; notifying information related to the used signal waveform by using a predetermined signal waveform among the plurality of signal waveforms; and Downlink communication is performed with the terminal device by using the notified usage signal waveform.

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