JP2019176243A - Base station, terminal, wireless communication system, and communication method - Google Patents

Abstract

To provide a base station, a terminal, a wireless communication system and a communication method that can increase transmission efficiency and suppress deterioration in transmission quality.SOLUTION: A base station that performs time-division duplex wireless communication with a terminal using a plurality of channels includes: a transmission unit for transmitting a downlink signal to the terminal using a first channel, in a transmission section of the downlink signal; and a reception unit for receiving a first uplink signal transmitted by the terminal using a first transmission method using a first reception period corresponding to the first transmission method in the reception section of the first uplink signal and receiving a second uplink signal transmitted by the terminal using a second transmission method having higher reception performance than that of the first transmission method using a second channel different from the first channel using a second reception method corresponding to the second transmission method in the transmission section of the downlink signal.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a base station, a terminal, a wireless communication system, and a communication method.

  2. Description of the Related Art Conventionally, an FPU (Field Pick-up Unit) is known as a device used in a wireless communication system that performs video transmission such as live television broadcasts and emergency reports. This FPU is used for transmission of materials in the broadcasting field, and transmits an uplink (UL) signal of main line information from a mobile station (terminal) on the relay site side to a base station on the broadcasting station side. A downlink (DL) signal of transmission information is transmitted from the base station to the mobile station on the relay site side. Video captured by the camera is file-transmitted in real time, transmitted as a UL signal from the mobile station to the base station, stored in a storage medium, and played back.

  In order to improve transmission efficiency, FPU is also studying a method of transmitting UL signals and DL signals by simultaneously using a plurality of frequency channels (hereinafter referred to as channels).

  When using a plurality of channels simultaneously, in order to improve the transmission efficiency of the FPU, the base station transmits a DL signal using at least one of the plurality of channels in the DL signal transmission period, and the DL signal It is conceivable to receive a UL signal using a channel that does not transmit.

  For example, Patent Literature 1 discloses a technique using a pattern in which transmission of a DL signal and reception of a UL signal are fixed in advance for each slot constituting a frame in cellular communication between a base station and a plurality of terminals.

Japanese Patent Laying-Open No. 2015-165605

  However, since the transmission power of the terminal is large in the FPU, when DL signal transmission and UL signal reception are performed simultaneously, interference between channels occurs due to out-of-band leakage in an adjacent channel that receives the UL signal, resulting in transmission quality. (For example, the reception quality of the UL signal) may be deteriorated.

  A non-limiting example of the present disclosure is to contribute to provision of a base station, a terminal, a wireless communication system, and a communication method that can improve transmission efficiency and suppress deterioration of transmission quality.

  A base station according to an aspect of the present disclosure is a base station that performs time-division duplex wireless communication with a terminal using a plurality of channels, and transmits a first signal to the terminal in a downlink signal transmission period. A transmitter for transmitting the downlink signal using the channel of the first uplink signal transmitted by the terminal using the first transmission method in a reception period of the first uplink signal; , Using a first reception method corresponding to the first transmission method, and using a second channel different from the first channel in the downlink signal transmission period, A receiving unit that receives, using a second reception method corresponding to the second transmission method, a second uplink signal transmitted using the second transmission method having higher reception performance than the first transmission method; .

  A terminal according to an aspect of the present disclosure is a terminal that performs time-division duplex wireless communication with a base station using a plurality of channels, wherein the base station is the first in a downlink signal reception period. A receiving unit that receives the downlink signal transmitted using the channel, and the first uplink using the first transmission method to the base station in a transmission period of the first uplink signal. A second transmission having a higher reception performance than the first transmission method using a second channel different from the first channel to the base station in a reception period of the downlink signal. And a transmitter that transmits the second uplink signal using the method.

  A radio communication system according to an aspect of the present disclosure is a radio communication system in which a terminal and a base station perform radio communication in a time division duplex scheme using a plurality of channels, and the base station includes a downlink In the signal section, the transmission unit transmits the downlink signal to the terminal using the first channel, and in the first uplink signal section, the terminal transmits using the first transmission method. The first uplink signal is received using a first reception method corresponding to the first transmission method, and a second channel different from the first channel is received in a section of the downlink signal. A second reception method corresponding to the second transmission method, using a second uplink signal transmitted by the terminal using the second transmission method having higher reception performance than the first transmission method. Receive using And the terminal receives the downlink signal using the first channel in the downlink signal interval, and the terminal in the first uplink signal interval The first uplink signal is transmitted using a first transmission method, the second channel is used in the downlink signal section, and the second uplink signal is transmitted using the second transmission method. A transmission unit that transmits a link signal.

  A communication method according to an aspect of the present disclosure is a communication method in which a terminal and a base station perform radio communication of time division duplex using a plurality of channels, and the base station transmits a downlink signal. In the section, the downlink signal is transmitted to the terminal using the first channel, and the terminal transmits the first uplink signal using the first transmission method in the section of the first uplink signal. Receiving an uplink signal using a first reception method corresponding to the first transmission method, using a second channel different from the first channel in a section of the downlink signal, and the terminal Receives a second uplink signal transmitted using a second transmission method having higher reception performance than the first transmission method using a second reception method corresponding to the second transmission method. The terminal transmits the downlink signal. In the interval, the downlink signal is received using the first channel, and the first uplink signal is transmitted using the first transmission method in the interval of the first uplink signal. Then, in the downlink signal section, the second channel is used, and the second uplink signal is transmitted using the second transmission method.

  Note that these comprehensive or specific aspects may be realized by a system, an integrated circuit, a computer program, or a recording medium, and any combination of the system, apparatus, method, integrated circuit, computer program, and recording medium. It may be realized with.

  According to one aspect of the present disclosure, it contributes to the provision of a base station, a terminal, a wireless communication system, and a communication method that can improve transmission efficiency and suppress degradation of transmission quality.

  Further advantages and effects in one aspect of the present disclosure will become apparent from the specification and drawings. Such advantages and / or effects are provided by some embodiments and features described in the description and drawings, respectively, but all need to be provided in order to obtain one or more identical features. There is no.

FIG. 4 is a block diagram illustrating a configuration example of a base station according to an embodiment of the present disclosure. The block diagram which shows the structural example of the terminal which concerns on embodiment of this indication The figure which shows the 1st example of the transmission / reception signal which concerns on embodiment of this indication The figure which shows the 2nd example of the transmission / reception signal which concerns on embodiment of this indication The figure which shows the 3rd example of the transmission / reception signal which concerns on embodiment of this indication The figure which shows the 4th example of the transmission / reception signal which concerns on embodiment of this indication The figure which shows an example of the format of the frame contained in DL signal The flowchart which shows the processing flow of the base station in embodiment of this indication The flowchart which shows the processing flow of the terminal in embodiment of this indication

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(One embodiment)
The radio communication system according to the present embodiment includes base station 100 shown in FIG. 1 and terminal 200 shown in FIG. Base station 100 and terminal 200 are, for example, FPUs used for material transmission in the broadcasting field. That is, terminal 200 transmits video information or the like as a UL signal to base station 100, and base station 100 transmits DL control information or the like to be fed back to terminal 200 as a DL signal.

  In the radio communication system according to the present embodiment, UL signals and DL signals are transmitted and received using a time division duplex (TDD) method. In addition, a signal non-transmission section called a guard time is provided between the UL signal and the DL signal. In the radio communication system according to the present embodiment, a plurality of frequency bands can be used, and each frequency band includes a plurality of channels. In the radio communication system according to the present embodiment, UL signals and DL signals are transmitted and received using at least one of a plurality of channels included in each of a plurality of frequency bands.

<Base station configuration>
A configuration example of base station 100 according to the present embodiment will be described using FIG. FIG. 1 is a block diagram showing a configuration example of base station 100 according to the present embodiment.

  As illustrated in FIG. 1, the base station 100 includes a transmission / reception switching unit 101, radio reception units 102-1 to 102-M (M is an integer of 2 or more), a baseband reception processing unit 103, and AGC / synchronization detection. Unit 104, reception processing control unit 105, interference measurement unit 106, channel selection unit 107, UL / DL selection unit 108, channel information generation unit 109, baseband transmission processing unit 110, and preamble generation unit 111 And an addition unit 112 and wireless transmission units 113-1 to 113-N (N is an integer of 2 or more).

  And reception mainly composed of radio reception sections 102-1 to 102-M, baseband reception processing section 103, AGC / synchronization detection section 104, reception processing control section 105, and interference measurement section 106. Unit 114 receives the UL signal from terminal 200. In addition, a transmission unit 115 mainly including a baseband transmission processing unit 110, a preamble generation unit 111, an addition unit 112, and radio transmission units 113-1 to 113-N transmits a DL signal to the terminal 200. Send. Note that M is, for example, the number of channels through which the reception unit 114 can receive UL signals, and N is the number of channels through which the transmission unit 115 can transmit DL signals, for example. M and N may be the same or different.

  The transmission / reception switching unit 101 acquires setting information from a UL / DL selection unit 108 (to be described later), and transmits signals in an uplink section (UL (Uplink) section) and a downlink section (DL (Downlink) section) of each frame. And switch reception. For example, the transmission / reception switching unit 101 performs switching so as to receive the UL signal via the antenna using each channel indicated by the setting information in the UL section. In addition, the transmission / reception switching unit 101 switches between signal transmission and reception so as to perform reception of the UL signal or transmission of the DL signal using each channel indicated by the setting information in the DL section. The channel indicated by the setting information is a channel that is selected by the channel selection unit 107 described later and used for communication.

  When the setting information includes information indicating a reception method for receiving the UL signal in the DL section, the transmission / reception switching unit 101 receives the UL signal by applying the reception method for receiving the UL signal in the DL section. May be. For example, the transmission / reception switching unit 101 may apply a reception method of receiving UL signals using a plurality of antennas in the DL section. When the reception method of the UL signal received in the DL section is set for each channel, the transmission / reception switching unit 101 applies the reception method set for each channel.

  The radio receiving units 102-1 to 102-M receive radio signals (UL) acquired via the transmission / reception switching unit 101 based on AGC (Automatic Gain Control) information one frame before acquired from the reception processing control unit 105 described later. Signal) is subjected to wireless reception processing such as amplification and filtering. Then, radio reception sections 102-1 to 102-M downconvert the signals after the radio reception processing based on the carrier frequency of each channel indicated by the setting information to obtain a baseband signal of each channel. Radio receiving sections 102-1 to 102-M output baseband signals for each channel.

  The baseband reception processing unit 103 is based on the timing information acquired from the reception processing control unit 105 (to be described later) and the setting information acquired from the UL / DL selection unit 108, and the baseband acquired from the radio reception units 102-1 to 102-M. Baseband reception processing such as FFT (Fast Fourier Transform) processing, demodulation processing, and error correction processing is performed on the signal. Then, the baseband reception processing unit 103 outputs the reception data that has undergone the baseband reception processing.

  For example, when the setting information includes information related to the reception method of the UL signal received in the DL section, the baseband reception processing unit 103 performs an operation on the baseband signal of the UL signal received in the DL section based on the setting information. , Baseband reception processing is performed. For example, the baseband reception processing unit 103 performs corresponding demodulation and / or corresponding error correction processing based on information on the modulation scheme and / or error correction coding scheme of the UL signal received in the DL section. When the reception method of the UL signal received in the DL section is set for each channel, the baseband reception processing unit 103 performs the baseband reception processing set for each channel.

  Note that the baseband reception processing unit 103 may perform a predetermined baseband reception process on the baseband signal of the UL signal received in the UL section, or based on the setting information. May be performed.

  The AGC / synchronization detection unit 104, based on the preamble included in the baseband signal acquired from the radio reception units 102-1 to 102-M, information on timing for synchronization between transmission and reception, and gain in reception processing, etc. Information (eg, signal level) for control (AGC) is detected. Then, the AGC / synchronization detection unit 104 outputs the detection result of information for timing and AGC to the reception processing control unit 105.

  The reception processing control unit 105 controls the timing of reception processing and AGC based on the detection result acquired from the AGC / synchronization detection unit 104. Specifically, the reception processing control unit 105 outputs timing information indicating processing timing such as a start time and an end time of the baseband reception processing to the baseband reception processing unit 103. Further, the reception processing control unit 105 outputs timing information indicating processing timing such as the start time and end time of interference measurement to the interference measurement unit 106. Reception processing control section 105 outputs AGC information to radio reception sections 102-1 to 102-M.

  At that time, when acquiring the detection result from the AGC / synchronization detection unit 104, the reception processing control unit 105 generates timing information and AGC information based on the acquired detection result.

  Based on the timing information acquired from the reception processing control unit 105, the interference measurement unit 106 uses the guard time interval as the interference measurement interval, and receives the reception level (interference amount) of each channel included in each available frequency band in the interference measurement interval. For example, the received signal strength (RSSI: Received Signal Strength Indicator) is measured. Alternatively, interference measurement may be performed using the result of performing FFT (Fast Fourier Transform) processing on the received signal in the guard time section. For example, the interference measurement unit 106 outputs the measurement result to the channel selection unit 107.

  Channel selection section 107 selects a channel to be used for communication based on the reception level of each channel included in each frequency band measured by interference measurement section 106. For example, the channel selection unit 107 selects a channel whose reception level is a predetermined value or less as a channel used for communication. Note that the channels selected by the channel selection unit 107 may be included in the same frequency band or may be included in different frequency bands.

  The UL / DL selection unit 108 uses, for each channel selected by the channel selection unit 107, reception of UL signals in the DL section (UL reception), or transmission of DL signals in the DL section (DL transmission). Select whether to use. For example, the UL / DL selection unit 108 uses a channel selected by the channel selection unit 107 for receiving a UL signal in the DL section (UL reception) or transmitting a DL signal in the DL section (DL transmission). ) Is set to the channel to be used.

  Hereinafter, the channel used by the base station 100 for DL signal transmission (DL transmission) in the DL section may be described as a D-DL channel. Further, a channel used by base station 100 for receiving a UL signal (UL reception) in the DL section may be described as a D-UL channel. Moreover, the UL signal transmitted / received in the DL section may be described as a D-UL signal. Moreover, the UL signal transmitted / received in a UL section may be described as a U-UL signal. Further, the D-UL signal and the U-UL signal may be appropriately described as UL signals without being distinguished from each other.

  The D-DL channel is a channel through which DL signals are transmitted / received in the DL section and U-UL signals are transmitted / received in the UL section. The D-UL channel is a channel through which a D-UL signal is transmitted and received in the DL section and a U-UL signal is transmitted and received in the UL section.

  For example, the UL / DL selection unit 108 sets a channel having a relatively low carrier frequency among the channels selected by the channel selection unit 107 as a D-DL channel. Then, the UL / DL selection unit 108 sets all or part of the channels other than the D-DL channel among the channels selected by the channel selection unit 107 as D-UL channels.

  Then, the UL / DL selection unit 108 sets signal processing parameters of the D-UL signal transmitted / received using the D-UL channel. The signal processing parameter of the D-UL signal is a parameter related to a transmission method and / or a reception method (hereinafter referred to as a transmission / reception method) of the D-UL signal. When a plurality of D-UL channels are set, the UL / DL selection unit 108 may set the signal processing parameters of the D-UL signal for each of the plurality of D-UL channels.

  The signal processing parameter includes, for example, a modulation scheme parameter (for example, modulation multi-level number) and / or an error correction coding scheme parameter (for example, coding rate). In addition, the signal processing parameter may include information indicating whether the terminal 200 transmits UL signals from a plurality of antennas using STC (Space Time Coding).

  For example, the UL / DL selection unit 108 sets the signal processing parameter of the D-UL signal based on the parameter related to the transmission / reception method of the U-UL signal. As an example, the UL / DL selection unit 108 sets a transmission / reception method having higher reception performance than the transmission / reception method of the U-UL signal to the transmission / reception method of the D-UL signal. It should be noted that the parameters regarding the method for transmitting and receiving the U-UL signal may be set by the UL / DL selection unit 108. Or the parameter regarding the transmission / reception method of a U-UL signal may be preset to a known parameter between the base station 100 and the terminal 200.

  A transmission / reception method with high reception performance is a transmission / reception method that is expected to improve reception quality. For example, at least one of a transmission / reception method with a low reception error rate, a transmission / reception method with a low demodulation error rate, and a transmission / reception method with a low decoding error rate is used. It is.

  For example, the UL / DL selection unit 108 sets a modulation scheme having a smaller modulation multi-value number than the modulation scheme used for modulating the U-UL signal as the modulation scheme used for modulating the D-UL signal. Alternatively, the UL / DL selection unit 108 sets a coding rate smaller than the coding rate used for error correction coding of the U-UL signal as the coding rate used for error correction coding of the D-UL signal. To do.

  The UL / DL selection unit 108 may set at least one parameter among the parameters related to the transmission / reception method so as to be different between the U-UL signal and the D-UL signal. For example, when the UL / DL selection unit 108 sets a modulation scheme having a smaller modulation multi-value number than the modulation scheme used for the modulation of the U-UL signal as the modulation scheme used for the modulation of the D-UL signal, -The same coding rate may be set between the UL signal and the D-UL signal.

  The UL / DL selection unit 108 sets the transmission / reception method having higher reception performance than the transmission / reception method of the U-UL signal as the transmission / reception method of the D-UL signal. For example, even when the terminal 200 transmits a D-UL signal, the UL / DL selection unit 108 sets the transmission / reception method to transmit UL signals from a plurality of antennas using STC (Space Time Coding). Good.

  Further, the UL / DL selection unit 108 may set the signal processing parameter of the D-UL signal based on the interval (detuning frequency) in the frequency direction between the D-DL channel and the D-UL channel. .

  For example, the UL / DL selection unit 108 modulates a D-UL signal that is transmitted / received using the D-UL channel as the interval in the frequency direction between the D-DL channel and the D-UL channel decreases. The modulation multi-level number is set small. Alternatively, the UL / DL selection unit 108 increases the error correction code of the D-UL signal transmitted and received using the D-UL channel as the interval in the frequency direction between the D-DL channel and the D-UL channel is smaller. Set the coding rate of encoding.

  The UL / DL selection unit 108 is not limited to the above-described example, and the UL / DL selection unit 108 transmits / receives data using the D-UL channel as the interval in the frequency direction between the D-DL channel and the D-UL channel decreases. The UL signal transmission / reception method is set to a transmission / reception method with higher reception performance. For example, when the interval in the frequency direction between the D-DL channel and the D-UL channel is equal to or smaller than a predetermined value, the UL / DL selection unit 108 uses the STC to transmit D-UL signals from a plurality of antennas. Set the send / receive method to send.

  Moreover, you may combine the example mentioned above suitably. For example, the UL / DL selection unit 108 performs signal processing of a D-UL signal based on a parameter related to a method for transmitting and receiving a U-UL signal and an interval in the frequency direction between the D-DL channel and the D-UL channel. Parameters may be set.

  An example of setting the D-UL channel or D-DL channel and the signal processing parameters of the D-UL signal will be described later.

  The UL / DL selection unit 108 sets information (setting information) in which the channel selected by the channel selection unit 107 is associated with whether each selected channel is a D-DL channel or a D-UL channel. Output to transmission / reception switching unit 101, channel information generation unit 109, reception unit 114, and transmission unit 115. The setting information includes the signal processing parameters of the D-UL signal set by the UL / DL selection unit 108 for the D-UL channel. Note that the setting information may include parameters related to a method for transmitting and receiving U-UL signals.

  Channel information generation section 109 generates information (channel information) to be notified to terminal 200 based on the setting information acquired from UL / DL selection section 108. Channel information generation section 109 outputs the channel information to baseband transmission processing section 110. A specific example of information notified to the terminal 200 will be described later.

  Baseband transmission processing section 110 performs error correction coding and modulation on transmission data (DL data) and channel information, performs IFFT (Inverse Fast Fourier Transform) processing, and baseband of the number of channels indicated by the setting information Get a signal. Baseband transmission processing section 110 then outputs the baseband signal to addition section 112.

  Preamble generating section 111 generates a preamble having the number of channels indicated by the setting information, and outputs the preamble to adding section 112. The preamble data is symbol data or the like known in advance by the terminal 200 and the base station 100.

  The adding unit 112 adds the preamble acquired from the preamble generating unit 111 to the previous stage of the baseband signal of the transmission data based on a predetermined frame configuration. Then, adding section 112 outputs the baseband transmission signal with the preamble added to the previous stage of the transmission data baseband signal to radio transmitting sections 113-1 to 113-N.

  The wireless transmission units 113-1 to 113-N perform wireless transmission processing such as amplification and filtering on the baseband transmission signal to which the preamble is added. Then, based on the carrier frequency of each channel indicated by the setting information, radio transmission sections 113-1 to 113-N upconvert the signal after the radio transmission processing to obtain a radio signal. Then, the wireless transmission units 113-1 to 113-N transmit a wireless signal (DL signal) from the antenna via the transmission / reception switching unit 101.

<Terminal configuration>
Next, a configuration example of terminal 200 according to the present embodiment will be described using FIG. FIG. 2 is a block diagram showing a configuration example of terminal 200 according to the present embodiment.

  As illustrated in FIG. 2, the terminal 200 includes a transmission / reception switching unit 201, wireless reception units 202-1 to 202-N, a baseband reception processing unit 203, an AGC / synchronization detection unit 204, and a reception processing control unit 205. A channel information extraction unit 206, a baseband transmission processing unit 207, a preamble generation unit 208, an addition unit 209, and radio transmission units 210-1 to 210-M.

  The reception unit 211 mainly composed of the wireless reception units 202-1 to 202-N, the baseband reception processing unit 203, the AGC / synchronization detection unit 204, and the reception processing control unit 205 is the base station 100. DL signal is received from. The transmission unit 212 mainly composed of the baseband transmission processing unit 207, the preamble generation unit 208, the addition unit 209, and the wireless transmission units 210-1 to 210 -M transmits the UL signal to the base station 100. Send.

  The transmission / reception switching unit 201 acquires channel information from a channel information extraction unit 206 described later, and performs switching between signal transmission and reception in the UL section and the DL section. For example, the transmission / reception switching unit 201 performs switching so as to transmit a UL signal (U-UL signal) via the antenna using each channel indicated by the channel information in the UL section. In addition, the transmission / reception switching unit 201 switches between transmission and reception of a signal so as to transmit a UL signal (D-UL signal) or receive a DL signal using each channel indicated by channel information in the DL section. . The channel indicated by the channel information is a channel that is selected by the above-described channel selection unit 107 and used for communication.

  In addition, when the information regarding the transmission method of a D-UL signal is contained in channel information, the transmission / reception switching part 201 may apply the transmission method of a D-UL signal, and may transmit a D-UL signal. For example, the transmission / reception switching unit 201 may apply a transmission method of transmitting a D-UL signal using a plurality of antennas in the DL section. When the transmission method of the D-UL signal is set for each channel, the transmission / reception switching unit 201 applies the transmission method set for each channel.

  Radio receiving sections 202-1 to 202-N amplify and filter radio signals (DL signals) received by the antenna based on AGC information one frame before acquired from reception processing control section 205, which will be described later. And so on. Then, radio reception sections 202-1 to 202-N downconvert the signals after the radio reception processing based on the carrier frequency of each channel indicated by the channel information to obtain a baseband signal of each channel. Radio receiving sections 202-1 to 202-N output baseband signals of the respective channels.

  The baseband reception processing unit 203 performs FFT (Fast Fourier Transform) processing on the baseband signals acquired from the wireless reception units 202-1 to 202-N based on timing information acquired from the reception processing control unit 205 described later. Baseband reception processing such as demodulation processing and error correction processing is performed. Then, the baseband reception processing unit 203 outputs the reception data that has undergone the baseband reception processing. Note that the received data includes the result of the baseband reception process of the channel information transmitted from the base station 100.

  The AGC / synchronization detection unit 204, based on the preamble included in the baseband signal acquired from the radio reception units 202-1 to 202-N, information on timing for synchronization between transmission and reception, and gain in reception processing, etc. Information (eg, signal level) for control (AGC) is detected. Then, the AGC / synchronization detection unit 204 outputs the detection result of information for timing and AGC to the reception processing control unit 205.

  The reception processing control unit 205 controls the timing of reception processing and AGC based on the detection result acquired from the AGC / synchronization detection unit 204. Specifically, the reception processing control unit 205 outputs timing information indicating processing timing such as the start time and end time of the baseband reception processing to the baseband reception processing unit 203. Reception processing control section 205 also outputs AGC information to radio reception sections 202-1 to 202-N.

  The channel information extraction unit 206 acquires reception data from the baseband reception processing unit 203 and extracts channel information. Channel information extraction section 206 then outputs the extracted channel information to transmission / reception switching section 201, reception section 211, and transmission section 212.

  Based on the channel information, the baseband transmission processing unit 207 performs baseband transmission processing such as error correction coding processing, modulation processing, and IFFT (Inverse Fast Fourier Transform) processing on transmission data (UL data). The baseband signal of the transmission data of the number of channels indicated by the channel information is obtained.

  For example, when the channel information includes information related to the D-UL signal transmission method, the baseband transmission processing unit 207 transmits transmission data (UL data) to be transmitted in the DL section based on the information related to the D-UL signal transmission method. Baseband transmission processing is performed on For example, the baseband transmission processing unit 207 performs error correction coding processing and / or modulation processing based on information regarding the modulation scheme and / or error correction coding scheme of the D-UL signal. When the D-UL signal transmission method is set for each channel, the baseband transmission processing unit 207 performs baseband transmission processing set for each channel.

  Note that the baseband transmission processing unit 207 may perform a predetermined baseband transmission process on transmission data to be transmitted in the UL section, or may perform a baseband transmission process based on channel information. .

  Baseband transmission processing section 207 then outputs the baseband signal of the transmission data to addition section 209.

  Preamble generating section 208 generates a preamble having the number of channels indicated by the channel information, and outputs the preamble to adding section 209.

  The adding unit 209 adds the preamble acquired from the preamble generating unit 208 to the previous stage of the baseband signal of the transmission data based on a predetermined frame configuration. Then, the addition unit 209 outputs the baseband transmission signal with the preamble added to the previous stage of the transmission data baseband signal to the radio transmission units 210-1 to 210-M.

  The wireless transmission units 210-1 to 210-M perform wireless transmission processing such as amplification and filtering on the baseband transmission signal to which the preamble is added. Then, radio transmission sections 210-1 to 210-M upconvert the signal after the radio transmission processing based on the carrier frequency of each channel indicated by the channel information to obtain a radio signal (UL signal). Then, the wireless transmission units 210-1 to 210 -M transmit UL signals from the antennas via the transmission / reception switching unit 201.

  As described above, in the radio communication system according to the present embodiment, base station 100 selects a plurality of channels used for radio communication. The base station 100 sets the selected plurality of channels as a channel for transmitting a DL signal in the DL section (D-DL channel) or a channel for receiving the UL signal in the DL section (D-UL channel). And the base station 100 sets the signal processing parameter of a D-UL signal with respect to the UL signal (D-UL signal) transmitted / received in DL section using a D-UL channel.

<Example of transmission / reception signal>
Next, referring to examples of signals transmitted and received between base station 100 and terminal 200 according to the present embodiment, setting of D-UL channel or D-DL channel and signal processing of D-UL signal An example of parameters will be described.

  In the following, an example in which the modulation multilevel number of the modulation scheme is set as an example of the signal processing parameter of the D-UL signal will be described.

  FIG. 3 is a diagram showing a first example of transmission / reception signals according to the present embodiment.

In FIG. 3, the horizontal axis indicates time, and the vertical axis indicates frequency. FIG 3, Band1 including the channel _{f 11} and the channel _{f 12} and the channel _{f 13} is shown. Detuning frequency between the channel _{f 11} and the channel _{f 12} is dfa, detuning frequency between channels _{f 12} and the channel _{f 13} is dfb, detuning between the channel _{f 11} and the channel _{f 13} The frequency is dfc. For example, dfa = dfb> 0 and dfc = 2 × dfa.

  FIG. 3 also shows two frames, an nth frame (frame #n) and an n + 1th frame (frame # n + 1), which are continuous in the time direction, and the UL section of each frame. And the DL section is shown. As described above, in the radio communication system according to the present embodiment, communication using the time division duplex method is performed. Therefore, as shown in FIG. 3, the UL section and the DL section are provided by time division. .

  A guard time (GT) may be provided between the UL section and the DL section (for example, between the UL signal and the DL signal), but is omitted for convenience of illustration. Similarly, GT is omitted in the following drawings.

  In the wireless communication system according to the present embodiment, for example, 1.2 GHz band or 2.3 GHz band is used as Band1.

FIG. 3 shows a case where the base station 100 selects the channel f ₁₁ and the channel f ₁₂ among the three channels, sets the channel f ₁₁ to the D-DL channel, and sets the channel f ₁₂ to the D-UL channel. It is an example of the transmitted / received signal.

In the example of FIG. 3, the UL duration, the terminal 200 transmits a UL signal (U-UL signal) using the channel _{f 11} and the channel _{f 12,} the base station 100 using the channel _{f 11} and the channel _{f 12} The U-UL signal is received. In the example of FIG. 3, the modulation scheme used for the U-UL signal is 256QAM. The modulation multi-level number of 256QAM is 256. Note that the modulation scheme used for the modulation of the U-UL signal may be described as a first modulation scheme.

In the example of FIG. 3, in the DL section, base station 100 transmits a DL signal using channel f ₁₁ , and terminal 200 transmits a UL signal (D-UL signal) using channel f _12. . In DL duration, the base station 100, using the channel _{f 12} receives the D-UL signals transmitted by the terminal 200, terminal 200, DL signal transmitted by the base station 100 using the channel _{f 11} Receive. In the example of FIG. 3, the modulation method used for modulating the D-UL signal is 16QAM. The modulation multi-level number of 16QAM is 16. The modulation method used for modulating the D-UL signal may be described as a second modulation method.

  As illustrated in FIG. 3, in the radio communication system according to the present embodiment, when the D-UL channel selected by the base station 100 is adjacent to the D-DL channel, the base station 100 performs D- The DL signal is transmitted using the DL channel, and the terminal 200 transmits the D-UL signal using the D-UL channel. At that time, the modulation scheme (second modulation scheme) used for modulating the D-UL signal has a smaller modulation multi-level number than the modulation scheme (first modulation scheme) used for modulating the U-UL signal. A modulation scheme is used.

  By using a modulation scheme having a smaller modulation multi-level number than the first modulation scheme for the second modulation scheme, even when interference between channels occurs in the DL section, the D-UL signal Since demodulation errors can be reduced, deterioration of transmission quality (for example, reception quality of D-UL signal) can be suppressed. In addition, since the UL signal (D-UL signal) can be transmitted and received using a channel (D-UL channel) that is not used for DL signal transmission and reception in the DL section, transmission efficiency (for example, UL signal transmission efficiency) is improved. Can be made.

  Although FIG. 3 shows the case where 256QAM is used as the modulation scheme used for the U-UL signal and 16QAM is used as the modulation scheme used for the modulation of the D-UL signal, the present disclosure is limited to these modulation schemes. Any modulation scheme can be used. In addition, although the case where the modulation system used for the modulation of the D-UL signal is changed has been described, the present disclosure can change the code rate of the error correction code in the D-UL signal, and the D-UL signal can be changed. In the signal transmission section, the same information can be transmitted from a plurality of antennas. In addition, for example, it is also possible to combine these, such as changing both the modulation scheme and the code rate of the error correction code.

  FIG. 3 shows an example in which two channels selected by the base station 100 are channels included in the same frequency band and adjacent to each other. For example, the channels selected by the base station 100 may be channels that are included in the same frequency band and are not adjacent to each other.

  Even when the channels are not adjacent to each other, there is a possibility that interference between channels may occur due to leakage outside the band. The influence of interference between channels due to out-of-band leakage varies depending on the magnitude of the detuning frequency between channels.

  Next, a case where the detuning frequency between the selected channels is different from the example of FIG. 3 will be described with reference to FIG.

  FIG. 4 is a diagram showing a second example of transmission / reception signals according to the present embodiment.

The horizontal axis in FIG. 4 indicates time, and the vertical axis indicates frequency. 4 shows, similarly to FIG. 3, Band1 including the channel _{f 11} and the channel _{f 12} and the channel _{f 13} is shown.

  FIG. 4 shows two frames, an nth frame (n is an integer equal to or greater than 1) (frame #n) and an n + 1th frame (frame # n + 1).

In FIG. 4, the base station 100 selects the channel f ₁₁ and the channel f ₁₃ among the three channels, sets the channel f ₁₁ to the D-DL channel, and sets the channel f ₁₃ to the D-UL channel. It is an example of the transmitted / received signal.

In the example of FIG. 4, in the UL section, the terminal 200 transmits a UL signal (U-UL signal) using the channel _{f 11} and the channel _{f 13,} the base station 100 using the channel _{f 11} and the channel _{f 13} The U-UL signal is received. In the example of FIG. 4, the modulation method (first modulation method) used for modulating the U-UL signal is 256QAM.

Then, in the example of FIG. 4, in the DL interval, the base station 100 transmits a DL signal by using the channel _{f 11,} the terminal 200 transmits a UL signal using the channel _{f 13} (D-UL signal) . In DL duration, base station 100 receives the D-UL signals transmitted by the terminal 200 using the channel _{f 13,} terminal 200, DL signal transmitted by the base station 100 using the channel _{f 11} Receive. In the example of FIG. 4, the modulation method (second modulation method) used for modulating the D-UL signal is 64QAM. The modulation level of 64QAM is 64.

  As shown in FIG. 4, in the radio communication system according to the present embodiment, when the D-UL channel selected by the base station 100 is a channel that is not adjacent to the D-DL channel, in the DL section, the base station 100 transmits a DL signal using a D-DL channel, and the terminal 200 transmits a D-UL signal using a D-UL channel. At that time, the modulation scheme (second modulation scheme) used for modulating the D-UL signal has a smaller modulation multi-level number than the modulation scheme (first modulation scheme) used for modulating the U-UL signal. A modulation scheme is used.

  By using a modulation scheme having a smaller modulation multi-level number than the first modulation scheme for the second modulation scheme, even when interference between channels occurs in the DL section, the D-UL signal Since demodulation errors can be reduced, deterioration of transmission quality (for example, reception quality of D-UL signal) can be suppressed. In addition, since the UL signal (D-UL signal) can be transmitted and received using a channel (D-UL channel) that is not used for DL signal transmission and reception in the DL section, transmission efficiency (for example, UL signal transmission efficiency) is improved. Can be made.

  As shown in FIGS. 3 and 4, the second modulation scheme is set based on the magnitude of the detuning frequency between channels.

  For example, since the detuning frequency between the D-DL channel and the D-UL channel is larger in the example of FIG. 4 than in the example of FIG. 3, the influence of interference between channels in the example of FIG. Smaller than. Therefore, the second modulation scheme in the example of FIG. 4 is set to a modulation scheme having a modulation multilevel number that is larger than the modulation multilevel number of the second modulation scheme in the example of FIG. As a result, an appropriate modulation scheme is set based on the magnitude of the influence of interference between channels due to the magnitude of the detuning frequency between channels, thereby suppressing the deterioration of transmission quality and improving the transmission efficiency. Can be balanced.

  In this way, by setting the second modulation method based on the magnitude of the detuning frequency between channels, it is possible to achieve both suppression of deterioration of transmission efficiency and improvement of transmission efficiency.

  In the above description, an example in which the base station 100 selects two channels has been described. Next, an example in which the base station 100 selects three channels will be described with reference to FIGS. When the base station 100 selects three channels, the second modulation scheme may be changed according to the channel (D-DL channel) in which the DL signal is transmitted and received in the DL section among the selected three channels. .

  FIG. 5 is a diagram illustrating a third example of the transmission / reception signal according to the present embodiment.

The horizontal axis in FIG. 5 indicates time, and the vertical axis indicates frequency. FIG. 5 shows Band 1 including channel f ₁₁ , channel f _12, and channel f ₁₃ as in FIGS. 3 and 4.

  FIG. 5 shows two frames, an nth frame (n is an integer equal to or greater than 1) (frame #n) and an n + 1th frame (frame # n + 1).

In FIG. 5, the base station 100 selects the channel f ₁₁ , the channel f _12, and the channel f ₁₃ included in Band 1, sets the channel f ₁₁ to the D-DL channel, and sets the channel f ₁₃ and the channel f ₁₃ to D. It is an example of the transmission / reception signal at the time of setting to -UL channel.

In the example of FIG. 5, in the UL section, the terminal 200 transmits a UL signal (U-UL signal) using the channel f ₁₁ , the channel f _12, and the channel f _13, and the base station 100 transmits the channel f ₁₁ and the channel f _13. using the f ₁₂ and the channel _{f 13} receives a U-UL signal. In the example of FIG. 5, the modulation scheme (first modulation scheme) used for modulating the U-UL signal is 256QAM.

In the example of FIG. 5, in the DL section, the base station 100 transmits a DL signal using the channel f ₁₁ , and the terminal 200 uses the channel f ₁₂ and the channel f ₁₃ to transmit the UL signal (D-UL Signal). In the DL section, the base station 100 receives the D-UL signal transmitted by the terminal 200 using the channel f ₁₂ and the channel f _13, and the terminal 200 is transmitted by the base station 100 using the channel f ₁₁ . The transmitted DL signal is received.

  In the example of FIG. 5, terminal 200 transmits a D-UL signal using each of a plurality of D-UL channels. In this case, a modulation method (second modulation method) used for modulating the D-UL signal is set according to the magnitude of the detuning frequency between the D-UL channel and the D-DL channel.

In the example of FIG. 5, the magnitude df _a of the detuning frequency between the channel f ₁₁ and the channel f ₁₂ is smaller than the magnitude df _c of the detuning frequency between the channel f ₁₁ and the channel f _13. The D-UL signal transmitted using the channel f ₁₂ uses a modulation scheme having a smaller modulation multi-value number than the modulation scheme of the D-UL signal transmitted using the channel f ₁₃ . In the example of FIG. 5, the modulation scheme of the D-UL signals transmitted using channel _{f 12} is 16QAM, the modulation method of the D-UL signals transmitted using channel _{f 13} is 64QAM.

  As shown in FIG. 5, when a plurality of D-UL channels are set, each of the plurality of D-UL channels is determined based on the magnitude of the detuning frequency between the D-UL channel and the D-DL channel. By setting the second modulation method, it is possible to achieve both suppression of deterioration of transmission efficiency and improvement of transmission efficiency.

  FIG. 6 is a diagram illustrating a fourth example of the transmission / reception signal according to the present embodiment.

In FIG. 6, the horizontal axis indicates time, and the vertical axis indicates frequency. FIG. 6 shows Band 1 including channel f ₁₁ , channel f _12, and channel f ₁₃ as in FIGS. 3 to 5.

  FIG. 6 shows two frames, an n-th frame (n is an integer equal to or greater than 1) (frame #n) and an n + 1-th frame (frame # n + 1).

The example of FIG. 6 is an example of transmission / reception signals when the base station 100 selects the channel f ₁₁ , the channel f _12, and the channel f ₁₃ included in Band 1, as in the example of FIG. However, in the example of FIG. 6, unlike the example of FIG. 5, the base station 100 sets the channel f ₁₂ to the D-DL channel and sets the channels f ₁₁ and f ₁₃ to the D-UL channel. . In the example of FIG. 6, the DL duration, the base station 100 transmits a DL signal by using the channel _{f 12,} the terminal 200 uses the channel _{f 11} and the channel _{f 13} UL signal (D-UL signal) Send.

  In the example of FIG. 6, as in the example of FIG. 5, the terminal 200 transmits a D-UL signal using each of a plurality of D-UL channels. In this case, a modulation scheme (second modulation scheme) used for modulation of the second UL signal is set according to the magnitude of the detuning frequency between the D-UL channel and the D-DL channel.

For example, in the example of FIG. 6, the magnitude df _a of the detuning frequency between the channel f ₁₁ and the channel f ₁₂ is the same as the magnitude df _b of the detuning frequency between the channel f ₁₂ and the channel f _13. Therefore, the D-UL signal transmitted using the channel f ₁₁ uses the same modulation multi-level modulation scheme as that of the D-UL signal transmitted using the channel f ₁₃ . In the example of FIG. 6, the modulation scheme of the D-UL signal transmitted using a modulation scheme and a channel _{f 13} of D-UL signals transmitted using channel _{f 11} are each an 16QAM.

  As shown in FIGS. 5 and 6, when a plurality of D-UL channels are set, a plurality of D-ULs are determined based on the magnitude of the detuning frequency between the D-UL channel and the D-DL channel. By setting the second modulation method for each channel, it is possible to achieve both suppression of deterioration of transmission efficiency and improvement of transmission efficiency.

  As described above, when the base station 100 selects a plurality of channels as channels used for communication, the base station 100 modulates the U-UL signal and / or the positional relationship between the D-DL channel and the D-UL channel ( For example, the D-UL signal modulation scheme (second modulation scheme) is set based on the magnitude of the detuning frequency. When a plurality of D-UL channels are set, the second modulation scheme is set for each D-UL signal transmitted / received using each of the plurality of D-UL channels. When base station 100 sets the second modulation scheme, base station 100 notifies terminal 200 of information indicating the set second modulation scheme.

<DL signal frame format>
Next, an example of a DL signal frame format including information to be notified to terminal 200 will be described.

  FIG. 7 is a diagram illustrating an example of a format of a frame included in the DL signal.

  The format shown in FIG. 7 includes a field F1 including information of “modulation scheme, coding rate, MIMO related information, and ACK / NACK”, a field F2 including information of “modulation scheme of UL signal in DL section,” The field F3 includes “interference amount information and frequency information”.

  Field F1 includes a modulation scheme of a UL signal transmitted using each of a plurality of channels in the UL section, a coding rate of error correction coding, and MIMO related information. The field F1 includes ACK (Acknowledgement) or NACK (Negative Acknowledgement) information indicating success or failure of reception of the UL signal. The plurality of channels may correspond to, for example, a channel selected by the base station 100, or may correspond to, for example, all usable channels. For example, the information included in the field F1 is indicated by 256 bits per channel. The size of the field F1 corresponds to, for example, 256 bits × the number of channels.

  Field F2 includes information such as the modulation scheme of the UL signal (D-UL signal) transmitted by terminal 200 in the DL section. For example, the information included in the field F2 is indicated by 8 bits per channel. When one channel is used for transmission / reception of a DL signal in the DL section among the channels selected by the base station 100, the size of the field F2 corresponds to 8 bits × (number of channels−1). However, as the modulation scheme of the UL signal (D-UL signal) transmitted by the terminal 200, if a value fixedly determined by the detuning frequency with the channel used for transmission / reception of the DL signal is used, the field F2 Can be unnecessary. However, by adding the field F2, it is possible to set the modulation scheme of the UL signal (D-UL signal) more flexibly, so that both the transmission efficiency and the communication quality of the UL signal (D-UL signal) are achieved. The degree of freedom for setting is improved.

  The field F3 includes frequency information and interference amount information for each of a plurality of channels. For example, the information included in the field F3 is indicated by 16 bits per channel. The size of the field F3 corresponds to, for example, 16 bits × the number of channels.

<Processing flow of base station 100>
Next, a processing flow of base station 100 in the present embodiment will be described. FIG. 8 is a flowchart showing an example of a processing flow of base station 100 in the present embodiment. In FIG. 8, the base station 100 selects two channels (channel # 1 and channel # 2), sets channel # 1 as a D-UL channel, and sets channel # 2 as D-DL. This is an example of setting a channel. FIG. 8 shows a processing flow of signal transmission / reception using two channels (channel # 1 and channel # 2) in the UL section and DL section of the nth frame.

  The base station 100 receives the UL signal transmitted by the terminal 200 using the channel # 1 and the channel # 2 in the UL section (S101). In S101, the UL signal received by base station 100 is a UL signal transmitted by terminal 200 using a first transmission method (for example, a transmission method including a 256QAM modulation scheme).

  The base station 100 performs reception signal processing on the received UL signal using a first reception method corresponding to the first transmission method (for example, a reception method including demodulation corresponding to 256QAM) (S102). .

  The base station 100 determines whether or not the DL signal transmission timing has arrived, that is, whether or not the DL section start timing has arrived (S103).

  If the DL signal transmission timing has not arrived (NO in S103), that is, if it is in the UL period, the flow returns to the processing of S101, and the base station 100 continues until the DL signal transmission timing arrives. , UL signal is received.

  When the DL signal transmission timing arrives (YES in S103), base station 100 receives the UL signal transmitted by terminal 200 using channel # 1 and uses channel # 2 in the DL section. The DL signal is transmitted to the terminal 200 (S104). In S104, the UL signal received by base station 100 is a UL signal transmitted by terminal 200 using a second transmission method (for example, a transmission method including a 16QAM modulation scheme).

  The base station 100 performs reception signal processing on the received UL signal using a second reception method corresponding to the second transmission method (for example, a reception method including demodulation corresponding to 16QAM) (S105). .

  Then, the UL signal is received and the DL signal is transmitted until the end of the DL section in the nth frame, and the flow ends.

<Processing flow of terminal 200>
Next, a processing flow of terminal 200 in the present embodiment will be described. FIG. 9 is a flowchart showing an example of a processing flow of terminal 200 in the present embodiment. In FIG. 9, the base station 100 selects two channels (channel # 1 and channel # 2), sets the channel # 1 to the D-UL channel, and sets the channel # 2 to the D-DL. This is an example of setting a channel. FIG. 9 shows a process flow of signal transmission / reception using two channels (channel # 1 and channel # 2) in the UL section and DL section of the nth frame.

  The terminal 200 performs transmission signal processing of the UL signal using a first transmission method (for example, a transmission method including a 256QAM modulation scheme) (S201).

  The terminal 200 transmits a UL signal to the base station 100 using the channel # 1 and the channel # 2 in the UL section (S202).

  The terminal 200 determines whether or not the DL signal reception timing has arrived, that is, whether or not the DL section start timing has arrived (S203).

  When the DL signal reception timing has not arrived (NO in S203), that is, in the UL period, the flow returns to the process of S201, and until the DL signal reception timing is reached, terminal 200 A UL signal is transmitted.

  When the reception timing of the DL signal has arrived (YES in S203), terminal 200 performs transmission signal processing of the UL signal using the second transmission method (for example, a transmission method including a 16QAM modulation scheme) ( S204).

  Then, in the DL section, terminal 200 transmits a UL signal to base station 100 using channel # 1, and receives a DL signal transmitted by base station 100 using channel # 2 (S205). ). Then, the UL signal is transmitted and the DL signal is received until the end of the DL section in the nth frame, and the flow ends.

  As described above, in the present embodiment, base station 100 transmits a DL signal to terminal 200 using the D-DL channel in the DL section. Then, the base station 100 receives the UL signal (U-UL signal) transmitted by the terminal 200 using the first transmission method in the UL section, uses the D-UL channel in the DL section, and transmits the terminal 200. Receives the UL signal (D-UL signal) transmitted using the second transmission method having higher reception performance than the first transmission method. With this configuration, even when interference between channels occurs between the D-DL channel and the D-UL channel, the D-UL signal received using the D-UL channel has a reception performance of Since a high transmission method is applied, deterioration of transmission quality can be suppressed. Moreover, since UL signals can be transmitted and received in the DL section in addition to the UL section, the transmission efficiency of the UL signal can be improved.

  Further, according to the present embodiment, UL / DL selection section 108 of base station 100 uses a channel with a relatively low carrier frequency among the channels selected by channel selection section 107 for DL transmission. select. With this selection method, the base station 100 can transmit a DL signal using a channel having a relatively small propagation loss, and therefore, it is possible to suppress deterioration in transmission quality of the DL signal.

  In the above-described embodiment, an example in which UL / DL selection section 108 selects a channel with a relatively low carrier frequency as a D-DL channel among the channels selected by channel selection section 107 has been described. However, the present disclosure is not limited to this.

  For example, the UL / DL selection unit 108 selects a channel having a relatively low reception level (interference amount) measured by the interference measurement unit 106 among the channels selected by the channel selection unit 107 as a D-DL channel. May be. With this selection method, the base station 100 can transmit a DL signal using a channel with relatively little interference from other systems, so that it is possible to suppress degradation in the transmission quality of the DL signal.

  In the embodiment described above, the channel selection unit 107 of the base station 100 selects a channel to be used for communication based on the result of interference measurement, and the UL / DL selection unit 108 is An example in which each selected channel is set to a D-UL channel or a D-DL channel has been described. The present disclosure is not limited to this. For example, the base station 100 and the terminal 200 may use a preset channel, or a D-UL channel or a D-DL channel may be preset. In this case, the signal processing parameter of the D-UL signal transmitted / received using the D-UL channel may be set in advance.

  For example, when the channel used for communication and the setting of whether the channel is used for the D-UL channel or the D-DL channel are known between the base station 100 and the terminal 200, the base station 100 does not need to transmit channel information to the terminal 200.

  Further, in the embodiment described above, the available frequency bands and the number of channels included in each frequency band are examples, and the present disclosure is not limited thereto. For example, two or more usable frequency bands may be used, and the number of channels included in each frequency band may be four or more, or two or less. The number of channels included in each frequency band may be different from each other.

  Moreover, in embodiment described above, the example which the base station 100 selects as a channel used for communication was shown in FIGS. 3-6 by the channel contained in the same frequency band. The present disclosure is not limited to this. For example, the base station 100 may select channels included in different frequency bands as channels used for communication, and set the selected channel as a D-DL channel or a D-UL channel. In this case, the base station 100 uses the D-UL channel based on the modulation scheme of the U-UL signal and / or the positional relationship between the D-DL channel and the D-UL channel (for example, the magnitude of the detuning frequency). May be used to set signal processing parameters for D-UL signals transmitted and received.

  Further, in the embodiment described above, an example in which one channel is set as a D-DL channel is shown. The present disclosure is not limited to this. For example, the base station 100 may set two or more channels as D-DL channels. In this case, the base station 100 determines the D-UL channel based on the U-UL signal transmission / reception method and / or the positional relationship between the D-DL channel and the D-UL channel (for example, the magnitude of the detuning frequency). May be used to set signal processing parameters for D-UL signals transmitted and received.

  While various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present disclosure. Understood. In addition, the constituent elements in the above embodiments may be arbitrarily combined within the scope not departing from the spirit of the disclosure.

  In each of the above-described embodiments, the present disclosure has been described for an example configured using hardware. However, the present disclosure can also be realized by software in cooperation with hardware.

  Each functional block used in the description of the above embodiment is typically realized as an LSI which is an integrated circuit. The integrated circuit may control each functional block used in the description of the above embodiment, and may include an input and an output. These may be individually made into one chip, or may be made into one chip so as to include a part or all of each functional block. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

  Further, the method of circuit integration is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor in which connection and setting of circuit cells in the LSI can be reconfigured may be used.

  Furthermore, if integrated circuit technology that replaces LSI appears as a result of progress in semiconductor technology or other derived technology, the functional blocks may naturally be integrated using another technology. Biotechnology can be applied as a possibility.

  In addition, this indication can be expressed as a control method performed in a radio | wireless communication apparatus or a control apparatus. In addition, the present disclosure can be expressed as a program for operating such a control method by a computer. Furthermore, the present disclosure can be expressed as a recording medium in which such a program is recorded in a state that can be read by a computer. That is, the present disclosure can be expressed in any category of an apparatus, a method, a program, and a recording medium.

  Further, the present disclosure is not limited to the above-described embodiment in terms of the type, arrangement, number, and the like of the members, and departs from the gist of the invention, such as appropriately replacing the constituent elements with those having the same effects. It can change suitably in the range which does not. For example, it goes without saying that the present disclosure can be similarly applied to a communication mode in which video information and user data are transmitted by DL and control information on DL is transmitted by UL.

  The present disclosure is suitable for use in a terminal such as an FPU and a base station.

100 base station 101, 201 transmission / reception switching unit 102-1 to 102-M, 202-1 to 202-N wireless reception unit 103, 203 baseband reception processing unit 104, 204 AGC / synchronization detection unit 105, 205 reception processing control unit 106 Interference measurement unit 107 Channel selection unit 108 UL / DL selection unit 109 Channel information generation unit 110, 207 Baseband transmission processing unit 111, 208 Preamble generation unit 112, 209 Addition unit 113-1 to 113-N, 210-1 210-M wireless transmission unit 114, 211 reception unit 115, 212 transmission unit 200 terminal 206 channel information extraction unit

Claims (10)

A base station that uses a plurality of channels to perform time-division duplex wireless communication with a terminal,
A transmission unit that transmits the downlink signal to the terminal using the first channel in a transmission period of the downlink signal;
In the reception period of the first uplink signal, the terminal transmits the first uplink signal transmitted using the first transmission method using the first reception method corresponding to the first transmission method. Receiving, using a second channel different from the first channel in the transmission period of the downlink signal, and using the second transmission method in which the terminal has higher reception performance than the first transmission method. A reception unit that receives the transmitted second uplink signal using a second reception method corresponding to the second transmission method;
Comprising
base station. As the interval in the frequency direction between the first channel and the second channel is narrower, the reception performance of the second transmission method is higher than the reception performance of the first transmission method.
The base station according to claim 1. The first channel and the second channel are included in the same frequency band.
The base station according to claim 1. A channel selection unit that selects the plurality of channels from among available channels;
A UL / DL selector configured to set each of the plurality of channels to the first channel or the second channel, and to set the second transmission method for the second channel;
With
The downlink signal includes information indicating whether each of the plurality of channels is the first channel or the second channel, and information indicating the second transmission method.
The base station according to claim 1. The first transmission method includes a modulation scheme having a first modulation multilevel number,
The second transmission method includes a modulation scheme having a modulation multilevel number smaller than the first modulation multilevel number,
The base station according to claim 1. The first transmission method includes an error correction coding method having a first coding rate,
The second transmission method includes an error correction coding method having a coding rate smaller than the first coding rate.
The base station according to claim 1. The second transmission method includes a method of transmitting from a plurality of antennas using a space-time code.
The base station according to claim 1. A terminal that performs time division duplex wireless communication with a base station using a plurality of channels,
A receiving unit that receives the downlink signal transmitted by the base station using the first channel in a reception period of a downlink signal;
In the first uplink signal transmission section, the first uplink signal is transmitted to the base station using a first transmission method, and in the downlink signal reception section, the base station A transmitter that uses a second channel different from the first channel and transmits a second uplink signal using a second transmission method having higher reception performance than the first transmission method;
Comprising
Terminal. A wireless communication system in which a terminal and a base station perform time division duplex wireless communication using a plurality of channels,
The base station
A transmitter that transmits the downlink signal to the terminal using the first channel in a section of the downlink signal;
In the first uplink signal section, the terminal receives the first uplink signal transmitted using the first transmission method, using the first reception method corresponding to the first transmission method. In the downlink signal section, a second channel different from the first channel is used, and the terminal transmits using a second transmission method having higher reception performance than the first transmission method. A reception unit that receives a second uplink signal using a second reception method corresponding to the second transmission method;
With
The terminal
A receiver that receives the downlink signal using the first channel in a section of the downlink signal;
In the first uplink signal section, the first transmission signal is transmitted using the first transmission method, and in the downlink signal section, the second channel is used, and A transmission unit that transmits the second uplink signal using the transmission method 2;
Comprising
Wireless communication system. A communication method in which a terminal and a base station perform wireless communication of time division duplex using a plurality of channels,
The base station
In the downlink signal section, the downlink signal is transmitted to the terminal using the first channel,
In the first uplink signal section, the terminal receives the first uplink signal transmitted using the first transmission method, using the first reception method corresponding to the first transmission method. And
A second channel transmitted using a second transmission method having higher reception performance than the first transmission method by using a second channel different from the first channel in the downlink signal section And receiving an uplink signal using a second reception method corresponding to the second transmission method,
The terminal
Receiving the downlink signal using the first channel in a section of the downlink signal;
Transmitting the first uplink signal using the first transmission method in a section of the first uplink signal;
In the section of the downlink signal, the second channel is used, and the second uplink signal is transmitted using the second transmission method.
Communication method.

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