WO2011093511A1 - Wireless communication system, transmitter and multicarrier communication method - Google Patents

Wireless communication system, transmitter and multicarrier communication method Download PDF

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WO2011093511A1
WO2011093511A1 PCT/JP2011/052075 JP2011052075W WO2011093511A1 WO 2011093511 A1 WO2011093511 A1 WO 2011093511A1 JP 2011052075 W JP2011052075 W JP 2011052075W WO 2011093511 A1 WO2011093511 A1 WO 2011093511A1
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signals
digital signal
communication system
transmitter
complex
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PCT/JP2011/052075
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French (fr)
Japanese (ja)
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高木　直
亀田　卓
坪内　和夫
細谷　健一
丸橋　建一
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日本電気株式会社
国立大学法人東北大学
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Priority to JP2011551967A priority Critical patent/JP5799463B2/en
Publication of WO2011093511A1 publication Critical patent/WO2011093511A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2637—Modulators with direct modulation of individual subcarriers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/30—Systems using multi-frequency codes wherein each code element is represented by a combination of frequencies

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  • the present invention relates to a high-speed wireless communication system using a multicarrier with high frequency utilization efficiency such as OFDM (Orthogonal Frequency Domain Modulation), and more particularly to a transmitter using an RF amplifier with high power efficiency.
  • OFDM Orthogonal Frequency Domain Modulation
  • the OFDM wireless communication system is currently used in a wireless local area network (LAN) and is one of methods for realizing high-speed wireless communication.
  • a general configuration of a transmitter used in an existing OFDM wireless communication system is described in Non-Patent Document 1, for example.
  • a transmitter used in the OFDM wireless communication system disclosed in Non-Patent Document 1 is shown in FIG.
  • an input digital signal sequence t ⁇ D ⁇ is converted into a parallel complex symbol sequence ⁇ S ⁇ by a symbol mapper 100 and a serial-parallel converter 101.
  • the parallel complex symbol sequence ⁇ S ⁇ is subjected to matrix calculation processing by the frequency mapper 102, the inverse discrete Fourier transformer 103, and the parallel-serial converter 104.
  • a complex OFDM symbol sample value sequence t ⁇ V ⁇ is generated.
  • An appropriate guard interval is added to the complex OFDM symbol sample value sequence t ⁇ V ⁇ by the guard interval circuit 105 and further converted into a complex analog OFDM signal V BB (t) by the DA converter 106.
  • the complex analog OFDM signal V BB (t) is converted into a quadrature modulated RF signal V RF (t) by a quadrature modulator 109 including a quadrature modulation mixer 107 and a local oscillator 108.
  • the RF signal V RF (t) is amplified to a high output by the RF amplifier 110 and is transmitted from the antenna 111 to the space.
  • the OFDM wireless communication system having the above configuration generally has excellent characteristics such as high frequency utilization efficiency and resistance to multipath fading by providing an appropriate guard interval.
  • the configuration of the OFDM modulation circuit used in the OFDM wireless communication system is also described in Patent Document 1.
  • the input signal sequence is divided into a plurality of systems and assigned to each subcarrier, and then the D / A conversion circuit and the orthogonal modulation circuit of each system are used. Then, a plurality of systems are input to the synthesizer, and an output signal input to the amplifier is generated.
  • the RF signal V RF (t) input to the RF amplifier is a multi-carrier modulation signal including a large number of carriers, and the peak power with respect to the average power of the signal.
  • PAPR Peak to Average Power Ratio
  • FIG. 11 is an example of output power and power efficiency characteristics of an amplifier in a wireless communication system.
  • the power efficiency of an amplifier is generally maximized when operating at a saturated output power level and significantly decreases when operated with a large backoff from saturation. The increase in power consumption resulting from this result becomes a problem for the wireless communication system.
  • a high-power amplifier having a large saturation output power is required to construct a wireless communication system.
  • an input digital signal sequence is serial-parallel converted and input to a plurality of DA converters, and analog signals obtained from the plurality of DA converters are combined into an input system.
  • a signal synthesizer that combines two or more outputs, a plurality of quadrature modulation mixers that modulate the analog signals combined and output by the signal synthesizer into a quadrature-modulated RF signal, and the plurality of quadrature modulation mixers
  • a transmitter that performs multicarrier communication, and includes a plurality of RF amplifiers that individually amplify a plurality of orthogonally modulated RF signals in correspondence with subcarrier frequencies.
  • a multi-carrier communication method in a communication system using a multicarrier modulation signal, a transmitter, a wireless communication system, and a transmitter that realize high power efficiency while reducing backoff of an RF amplifier used in the transmitter and maintaining high frequency utilization efficiency
  • a multi-carrier communication method can be provided.
  • a local oscillator having a common frequency or a common local oscillator can be used.
  • FIG. 1 is a configuration diagram of a transmitter of a wireless communication system according to the first embodiment of the present invention.
  • FIG. 2 is a configuration diagram of the transmitter of the wireless communication system according to the third embodiment of the present invention.
  • FIG. 3 is a configuration diagram of the transmitter of the radio communication system according to the fourth embodiment of the present invention.
  • FIG. 4 is a configuration diagram of a transmitter of a wireless communication system according to the fifth embodiment of the present invention.
  • FIG. 5 is a configuration diagram of the transmitter of the wireless communication system according to the sixth embodiment of the present invention.
  • FIG. 6 is an explanatory diagram showing the state of signals when the windowing processing circuit according to the present invention is loaded.
  • FIG. 7 is a configuration diagram of a transmitter of a wireless communication system according to the seventh embodiment of the present invention.
  • FIG. 8 is a configuration diagram of the transmitter of the wireless communication system according to the eighth embodiment of the present invention.
  • FIG. 9 is a configuration diagram of a transmitter of a wireless communication system according to the ninth embodiment of the present invention.
  • FIG. 10 is a general configuration diagram of a transmitter used in an OFDM wireless communication system.
  • FIG. 11 is an explanatory diagram illustrating an example of output power and power efficiency characteristics of an amplifier.
  • FIG. 1 is a configuration diagram of a transmitter of a wireless communication system according to the first embodiment of the present invention.
  • the illustrated transmitter includes a symbol mapper 1 that converts an input digital signal sequence t ⁇ D ⁇ into a complex symbol sequence, and a serial-parallel converter 2 that converts the generated complex symbol sequence into parallel complex symbols (S).
  • the frequency mapper 3 for assigning individual frequencies to each of the complex symbols (s 0 to s N-1 ) included in the parallel complex symbol (S), and the phase rotation corresponding to the assigned frequency, respectively.
  • the complex digital signal sampled sequence (t ⁇ v 0 ⁇ ⁇ t ⁇ v N-1 ⁇ ) digital signal processing circuit 4 for generating the generated complex digital signal samples train (t ⁇ v 0 ⁇ ⁇ t ⁇ v N- 1 ⁇ ) are converted from complex analog signals (V BB.0 (t) to V BB.N-1 (t)), and output from the plurality of DA converters, respectively.
  • N complex ana Grayed signal (V BB.0 (t) ⁇ V BB.N-1 (t)) and a combiner 16 for combining the M signals, the real part from each of the complex analog signal is quadrature gathered into M
  • a plurality of orthogonal modulation mixers 6 that generate modulated RF signals (V RF.0 (t) to V RF.M-1 (t)), and a plurality of local oscillation signals that supply local oscillation signals to the respective orthogonal modulation mixers.
  • the digital signal processing circuit 4 operates as signal processing means.
  • the DA converter 5 operates as DA conversion means.
  • the synthesizer 16 operates as a signal synthesizer.
  • a set of the quadrature modulation mixer 6 and the local oscillator 7 operates as a set of quadrature modulation means or circuit.
  • the RF amplifier 8 operates as RF amplification means or a circuit. Next, the operation will be described.
  • the input digital signal sequence t ⁇ D ⁇ is converted into a parallel complex symbol (s) including N complex symbols (s 0 to s N-1 ) by the symbol mapper 1 and the serial-parallel converter 2.
  • an individual frequency (f 0 , f 1 ,..., F k ,..., F N ⁇ 1 ) is assigned to each complex symbol (s 0 to s N ⁇ 1 ) by the frequency mapper 3,
  • the digital signal processing circuit 4 generates a complex digital signal sample sequence t (v) to which a phase rotation corresponding to each assigned frequency is given.
  • f k (1 ⁇ k ⁇ N ⁇ 1) shown as the phase term in (3) and (5) corresponds to the frequency given by this operation.
  • the N complex digital signal sample sequences ( t ⁇ v 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ) are respectively converted into complex analog signals (V BB.0 (t) to V BB.N ⁇ by the DA converter 5. 1 (t)).
  • the N complex analog signals (V BB.0 (t) to V BB.N-1 (t)) output from each DA converter 5 are combined into M signals by the synthesizer 16 and synthesized.
  • the combined complex analog signal is converted into an RF signal (V RF.0 (t) to V RF.M-1 (t)) that is quadrature modulated by the quadrature modulation mixer 6 and the local oscillator 7.
  • the quadrature-modulated RF signals (V RF.0 (t) to V RF.M ⁇ 1 (t)) are respectively amplified by the RF amplifier 8 and transmitted from the antenna 9 to the air.
  • V RF.0 (t) to V RF.M ⁇ 1 (t) are respectively amplified by the RF amplifier 8 and transmitted from the antenna 9 to the air.
  • the power consumption of the transmitter can be reduced while maintaining frequency use efficiency, and high frequency use can be achieved.
  • the power consumption per bit can be reduced while maintaining the efficiency (bit / Hz).
  • the matrix (F ⁇ 1 ) is an inverse discrete Fourier transform matrix (IDFT), and the matrix (F) is a discrete Fourier transform matrix (DFT).
  • IDFT inverse discrete Fourier transform matrix
  • DFT discrete Fourier transform matrix
  • RF signals (V RF.0 (t) to V RF.M-1 ) orthogonally modulated from each of the complex digital signal sample sequences ( t ⁇ v 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ). (T)) can be generated and each RF signal (V RF.0 (t) to V RF.N-1 (t)) can be individually amplified, which is a problem with existing OFDM modulated signals.
  • the problem of large PAPR is reduced.
  • FIG. 2 is a configuration diagram of the transmitter of the wireless communication system according to the third embodiment of the present invention. The difference from the configuration of FIG. 1 is that a local oscillator that supplies local oscillation signals to N orthogonal modulation mixers 6 is configured by a single common local oscillator 10 that generates a common local oscillation signal. is there. Next, the operation will be described.
  • each frequency (f 0 , f 1 ) is divided by the frequency mapper 3 for each of the complex symbols (s 0 to s N-1 ) included in the parallel complex symbols (S). 1 ,..., F k ,..., F N ⁇ 1 ), and further, a complex digital signal sample sequence ( t) given a phase rotation corresponding to each assigned frequency by the digital signal processing circuit 4 ⁇ V 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ).
  • the local signal supplied to each quadrature modulation mixer 6 in FIG. 2 may have the same frequency.
  • one common local oscillator 10 can be used.
  • FIG. 3 is a configuration diagram of a radio communication system according to the fourth embodiment of the present invention. Compared with the configuration of FIG. 1 and FIG. 2, a plurality of power combiners 11 for combining the RF signals individually amplified by each RF amplifier 8, and the combined RF signals corresponding to each power combiner 11. Is different in that it includes a plurality of antennas 12 that transmit the signal to the air. Next, the operation will be described.
  • a plurality of RF signals individually amplified by each RF amplifier 8 are combined by the power combiner 11 and then transmitted from the antenna 12 to the air, so that the number of antennas to be used can be reduced.
  • the configuration shown in FIG. 3 is an example in which all of the RF signals individually amplified by each RF amplifier 8 are combined by one power combiner and transmitted from one antenna to the air.
  • a plurality of power combiners may be used.
  • the number n of the power combiners 11 is the number of input systems that is the number of RF amplifiers 8> n ⁇ 1.
  • FIG. 4 is a configuration diagram of a radio communication system according to the fifth embodiment of the present invention. Compared with FIGS. 1 to 3, the transmitter of the wireless communication system in FIG.
  • FIG. 5 is a configuration diagram of a radio communication system according to the sixth embodiment of the present invention. Compared to FIG. 4, the windowing processing circuit 14 is loaded between the guard interval circuit 13 and the plurality of DA converters 5.
  • FIG. 6 is a diagram showing the state of signals when the windowing processing circuit 14 is loaded. As shown in FIG.
  • FIG. 7 is a configuration diagram of a transmitter of a wireless communication system according to the seventh embodiment of the present invention.
  • the illustrated transmitter includes a symbol mapper 1 that converts an input digital signal sequence t ⁇ D ⁇ into a complex symbol sequence, and a serial-parallel converter 2 that converts the generated complex symbol sequence into parallel complex symbols (S).
  • the frequency mapper 3 for assigning individual frequencies to each of the complex symbols (s 0 to s N-1 ) included in the parallel complex symbol (S), and the phase rotation corresponding to the assigned frequency, respectively.
  • Digital signal processing circuit 4 for generating a complex digital signal sample sequence, a filter 15 for limiting the band of each complex digital signal sample sequence, and a complex analog signal (V BB.0 ( t) ⁇ V BB.N-1 ( t)) and the N DA converter 5 for converting into, the N complex analog signals output from the DA converter 5 (V B .0 (t) ⁇ V BB.N- 1 (t)) and the synthesizer 16 for synthesizing, synthesized the orthogonal modulated RF signal from the signal (V RF.0 (t) ⁇ V RF.M ⁇ 1 (t)), a plurality of local oscillators 7 for supplying local signals to the respective quadrature modulation mixers, and RF signals (V RF.0 (t ) To V RF.M-1 (t)), and a plurality of RF amplifiers 8 and antennas 9 for transmitting the amplified RF signals to the air.
  • the transmitter according to the seventh embodiment is different from the transmitter according to the first embodiment in that the filter 15 is provided.
  • the input digital signal sequence t ⁇ D ⁇ is converted into N complex symbols (s 0 to s N-1 ) by the symbol mapper 1 and the serial / parallel converter 2.
  • an individual frequency (f 0 , f 1 ,..., F k ,..., F N ⁇ 1 ) is assigned to each complex symbol (s 0 to s N ⁇ 1 ) by the frequency mapper 3
  • the digital signal processing circuit 4 applies a phase rotation corresponding to each assigned frequency to generate a complex digital signal sample sequence ( t ⁇ v 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ).
  • each complex symbol is expanded to a different frequency domain, and phase rotation is given to each so that a single carrier signal that can be individually demodulated can be generated.
  • N complex digital signal sample sequences ( t ⁇ V 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ) are generated.
  • the band of each complex digital signal sample sequence ( t ⁇ v 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ) is limited by the filter 15.
  • a roll-off filter is used as the filter 15.
  • each of the filtered complex digital signal sample sequences ( t ⁇ v 0 ⁇ to t ⁇ v N ⁇ 1 ⁇ ) is respectively converted into a complex analog signal (V BB.0 (t) to V BB.N by the DA converter 5. -1 (t)).
  • the combined complex analog signals are further converted into RF signals (V RF.0 (t) to V RF.M-1 (t)) that are quadrature modulated by the quadrature modulation mixer 6 and the local oscillator 7.
  • the quadrature-modulated RF signals (V RF.0 (t) to V RF.M-1 (t)) are further amplified by the RF amplifier 8 and transmitted from the antenna 9 into the air.
  • the quadrature modulated RF signals (V RF.0 (t) to V RF.M-1 (t)) amplified by the respective RF amplifiers 8 are single carrier modulation signals.
  • single carrier modulation for example, BPSK, QPSK, 8PSK, 16QAM, and 64QAM are applicable.
  • FIG. 8 is a configuration diagram of the transmitter of the wireless communication system according to the eighth embodiment of the present invention. The difference from the configuration of FIG. 7 is that a local oscillator that supplies local signals to N orthogonal modulation mixers 6 is configured by a single common local oscillator 10. Next, the operation will be described.
  • individual frequencies f 0 , f 1 ,..., F k ,..., F N ⁇ 1 ) are assigned to each parallel complex symbol s k. ing.
  • the digital signal processing circuit 4 provides phase rotation so that each complex symbol is developed in a separate frequency domain and can be individually demodulated, and as a result, N pieces of signals are generated.
  • complex digital signal samples train (t ⁇ v 0 ⁇ ⁇ t ⁇ v N-1 ⁇ ) is generated.
  • the local signal supplied to each quadrature modulation mixer 6 in FIG. 8 may have the same frequency.
  • one common local oscillator 10 can be used. Since only one local oscillator is required, the size can be reduced, and there is an advantage that the configuration can be simplified because it is not necessary to consider the frequency deviation between the local signals supplied to each quadrature modulation mixer 6.
  • a function capable of outputting a complex digital signal sample sequence corresponding to a multi-carrier communication system other than OFDM and OFDM is prepared in the circuit in advance in the signal processing circuit 4 ′. As a result, it is possible to selectively use the control signal according to the situation, and it is possible to realize that one wireless device supports two systems.
  • each of the N complex symbols is assigned to each of the N complex symbols, combined into a total of M signals (M ⁇ N), and further orthogonal modulation is performed. Then, each quadrature-modulated RF signal is individually amplified.
  • M ⁇ N M signals
  • each quadrature-modulated RF signal is individually amplified.
  • the signal processing circuit 4 and the signal processing circuit 4 ′ in the OFDM communication system and the filter 15 in the multicarrier communication system shown in the seventh and eighth embodiments are digital circuits. It is possible to change the presence / absence of the circuit and the order. On the other hand, it is desirable that the RF amplifier is provided at a stage subsequent to the quadrature modulator. Therefore, it is necessary to provide a process (combining) for grouping complex analog signals before the quadrature modulator.
  • the order is synthesizer ⁇ quadrature modulator ⁇ RF amplifier.
  • the specific configuration of the present invention is not limited to the above-described embodiment, and changes within a range not departing from the gist of the present invention are included in the present invention.
  • This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2010-017701 for which it applied on January 29, 2010, and takes in those the indications of all here.

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  • Computer Networks & Wireless Communication (AREA)
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Abstract

A transmitter in a wireless communication system is provided with: a signal synthesiser, which synthesises respective analogue signals, obtained by carrying out serial-parallel conversion on input digital signal sequences and inputting the signals into a plurality of DA converters, into at least two outputs combined with input lines; a plurality of quadrature modulation mixers, which modulate the analogue signals integrated and output by the signal synthesiser into quadrature modulated RF signals; and a plurality of RF amplifiers which amplify the plurality of quadrature modulated RF signals from the quadrature modulation mixers to correspond to individual subcarrier frequencies.

Description

無線通信システム、送信機およびマルチキャリア通信方法Wireless communication system, transmitter, and multicarrier communication method
　本発明は、ＯＦＤＭ（Ｏｒｔｈｏｇｏｎａｌ　Ｆｒｅｑｕｅｎｃｙ　Ｄｏｍａｉｎ　Ｍｏｄｕｌａｔｉｏｎ）など周波数利用効率が高いマルチキャリアを使用する高速無線通信システムに関し、詳しくは電力効率が高いＲＦ増幅器を用いる送信機に関する。 The present invention relates to a high-speed wireless communication system using a multicarrier with high frequency utilization efficiency such as OFDM (Orthogonal Frequency Domain Modulation), and more particularly to a transmitter using an RF amplifier with high power efficiency.
　ＯＦＤＭ無線通信システムは、現在、無線ＬＡＮ（ｗｉｒｅｌｅｓｓ　Ｌｏｃａｌ　Ａｒｉａ　Ｎｅｔｗｏｒｋ）などにおいて使用されており、高速な無線通信を実現する方式の１つである。
　既存のＯＦＤＭ無線通信システムに用いる送信機の一般的な構成は、例えば非特許文献１に記載されている。非特許文献１に示されたＯＦＤＭ無線通信システムに用いる送信機を図１０に示す。
　図１０の送信機において、入力デジタル信号列ｔ｛Ｄ｝はシンボルマッパ１００および直並列変換器１０１により、並列複素シンボル列｛Ｓ｝に変換される。並列複素シンボル列｛Ｓ｝は、周波数マッパ１０２、逆離散フーリエ変換器１０３および並直列変換器１０４によりマトリクス計算処理される。その結果、複素ＯＦＤＭシンボル標本値列ｔ｛Ｖ｝が生成される。複素ＯＦＤＭシンボル標本値列ｔ｛Ｖ｝は、ガードインターバル回路１０５により適切なガードインターバルを付加され、さらにＤＡ変換器１０６によって複素アナログＯＦＤＭ信号ＶＢＢ（ｔ）へと変換される。複素アナログＯＦＤＭ信号ＶＢＢ（ｔ）は、直交変調ミクサ１０７と局発発振器１０８とで構成される直交変調器１０９により直交変調されたＲＦ信号ＶＲＦ（ｔ）に変換される。その後、ＲＦ信号ＶＲＦ（ｔ）は、ＲＦ増幅器１１０によって高出力に増幅され、アンテナ１１１から空間に送出される。
　上記構成のＯＦＤＭ無線通信システムは、一般に周波数利用効率が良く、適切なガードインターバルを設けることにより、マルチパスフェージングに強いなどの優れた特長を有する。
　また、ＯＦＤＭ無線通信システムに用いるＯＦＤＭ変調回路の構成は、特許文献１にも記載されている。特許文献１に記載された構成では、上記非特許文献１と異なり、入力信号列を複数系統に分割して各サブキャリアに割当てた後、各系統のＤ／Ａ変換回路および直交変調回路を介して、合成器に複数系統を入力して、増幅器に入力される出力信号を生成する。 The OFDM wireless communication system is currently used in a wireless local area network (LAN) and is one of methods for realizing high-speed wireless communication.
A general configuration of a transmitter used in an existing OFDM wireless communication system is described in Non-Patent Document 1, for example. A transmitter used in the OFDM wireless communication system disclosed in Non-Patent Document 1 is shown in FIG.
In the transmitter of FIG. 10, an input digital signal sequence t {D} is converted into a parallel complex symbol sequence {S} by a symbol mapper 100 and a serial-parallel converter 101. The parallel complex symbol sequence {S} is subjected to matrix calculation processing by the frequency mapper 102, the inverse discrete Fourier transformer 103, and the parallel-serial converter 104. As a result, a complex OFDM symbol sample value sequence t {V} is generated. An appropriate guard interval is added to the complex OFDM symbol sample value sequence t {V} by the guard interval circuit 105 and further converted into a complex analog OFDM signal V BB (t) by the DA converter 106. The complex analog OFDM signal V BB (t) is converted into a quadrature modulated RF signal V RF (t) by a quadrature modulator 109 including a quadrature modulation mixer 107 and a local oscillator 108. Thereafter, the RF signal V RF (t) is amplified to a high output by the RF amplifier 110 and is transmitted from the antenna 111 to the space.
The OFDM wireless communication system having the above configuration generally has excellent characteristics such as high frequency utilization efficiency and resistance to multipath fading by providing an appropriate guard interval.
The configuration of the OFDM modulation circuit used in the OFDM wireless communication system is also described in Patent Document 1. In the configuration described in Patent Document 1, unlike the Non-Patent Document 1, the input signal sequence is divided into a plurality of systems and assigned to each subcarrier, and then the D / A conversion circuit and the orthogonal modulation circuit of each system are used. Then, a plurality of systems are input to the synthesizer, and an output signal input to the amplifier is generated.
特開２００２−２９０３６８号公報JP 2002-290368 A
　しかしながら、特許文献１または非特許文献１のＯＦＤＭ通信システムでは、ＲＦ増幅器に入力されるＲＦ信号ＶＲＦ（ｔ）は多数のキャリアを含んだマルチキャリア変調信号であり、信号の平均電力に対するピーク電力の比（ＰＡＰＲ：Ｐｅａｋ　ｔｏ　Ａｖｅｒａｇｅ　Ｐｏｗｅｒ　Ｒａｔｉｏ）が大きくなる。このため、線形に信号を増幅するためにはＲＦ増幅器の飽和出力電力が信号のピーク電力より大きくなるように飽和出力電力に対して十分大きなバックオフを持たせて動作させる必要が生ずる。換言すれば、大きな飽和出力が得られるＲＦ増幅器を用い、かつ、大きなバックオフ点でＲＦ増幅器を動作させる必要がある。図１１は、無線通信システムにおける増幅器の出力電力および電力効率特性の一例である。当該図面に示すように、一般に増幅器の電力効率は、飽和出力電力レベルで動作させる場合に最大となり、飽和から大きなバックオフを持たせて動作させると著しく低下する。この結果からくる消費電力の増加が無線通信システムにとって問題となる。また、無線通信システムの構築に大きな飽和出力電力を有する高出力増幅器が必要となるが、ミリ波などの極めて短い波長を用いる無線通信システムでは、高効率・高出力増幅器の実現が困難となる問題もある。以上のことから、無線通信システム中でのＯＦＤＭの様な高い周波数利用効率（ｂｉｔ／Ｈｚ）を維持しながら、消費電力を下げることが著しく難しく、１ｂｉｔあたりの消費電力が高いという課題がある。
　既存のＯＦＤＭ通信システムと異なる方式を使用するマルチキャリア通信システムにおいても、上記ＯＦＤＭ通信システムと同様に、スペクトルの広がりを抑えること、相互歪み成分の影響を抑えること等が要求されるために、ＰＡＰＲを大きくとる必要がある。そのため、そのマルチキャリア通信システムも大きなバックオフ点でＲＦ増幅器を動作させる必要がある。従って、ＯＦＤＭ通信システムと同様、増幅器の消費電力が増加する問題がある。その結果、無線通信システム中での１ｂｉｔあたりの消費電力を低下させることができないと云う問題がある。
　また、特許文献１に示される通信システムのように、並直列変換を行なわずに、各系統にて直交した信号を作成した後に合成器によって入力波形を合成し、その後増幅器に送信する構成でも、上記説明と同様マルチキャリア変調信号を用いるのでＰＡＰＲを大きくする必要がある。
　本発明は、ＯＦＤＭ通信システムに代表されるマルチキャリア変調信号を用いる通信システムにおいて、送信機に用いるＲＦ増幅器に大きなバックオフを持たせる必要がなく、その結果、低い飽和出力電力のＲＦ増幅器を使用することが可能となり、かつ、そのＲＦ増幅器を高い電力効率で使用でき、その結果送信機の消費電力を著しく低減でき、１ｂｉｔあたりの消費電力を下げられる無線通信システムを提供する。 However, in the OFDM communication system of Patent Document 1 or Non-Patent Document 1, the RF signal V RF (t) input to the RF amplifier is a multi-carrier modulation signal including a large number of carriers, and the peak power with respect to the average power of the signal. (PAPR: Peak to Average Power Ratio) increases. For this reason, in order to amplify the signal linearly, it is necessary to operate with a sufficiently large back-off to the saturated output power so that the saturated output power of the RF amplifier becomes larger than the peak power of the signal. In other words, it is necessary to use an RF amplifier capable of obtaining a large saturated output and to operate the RF amplifier at a large back-off point. FIG. 11 is an example of output power and power efficiency characteristics of an amplifier in a wireless communication system. As shown in the drawing, the power efficiency of an amplifier is generally maximized when operating at a saturated output power level and significantly decreases when operated with a large backoff from saturation. The increase in power consumption resulting from this result becomes a problem for the wireless communication system. In addition, a high-power amplifier having a large saturation output power is required to construct a wireless communication system. However, in a wireless communication system using extremely short wavelengths such as millimeter waves, it is difficult to realize a high-efficiency and high-power amplifier. There is also. From the above, it is extremely difficult to reduce power consumption while maintaining high frequency utilization efficiency (bit / Hz) like OFDM in a wireless communication system, and there is a problem that power consumption per bit is high.
Even in a multi-carrier communication system that uses a scheme different from the existing OFDM communication system, it is necessary to suppress the spread of spectrum and the influence of mutual distortion components as in the OFDM communication system. It is necessary to take a large. Therefore, the multi-carrier communication system also needs to operate the RF amplifier at a large back-off point. Therefore, there is a problem that the power consumption of the amplifier increases as in the OFDM communication system. As a result, there is a problem that the power consumption per bit in the wireless communication system cannot be reduced.
Further, as in the communication system shown in Patent Document 1, the configuration in which an input waveform is synthesized by a synthesizer after creating orthogonal signals in each system without performing parallel-serial conversion, and then transmitted to an amplifier, Since a multicarrier modulation signal is used as described above, it is necessary to increase the PAPR.
In a communication system using a multicarrier modulation signal typified by an OFDM communication system, the present invention does not require a large back-off in an RF amplifier used in a transmitter, and as a result, an RF amplifier having a low saturation output power is used. And a radio communication system capable of using the RF amplifier with high power efficiency, and as a result, significantly reducing the power consumption of the transmitter and reducing the power consumption per bit.
　本発明に係る無線通信システムは、入力デジタル信号列を直並列変換して複数のＤＡ変換器に入力して、当該複数のＤＡ変換器から得られた夫々のアナログ信号を、入力系統をまとめて２以上の出力に合成する信号合成器と、前記信号合成器によってまとめられて出力されたアナログ信号を、直交変調されたＲＦ信号に変調する複数の直交変調ミクサと、前記複数の直交変調ミクサによって直交変調された複数のＲＦ信号を個別にサブキャリアの周波数に対応させて増幅する複数のＲＦ増幅器とを備えるマルチキャリア通信を行なう送信機を有する。 In the wireless communication system according to the present invention, an input digital signal sequence is serial-parallel converted and input to a plurality of DA converters, and analog signals obtained from the plurality of DA converters are combined into an input system. A signal synthesizer that combines two or more outputs, a plurality of quadrature modulation mixers that modulate the analog signals combined and output by the signal synthesizer into a quadrature-modulated RF signal, and the plurality of quadrature modulation mixers A transmitter that performs multicarrier communication, and includes a plurality of RF amplifiers that individually amplify a plurality of orthogonally modulated RF signals in correspondence with subcarrier frequencies.
　本発明によれば、マルチキャリア変調信号を用いる通信システムにおいて、送信機に用いるＲＦ増幅器のバックオフを軽減し、高い周波数利用効率を維持しながら高い電力効率を実現する送信機、無線通信システムおよびマルチキャリア通信方法を提供できる。またこの効果を得るにあたり、共通の周波数を有する局発発振器あるいは、共通の局発発振器を利用することが可能になる。 According to the present invention, in a communication system using a multicarrier modulation signal, a transmitter, a wireless communication system, and a transmitter that realize high power efficiency while reducing backoff of an RF amplifier used in the transmitter and maintaining high frequency utilization efficiency A multi-carrier communication method can be provided. In order to obtain this effect, a local oscillator having a common frequency or a common local oscillator can be used.
　図１は、本発明の第１の実施の形態における無線通信システムの送信機の構成図である。
　図２は、本発明の第３の実施の形態における無線通信システムの送信機の構成図である。
　図３は、本発明の第４の実施の形態における無線通信システムの送信機の構成図である。
　図４は、本発明の第５の実施の形態における無線通信システムの送信機の構成図である。
　図５は、本発明の第６の実施の形態における無線通信システムの送信機の構成図である。
　図６は、本発明に係るウインドウイング処理回路を装荷した場合の信号の様子を示す説明図である。
　図７は、本発明の第７の実施の形態における無線通信システムの送信機の構成図である。
　図８は、本発明の第８の実施の形態における無線通信システムの送信機の構成図である。
　図９は、本発明の第９の実施の形態における無線通信システムの送信機の構成図である。
　図１０は、ＯＦＤＭ無線通信システムに用いる送信機の一般的な構成図である。
　図１１は、増幅器の出力電力および電力効率特性の一例を示す説明図である。 FIG. 1 is a configuration diagram of a transmitter of a wireless communication system according to the first embodiment of the present invention.
FIG. 2 is a configuration diagram of the transmitter of the wireless communication system according to the third embodiment of the present invention.
FIG. 3 is a configuration diagram of the transmitter of the radio communication system according to the fourth embodiment of the present invention.
FIG. 4 is a configuration diagram of a transmitter of a wireless communication system according to the fifth embodiment of the present invention.
FIG. 5 is a configuration diagram of the transmitter of the wireless communication system according to the sixth embodiment of the present invention.
FIG. 6 is an explanatory diagram showing the state of signals when the windowing processing circuit according to the present invention is loaded.
FIG. 7 is a configuration diagram of a transmitter of a wireless communication system according to the seventh embodiment of the present invention.
FIG. 8 is a configuration diagram of the transmitter of the wireless communication system according to the eighth embodiment of the present invention.
FIG. 9 is a configuration diagram of a transmitter of a wireless communication system according to the ninth embodiment of the present invention.
FIG. 10 is a general configuration diagram of a transmitter used in an OFDM wireless communication system.
FIG. 11 is an explanatory diagram illustrating an example of output power and power efficiency characteristics of an amplifier.
　本発明の実施の形態について、図を参照しながら説明する。
（第１の実施の形態）
　図１は、本発明の第１の実施の形態における無線通信システムの送信機の構成図である。
　図示された送信機は、入力デジタル信号列ｔ｛Ｄ｝を複素シンボル列に変換するシンボルマッパ１と、生成された複素シンボル列を並列複素シンボル（Ｓ）へと変換する直並列変換器２と、並列複素シンボル（Ｓ）に含まれる各複素シンボル（ｓ０~ｓＮ−１）のそれぞれに対して個別の周波数を割り当てる周波数マッパ３と、割り当てられた周波数に対応した位相回転を与えたそれぞれの複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）を生成するデジタル信号処理回路４と、生成した複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）のそれぞれを複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））へと変換する複数のＤＡ変換器５と、複数のＤＡ変換器からそれぞれ出力されるＮ個の複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））をＭ個の信号に合成する合成器１６と、Ｍ個にまとめられた複素アナログ信号のそれぞれから実数部が直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））を生成する複数の直交変調ミクサ６と、各直交変調ミクサに局発信号を供給する複数の局発発振器７と、各直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））をそれぞれ増幅する複数のＲＦ増幅器８と、増幅されたそれぞれのＲＦ信号を空中に送出する複数のアンテナ９とから構成されている。
　ここで、デジタル信号処理回路４は、信号処理手段として動作する。また、ＤＡ変換器５は、ＤＡ変換手段として動作する。また、合成器１６は、信号合成手段として動作する。また、直交変調ミクサ６と局発発振器７との組は、１組の直交変調手段ないし回路として動作する。また、ＲＦ増幅器８は、ＲＦ増幅手段ないし回路として動作する。
　次に、動作について説明する。
　入力デジタル信号列ｔ｛Ｄ｝は、シンボルマッパ１および直並列変換器２により、Ｎ個の複素シンボル（ｓ０~ｓＮ−１）を含む並列複素シンボル（ｓ）に変換される。次に、周波数マッパ３により各複素シンボル（ｓ０~ｓＮ−１）に個別の周波数（ｆ０，ｆ１，・・・，ｆｋ，・・・，ｆＮ−１）が割り当てられ、さらに、デジタル信号処理回路４により、各割り当てられた周波数に対応した位相回転を与えた複素デジタル信号標本列ｔ（ｖ）を生成する。以上を式で表すと、
Figure JPOXMLDOC01-appb-I000001
ここで、
Figure JPOXMLDOC01-appb-I000002
　このとき、（３）および（５）の中で位相項として示されているｆｋ（１＜ｋ＜Ｎ−１）が、この操作で与えられる周波数に対応している。上記Ｎ個の複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）は、それぞれＤＡ変換器５にて複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））に変換される。各ＤＡ変換器５から出力されるＮ個の複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））は、合成器１６により、Ｍ個にまとめられて、合成される。例えばＮ＝３２、Ｍ＝１６の場合には、夫々２個の複素アナログ信号がとりまとめられ、合成される。
　合成された複素アナログ信号は、直交変調ミクサ６と局発発振器７とで直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））に変換される。直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））は、ＲＦ増幅器８にてそれぞれ増幅され、アンテナ９から空中に送出される。
　これにより、既存のＯＦＤＭなどのマルチキャリアを使用する無線通信システムにおいて問題となったマルチキャリア信号を１つの増幅器で増幅する必要性がなくなり、増幅器におけるＰＡＰＲが増加する問題が軽減される。
　この結果、大きな飽和出力のＲＦ増幅器が不要となり、また、ＰＡＰＲの増加に伴うＲＦ増幅器の効率低下の問題を回避できる。すなわち、小さな出力電力のＲＦ増幅器を使用することが可能となり、かつ、そのＲＦ増幅器を高い電力効率で使用でき、その結果　周波数利用効率を維持しつつ送信機の消費電力を低減でき、高い周波数利用効率（ｂｉｔ／Ｈｚ）を維持しながら、消費電力を下げ、１ｂｉｔあたりの消費電力を下げられる利点がある。
（第２の実施の形態）
　第２の実施の形態の無線通信システムは、図１の構成において、各並列複素シンボルのそれぞれに割り当てる個別の周波数を、シンボル周期Ｔの逆数で定義される基本周波数ｆ０（＝１／Ｔ）の整数倍でなる周波数ｆｋ＝ｋｆ０（ｋは整数）としている点で第１の実施形態と異なっている。
　この場合、行列（Ｆ−１）は逆離散フーリエ変換行列（ＩＤＦＴ）になり、行列（Ｆ）は離散フーリエ変換行列（ＤＦＴ）になる。その結果、式（１）~（５）は以下のように変更して表せる。
Figure JPOXMLDOC01-appb-I000003
ここで、
Figure JPOXMLDOC01-appb-I000004
Figure JPOXMLDOC01-appb-I000005
　ここで、生成されたＮ個の複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）を標本時間ごとに加算すると既存のＯＦＤＭ変調信号と同一の信号となる。このことから、本発明により生成したＲＦ信号は、周波数利用効率が良く、マルチパスフェージングに強いなどの既存のＯＦＤＭ変調信号の優れた特長を有する。
　一方、本発明では、複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）のそれぞれから直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））を生成し、各ＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｎ−１（ｔ））をそれぞれ個別に増幅することができ、既存のＯＦＤＭ変調信号で問題となった大きなＰＡＰＲの問題が軽減される。その結果、ＲＦ増幅器に大きなバックオフを持たせる必要がなく、実現が容易な低出力な増幅器を用いることができ、また、高い電力効率で動作させることができ、高い周波数利用効率（ｂｉｔ／Ｈｚ）を維持しながら、消費電力を下げ、１ｂｉｔあたりの消費電力を下げられる利点がある。
　以上のように、第２の実施形態に係る無線通信システムでは、既存のＯＦＤＭ変調信号を用いた無線通信システムの優れた特長を有しながら、単一増幅器を用いる欠点である大きなＰＡＰＲによる送信機の効率低下の問題を回避できる。
（第３の実施の形態）
　図２は、本発明の第３の実施の形態における無線通信システムの送信機の構成図である。
　図１の構成と異なる点は、Ｎ個の直交変調ミクサ６に局発信号を供給する局発発振器を共通の局発信号を生成する単一の共通局発発振器１０で構成していることである。
　次に、動作について説明する。本実施の形態の無線通信システムの送信機では並列複素シンボル（Ｓ）に含まれる各複素シンボル（ｓ０~ｓＮ−１）のそれぞれに対して周波数マッパ３によって個別の周波数（ｆ０，ｆ１，・・・，ｆｋ，・・・，ｆＮ−１）が割り当てられ、さらに、デジタル信号処理回路４により各割り当てられた周波数に対応した位相回転を与えた複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）を生成している。
　このため、図２の各直交変調ミクサ６に供給する局発信号は、同一の周波数でよい。その結果、一つの共通局発発振器１０を用いることが可能となる。局発発振器が１つでよいので小型化が可能であり、かつ、各直交変調ミクサ６に供給する局発信号間の周波数偏差を考慮する必要がないため構成が簡単になる利点がある。
（第４の実施の形態）
　図３は、本発明の第４の実施の形態における無線通信システムの構成図である。図１および図２の構成と比較すると、各ＲＦ増幅器８で個別に増幅されたＲＦ信号を合成するための複数の電力合成器１１、および各電力合成器１１に対応して、合成したＲＦ信号を空中に送出する複数のアンテナ１２を備えた点が異なる。
　次に、動作について説明する。各ＲＦ増幅器８で個別に増幅された複数のＲＦ信号を電力合成器１１にて合成した後にアンテナ１２から空中に送出することにより、使用するアンテナの削減が可能となる。図３に示した構成は、各ＲＦ増幅器８で個別に増幅されたＲＦ信号の全てを１つの電力合成器で合成し、１つのアンテナから空中に送出する例である。他方、複数の電力合波器を用いるようにしてもよい。換言すれば、電力合成器１１の個数ｎは、ＲＦ増幅器８の個数となる入力系統数＞ｎ≧１である。他方、信号増幅器１６は、低い飽和出力電力のＲＦ増幅器を使用できるようにＲＦ増幅器のバックオフを考慮し、入力系統数と２以上の出力系統数を設定する必要がある。
　以上のように、第４の実施形態に係る無線通信システムでは、既存のＯＦＤＭ変調信号を用いた無線通信システムの優れた特長を有しながら、単一増幅器を用いる欠点である大きなＰＡＰＲによる送信機の効率低下の問題を回避でき、且つ、ＲＦ増幅器及びアンテナの個数を所望の個数まで削減できる。
（第５の実施の形態）
　図４は、本発明の第５の実施の形態における無線通信システムの構成図である。図１ないし図３と比較すると、図４における無線通信システムの送信機では、デジタル信号処理回路４及び複数のＤＡ変換器５との間にガードインターバル回路１３を装荷する点が異なる。
　次に、動作について説明する。ガードインターバル回路１３を装荷することにより、デジタル信号処理回路４にて生成した複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）のそれぞれに、適切なガードインターバル（ＧＩ）が付加される。付加したＧＩにより、マルチパス干渉波の影響を低減することが可能となる。
（第６の実施の形態）
　図５は、本発明の第６の実施の形態における無線通信システムの構成図である。図４と比較すると、ガードインターバル回路１３と複数のＤＡ変換器５との間に、ウインドウイング処理回路１４を装荷する点が異なる。図６はウインドウイング処理回路１４を装荷した場合の信号の様子を示す図である。
　図４に示すように、ガードインターバル回路（ＧＩ）１３を付加した場合、図６に示すように、連続する信号間（図ではＡ点）に不連続が生じる。このような不連続が生じるとスプリアス成分が発生することになる。これに対し、図６に示すように、ウインドウイング処理回路１４を設け、ランプ状（傾斜状）のウインドウイング処理を行うと不連続部分の振幅が小さくなり、滑らかになる。これにより、信号のスプリアス成分の抑制やピーク電力の削減等が可能となる。
（第７の実施の形態）
　図７は、本発明の第７の実施の形態における無線通信システムの送信機の構成図である。
　図示された送信機は、入力デジタル信号列ｔ｛Ｄ｝を複素シンボル列に変換するシンボルマッパ１と、生成された複素シンボル列を並列複素シンボル（Ｓ）へと変換する直並列変換器２と、並列複素シンボル（Ｓ）に含まれる各複素シンボル（ｓ０~ｓＮ−１）のそれぞれに対して個別の周波数を割り当てる周波数マッパ３と、割り当てられた周波数に対応した位相回転を与えたそれぞれの複素デジタル信号標本列を生成するデジタル信号処理回路４と、各複素デジタル信号標本列の帯域を制限するフィルタ１５と、生成した複素デジタル信号標本列のそれぞれを複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））へと変換するＮ個のＤＡ変換器５と、それぞれのＤＡ変換器５から出力されるＮ個の複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））を合成する合成器１６と、合成された信号のそれぞれから直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））を生成する複数の直交変調ミクサ６と、各直交変調ミクサに局発信号を供給する複数の局発発振器７と、各直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））をそれぞれ増幅する複数のＲＦ増幅器８と、増幅されたそれぞれのＲＦ信号を空中に送出するアンテナ９とから構成されている。即ち、フィルタ１５を設けた点で、第７の実施の形態に係る送信機は、第１の実施の形態に係る送信機とは異なっている。
　次に、動作について説明する。
　入力デジタル信号列ｔ｛Ｄ｝は、シンボルマッパ１および直並列変換器２により、Ｎ個の複素シンボル（ｓ０~ｓＮ−１）に変換される。次に、周波数マッパ３により各複素シンボル（ｓ０~ｓＮ−１）に個別の周波数（ｆ０，ｆ１，・・・，ｆｋ，・・・，ｆＮ−１）が割り当てられ、さらに、デジタル信号処理回路４により、各割り当てられた周波数に対応した位相回転を与えて複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）を生成する。このとき各複素シンボルがそれぞれ別の周波数領域に展開され、かつ個別に復調可能であるシングルキャリア信号が生成できるように位相回転がそれぞれに与えられ、その結果Ｎ個の複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）が生成される。さらに各複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）は、フィルタ１５により帯域が制限される。このときにフィルタ１５として、例えばロールオフフィルタが用いられる。さらに、フィルタリングされた各複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）はそれぞれＤＡ変換器５にて複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））に変換される。各ＤＡ変換器５から出力されるＮ個の複素アナログ信号（ＶＢＢ．０（ｔ）~ＶＢＢ．Ｎ−１（ｔ））は、合成器１６により、Ｍ個にまとめられる。例えばＮ＝３２、Ｍ＝１６の場合には、夫々２個の複素アナログ信号がとりまとめられる。まとめられた複素アナログ信号は、さらに直交変調ミクサ６と局発発振器７とで直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））に変換される。直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））はさらにＲＦ増幅器８にてそれぞれ増幅され、アンテナ９から空中に送出される。
　以上の動作原理から、各ＲＦ増幅器８で増幅される直交変調されたＲＦ信号（ＶＲＦ．０（ｔ）~ＶＲＦ．Ｍ−１（ｔ））は、シングルキャリア変調信号となっている。シングルキャリア変調としては、例えばＢＰＳＫ、ＱＰＳＫ、８ＰＳＫ、１６ＱＡＭ、６４ＱＡＭが適用可能である。
　これにより、既存のＯＦＤＭなどのマルチキャリアを使用する通信システムにおいて問題となったマルチキャリア信号を１つの増幅器で増幅をする必要性がなくなり、増幅器におけるＰＡＰＲが増加する問題が軽減される。この結果、大きな飽和出力のＲＦ増幅器が不要となり、また、ＰＡＰＲの増加に伴うＲＦ増幅器の効率低下の問題を回避できる。すなわち、小さな出力電力のＲＦ増幅器を使用することが可能となり、かつ、そのＲＦ増幅器を高い電力効率で使用でき、その結果送信機の消費電力を低減できる利点がある。
　また、フィルタをサブキャリアごとに使うことによって、各サブキャリアのサイドローブが低減されるため、サブキャリア間隔を狭くしても、サブキャリアをそれぞれシングルキャリア信号として扱うことができる。
（第８の実施の形態）
　図８は、本発明の第８の実施の形態における無線通信システムの送信機の構成図である。図７の構成と異なる点は、Ｎ個の直交変調ミクサ６に局発信号を供給する局発発振器を単一の共通局発発振器１０で構成していることである。
　次に、動作について説明する。本発明の無線通信システムの送信機では各並列複素シンボルｓｋのそれぞれに対して個別の周波数（ｆ０，ｆ１，・・・，ｆｋ，・・・，ｆＮ−１）が割り当てられている。
　さらに、デジタル信号処理回路４により、各複素シンボルがそれぞれ固別の周波数領域に展開され、かつ個別に復調可能なシングルキャリア信号が生成可能なように位相回転が与えられ、その結果、Ｎ個の複素デジタル信号標本列（ｔ｛ｖ０｝~ｔ｛ｖＮ−１｝）が生成される。このため、図８の各直交変調ミクサ６に供給する局発信号は同一の周波数でよい。その結果、一つの共通局発発振器１０を用いることが可能となる。局発発振器が１つでよいので小型化が可能であり、かつ、各直交変調ミクサ６に供給する局発信号間の周波数偏差を考慮する必要がないため構成が簡単になる利点がある。
（第９の実施の形態）
　図９に示された第９の実施の形態に係る送信機は、複数の複素デジタル信号標本列ｔ｛ｖｋ｝を生成する機能を有する信号処理回路４’に、いずれか一つの複素デジタル信号標本列ｔ｛ｖｋ｝を選択する制御部を設けている点で、図２に示された送信機と異なっている。
　例えば、信号処理回路４’内に、ＯＦＤＭとＯＦＤＭではないマルチキャリア通信システムに対応した複素デジタル信号標本列を出力できる機能を予め回路内に用意する。これにより、制御信号を用いて状況に応じた使い分けが可能になり、１つの無線機が２つの方式をサポートすることが実現できる。
　以上説明したように、本発明における無線通信システムの送信機では、Ｎ個の複素シンボルのそれぞれに対して個別の周波数を割り当て、計Ｍ個の信号にまとめて（Ｍ＜Ｎ）、さらに直交変調し、各直交変調したＲＦ信号をそれぞれ個別に増幅するように構成する。
　上記構成とすることにより、多数のサブキャリア信号を含むマルチキャリア信号を１つの増幅器で増幅をする必要がなくなり、増幅器におけるＰＡＰＲが増加する問題が軽減される。この結果、大きな飽和出力のＲＦ増幅器が不要となり、また、ＰＡＰＲの増加に伴うＲＦ増幅器の効率低下の問題を回避できる。すなわち、小さな出力電力のＲＦ増幅器を使用することが可能となり、かつ、そのＲＦ増幅器を高い電力効率で使用でき、その結果　周波数利用効率を維持しつつ送信機の消費電力を著しく低減できる。
　尚、以上に述べた発明の実施の形態においては、ＯＦＤＭ通信システムにおける信号処理回路４、信号処理回路４’と、実施の形態７や８で示したマルチキャリア通信システムにおけるフィルタ１５は、デジタル回路で構成することができ、回路の有無や順序の変更が可能である。他方、ＲＦ増幅器は、直交変調器よりも後段に設けることが望ましい。このことから、複素アナログ信号をまとめる処理（合成）を、直交変調器よりも前段に設ける必要が生ずる。即ち、合成器⇒直交変調器⇒ＲＦ増幅器の順となる。
　また、本発明の具体的な構成は前述の実施の形態に限られるものではなく、この発明の要旨を逸脱しない範囲の変更があってもこの発明に含まれる。
　この出願は、２０１０年１月２９日に出願された日本出願特願２０１０−０１７７０１号を基礎とする優先権を主張し、その開示の全てをここに取り込む。 Embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram of a transmitter of a wireless communication system according to the first embodiment of the present invention.
The illustrated transmitter includes a symbol mapper 1 that converts an input digital signal sequence t {D} into a complex symbol sequence, and a serial-parallel converter 2 that converts the generated complex symbol sequence into parallel complex symbols (S). The frequency mapper 3 for assigning individual frequencies to each of the complex symbols (s 0 to s N-1 ) included in the parallel complex symbol (S), and the phase rotation corresponding to the assigned frequency, respectively. the complex digital signal sampled sequence (t {v 0} ~ t {v N-1}) digital signal processing circuit 4 for generating the generated complex digital signal samples train (t {v 0} ~ t {v N- 1 }) are converted from complex analog signals (V BB.0 (t) to V BB.N-1 (t)), and output from the plurality of DA converters, respectively. N complex ana Grayed signal (V BB.0 (t) ~ V BB.N-1 (t)) and a combiner 16 for combining the M signals, the real part from each of the complex analog signal is quadrature gathered into M A plurality of orthogonal modulation mixers 6 that generate modulated RF signals (V RF.0 (t) to V RF.M-1 (t)), and a plurality of local oscillation signals that supply local oscillation signals to the respective orthogonal modulation mixers. An oscillator 7, a plurality of RF amplifiers 8 that respectively amplify each quadrature-modulated RF signal (V RF.0 (t) to V RF.M−1 (t)), and each amplified RF signal in the air And a plurality of antennas 9 for transmitting to the network.
Here, the digital signal processing circuit 4 operates as signal processing means. The DA converter 5 operates as DA conversion means. The synthesizer 16 operates as a signal synthesizer. A set of the quadrature modulation mixer 6 and the local oscillator 7 operates as a set of quadrature modulation means or circuit. The RF amplifier 8 operates as RF amplification means or a circuit.
Next, the operation will be described.
The input digital signal sequence t {D} is converted into a parallel complex symbol (s) including N complex symbols (s 0 to s N-1 ) by the symbol mapper 1 and the serial-parallel converter 2. Next, an individual frequency (f 0 , f 1 ,..., F k ,..., F N−1 ) is assigned to each complex symbol (s 0 to s N−1 ) by the frequency mapper 3, Further, the digital signal processing circuit 4 generates a complex digital signal sample sequence t (v) to which a phase rotation corresponding to each assigned frequency is given. The above is expressed by an equation:
Figure JPOXMLDOC01-appb-I000001
here,
Figure JPOXMLDOC01-appb-I000002
At this time, f k (1 <k <N−1) shown as the phase term in (3) and (5) corresponds to the frequency given by this operation. The N complex digital signal sample sequences ( t {v 0 } to t {v N−1 }) are respectively converted into complex analog signals (V BB.0 (t) to V BB.N− by the DA converter 5. 1 (t)). The N complex analog signals (V BB.0 (t) to V BB.N-1 (t)) output from each DA converter 5 are combined into M signals by the synthesizer 16 and synthesized. The For example, when N = 32 and M = 16, two complex analog signals are collected and synthesized.
The combined complex analog signal is converted into an RF signal (V RF.0 (t) to V RF.M-1 (t)) that is quadrature modulated by the quadrature modulation mixer 6 and the local oscillator 7. The quadrature-modulated RF signals (V RF.0 (t) to V RF.M−1 (t)) are respectively amplified by the RF amplifier 8 and transmitted from the antenna 9 to the air.
As a result, there is no need to amplify a multicarrier signal, which has become a problem in a wireless communication system using multicarriers such as existing OFDM, with one amplifier, and the problem of an increase in PAPR in the amplifier is reduced.
As a result, an RF amplifier with a large saturation output is not necessary, and the problem of a decrease in efficiency of the RF amplifier due to an increase in PAPR can be avoided. In other words, it is possible to use an RF amplifier with a small output power, and the RF amplifier can be used with high power efficiency. As a result, the power consumption of the transmitter can be reduced while maintaining frequency use efficiency, and high frequency use can be achieved. There is an advantage that the power consumption per bit can be reduced while maintaining the efficiency (bit / Hz).
(Second Embodiment)
In the wireless communication system according to the second embodiment, in the configuration of FIG. 1, the fundamental frequency f 0 (= 1 / T) defined by the reciprocal number of the symbol period T is assigned to each individual frequency of each parallel complex symbol. This is different from the first embodiment in that the frequency f k = kf 0 (k is an integer) that is an integer multiple of.
In this case, the matrix (F −1 ) is an inverse discrete Fourier transform matrix (IDFT), and the matrix (F) is a discrete Fourier transform matrix (DFT). As a result, the expressions (1) to (5) can be expressed by changing as follows.
Figure JPOXMLDOC01-appb-I000003
here,
Figure JPOXMLDOC01-appb-I000004
Figure JPOXMLDOC01-appb-I000005
Here, when the generated N complex digital signal sample sequences ( t {v 0 } to t {v N−1 }) are added for each sample time, the signal becomes the same as the existing OFDM modulated signal. For this reason, the RF signal generated by the present invention has excellent features of existing OFDM modulation signals such as high frequency utilization efficiency and resistance to multipath fading.
On the other hand, in the present invention, RF signals (V RF.0 (t) to V RF.M-1 ) orthogonally modulated from each of the complex digital signal sample sequences ( t {v 0 } to t {v N−1 }). (T)) can be generated and each RF signal (V RF.0 (t) to V RF.N-1 (t)) can be individually amplified, which is a problem with existing OFDM modulated signals. The problem of large PAPR is reduced. As a result, it is not necessary to give the RF amplifier a large back-off, and a low-power amplifier that can be easily realized can be used, and can be operated with high power efficiency, and high frequency utilization efficiency (bit / Hz). ), While reducing power consumption, there is an advantage that power consumption per bit can be reduced.
As described above, in the wireless communication system according to the second embodiment, a transmitter using a large PAPR, which is a drawback of using a single amplifier, while having the excellent features of a wireless communication system using an existing OFDM modulated signal. It is possible to avoid the problem of efficiency reduction.
(Third embodiment)
FIG. 2 is a configuration diagram of the transmitter of the wireless communication system according to the third embodiment of the present invention.
The difference from the configuration of FIG. 1 is that a local oscillator that supplies local oscillation signals to N orthogonal modulation mixers 6 is configured by a single common local oscillator 10 that generates a common local oscillation signal. is there.
Next, the operation will be described. In the transmitter of the wireless communication system of the present embodiment, each frequency (f 0 , f 1 ) is divided by the frequency mapper 3 for each of the complex symbols (s 0 to s N-1 ) included in the parallel complex symbols (S). 1 ,..., F k ,..., F N−1 ), and further, a complex digital signal sample sequence ( t) given a phase rotation corresponding to each assigned frequency by the digital signal processing circuit 4 {V 0 } to t {v N−1 }).
For this reason, the local signal supplied to each quadrature modulation mixer 6 in FIG. 2 may have the same frequency. As a result, one common local oscillator 10 can be used. Since only one local oscillator is required, the size can be reduced, and there is an advantage that the configuration can be simplified because it is not necessary to consider the frequency deviation between the local signals supplied to each quadrature modulation mixer 6.
(Fourth embodiment)
FIG. 3 is a configuration diagram of a radio communication system according to the fourth embodiment of the present invention. Compared with the configuration of FIG. 1 and FIG. 2, a plurality of power combiners 11 for combining the RF signals individually amplified by each RF amplifier 8, and the combined RF signals corresponding to each power combiner 11. Is different in that it includes a plurality of antennas 12 that transmit the signal to the air.
Next, the operation will be described. A plurality of RF signals individually amplified by each RF amplifier 8 are combined by the power combiner 11 and then transmitted from the antenna 12 to the air, so that the number of antennas to be used can be reduced. The configuration shown in FIG. 3 is an example in which all of the RF signals individually amplified by each RF amplifier 8 are combined by one power combiner and transmitted from one antenna to the air. On the other hand, a plurality of power combiners may be used. In other words, the number n of the power combiners 11 is the number of input systems that is the number of RF amplifiers 8> n ≧ 1. On the other hand, the signal amplifier 16 needs to set the number of input systems and the number of output systems of 2 or more in consideration of the back-off of the RF amplifier so that an RF amplifier with low saturation output power can be used.
As described above, in the radio communication system according to the fourth embodiment, a transmitter using a large PAPR which is a drawback of using a single amplifier while having the excellent features of the radio communication system using the existing OFDM modulated signal. The problem of efficiency reduction can be avoided, and the number of RF amplifiers and antennas can be reduced to a desired number.
(Fifth embodiment)
FIG. 4 is a configuration diagram of a radio communication system according to the fifth embodiment of the present invention. Compared with FIGS. 1 to 3, the transmitter of the wireless communication system in FIG. 4 is different in that a guard interval circuit 13 is loaded between the digital signal processing circuit 4 and the plurality of DA converters 5.
Next, the operation will be described. By loading the guard interval circuit 13, the respective digital signal processing complex digital signal samples string generated by circuit 4 (t {v 0} ~ t {v N-1}), appropriate guard interval (GI) Is added. The added GI can reduce the influence of multipath interference waves.
(Sixth embodiment)
FIG. 5 is a configuration diagram of a radio communication system according to the sixth embodiment of the present invention. Compared to FIG. 4, the windowing processing circuit 14 is loaded between the guard interval circuit 13 and the plurality of DA converters 5. FIG. 6 is a diagram showing the state of signals when the windowing processing circuit 14 is loaded.
As shown in FIG. 4, when the guard interval circuit (GI) 13 is added, as shown in FIG. 6, discontinuity occurs between successive signals (point A in the figure). When such a discontinuity occurs, spurious components are generated. On the other hand, as shown in FIG. 6, when the windowing processing circuit 14 is provided and the ramp-like (inclined) windowing process is performed, the amplitude of the discontinuous portion becomes small and smooth. This makes it possible to suppress spurious components of the signal, reduce peak power, and the like.
(Seventh embodiment)
FIG. 7 is a configuration diagram of a transmitter of a wireless communication system according to the seventh embodiment of the present invention.
The illustrated transmitter includes a symbol mapper 1 that converts an input digital signal sequence t {D} into a complex symbol sequence, and a serial-parallel converter 2 that converts the generated complex symbol sequence into parallel complex symbols (S). The frequency mapper 3 for assigning individual frequencies to each of the complex symbols (s 0 to s N-1 ) included in the parallel complex symbol (S), and the phase rotation corresponding to the assigned frequency, respectively. Digital signal processing circuit 4 for generating a complex digital signal sample sequence, a filter 15 for limiting the band of each complex digital signal sample sequence, and a complex analog signal (V BB.0 ( t) ~ V BB.N-1 ( t)) and the N DA converter 5 for converting into, the N complex analog signals output from the DA converter 5 (V B .0 (t) ~ V BB.N- 1 (t)) and the synthesizer 16 for synthesizing, synthesized the orthogonal modulated RF signal from the signal (V RF.0 (t) ~ V RF.M −1 (t)), a plurality of local oscillators 7 for supplying local signals to the respective quadrature modulation mixers, and RF signals (V RF.0 (t ) To V RF.M-1 (t)), and a plurality of RF amplifiers 8 and antennas 9 for transmitting the amplified RF signals to the air. That is, the transmitter according to the seventh embodiment is different from the transmitter according to the first embodiment in that the filter 15 is provided.
Next, the operation will be described.
The input digital signal sequence t {D} is converted into N complex symbols (s 0 to s N-1 ) by the symbol mapper 1 and the serial / parallel converter 2. Next, an individual frequency (f 0 , f 1 ,..., F k ,..., F N−1 ) is assigned to each complex symbol (s 0 to s N−1 ) by the frequency mapper 3, Further, the digital signal processing circuit 4 applies a phase rotation corresponding to each assigned frequency to generate a complex digital signal sample sequence ( t {v 0 } to t {v N−1 }). At this time, each complex symbol is expanded to a different frequency domain, and phase rotation is given to each so that a single carrier signal that can be individually demodulated can be generated. As a result, N complex digital signal sample sequences ( t {V 0 } to t {v N−1 }) are generated. Further, the band of each complex digital signal sample sequence ( t {v 0 } to t {v N−1 }) is limited by the filter 15. At this time, for example, a roll-off filter is used as the filter 15. Further, each of the filtered complex digital signal sample sequences ( t {v 0 } to t {v N−1 }) is respectively converted into a complex analog signal (V BB.0 (t) to V BB.N by the DA converter 5. -1 (t)). The N complex analog signals (V BB.0 (t) to V BB.N−1 (t)) output from each DA converter 5 are combined into M by the synthesizer 16. For example, when N = 32 and M = 16, two complex analog signals are collected. The combined complex analog signals are further converted into RF signals (V RF.0 (t) to V RF.M-1 (t)) that are quadrature modulated by the quadrature modulation mixer 6 and the local oscillator 7. The quadrature-modulated RF signals (V RF.0 (t) to V RF.M-1 (t)) are further amplified by the RF amplifier 8 and transmitted from the antenna 9 into the air.
From the above principle of operation, the quadrature modulated RF signals (V RF.0 (t) to V RF.M-1 (t)) amplified by the respective RF amplifiers 8 are single carrier modulation signals. As single carrier modulation, for example, BPSK, QPSK, 8PSK, 16QAM, and 64QAM are applicable.
As a result, there is no need to amplify a multicarrier signal that has become a problem in a communication system using multicarriers such as the existing OFDM with one amplifier, and the problem of an increase in PAPR in the amplifier is reduced. As a result, an RF amplifier with a large saturation output is not necessary, and the problem of a decrease in efficiency of the RF amplifier due to an increase in PAPR can be avoided. That is, it is possible to use an RF amplifier having a small output power, and there is an advantage that the RF amplifier can be used with high power efficiency, and as a result, the power consumption of the transmitter can be reduced.
Further, since the side lobe of each subcarrier is reduced by using a filter for each subcarrier, each subcarrier can be treated as a single carrier signal even if the subcarrier interval is narrowed.
(Eighth embodiment)
FIG. 8 is a configuration diagram of the transmitter of the wireless communication system according to the eighth embodiment of the present invention. The difference from the configuration of FIG. 7 is that a local oscillator that supplies local signals to N orthogonal modulation mixers 6 is configured by a single common local oscillator 10.
Next, the operation will be described. In the transmitter of the wireless communication system of the present invention, individual frequencies (f 0 , f 1 ,..., F k ,..., F N−1 ) are assigned to each parallel complex symbol s k. ing.
Further, the digital signal processing circuit 4 provides phase rotation so that each complex symbol is developed in a separate frequency domain and can be individually demodulated, and as a result, N pieces of signals are generated. complex digital signal samples train (t {v 0} ~ t {v N-1}) is generated. For this reason, the local signal supplied to each quadrature modulation mixer 6 in FIG. 8 may have the same frequency. As a result, one common local oscillator 10 can be used. Since only one local oscillator is required, the size can be reduced, and there is an advantage that the configuration can be simplified because it is not necessary to consider the frequency deviation between the local signals supplied to each quadrature modulation mixer 6.
(Ninth embodiment)
The transmitter according to the ninth embodiment shown in FIG. 9 includes any one of the complex digital signals in the signal processing circuit 4 ′ having a function of generating a plurality of complex digital signal sample sequences t {v k }. It differs from the transmitter shown in FIG. 2 in that a control unit for selecting the sample sequence t {v k } is provided.
For example, a function capable of outputting a complex digital signal sample sequence corresponding to a multi-carrier communication system other than OFDM and OFDM is prepared in the circuit in advance in the signal processing circuit 4 ′. As a result, it is possible to selectively use the control signal according to the situation, and it is possible to realize that one wireless device supports two systems.
As described above, in the transmitter of the wireless communication system according to the present invention, individual frequencies are assigned to each of the N complex symbols, combined into a total of M signals (M <N), and further orthogonal modulation is performed. Then, each quadrature-modulated RF signal is individually amplified.
With the above configuration, it is not necessary to amplify a multicarrier signal including a large number of subcarrier signals with one amplifier, and the problem of an increase in PAPR in the amplifier is reduced. As a result, an RF amplifier with a large saturation output is not necessary, and the problem of a decrease in efficiency of the RF amplifier due to an increase in PAPR can be avoided. That is, it is possible to use an RF amplifier with a small output power, and the RF amplifier can be used with high power efficiency. As a result, the power consumption of the transmitter can be significantly reduced while maintaining the frequency utilization efficiency.
In the embodiment of the invention described above, the signal processing circuit 4 and the signal processing circuit 4 ′ in the OFDM communication system and the filter 15 in the multicarrier communication system shown in the seventh and eighth embodiments are digital circuits. It is possible to change the presence / absence of the circuit and the order. On the other hand, it is desirable that the RF amplifier is provided at a stage subsequent to the quadrature modulator. Therefore, it is necessary to provide a process (combining) for grouping complex analog signals before the quadrature modulator. That is, the order is synthesizer → quadrature modulator → RF amplifier.
In addition, the specific configuration of the present invention is not limited to the above-described embodiment, and changes within a range not departing from the gist of the present invention are included in the present invention.
This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2010-017701 for which it applied on January 29, 2010, and takes in those the indications of all here.
１　　　　シンボルマッパ（シンボルマッピング手段）
２　　　　直並列変換器（直並列変換手段）
３　　　　周波数マッパ（周波数マッピング手段）
４，４’　信号処理回路（信号処理手段）
５　　　　ＤＡ変換器（ＤＡ変換手段）
６　　　　直交変調ミクサ（直交変調手段の一部）
７　　　　局発発振器（直交変調手段の一部）
８　　　　ＲＦ増幅器（ＲＦ増幅手段）
９，１２　アンテナ
１０　　　共通局発発振器（共通局発発振手段）
１１　　　電力合成器（電力合成手段）
１３　　　ガードインターバル回路（ガードインターバル生成手段）
１４　　　ウインドウ処理回路（ウインドウ処理手段）
１５　　　フィルタ（フィルタ手段）
１６　　　信号合成器（信号合成手段）
１００　　シンボルマッパ
１０１　　直並列変換器
１０２　　周波数マッパ
１０３　　逆離散フーリエ変換器
１０４　　並直列変換器
１０５　　ガードインターバル回路
１０６　　ＤＡ変換器
１０７　　直交変調ミクサ
１０８　　局発発振器
１０９　　ＲＦ増幅器
１１１　　アンテナ 1 Symbol mapper (symbol mapping means)
2 Series-parallel converter (series-parallel conversion means)
3 Frequency mapper (frequency mapping means)
4,4 'signal processing circuit (signal processing means)
5 DA converter (DA conversion means)
6 Quadrature modulation mixer (part of quadrature modulation means)
7 Local oscillator (part of quadrature modulation means)
8 RF amplifier (RF amplification means)
9,12 Antenna 10 Common local oscillator (common local oscillator)
11 Power combiner (Power combiner)
13 Guard interval circuit (guard interval generating means)
14 Window processing circuit (window processing means)
15 Filter (filter means)
16 Signal synthesizer (signal synthesis means)
DESCRIPTION OF SYMBOLS 100 Symbol mapper 101 Serial / parallel converter 102 Frequency mapper 103 Inverse discrete Fourier transformer 104 Parallel / serial converter 105 Guard interval circuit 106 DA converter 107 Orthogonal modulation mixer 108 Local oscillator 109 RF amplifier 111 Antenna

Claims (22)

  1. 　入力デジタル信号列を直並列変換して複数のＤＡ変換器に入力し、当該複数のＤＡ変換器から得られた夫々のアナログ信号のうち、複数のアナログ信号をまとめて２以上の出力アナログ信号に合成して出力する信号合成器と、
    　前記信号合成器によってまとめられて出力されたアナログ信号を、直交変調されたＲＦ信号に変調する複数の直交変調ミクサと、
    　前記複数の直交変調ミクサによって直交変調された複数のＲＦ信号を、個別にサブキャリアの周波数に対応させて増幅する複数のＲＦ増幅器と
    を備えるマルチキャリア通信を行なう送信機を有することを特徴とする無線通信システム。     The input digital signal sequence is serial-parallel converted and input to a plurality of DA converters, and among the analog signals obtained from the plurality of DA converters, a plurality of analog signals are combined into two or more output analog signals. A signal synthesizer for combining and outputting;
    A plurality of quadrature modulation mixers that modulate the analog signals output together by the signal synthesizer into quadrature modulated RF signals;
    A transmitter for performing multicarrier communication, comprising: a plurality of RF amplifiers for individually amplifying a plurality of RF signals orthogonally modulated by the plurality of orthogonal modulation mixers in correspondence with subcarrier frequencies. Wireless communication system.
  2. 　請求項１記載の無線通信システムにおいて、
    　直並列変換によって得られる各並列複素シンボルの夫々に対して割り当てる個別の周波数を、シンボル周期Ｔの逆数で定義される基本周波数ｆ０（＝１／Ｔ）の整数倍でなる周波数ｆｋ＝ｋｆ０（ｋは整数）とする信号処理回路
    を有することを特徴とする無線通信システム。     The wireless communication system according to claim 1, wherein
    A frequency f k = kf that is an integer multiple of the fundamental frequency f 0 (= 1 / T) defined by the reciprocal of the symbol period T is assigned to each individual parallel complex symbol obtained by serial-parallel conversion. A radio communication system comprising a signal processing circuit for setting 0 (k is an integer).
  3. 　請求項２に記載の無線通信システムにおいて、
    　前記複数の直交変調ミクサにより、並列複素シンボルを位相回転させて相互に直交させた複素デジタル信号標本列をアナログ変換するとともに、所定数にまとめたアナログ信号を、共通の局発信号を使用して夫々のＲＦ信号に変調することを特徴とする無線通信システム。     The wireless communication system according to claim 2,
    Using the plurality of orthogonal modulation mixers, analog conversion is performed on complex digital signal sample sequences in which parallel complex symbols are rotated in phase with each other, and a predetermined number of analog signals are collected using a common local oscillation signal. A radio communication system characterized by modulating each RF signal.
  4. 　請求項２又は３に記載の無線通信システムにおいて、
    　各ＲＦ増幅器で増幅されたＲＦ信号の一部または全てを合成する少なくとも１つの電力合成器を備えることを特徴とする無線通信システム。     The wireless communication system according to claim 2 or 3,
    A wireless communication system comprising at least one power combiner for combining a part or all of the RF signals amplified by each RF amplifier.
  5. 　請求項２ないし４の何れか一項に記載の無線通信システムにおいて、
    　前記信号処理回路と前記複数のＤＡ変換器との間に、各複素デジタル信号標本列のそれぞれに対してガードインターバルを与えるガードインターバル回路を備えることを特徴とする無線通信システム。     The wireless communication system according to any one of claims 2 to 4,
    A radio communication system comprising a guard interval circuit for providing a guard interval for each complex digital signal sample sequence between the signal processing circuit and the plurality of DA converters.
  6. 　請求項５記載の無線通信システムにおいて、
    　前記ガードインターバル回路と前記複数のＤＡ変換器との間に、各複素デジタル信号標本列のそれぞれに対してウインドウイング処理を行うウインドウイング処理回路を備えることを特徴とする無線通信システム。     The wireless communication system according to claim 5, wherein
    A wireless communication system, comprising: a windowing processing circuit that performs a windowing process on each of the complex digital signal sample sequences between the guard interval circuit and the plurality of DA converters.
  7. 　請求項１ないし６の何れか一項に記載の無線通信システムにおいて、
    　入力デジタル信号列を直並列変換した後にであって前記複数のＤＡ変換器に入力する前に帯域を制限するフィルタを備えることを特徴とする無線通信システム。     The wireless communication system according to any one of claims 1 to 6,
    A wireless communication system comprising a filter for limiting a band after serially parallel conversion of an input digital signal sequence and before input to the plurality of DA converters.
  8. 　請求項２ないし７の何れか一項に記載の無線通信システムにおいて、
    　前記信号処理回路は、
    　複数の異なる方式に対応する複数種類の複素デジタル信号標本列をそれぞれ生成できると共に、
    　入力された制御信号に基づいて、前記複数種類の複素デジタル信号標本列の中から、選択された複素デジタル信号標本列を生成する
    ことを特徴とする無線通信システム。     The wireless communication system according to any one of claims 2 to 7,
    The signal processing circuit includes:
    It can generate multiple types of complex digital signal sample sequences corresponding to multiple different methods,
    A wireless communication system, wherein a complex digital signal sample sequence selected from the plurality of types of complex digital signal sample sequences is generated based on an input control signal.
  9. 　入力デジタル信号列を複素シンボル列に変換するシンボルマッパと、
    　生成された複素シンボルの列をＮ個の並列複素シンボル（Ｎは正整数）へと変換する直並列変換器と、
    　前記Ｎ個の並列複素シンボルのそれぞれに対してＮ種類の個別の周波数を割り当てる周波数マッパと、
    　前記周波数を割り当てられたＮ個の並列複素シンボルそれぞれに対して、割り当てられた周波数に対応して位相回転を与えてＮ個の複素デジタル信号標本列を生成するデジタル信号処理回路と、
    　生成して位相回転を与えられた前記Ｎ個の複素デジタル信号標本列のそれぞれを、複素アナログ信号へと変換するＮ個のＤＡ変換器と、
    　前記Ｎ個のＤＡ変換器で変換されたＮ個の複素アナログ信号を、Ｍ個（Ｍは正整数）にまとめる信号合成器と、
    　Ｍ個にまとめられた信号から実数の直交変調されたＭ個のＲＦ信号を生成するＭ個の直交変調ミクサと、
    　前記Ｍ個の直交変調ミクサに供給する局発信号を与える局発発振器と、
    　直交変調された前記Ｍ個のＲＦ信号のそれぞれを個別に増幅するＭ個のＲＦ増幅器と、
    　増幅されたそれぞれのＲＦ信号を空中に送出するアンテナと
    を備えて構成された送信機を有することを特徴とする無線通信システム。     A symbol mapper that converts an input digital signal sequence into a complex symbol sequence;
    A serial-parallel converter for converting the generated sequence of complex symbols into N parallel complex symbols (N is a positive integer);
    A frequency mapper for assigning N individual frequencies to each of the N parallel complex symbols;
    A digital signal processing circuit that applies phase rotation to each of the N parallel complex symbols to which the frequency is assigned in accordance with the assigned frequency to generate N complex digital signal sample sequences;
    N DA converters for converting each of the N complex digital signal sample sequences generated and given a phase rotation into complex analog signals;
    A signal synthesizer that combines N complex analog signals converted by the N DA converters into M (M is a positive integer);
    M quadrature modulation mixers that generate M quadrature modulated RF signals from the M combined signals;
    A local oscillator for supplying a local signal to be supplied to the M orthogonal modulation mixers;
    M RF amplifiers that individually amplify each of the M RF signals that are orthogonally modulated;
    A wireless communication system comprising a transmitter configured to include an antenna for transmitting each amplified RF signal into the air.
  10. 　入力デジタル信号列を直並列変換して複数のＤＡ変換器に入力することによって得られた夫々のアナログ信号を、入力系統をまとめて２以上の出力に合成する信号合成器と、
    　前記信号合成器によってまとめられて出力されたアナログ信号を、直交変調されたＲＦ信号に変調する複数の直交変調ミクサと、
    　前記複数の直交変調ミクサによって直交変調された複数のＲＦ信号を、個別にサブキャリアの周波数に対応させて増幅する複数のＲＦ増幅器と
    を備えるマルチキャリア通信を行なう送信機。     A signal synthesizer that synthesizes each of the analog signals obtained by serial-parallel conversion of the input digital signal sequence and inputs the input digital signals to a plurality of DA converters into two or more outputs together;
    A plurality of quadrature modulation mixers that modulate the analog signals output together by the signal synthesizer into quadrature modulated RF signals;
    A transmitter that performs multi-carrier communication including a plurality of RF amplifiers that individually amplify a plurality of RF signals that are orthogonally modulated by the plurality of orthogonal modulation mixers in correspondence with subcarrier frequencies.
  11. 　請求項１０記載の送信機において、
    　直並列変換によって得られる各並列複素シンボルの夫々に対して割り当てる個別の周波数を、シンボル周期Ｔの逆数で定義される基本周波数ｆ０（＝１／Ｔ）の整数倍でなる周波数ｆｋ＝ｋｆ０（ｋは整数）とする信号処理回路
    を有することを特徴とする送信機。     The transmitter of claim 10, wherein
    A frequency f k = kf that is an integer multiple of the fundamental frequency f 0 (= 1 / T) defined by the reciprocal of the symbol period T is assigned to each individual parallel complex symbol obtained by serial-parallel conversion. A transmitter having a signal processing circuit for setting 0 (k is an integer).
  12. 　請求項１１に記載の送信機において、
    　前記複数の直交変調ミクサで用いられる共通の局発信号を生成する共通局発発振器を有することを特徴とする送信機。     The transmitter of claim 11, wherein
    A transmitter comprising: a common local oscillator that generates a common local signal used in the plurality of orthogonal modulation mixers.
  13. 　請求項１１又は１２に記載の送信機において、
    　各ＲＦ増幅器で増幅されたＲＦ信号の一部または全てを合成する少なくとも１つの電力合成器を備えることを特徴とする送信機。     The transmitter according to claim 11 or 12,
    A transmitter comprising at least one power combiner that combines a part or all of the RF signals amplified by each RF amplifier.
  14. 　請求項１１ないし１３の何れか一項に記載の送信機において、
    　前記信号処理回路と前記複数のＤＡ変換器との間に、各複素デジタル信号標本列のそれぞれに対してガードインターバルを与えるガードインターバル生成回路を備えることを特徴とする送信機。     The transmitter according to any one of claims 11 to 13,
    A transmitter comprising: a guard interval generation circuit that provides a guard interval for each of the complex digital signal sample sequences between the signal processing circuit and the plurality of DA converters.
  15. 　請求項１４記載の送信機において、
    　前記ガードインターバル生成回路と前記複数のＤＡ変換器との間に、各複素デジタル信号標本列のそれぞれに対してウインドウイング処理を行うウインドウイング処理回路を備えることを特徴とする送信機。     The transmitter of claim 14, wherein
    A transmitter comprising: a windowing processing circuit that performs a windowing process on each of the complex digital signal sample sequences between the guard interval generation circuit and the plurality of DA converters.
  16. 　請求項１０ないし１５の何れか一項に記載の送信機において、
    　入力デジタル信号列を直並列変換した後にであって前記複数のＤＡ変換器に入力する前に帯域を制限するフィルタを備えることを特徴とする送信機。     The transmitter according to any one of claims 10 to 15,
    A transmitter comprising: a filter for limiting a band after serially parallel converting an input digital signal sequence and before inputting to the plurality of DA converters.
  17. 　請求項１１ないし１６の何れか一項に記載の送信機において、
    　前記信号処理回路は、
    　複数の異なる方式に対応する複数種類の複素デジタル信号標本列をそれぞれ生成できると共に、
    　入力された制御信号に基づいて、前記複数種類の複素デジタル信号標本列の中から、選択された複素デジタル信号標本列を生成する
    ことを特徴とする送信機。     The transmitter according to any one of claims 11 to 16,
    The signal processing circuit includes:
    It can generate multiple types of complex digital signal sample sequences corresponding to multiple different methods,
    A transmitter which generates a complex digital signal sample sequence selected from the plurality of types of complex digital signal sample sequences based on an input control signal.
  18. 　入力デジタル信号列をシンボル変換、直並列変換およびアナログ変換を行い得られた夫々のアナログ信号を、入力系統をまとめて後段の２以上の個々に独立したＲＦ増幅器の台数に成るように合成し、
    　合成されたそれぞれの信号を、複数の直交変調ミクサを用いて、直交変調された複数のＲＦ信号に変調し、
    　前記複数のＲＦ信号の夫々を、複数のＲＦ増幅器を用いて、個別にサブキャリアの周波数に対応させて増幅し、
    　前記独立して個別に増幅した夫々のＲＦ信号を、アンテナを用いて空中に送出する
    ことを特徴とするマルチキャリア通信方法。     Each analog signal obtained by performing symbol conversion, serial-parallel conversion, and analog conversion on the input digital signal sequence is combined so that the input system is combined into the number of two or more independent RF amplifiers in the subsequent stage,
    Each synthesized signal is modulated into a plurality of quadrature modulated RF signals using a plurality of quadrature modulation mixers,
    Each of the plurality of RF signals is amplified by using a plurality of RF amplifiers individually corresponding to the subcarrier frequency,
    A multicarrier communication method, wherein each independently amplified RF signal is transmitted to the air using an antenna.
  19. 　請求項１８記載のマルチキャリア通信方法において、
    　直並列変換によって得られる各並列複素シンボルの夫々に対して割り当てる個別の周波数を、シンボル周期Ｔの逆数で定義される基本周波数ｆ０（＝１／Ｔ）の整数倍でなる周波数ｆｋ＝ｋｆ０（ｋは整数）とする
    ことを特徴とするマルチキャリア通信方法。     The multi-carrier communication method according to claim 18.
    A frequency f k = kf that is an integer multiple of the fundamental frequency f 0 (= 1 / T) defined by the reciprocal of the symbol period T is assigned to each individual parallel complex symbol obtained by serial-parallel conversion. A multicarrier communication method characterized in that 0 (k is an integer).
  20. 　請求項１８または１９に記載のマルチキャリア通信方法において、
    　シンボル変換および直並列変換により、相互に直交させた複素デジタル信号標本列をアナログ変換および合成して得た夫々のアナログ信号を、共通の局発信号を使用して夫々のＲＦ信号に変調する
    ことを特徴とするマルチキャリア通信方法。     The multicarrier communication method according to claim 18 or 19,
    Each analog signal obtained by converting and synthesizing complex digital signal sample sequences orthogonal to each other by symbol conversion and serial / parallel conversion is modulated to each RF signal using a common local oscillation signal. A multi-carrier communication method characterized by the above.
  21. 　請求項１８ないし２０の何れか一項に記載のマルチキャリア通信方法において、
    　直並列変換後アナログ変換前に、サブキャリアの周波数帯域に基づくフィルタ処理を行うと共に、
    　アナログ変換前に、各複素デジタル信号標本列のそれぞれに対してガードインターバルを加え、
    　前記ガードインターバルを加えた各複素デジタル信号標本列のそれぞれに対してウインドウイング処理を加え、
    　且つ、前記複数のＲＦ増幅器で増幅されたＲＦ信号の一部または全てを電力合成し、
    　合成したＲＦ信号を、アンテナを用いて空中に送出する
    ことを特徴とするマルチキャリア通信方法。     The multicarrier communication method according to any one of claims 18 to 20,
    Performs filter processing based on the frequency band of the subcarrier before analog conversion after series-parallel conversion,
    Before analog conversion, add a guard interval for each complex digital signal sample sequence,
    A windowing process is applied to each of the complex digital signal sample sequences to which the guard interval is added,
    And power combining some or all of the RF signals amplified by the plurality of RF amplifiers,
    A multicarrier communication method characterized by transmitting a synthesized RF signal into the air using an antenna.
  22. 　請求項１８ないし２１の何れか一項に記載のマルチキャリア通信方法において、
    　直並列変換により、相互に直交する並列デジタル信号を生成する複数種類の方式に対応すると共に、
    　入力される制御信号に従って、相互に直交する並列デジタル信号を生成する複数種類の方式の中からいずれか一つを選択する制御部を備え、
    　前記制御部に入力される前記制御信号に基づいて、選択された並列デジタル信号を生成し、
    　当該直交している並列デジタル信号を、夫々アナログ変換、信号合成、ＲＦ信号への変調、および個別に増幅し、
    　アンテナを用いて空中に送出する
    ことを特徴とするマルチキャリア通信方法。     The multicarrier communication method according to any one of claims 18 to 21,
    Supports multiple types of parallel digital signals that are orthogonal to each other by serial-parallel conversion.
    A control unit that selects any one of a plurality of methods for generating parallel digital signals orthogonal to each other according to an input control signal,
    Based on the control signal input to the control unit, to generate a selected parallel digital signal,
    The orthogonal parallel digital signals are respectively converted into analog signals, signal synthesis, modulation into RF signals, and individually amplified,
    A multi-carrier communication method characterized by transmitting to the air using an antenna.
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