JP2007282156A - Radio repeating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio repeating apparatus which has reduced circuit scale while maintaining frequency utilization efficiency. <P>SOLUTION: The radio repeating apparatus 100 includes a transmission section 74 which outputs as a transmission signal, a main signal for transmitting transmission data and an auxiliary signal for transmitting status information of radio equipment used for repetition, and a reception section 76 which acquires transmission signal from another station and separates it into a main signal and an auxiliary signal. The transmission section 74 includes an IQ separator 11, an IQ distributor 12, a complex multiplier 13, a complex vector generator 14, an in-phase adder 15, a low-pass filter 16, a D/A converter 17, a quadrature modulator 19, a synthesizer 20, and an amplifier 21. The reception section 76 includes an amplifier 31, a distributor 32, a quadrature demodulator 33, a capacitor 34, a low-pass filter 35, an A/D converter 36, and an IQ synthesizer 37. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention acquires a transmission signal from another station, a transmission unit that outputs a main signal for transmitting transmission data, an auxiliary signal that transmits state information of a radio used for relaying, and a transmission signal. In particular, the present invention relates to a radio relay apparatus that includes a receiver that separates a main signal and an auxiliary signal, amplifies a signal received by the receiver, and retransmits the signal from the transmitter.

  In terrestrial digital broadcasting and mobile communication, a wireless relay device receives a broadcast signal or mobile communication signal, amplifies power, and retransmits it to enable communication area expansion and effective use of frequency. This wireless relay device includes a transmission unit that outputs, as a transmission signal, a main signal for transmitting transmission data and an auxiliary signal that transmits state information of a radio device used for relaying, and transmission signals from other stations. And a receiving unit that acquires and separates into a main signal and an auxiliary signal.

  In view of frequency utilization efficiency, the auxiliary signal is often relayed in the same frequency band as the main signal, and the auxiliary signal is injected into the main signal transmitted from the transmitter and output. For this reason, since the auxiliary signal interferes with the main signal, it is necessary to set the power ratio of the main signal to the auxiliary signal as low as possible, and a narrow-band subcarrier signal is generally used.

  However, the narrow-band subcarrier signal may be locally suppressed by frequency selective fading in the wireless section, and communication may be disabled. For this reason, it is desirable that the frequency bandwidth of the weak auxiliary signal be as wide as possible.

  In order to satisfy such a requirement, Patent Document 1 discloses a system that wirelessly relays information such as video and audio shot and recorded by a camera or a microphone in a digital manner. In this system, auxiliary signals (for example, control / monitoring signals and GPS data of various devices) are transmitted based on the standards of ARIB-B11 and B12 at the Association of Radio Industries and Business (ARIB). Can be transmitted simultaneously with the main signal.

JP 2005-167642 A

  However, since the technique of Patent Document 1 increases the bit rate for the auxiliary signal area, the symbol rate is set high in advance so that the main signal and the auxiliary signal are within the channel bandwidth determined by the standard. Yes. Especially when the auxiliary signal is not transmitted, data called stuffing (stuffing) is transmitted at a predetermined bit rate, so that unnecessary data transmission occurs and the circuit becomes complicated for effective use of the frequency. It was.

  Further, in Patent Document 1, data to be transmitted has a frame structure based on MPEG2-TS (Moving Picture Experts Group 2-Transport Stream) packets, and wireless transmission from the transmission side relay apparatus to the reception side relay apparatus is performed by a digital QAM modulation method. ing. For this reason, high communication quality is required, and the circuit scale is large on the receiving side, and there is a drawback that it is difficult to reduce the size and cost of the apparatus.

  The present invention has been made to solve the above-described problems, and provides a wireless relay device that has less influence on the main signal, increases frequency use efficiency, reduces the circuit scale, reduces the size of the device, and reduces the cost. The purpose is to do.

  A radio relay apparatus according to the present invention includes a transmission unit that outputs a main signal for transmitting transmission data, an auxiliary signal that transmits state information of a radio device used for relay, and a transmission signal from another station. A wireless relay device that amplifies a signal received by the receiver and retransmits the signal from the transmitter. A multi-carrier spreader that performs pseudo-spreading at a multi-carrier frequency by complex-multiplying the carrier frequency of the main signal by an integer multiple of a predetermined frequency width and an in-phase adder that adds a plurality of pseudo-spread IQ signals in phase A D / A converter that converts the in-phase added IQ signal into analog data, a quadrature modulator that converts the obtained IQ signal into a quadrature-modulated auxiliary signal, and a main signal An amplifier that synthesizes and outputs the spread auxiliary signal, and a reception unit obtains a transmission signal including the pseudo-spread auxiliary signal and orthogonally demodulates the transmission signal to the IQ signal; And an A / D converter that performs undersampling at the carrier frequency of the main signal.

  In the radio relay apparatus according to the present invention, the multicarrier spreader performs pseudo-spreading by performing complex multiplication on the carrier frequency of the main signal by an integral multiple of a predetermined frequency width within the frequency range of the main signal. It is characterized by.

  Furthermore, in the wireless relay device according to the present invention, the reception unit includes an auxiliary signal remover that removes an auxiliary signal included in the transmission signal.

  By using the present invention, it is possible to extract an auxiliary signal that is pseudo-spread with a simple circuit configuration, and it is possible to provide a wireless relay device with a reduced circuit scale.

  Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 5 shows an overall configuration of a radio relay apparatus 200 that performs code spreading processing on an auxiliary signal as a configuration (hereinafter referred to as a “reference configuration”) that serves as a reference for understanding the present invention. This radio relay apparatus 200 includes a transmission unit 70 that outputs a main signal for transmitting transmission data, an auxiliary signal for transmitting state information of a radio used for relaying, and the like as a transmission signal, And a receiver 72 that acquires a transmission signal and separates it into a main signal and an auxiliary signal. The wireless relay device 200 includes a control unit 30. The control unit 30 monitors the control and state of the wireless device and outputs the information as an auxiliary signal.

  The transmission unit 70 includes a spread processor 51, two low-pass filters 16, two D / A converters 17, a quadrature modulator 19, a combiner 20, and an amplifier 21. The auxiliary signal input to the transmission unit 70 is spread with a spreading code by the spread processor 51 and input to the two low-pass filters 16 as an IQ signal. The IQ signal is filtered by two low-pass filters 16, converted to an analog signal by two D / A converters 17, orthogonally modulated by a quadrature modulator 19, and then synthesized with a main signal by a synthesizer 20, It is output after amplification by the amplifier 21. In this way, the transmission unit 70 spreads the information from the control unit 30 with the spreading code as an auxiliary signal and outputs it as a transmission signal.

  The receiving unit 72 includes an amplifier 31, a distributor 32, a main signal system that outputs a main signal, and an auxiliary signal system that outputs an auxiliary signal. The auxiliary signal system includes an orthogonal demodulator 33, two low-pass filters 35, two A / D converters 36, two delay units 52, a synchronization processor 53, a spread code generator 54, and a despreading process. Instrument 55. The main signal system also includes an auxiliary signal remover 38 that removes the auxiliary signal from the main signal using the auxiliary signal obtained by the auxiliary signal system. The delay unit 52 to the despreading unit 55 are referred to as a synchronization acquisition circuit.

  When the receiving unit 72 acquires a transmission signal from another station, the amplifier 31 amplifies the transmission signal by the amplifier 31 and branches the main signal system and the auxiliary signal system by the distributor 32.

  In the auxiliary signal system, the receiving unit 72 separates the IQ signal by the quadrature demodulator 33, performs filter processing by the two low-pass filters 35, and converts the digital signal by the two A / D converters 36. The converted digital signal is input to the two delay units 52 and the synchronization processor 53, and the respective outputs and the output of the spread code generator 54 are input to the despreading processor 55. The despreading processor 55 that has acquired the signal despreads the spread auxiliary signal and outputs the auxiliary signal.

  As described above, in the receiving unit 72, in order to despread the signal spread by the transmitting unit 70, it is necessary to multiply the same spreading code as the spreading code used in the transmitting unit 70 in accordance with the timing at which the correlation peak is obtained. . In order to detect an appropriate timing, despreading is necessary at two timings, a slightly earlier timing and a slightly later timing, and the amount of processing is large. In order to perform such processing without delay, the processing circuit of the receiving unit becomes complicated, and there is a disadvantage that the circuit scale is large. For this reason, the diffusion / despreading circuit as shown in the reference configuration cannot reduce the circuit scale, and it is difficult to reduce the size and cost of the device.

Embodiment 1

  FIG. 1 shows an overall configuration of a wireless relay device 100 that performs pseudo-spreading processing by spreading signals in a plurality of frequency bands according to the first embodiment of the present invention. The configuration shown in FIG. 1 uses, for example, four multicarriers to extract an auxiliary signal spread with a simple circuit configuration compared to the reference configuration. The basic configuration of the wireless relay device 100 is the same as the reference configuration shown in FIG.

  The transmission unit 74 includes an IQ separator 11, six IQ distributors 12, four complex multipliers 13, four complex vector generators 14, two in-phase adders 15, and two low-pass filters 16 , Two D / A converters 17, a quadrature modulator 19, a combiner 20, and an amplifier 21.

  The auxiliary signal input to the transmission unit 74 is separated into IQ signals by the IQ separator 11 and input to each complex multiplier 13 by the six distributors 12. Four complex multipliers 13 create complex vectors corresponding to multicarrier frequencies generated by four complex vector generators 14 and add them by two in-phase adders 15. The added IQ signal is filtered by two low-pass filters 16, converted to an analog signal by two D / A converters 17, modulated by a quadrature modulator 19, and then combined with a main signal by a combiner 20. And output after amplification by the amplifier 21. In this way, the transmission unit 74 outputs information from the control unit as a transmission signal that is pseudo-spread at the multicarrier frequency as an auxiliary signal.

  The receiving unit 76 includes an amplifier 31, a distributor 32, a main signal system that outputs a main signal, and an auxiliary signal system that outputs an auxiliary signal. The auxiliary signal system includes a quadrature demodulator 33, two capacitors 34, two low-pass filters 35, two A / D converters 36, and an IQ synthesizer 37. The main signal system also includes an auxiliary signal remover 38 that removes the auxiliary signal from the main signal using the auxiliary signal obtained by the auxiliary signal system.

  When receiving the transmission signal from the other station, the receiving unit 76 amplifies the transmission signal by the amplifier 31 and causes the distributor 32 to branch the main signal system and the auxiliary signal system. The auxiliary signal system is separated into IQ signals by the quadrature demodulator 33, filtered by the two capacitors 34 and the two low-pass filters 35, and converted into digital signals by the two A / D converters 36. The converted digital signal is input to an IQ combiner 37, which outputs an auxiliary signal.

  FIG. 2 shows frequency folding due to undersampling, which is one of the features of the present invention. In the figure, a horizontal carrier sampling frequency Δf, a vertical carrier amplitude multicarrier signal, and a low-pass filter extracted as a signal including aliasing are shown. In the transmission unit 74 shown in FIG. 1, the auxiliary signal is IQ-isolated and Δf × N (N is an integer: 4) frequency conversion is performed by complex multiplication processing. This process copies four auxiliary signals having the same spectrum. FIG. 2 shows the case of N = −2, −1, +1, +2, but N may be an integer and is set to be within the frequency range of the main signal.

  The receiving unit 76 branches the received signal and performs quadrature demodulation. Assuming that the sampling frequency of the A / D converter 36 is Δf, all frequency components of Δf × N are folded and synthesized as shown in FIG. By the folding, the noise component existing in Δf × N is uncorrelated and the auxiliary signal existing in Δf × N is added in phase, so that a gain of 10 logK (dB) is obtained. Here, K is the number of copies, for example, a gain of 3 dB when K = 2, and 10 dB when K = 10.

  Note that if there is an N = 0 component, it is also added in phase, but as shown in FIG. 1, it is possible to reduce the influence of a DC offset or the like by using a DC cut without using the N = 0 component. This is because it is easily affected by the carrier leak of the quadrature modulator 19 and the DC offset of the quadrature demodulator 33.

  Thus, by making a copy of the auxiliary signal to Δf × N in advance by the transmission unit 74, the reception unit 76 can perform despreading only by undersampling at the sampling frequency Δf. Furthermore, the synchronization acquisition circuit (52 to 55) shown in the reference configuration of FIG. 5 is not required simply by creating a copy of the auxiliary signal at the transmission unit 74, so that the circuit scale can be reduced in total. It is.

Embodiment 2

  FIG. 3 shows a second embodiment of the transmission unit 74. What is characteristic in this embodiment is that band limitation is performed after complex multiplication. The transmission unit 74 includes an IQ separator 11, six IQ distributors 12, four complex multipliers 13, four complex vector generators 14, eight low-pass filters 22, and two in-phase adders 15. , And two D / A converters 17. Other parts are omitted.

  The auxiliary signal input to the transmission unit 74 is separated into IQ signals by the IQ separator 11 and input to each complex multiplier 13 by the six distributors 12. The four complex multipliers 13 create signals with complex vectors corresponding to multicarrier frequencies generated by the four complex vector generators 14 and individually limit the band with the low-pass filter 22, thereby spreading the spectrum of the auxiliary signal. It is possible to hold down. Thereafter, the signals are added by two in-phase adders 15, converted into analog signals by two D / A converters 17, and modulated by a quadrature modulator 19.

Embodiment 3

  FIG. 4 shows a third embodiment of the transmission unit 74. What is characteristic in this embodiment is that a spread auxiliary signal is obtained without using complex multiplication. The transmission unit 74 includes an IQ separator 11, a multiplier 18, a pulse generator 23, a low-pass filter 24, and a D / A converter 17. Other parts are omitted.

  The auxiliary signal input to the transmitter 74 is separated into an IQ signal by the IQ separator 11, and the multiplier 18 multiplies the IQ signal by the 1 / Δf step impulse waveform generated by the pulse generator 23 by the multiplier 18. Can be obtained. Then, after removing excess harmonic components by the two low-pass filters 24, they are converted into analog signals by the two D / A converters 17 and modulated by the quadrature modulator 19. With such a configuration, the circuit can be greatly simplified.

  As described above, the auxiliary signal can be spread over a plurality of frequency bands, and a signal obtained by spreading the spread auxiliary signal by undersampling can be synthesized. By using this embodiment, it is possible to extract an auxiliary signal that is pseudo-spread with a simple circuit configuration, and it is possible to provide a wireless relay device that has less influence on the main signal and has a smaller circuit scale.

1 is an overall configuration diagram of a wireless relay device according to an embodiment of the present invention. It is explanatory drawing of the frequency return by undersampling. It is a block diagram of the transmission part in 2nd Embodiment. It is a block diagram of the transmission part in 3rd Embodiment. It is a block diagram of the radio relay apparatus which becomes a reference in understanding this invention.

Explanation of symbols

  10, 30 control unit, 11 IQ separator, 12, 32 IQ distributor, 13 complex multiplier, 14 complex vector generator, 15 in-phase adder, 16 low-pass filter, 17 D / A converter, 18 multiplier, 19 orthogonal Modulator, 20 combiner, 32 distributor, 37 IQ combiner, 21, 31 amplifier, 22, 24 low pass filter, 23 pulse generator, 33 quadrature demodulator, 34 capacitor, 35 low pass filter, 36 A / D converter, 38 auxiliary signal remover, 51 spreading processor, 52 delay unit, 53 synchronization processor, 54 spreading code generator, 55 despreading processor, 70, 74 transmitting unit, 72, 76 receiving unit, 100, 200 wireless relay device .

Claims (3)

A transmission unit that outputs a main signal for transmitting transmission data, an auxiliary signal that transmits state information of a radio used for relaying as a transmission signal, a transmission signal from another station, and a main signal In a wireless relay device that includes a receiving unit that separates into an auxiliary signal, amplifies a signal received by the receiving unit, and retransmits the signal from the transmitting unit.
The transmitter
A multi-carrier spreader that performs pseudo-spreading at a multi-carrier frequency by IQ-separating the auxiliary signal and complex-multiplying the carrier frequency of the main signal by an integer multiple of a predetermined frequency width;
An in-phase adder for adding a plurality of pseudo-spread IQ signals in phase;
A D / A converter for converting the in-phase added IQ signal into analog data;
A quadrature modulator that quadrature modulates the obtained IQ signal to convert it into a pseudo-spread auxiliary signal;
An amplifier that synthesizes and outputs the main signal and the pseudo-spread auxiliary signal;
The receiver
An orthogonal demodulator that acquires a transmission signal including a pseudo-spread auxiliary signal and orthogonally demodulates the transmission signal to an IQ signal;
An A / D converter that performs undersampling at the carrier frequency of the main signal;
A wireless relay device comprising: The wireless relay device according to claim 1,
The multi-carrier spreader performs pseudo-spreading within the frequency range of the main signal and by performing complex multiplication on the carrier frequency of the main signal by an integral multiple of a predetermined frequency width. The wireless relay device according to claim 1,
The radio relay apparatus, wherein the reception unit includes an auxiliary signal remover that removes an auxiliary signal included in the transmission signal.

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