JP3287721B2 - Communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device used for digital radio communication for transmitting and receiving digital data between a master station and a slave station.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram showing a conventional communication device. 10A shows a master station, and FIG. 10B shows a slave station. The master station and the slave station have the same configuration. In the figure, 1 is a terminal device, 2 is a modulator for modulating a transmission data signal from the terminal device 1 into a transmission IF (intermediate frequency) signal, 3
Is a transmitting local oscillator of the modulator 2, 4 is a transmitting carrier wave which is an output of the transmitting local oscillator 3, and 5 is a converter for converting the transmission IF signal modulated by the modulator 2 into a transmission RF (radio frequency) signal. A transmitting frequency converter, 6 a transmitting amplifier for amplifying a transmitting RF signal, 7 an antenna for transmitting and receiving to and from a partner station,
8 is a receiving amplifier for amplifying a received RF signal, and 9 is a receiving R
A receiving frequency converter for converting the F signal into a receiving IF signal;
Reference numeral 10 denotes a demodulator that incorporates a carrier recovery circuit 11 and demodulates a received data signal from the received IF signal.

Next, the operation will be described. First, the operation on the transmission side will be described. The transmission data signal output from the terminal device 1 is input to the modulator 2. The modulator 2 modulates using the transmission carrier 4 generated by the transmission local oscillator 3 and outputs a transmission IF signal. The transmission IF signal is converted into a transmission RF signal by the transmission frequency converter 5, further amplified by the transmission amplifier 6, and transmitted from the antenna 7 to the partner station as a radio wave.

Next, the operation of the receiving side will be described. A radio wave from the partner station is received by the antenna 7 and is amplified by the receiving amplifier 8. Further, the signal is converted into a reception IF signal by the reception frequency converter 9 and input to the demodulator 10.
The demodulator 10 demodulates the data signal by reproducing the carrier by the built-in carrier recovery circuit 11 and outputs the demodulated data signal to the terminal device 1 as a received data signal. The above-described operation is performed in the same manner in the master station and the slave station.

Here, a digital phase modulation method by the modulator 2 will be described. As a digital phase modulation method, generally, M-ary PSK (PSK: Phase Shif)
t Keying) is used, but here, in particular, BPSK
(Binary Phase Shift Keying) will be described. FIG. 11 is a block diagram showing a modulator and a demodulator of the BPSK system. In FIG. 11, a modulator 2 transmits a transmission IF by multiplying a transmission data signal by a transmission carrier 4 generated by a transmission local oscillator 3.
The demodulator 10 for generating a BPSK wave as a signal includes a balanced modulator 2a. The demodulator 10 for demodulating the BPSK wave regenerates a carrier from a received wave and multiplies the received wave by the reproduced carrier to obtain a baseband signal. In addition to the carrier recovery circuit 11 which converts and outputs the carrier wave, the carrier recovery circuit 1
A determination circuit 12 is provided for determining the baseband signal output from 1 based on the level of the reference clock signal and outputting the received signal as a digital signal of "1" or "0" corresponding to the phase of the carrier.

As the carrier recovery circuit 11, a Costas loop type circuit is used. FIG. 12 is a block diagram showing a Costas loop type carrier recovery circuit. As is well known, the Costas loop type carrier recovery circuit converts a received wave input signal (BPSK) into a voltage-controlled oscillator described later.
A multiplier 11a for multiplying by the reproduction carrier as a reference signal from 11g to obtain an in-phase component synchronized with the reproduction carrier;
A multiplier 11b that obtains an orthogonal component orthogonal to a reproduced carrier by multiplying the input signal by a reference signal that has passed through a phase shifter 11h that obtains a reference signal having a different phase from the input signal.
And a low-pass filter 11c for obtaining only a baseband signal from the quadrature component from the multiplier 11b.
d, a multiplier 11e that multiplies the in-phase component and the quadrature component through the low-pass filters 11c and 11d, respectively, to obtain a doubled baseband signal, and a multiplier 11e
e, a loop filter 11f for obtaining a phase difference signal component corresponding to the phase difference between the reproduced carrier wave and the output signal of the voltage controlled oscillator 11c, and a feedback such that the phase difference becomes 0 based on the phase difference signal component. It includes a voltage-controlled oscillator 11g for performing control, that is, control for achieving synchronization, and the phase shifter 11h.

[0007]

Since the conventional communication apparatus is configured as described above, the transmission local oscillators 3 are provided in both the master station and the slave station, and the transmission local oscillators for the number of stations are provided. Needed. Also, usually, in a modem, I
The F signal frequency is generally the same for both transmission and reception, for example, 140 MHz. In this case, the carrier for transmission and the carrier for reproduction also have the same frequency, and the modulator 2 and the demodulator 10 are mounted in the same housing. When implemented, the carrier signal for transmission and the carrier signal for reproduction are not synchronized with each other, that is, they are not completely the same frequency, so that there is a possibility that a beat signal may be generated due to a slight frequency deviation between them. The beat signal is superimposed on, for example, a baseband signal of the demodulator 10 and may cause an error in data reproduction in the determination circuit 12. Therefore, it is necessary to design such that the modulator 2 and the demodulator 10 are structurally separated from each other, and there is a problem that the device becomes complicated and expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and eliminates the need for a local oscillator for transmission in a slave station. In addition, a beat signal is generated between a transmission carrier and a reproduced carrier. It is an object of the present invention to obtain a communication device that does not interfere with each other without being generated.

[0009]

According to the present invention, there is provided a communication apparatus comprising: a modulator for digitally modulating transmission data input from a terminal device with a transmission carrier and transmitting the intermediate data as an intermediate frequency signal to a master station and a slave station; , each comprise a demodulator for outputting the received data to the terminal apparatus demodulates the received intermediate frequency signal data, in a communication apparatus for digital radio communication between the master station and the slave station, to the master station , Reference
A reference signal generator that generates a signal
A reference signal transmitting means for adding to the frequency signal,
The slave station receives the reference signal from the received intermediate frequency signal.
From which the carrier is extracted and used as a carrier for transmission to the modulator on the slave station side
A signal receiving means is provided, and the modulator at the slave station uses a transmission carrier synchronized with a reproduced carrier used by the demodulator at the slave station.

[0010] Further, the demodulator on the slave station side outputs a phase difference signal doubled in a baseband band given by a product of an in-phase component synchronized with an output carrier and an orthogonal component orthogonal to the in-phase component. A Costas loop-type carrier recovery circuit that incorporates a voltage-controlled oscillator that performs feedback control so that the phase difference becomes 0 based on the input and obtains a recovered carrier synchronized with the received wave is provided, and outputs the output of the voltage-controlled oscillator to the slave station. It is characterized by being used as a carrier for transmission to a modulator.

The demodulator at the slave station converts the baseband signal into a baseband signal of an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while leaving the phase rotation component by the baseband conversion signal. A quasi-synchronous carrier recovery circuit for obtaining a recovered carrier synchronized with the received wave by processing the phase rotation component is provided.

Further, the quasi-synchronous carrier recovery circuit includes a fixed oscillator for outputting a baseband conversion signal,
The baseband conversion signal is used as a carrier for transmission to a modulator on the slave station side.

The modulator on the slave station side is provided with a transmission local oscillator for outputting a transmission carrier, and the transmission carrier is input to the quasi-synchronous carrier recovery circuit and used as a baseband conversion signal. It is characterized by having been.

[0014]

Further, the master station is provided with a multiplier for multiplying a reference signal added to the intermediate frequency signal, and the slave station is provided with a multiplier for multiplying the multiplied reference signal extracted from the received intermediate frequency signal. A frequency divider is provided, which is divided by a multiple of the frequency divider and used as a carrier for transmission to the modulator on the slave station side.

The base station demodulator converts the baseband signal into a baseband signal of an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while leaving the phase rotation component by the baseband conversion signal. A quasi-synchronous carrier recovery circuit that synchronizes the reproduced carrier with the reception wave by processing the phase rotation component is provided, and the transmission carrier obtained by the reference signal receiving means is input to the quasi-synchronous carrier recovery circuit and the baseband It is characterized in that it is used as a signal for conversion.

Further, the modulator of the master station uses a carrier for transmission based on a reference signal generated from the reference signal generator.

Further, the master station is provided with a transmission local oscillator for generating a transmission carrier to be output to the modulator.

[0019]

In the communication device according to the present invention, the master station
A reference signal generator for generating a reference signal;
With reference signal transmitting means for adding
In both cases, the slave station sends the above-mentioned reference signal from the received intermediate frequency signal.
Signal to be used as a carrier for transmission to the
With a quasi-signal receiving means, the modulator on the slave station side uses a carrier for transmission synchronized with the reproduced carrier used in the demodulator on the slave station side, so that it can be used as a carrier for transmission to the modulator on the slave station side.
Since the reference signal is used instead of extracting from the modulated wave,
A stable modulated wave can be output from the slave station, and
The reference signal generator provided in the master station can be used in common by all slave stations.
In addition, the configuration of the slave station can be simplified, a local oscillator for transmission in the slave station is not required, and no beat signal is generated between the transmission carrier and the reproduced carrier so that they do not interfere with each other. Therefore, it is not necessary to separate the modulator from the demodulator, the structure is simplified, and the slave station can have a simple configuration.

The demodulator on the slave station side outputs a phase difference signal doubled in a baseband band given by a product of an in-phase component synchronized with an output carrier and an orthogonal component orthogonal to the in-phase component. A Costas loop-type carrier recovery circuit that incorporates a voltage-controlled oscillator that performs feedback control so that the phase difference becomes 0 based on the input and obtains a recovered carrier synchronized with the received wave is provided, and outputs the output of the voltage-controlled oscillator to the slave station. By using the carrier for transmission to the modulator, the carrier for transmission can be completely synchronized with the recovered carrier.

The demodulator at the slave station converts the baseband signal into a baseband signal having an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while leaving the phase rotation component by the baseband conversion signal. By providing a quasi-synchronous carrier recovery circuit for obtaining a recovered carrier synchronized with the received wave by processing the phase rotation component, the carrier for transmission can be completely synchronized with the recovered carrier.

Further, the quasi-synchronous carrier recovery circuit includes a fixed oscillator for outputting a baseband conversion signal,
By using the baseband conversion signal as a carrier for transmission to the modulator on the slave station side, the frequency of the carrier for transmission can be stabilized by the fixed oscillator.

Also, the modulator on the slave station side is provided with a transmission local oscillator for outputting a transmission carrier, and the transmission carrier is input to the quasi-synchronous carrier recovery circuit and used as a baseband conversion signal. This eliminates the need to incorporate a fixed oscillator in the quasi-synchronous carrier recovery circuit.

[0024]

The master station is provided with a multiplier for multiplying a reference signal added to the intermediate frequency signal, and the slave station is provided with a multiplier for multiplying the multiplied reference signal extracted from the received intermediate frequency signal. By providing a frequency divider that divides the frequency by a multiple of the device and uses it as a carrier for transmission to the slave-side modulator, the frequency of the reference signal can be set arbitrarily.

The base station demodulator converts the baseband signal into an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while leaving the phase rotation component by the baseband conversion signal. A quasi-synchronous carrier recovery circuit that synchronizes the reproduced carrier with the reception wave by processing the phase rotation component is provided, and the transmission carrier obtained by the reference signal receiving means is input to the quasi-synchronous carrier recovery circuit and the baseband By using as a conversion signal, a configuration is adopted in which a reference signal is added on the transmission side of the master station, and a configuration is such that the transmission carrier in the slave station and the baseband conversion signal of the quasi-synchronous carrier recovery circuit are common. By doing so, the slave station can eliminate the need for an oscillator for both transmission and reception.

The modulator of the master station uses a carrier for transmission based on a reference signal generated from the reference signal generator, so that the carrier for transmission is stabilized and
Also on the slave station side, a stable carrier for transmission to the modulator on the slave station side can be easily obtained using the reference oscillator as a common signal source.

Further, since the master station is provided with a transmission local oscillator for generating a transmission carrier to be output to the modulator, the master station can separately control the transmission frequency and the reference signal.

[0029]

【Example】

Embodiment 1 FIG. FIG. 1 is a configuration diagram illustrating the communication device according to the first embodiment. In FIG. 1, (a) shows a master station, and (b) shows a slave station. 10, the same parts as those of the conventional example shown in FIG. 10 are denoted by the same reference numerals, 1 is a terminal device, 2 is a modulator for modulating a transmission data signal from the terminal device 1 into a transmission IF (intermediate frequency) signal, and 3 is a modulator. Local oscillator for transmission of modulator 2 on master station side, 4
Is a carrier for transmission which is the output of the local oscillator for transmission 3 and 5 is a transmitter for transmitting the transmission IF signal modulated by the modulator 2.
(Transmission frequency converter for converting into a (radio frequency) signal), 6 is a transmission amplifier for amplifying a transmission RF signal, 7 is an antenna for transmitting / receiving to / from a partner station, 8 is a reception amplifier for amplifying a reception RF signal, 9 Is a receiving frequency converter for converting a received RF signal into a received IF signal, and 10 is a demodulator which has a built-in carrier wave reproducing circuit 11 and which demodulates a received data signal from the received IF signal.

In the configuration in the slave station shown in FIG. 2B, reference numeral 14 denotes a transmission carrier as a new code, and the transmission carrier is reproduced by the carrier reproduction circuit 11 in the demodulator 10. Using a carrier wave, the slave station-side modulator 2 modulates a transmission data signal from the terminal device 1 into a transmission IF (intermediate frequency) signal using the reproduced carrier wave. The second local oscillator for transmission is unnecessary.

In the first embodiment, the modulator 2 and the demodulator 10 have the same BPSK circuit configuration as the conventional example shown in FIG. As the circuit 11, a Costas loop type carrier recovery circuit similar to the conventional example shown in FIG. 12 is used.

Next, the operation will be described. The operation of the master station is the same as that of the conventional example as described later. First, the operation on the transmission side will be described. The transmission data signal output from the terminal device 1 is input to the modulator 2. The modulator 2 modulates using the transmission carrier 4 generated by the transmission local oscillator 3 and outputs a transmission IF signal. This transmission IF signal is
After being converted into a transmission RF signal by the transmission frequency converter 5 and further amplified by the transmission amplifier 6, it is transmitted from the antenna 7 to the partner station as a radio wave.

Next, the operation on the receiving side will be described. A radio wave from the partner station is received by the antenna 7 and is amplified by the receiving amplifier 8. Further, the signal is converted into a reception IF signal by the reception frequency converter 9 and input to the demodulator 10.
The demodulator 10 demodulates the data signal by reproducing the carrier by the built-in carrier recovery circuit 11 and outputs the demodulated data signal to the terminal device 1 as a received data signal.

On the other hand, the operation of the slave station is as follows. First, the operation on the transmitting side will be described. In the slave station, the transmission data signal output from the terminal device 1 is input to the modulator 2. In the modulator 2, the carrier recovery circuit 1 in the demodulator 10
The reproduced carrier reproduced in step 1 is modulated by using the carrier for transmission 14 to output a transmission IF signal. The transmission IF signal is transmitted from the antenna 7 to the partner station as a radio wave via the transmission frequency converter 5 and the transmission amplifier 6 similarly to the master station.

Next, the operation of the receiving side will be described. Similarly to the master station side, the radio wave from the partner station becomes a reception IF signal via the reception amplifier 8 and the reception frequency converter 9 and is input to the demodulator 10. In the demodulator 10, the carrier is reproduced by the carrier recovery circuit 11, and the data signal is demodulated.
The signal is output to the terminal device 1 and the reproduced carrier is transmitted to the modulator 2 as the transmission carrier 14.

As described above, according to the first embodiment, the carrier reproduced by the demodulator 10 is used as the transmission carrier 14 used in the modulator 2 in the slave station. The local oscillator for transmission can be eliminated. Further, since the local oscillation frequency for transmission and the reproduced carrier frequency in the slave station are completely synchronized with each other and do not interfere with each other, no beat signal is generated due to a frequency deviation, and the modulator 2 and the demodulator 10
Since it is not necessary to isolate the slave station, the structure is simplified, and the slave station can have a simple configuration.

Embodiment 2 FIG. Next, FIG. 2 is a configuration diagram illustrating a communication device according to a second embodiment. 2A shows a master station, and FIG. 2B shows a slave station. In the figure, the same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. In Embodiment 2 shown in FIG. 2, Embodiment 1 shown in FIG.
The configuration different from that of the demodulator 1 on the slave station side shown in FIG.
A quasi-synchronous carrier recovery circuit 13 is used as a carrier recovery circuit built in
The baseband conversion signal output from the fixed oscillator in the above is the transmission carrier 14 input to the modulator 2.

This quasi-synchronous carrier wave recovery circuit 13 is shown in FIG.
As shown in FIG. 12, conventional multipliers 11a and 11b, low-pass filters 11c and 11d, and π /
Multipliers 13a and 13b and a low-pass filter 13 similar to the phase shifter 11h for obtaining signals having two different phases, respectively.
c and 13d, and a phase shifter 13h that obtains a signal having a different phase of π / 2, and an A / D converter that A / D converts the outputs of the low-pass filters 13c and 13d, respectively.
/ D converters 13e and 13f, fixed oscillator 13g for generating a signal for baseband conversion, and A / D converter 1
The phase error of the carrier wave is detected from the outputs of 3e and 13f, and the receiving point is reversely rotated by an amount corresponding to the phase error by digital arithmetic processing, thereby processing the residual phase rotation component and reproducing the carrier wave with perfect synchronization. Phase rotator 13i to perform
And

[0039] That is, and FIG. 2 (b) a quasi-synchronous carrier recovery circuit 13 shown in FIG. 3 to be used as a carrier recovery circuit incorporated in the demodulator 10 of the slave station side shown is shown in FIG. 12
Instead of using the voltage-controlled oscillator 11g in the Costas loop-type carrier recovery circuit to completely synchronize the recovered carrier with the received wave, the baseband signal is retained with the phase rotation component left by the baseband conversion signal generated from the fixed oscillator 13g. In this embodiment, complete synchronization is obtained by processing the residual phase rotation component by digital arithmetic processing by the phase rotator 13i after A / D conversion, and in this embodiment, FIG. The baseband signal output from the phase rotator 13i, that is, the baseband conversion signal generated from the fixed oscillator 13g, is used as the transmission carrier 14 input to the modulator 2 on the slave station side shown in FIG.

As described above, by using the baseband conversion signal in the demodulator 10 instead of the transmission local oscillator of the modulator 2 in the slave station, the transmission local oscillator in the slave station becomes unnecessary. Become. In addition, the local oscillation frequency for transmission on the slave station side and the oscillator frequency of the carrier recovery circuit are completely synchronized, and there is no mutual interference, so that the structure is simplified, and the slave station can have a simple configuration. it can. Further, in the second embodiment, since the fixed oscillator 13g is used, there is an effect that the transmission frequency is stabilized.

Embodiment 3 FIG. Next, FIG. 4 shows Embodiment 2 described above.
FIG. 9 is a configuration diagram illustrating a communication device according to a third embodiment in which is modified from the first embodiment. Components that are the same as or correspond to those in the configuration diagram illustrated in FIG. In the above-described second embodiment, the transmission carrier 14 input to the modulator 2 in the slave station uses the baseband conversion signal extracted from the fixed oscillator 13g incorporated in the quasi-synchronous carrier recovery circuit 13. In the third embodiment, on the contrary, the transmission carrier 4
Is input to a quasi-synchronous carrier recovery circuit 13 and used as a baseband conversion signal. That is, in this case, the quasi-synchronous carrier recovery circuit 1 shown in FIG.
3 does not need to include the fixed oscillator 13g.

As described above, according to the third embodiment, the configuration is such that the transmission carrier 4 output from the transmission local oscillator 3 is input to the quasi-synchronous carrier recovery circuit 13, which is similar to the second embodiment. The effect of can be obtained.

Embodiment 4 FIG. Next, FIG. 5 is a configuration diagram illustrating a communication device according to a fourth embodiment. The same or corresponding parts as those in FIG. 1 illustrating the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 5, 15 is used as a new code.
Is a reference signal generator for generating a reference signal, 16 is a reference signal output from the reference signal generator 15, and 17 is a reference signal 1
6 and a transmission IF signal, and 18 is a reference signal 1
6, a divider for distributing the received IF signal, 20 a band-pass filter for extracting a reference signal from the received IF signal, and 18 a divider for dividing the reference signal.

Next, the operation will be described. FIG. 5 (a)
In the transmission section of the master station shown in FIG. 2, the reference signal 16 output from the reference signal
The signal is combined with the signal and frequency-divided by the frequency divider 18 to obtain a transmission carrier frequency, which is used as the transmission carrier 4. Here, a highly stable reference signal generator is used. On the other hand, in the receiving section of the slave station shown in FIG. 5B, the received IF signal is distributed by the distributor 19, the bandpass filter 20 extracts the reference signal 16 added on the transmitting side, and the frequency divider 1
8, and is used as a transmission carrier frequency. At this time, the reproduced carrier reproduced by the carrier recovery circuit 11 of the slave station and the transmission carrier 14 input to the modulator 2 of the slave station are synchronized with each other because the reference signal generator 15 is used as a common signal source. They are related and do not interfere with each other. In addition, the highly stable reference signal generator 15 is generally large and expensive, and installing it in each slave station cannot simplify the configuration of the slave station. However, if it is installed in the master station, it can be used in common by all slave stations, and the slave station may have a simple configuration.

As described above, by configuring the transmitting side to add a highly stable reference signal, the same effect as in the first embodiment can be obtained, and a stable reference signal not extracted from the modulated wave can be obtained. Since it is used, the transmission wave from the slave station is stabilized.

Embodiment 5 FIG. Next, FIG. 6 shows Embodiment 4 described above.
FIG. 16 is a configuration diagram illustrating a communication device according to a fifth embodiment that illustrates a modification of the first embodiment. 6, the same or corresponding parts as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. Also,
As a new code, 21 is a multiplier.

In the fourth embodiment described above, the reference signal 16 in the transmitter of the master station is frequency-divided by the frequency divider 18 and input to the modulator 2, and In the fifth embodiment, the reference signal 16 is directly input to the modulator 2 and the reference signal 16 is multiplied by the multiplier 21 to the synthesizer 17 in the fifth embodiment. I entered it. In this case, the frequency divider 18 on the receiving side of the slave station may divide the frequency by the multiple of the multiplier 21.

As described above, even if the method of adding the reference signal on the transmission side is changed, the same effect as in the fourth embodiment can be obtained, and the frequency of the reference signal 16 can be set arbitrarily.

Embodiment 6 FIG. Next, FIG. 7 shows Embodiment 4 described above.
FIG. 19 is a configuration diagram illustrating a communication device according to a sixth embodiment that illustrates a modification of the first embodiment. 7, parts that are the same as or correspond to those in FIG. 5 are given the same reference numerals, and descriptions thereof will be omitted. Also,
As a new code, reference numeral 13 denotes a quasi-synchronous carrier recovery circuit similar to that used in the second embodiment.

In the fourth embodiment described above, the carrier recovery circuit 11 is used in the demodulator 10 of the slave station. In the sixth embodiment, the quasi-synchronous carrier recovery circuit 13 described in the second embodiment is used. Used. The quasi-synchronous carrier recovery circuit 13 uses a common oscillator for baseband signal conversion with the carrier 4 for transmission in the slave station, thereby realizing the third embodiment.
Similarly to the above, the quasi-synchronous carrier recovery circuit 13 does not need to include an oscillator.

As described above, the reference signal 16
Is added, and the transmission carrier in the slave station and the baseband conversion signal of the quasi-synchronous carrier recovery circuit 13 are made common, whereby the same effect as in the fourth embodiment can be obtained. At the same time, the slave station does not need an oscillator for both transmission and reception.

Embodiment 7 FIG. Next, FIG. 8 shows Embodiments 4 to 6.
FIG. 19 is a configuration diagram illustrating a communication device according to a seventh embodiment showing a modification example of FIG. 8, parts that are the same as or correspond to those in FIGS. 5 to 7 are given the same reference numerals, and descriptions thereof will be omitted. In the seventh embodiment, the multiplier 21 is used in the transmitter of the master station as described in the fifth embodiment, and the quasi-synchronous carrier wave circuit 13 is used in the receiver of the slave station as described in the sixth embodiment. Is used.

As described above, the same effects as those of the fourth embodiment can be obtained by combining the structures of the fifth and sixth embodiments.

Embodiment 8 FIG. Next, FIG. 9 is a configuration diagram illustrating a communication device according to an eighth embodiment, which is a modification of the fourth and sixth embodiments. In FIG. 9, the same or corresponding parts as those in FIGS. 5 and 7 are denoted by the same reference numerals, and description thereof will be omitted.
In the eighth embodiment, the reference signal 16 which is the output of the reference signal generator 15 in the transmission unit of the master station shown in the fourth embodiment is input to the synthesizer 17, and the transmission carrier 4 to the modulator 2 is transmitted. Uses a local oscillator 3 for transmission. The configuration of the slave station is the same as that of the sixth embodiment. In this case, there are two reference signals on the transmitting side: the transmission carrier 4 and the reference signal 16, but the slave station does not need an oscillator.

As described above, the reference signal 16 different from the transmission carrier 4 is provided on the transmission side of the master station, and the baseband conversion signal of the quasi-synchronous carrier and the transmission carrier are shared on the reception side of the slave station. With this configuration, the same effects as those of the fourth and sixth embodiments can be obtained, and the frequency of the transmission carrier 4 and the reference signal 16 can be separately controlled by the master station.

[0056]

As described above, according to the present invention, the master station
And a built-in reference signal generator for generating a reference signal.
A reference signal transmitting means for adding the signal to the intermediate frequency signal;
And the slave station receives the above intermediate frequency signal from the received intermediate frequency signal.
Extract the quasi-signal and use it as the carrier for transmission to the modulator on the slave station side.
Since a reference signal receiving means is provided and a carrier for transmission synchronized with a reproduced carrier used in a demodulator of the slave station is used as a carrier for transmission of the modulator of the slave station,
Since it is extracted from the modulated wave as a carrier for transmission to the modulator,
Use the reference signal instead of the
Wave, and the reference signal provided at the master station.
Signal generator can be used in common for all slave stations, simplifying the configuration of slave stations
In addition, since a local oscillator for transmission in a slave station is not required, and a beat signal does not occur between a transmission carrier and a reproduced carrier and no mutual interference occurs, a modulator and a demodulator are used. This eliminates the need for isolation, simplifies the structure, and has the effect that the slave station can have a simple configuration.

Further, the demodulator on the slave station side outputs the phase difference signal doubled in the baseband band given by the product of the in-phase component synchronized with the output carrier and the quadrature component orthogonal to the in-phase component. A Costas loop-type carrier recovery circuit that incorporates a voltage-controlled oscillator that performs feedback control so that the phase difference becomes 0 based on the input and obtains a recovered carrier synchronized with the received wave is provided, and outputs the output of the voltage-controlled oscillator to the slave station. By using the carrier for transmission to the modulator, the carrier for transmission can be completely synchronized with the recovered carrier.

The demodulator at the slave station converts the baseband signal into an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while leaving the phase rotation component by the baseband conversion signal. By providing a quasi-synchronous carrier recovery circuit for obtaining a recovered carrier synchronized with the received wave by processing the phase rotation component, the carrier for transmission can be completely synchronized with the recovered carrier. .

Further, the quasi-synchronous carrier recovery circuit has a built-in fixed oscillator for outputting a baseband conversion signal,
By using the baseband conversion signal as a carrier for transmission to the modulator on the slave station side, the frequency of the carrier for transmission can be stabilized by the fixed oscillator.

The modulator on the slave station side is provided with a transmission local oscillator for outputting a carrier wave for transmission. The carrier wave for transmission is input to the quasi-synchronous carrier wave recovery circuit and used as a signal for baseband conversion. As a result, there is an effect that it is not necessary to incorporate a fixed oscillator in the quasi-synchronous carrier recovery circuit.

[0061]

The master station is provided with a multiplier for multiplying a reference signal added to the intermediate frequency signal, and the slave station is provided with a multiplier for multiplying the multiplied reference signal extracted from the received intermediate frequency signal. Providing a frequency divider that divides the frequency by the number of multipliers and uses it as a carrier for transmission to the modulator on the slave station side has the effect that the frequency of the reference signal can be set arbitrarily.

The demodulator at the slave station converts the baseband signal into an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while leaving the phase rotation component by the baseband conversion signal. A quasi-synchronous carrier recovery circuit that synchronizes the reproduced carrier with the reception wave by processing the phase rotation component is provided, and the transmission carrier obtained by the reference signal receiving means is input to the quasi-synchronous carrier recovery circuit and the baseband By using as a conversion signal, a configuration is adopted in which a reference signal is added on the transmission side of the master station, and a configuration is such that the transmission carrier in the slave station and the baseband conversion signal of the quasi-synchronous carrier recovery circuit are common. By doing so, it is possible to eliminate the need for an oscillator for both transmission and reception in the slave station.

Further, the modulator of the master station uses a transmission carrier based on the reference signal generated from the reference signal generator, so that the transmission carrier is stabilized and
Also on the slave station side, there is an effect that a stable carrier wave for transmission to the modulator on the slave station side can be easily obtained using the reference oscillator as a common signal source.

Further, by providing the master station with a transmission local oscillator for generating a carrier for transmission to be output to the modulator, the master station can control the transmission frequency and the reference signal separately. is there.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a communication device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a communication device according to a second embodiment of the present invention.

FIG. 3 is an internal configuration diagram showing a quasi-synchronous carrier recovery circuit 13 of FIG. 2;

FIG. 4 is a configuration diagram illustrating a communication device according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating a communication device according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram illustrating a communication device according to a fifth embodiment of the present invention.

FIG. 7 is a configuration diagram illustrating a communication device according to a sixth embodiment of the present invention.

FIG. 8 is a configuration diagram illustrating a communication device according to a seventh embodiment of the present invention.

FIG. 9 is a configuration diagram illustrating a communication device according to an eighth embodiment of the present invention.

FIG. 10 is a configuration diagram showing a communication device according to a conventional example.

FIG. 11 is an explanatory diagram of BPSK modulation in FIG. 10;

FIG. 12 is an internal configuration diagram showing a carrier recovery circuit 11 of FIG. 10;

[Explanation of symbols]

2 modulator, 3 local oscillator for transmission, 4, 14 carrier for transmission, 10 demodulator, 11 carrier recovery circuit, 13
Quasi-synchronous carrier recovery circuit, 13g fixed oscillator, 15
Reference signal generator, 16 reference signals, 18 frequency divider, 21
Multiplier.

Claims (9)

(57) [Claims] A modulator for digitally modulating transmission data input from a terminal device by a transmission carrier and transmitting the intermediate frequency signal as an intermediate frequency signal to a master station and a slave station; each comprise a demodulator for outputting the received data to the terminal device, a communication device for a digital radio communication between the master station and the slave station, the master station
And a built-in reference signal generator for generating a reference signal.
A reference signal transmitting means for adding the signal to the intermediate frequency signal;
At the same time as above,
The reference signal is extracted and the carrier wave for transmission to the slave station modulator
A communication device, comprising: a reference signal receiving means; and the modulator on the slave station side uses a transmission carrier synchronized with a reproduced carrier used in a demodulator on the slave station side. 2. A demodulator on the slave station side, which outputs a phase difference signal doubled in a baseband band given by a product of an in-phase component synchronized with an output carrier and an orthogonal component orthogonal to the in-phase component. A Costas loop-type carrier recovery circuit that incorporates a voltage-controlled oscillator that performs feedback control so that the phase difference becomes 0 based on the input and obtains a recovered carrier synchronized with the received wave is provided, and outputs the output of the voltage-controlled oscillator to the slave station. 2. The communication device according to claim 1, wherein the communication device is used as a carrier for transmission to a modulator. 3. The demodulator on the slave station side converts the baseband signal into an in-phase component synchronized with the carrier and a quadrature component orthogonal to the synchronous component while retaining the phase rotation component by the baseband conversion signal. 2. The communication device according to claim 1, further comprising a quasi-synchronous carrier recovery circuit for obtaining a recovered carrier synchronized with the received wave by processing the phase rotation component. 4. The quasi-synchronous carrier recovery circuit includes a fixed oscillator for outputting a baseband conversion signal, and uses the baseband conversion signal as a carrier for transmission to a modulator on the slave station side. The communication device according to claim 3, wherein: 5. A transmitter local oscillator for outputting a carrier wave for transmission in the modulator on the slave station side, wherein the carrier wave for transmission is inputted to the quasi-synchronous carrier wave recovery circuit and used as a signal for baseband conversion. The communication device according to claim 3, wherein 6. The base station adds the intermediate frequency signal to the master station.
A multiplier for multiplying the reference signal
And the multiplied from the received intermediate frequency signal
Divide the reference signal by the number of multiplications of the above multiplier and modulate the slave station.
And a frequency divider as a carrier wave for transmission to the device.
The communication device according to claim 1 . 7. The base station demodulator according to claim 1, further comprising:
Synchronized with carrier while leaving phase rotation component by substitute signal
Of the in-phase component and the quadrature component orthogonal to the synchronous component
By converting it to a band signal and processing the residual phase rotation component
Quasi-synchronous carrier recovery circuit that synchronizes the recovered carrier with the received wave
A transmission path obtained by the reference signal receiving means.
Input the carrier into the quasi-synchronous carrier recovery circuit and base
Claims used as a signal for band conversion
7. The communication device according to 1 or 6 . 8. The modulator of the master station generates the reference signal.
Using a carrier for transmission based on a reference signal generated by the
The communication device according to any one of claims 1, 6 , and 7 , wherein 9. A transmission carrier for outputting to a modulator to the master station.
A transmission local oscillator for generating a transmission wave.
The communication device according to any one of claims 1, 6 , and 7 , wherein