JP2003032160A - Method for modulating/demodulating phase of distribution line carrier signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for modulating/demodulating a phase of a distribution line carrier signal with a simple circuit configuration that can execute accurate demodulation. SOLUTION: A transmitter 1 generates a phase reference signal from a commercial frequency signals, a receiver extracts a phase reference signal from a synchronizing signal of a carrier signal and demodulates the carrier signal on the basis of the extracted phase reference signal to output information sent from the transmitter 1 by using the carrier signal on the basis of the phase reference signal. Thus, even when a phase difference takes place between the commercial frequency signal and the phase reference signal generated by the transmitter due to a signal transmission line such as a distribution line 400 or a load or the like, since no phase difference exists between the phase reference signal of the transmitter 1 and the phase reference signal of the receiver 2, the receiver can quickly and accurately demodulate the information just after the reception and the circuit configuration of the receiver 2 can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution line carrier signal phase modulation / demodulation method for modulating / demodulating a carrier signal carried by a signal transmission path through a distribution line for distributing power of a commercial frequency with a phase reference signal.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 7-101855 (Patent No. 207) has heretofore been known as a phase modulation / demodulation method for a distribution line carrier signal of this type.
5959) and JP-A-7-297766 (Patent No. 3).
No. 149311), which is shown in FIGS. 6 and 7. 6 and 7 are block diagrams of a conventional distribution line carrier signal phase modulation / demodulation method.

In the conventional distribution line carrier signal phase modulation / demodulation method shown in FIG. 6, the carrier signal frequency is set to a frequency obtained by a harmonic of the commercial frequency of the distribution line 400 or a frequency division of the harmonic, and a carrier signal transmitter. 100 and receiver 200
In both, the phase reference signal of the carrier signal frequency is generated from the commercial frequency, the transmitter 100 performs phase modulation by changing the phase of the phase reference signal according to information, and the receiver 200 In this configuration, the received carrier signal is demodulated using the phase reference signal. As described above, the phase reference signal can be obtained by a simple filter, and the synchronization deviation between the phase reference signals of the transmitter 100 and the receiver 200 can be eliminated.

First, in the transmitter 100, transmission data is filtered by a transmission filter 101 which is a roll-off filter for limiting its spectrum, and a modulation circuit 102.
Sent to. The pulsing circuit 103 generates harmonics from the commercial frequency, and the harmonic generation filter 104 generates harmonics of a desired frequency (when the harmonics are of even order, the pulse duty of the pulsing circuit 103 is 1: 1). Must be other than pulse duty). The harmonics are pulsed again by the pulsing circuit 105, and the frequency dividing circuit 106 obtains a pulse having a predetermined carrier signal frequency.

The carrier signal frequency pulse thus generated is made into a sine wave by the phase reference signal filter 107, and this becomes a phase reference signal used for phase modulation. The modulation circuit 102 is a delay circuit, and delays the phase reference signal generated as described above according to the transmission data signal output from the transmission filter 101 to perform phase modulation.
The phase-modulated carrier signal has its unnecessary spectrum removed by the bandpass filter 108, is amplified to a predetermined signal level by the transmission amplifier 109, and is injected into the distribution line 400 via the coupling circuit 110.

Next, in the receiver 200, the distribution line 40
The carrier signal detected from 0 is filtered by the band-pass filter 211, and arrival of the carrier signal is detected by the carrier detection circuit 212. Pulsing circuit 213, harmonic generation filter 214, pulsing circuit 215, frequency dividing circuit 216
The phase reference signal filter 217 is the same circuit as the circuit of the transmitter 100, and generates a phase reference signal for demodulation from the commercial frequency.

The phase control circuit (delay circuit) 218 determines the phase of the received signal and the phase of the phase reference signal at the beginning of the received signal by the control signal of the demodulation control circuit 219 activated by the signal from the carrier detection circuit 212. The phase reference signal is delayed so as to have the phase relationship of, and thereafter, the phase relationship is maintained during the reception of the signal. The phase reference signal from the phase control circuit 218 and the received data signal from the bandpass filter 211 are subjected to multiplication detection by the multiplication circuit 220, waveform shaped by the reception filter 221 and output as reception data by the demodulation control circuit 219.

In another conventional distribution line carrier signal phase modulation / demodulation method shown in FIG. 7, a carrier signal is transmitted from a transmission side (not shown) to a receiver 300 using the distribution line 400 as a signal transmission path. In the receiver 300, the multiplication circuit 307,
A phase reference signal is generated by the frequency dividing circuit 308 and the 90 ° phase circuit 309, the carrier signal frequency filtered by the bandpass filter 306 is output to the subsequent stage, and the arrival of the carrier signal synchronization signal by the signal detection circuit 312. The in-phase component and the quadrature component of the synchronization signal of the multiplication detection circuits 310 and 311 at the time of detection are stored in the storage circuit 303 as a phase correction value, and the in-phase component and the quadrature component of the signal in the modulation section of the multiplication detection circuits 310 and 311 are stored. The complex multiplication circuit 304 multiplies the complex number by the complex complex conjugate number of the in-phase component and the quadrature component of the synchronization signal of the storage circuit 303, and outputs the phase-corrected reception data. Thus, even when there is a phase difference between the carrier wave of the received signal and the phase reference signal of the receiver 300, this phase difference can be easily corrected and the length of the synchronization signal section can be shortened. it can.

[0009]

Since each of the conventional distribution line carrier signal phase modulation / demodulation methods is configured as described above, both the transmitter 100 and the receiver 200 (or 300) are individually operated at commercial frequencies. Since a phase reference signal is generated in the phase difference between the transmitter 100 and the receiver 200 (or 300), accurate demodulation cannot be performed unless a circuit for correcting and controlling the phase difference is separately provided. Had a problem.

In the distribution line carrier signal phase modulation / demodulation method shown in FIG. 6, the pulse conversion circuit 213, the harmonic generation filter 214, and the pulse conversion circuit for generating the phase reference signal in the receiver 200 as in the transmitter 100. 215, the frequency dividing circuit 216 and the phase reference signal filter 217 are required, and the phase control circuit 218 and the feedback circuit for correcting and controlling the phase difference are required.
Since the phase control circuit 218 corrects the phase difference by the feedback signal of the feedback circuit, there is a problem that a fixed processing time is required for the phase correction and a rapid demodulation operation cannot be performed.

In the distribution line carrier signal phase modulation / demodulation method shown in FIG. 7, the phase difference between the phase reference signals individually generated at the transmission side and the receiver 300 is corrected and controlled by an open loop. However, when a noise component is superimposed on the phase reference signal transmitted from the transmitting side, there is a problem in that the noise component cannot be completely corrected and an accurate demodulation operation cannot be performed. The present invention has been made to solve the above problems, and an object of the present invention is to provide a distribution line carrier signal phase modulation / demodulation method capable of performing an accurate demodulation operation with a simple circuit configuration.

[0012]

According to the distribution line carrier signal phase modulation / demodulation method of the present invention, a distribution line for distributing power of a commercial frequency is used as a signal transmission line, and the commercial frequency is transmitted from the transmission side through the signal transmission line. In the distribution line carrier signal phase modulation / demodulation method for transmitting information to the receiving side by the phase reference signal based on, the transmitting side generates a phase reference signal of the carrier signal frequency from the commercial frequency, and the phase of the phase reference signal is the content of the information. The carrier signal that is phase-modulated by being changed in accordance with the above is transmitted, the receiving side extracts the phase reference signal from the synchronization signal of the carrier signal transmitted through the distribution line, and the carrier is carried based on the extracted phase reference signal. It demodulates a signal and outputs information.

As described above, according to the present invention, the phase reference signal is generated from the commercial frequency by the transmitting side, and the information transmitted from the transmitting side by the carrier signal based on this phase reference signal is received by the receiving side from the synchronizing signal of this carrier signal. Since the reference signal is extracted and the carrier signal is demodulated based on the extracted phase reference signal to output information, the phase generated at the commercial frequency and the transmission side by the signal transmission line of the distribution line or the load. Even if a phase difference occurs with the reference signal, since there is no phase difference in each phase reference signal on the transmitting side and the receiving side, it is possible to perform quick and accurate demodulation immediately after reception,
The circuit configuration on the receiving side can be simplified.

Further, in the distribution line carrier signal phase modulation / demodulation method according to the present invention, the receiving side integrates a plurality of periods of the synchronization signal, and the phase reference signal is extracted from the integrated value, if necessary. As described above, in the present invention, the phase reference signal is extracted by integrating a plurality of cycles of the received synchronization signal, so that more accurate demodulation is possible even when noise or the like is superimposed.

Furthermore, in the distribution line carrier signal phase modulation / demodulation method according to the present invention, the receiving side multiplies or multiplies the commercial frequency to generate a sampling clock signal, if necessary.
The phase reference signal is extracted from the synchronization signal of the carrier signal based on the sampling clock signal. As described above, in the present invention, the sampling clock signal used when the phase reference signal is extracted from the carrier signal synchronization signal is generated by multiplying the commercial frequency or by dividing the frequency after the multiplication. The demodulation operation can be reliably performed with a simple circuit configuration without providing a generation circuit.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment of the Invention) Hereinafter, a distribution line carrier signal phase modulation / demodulation apparatus for executing a distribution line carrier signal phase modulation / demodulation method according to a first embodiment of the present invention will be described. Description will be made with reference to FIGS. FIG. 1 is an overall block configuration diagram of a distribution line carrier signal phase modulation / demodulation device according to the present embodiment, FIG. 2 is a phase relation diagram in a transmitter / receiver of the distribution line carrier signal phase modulation / demodulation device shown in FIG. 1, and FIG.
Shows an arrangement mode diagram in which the distribution line carrier signal phase modulator / demodulator shown in FIG. 1 is installed in a distribution line.

In each of the drawings, the distribution line carrier signal phase modulator / demodulator according to the present embodiment uses a distribution line 400 for distributing a commercial frequency current as a signal transmission path, and the transmitter 1 transmits the commercial line through the distribution line 400 to the commercial line. Information is transmitted to a receiver 2 by a frequency-based phase reference signal, the transmitter 1 generates a phase reference signal of a carrier signal frequency from the commercial frequency, and the phase of the phase reference signal is changed according to the content of information. Then, the phase-modulated carrier signal is transmitted, the receiver 2 extracts the phase reference signal based on the synchronization signal of the carrier signal transmitted via the distribution line 400, and based on the extracted phase reference signal In this configuration, the carrier signal is demodulated and the received data is output.

The transmitter 1 includes a transmission filter 11 (corresponding to 101), a modulation circuit 12 (corresponding to 102), a pulse forming circuit 13 (corresponding to 103), and a harmonic wave as in the conventional device shown in FIG. Generation filter 14 (corresponding to 104), pulse conversion circuit 15 (corresponding to 105), frequency dividing circuit 16 (10
6), a phase reference signal filter 17 (corresponding to 107), a bandpass filter 18 (corresponding to 108), a transmission amplifier 19 (corresponding to 109), and a coupling circuit 10 (corresponding to 110). .

The receiver 2 has a band-pass filter 21 (corresponding to 211), a carrier detecting circuit 22 (corresponding to 212), and a multiplying circuit 24 (220) as in the conventional device shown in FIG.
, A reception filter 25 (corresponding to 221) and a demodulation control circuit 26 (corresponding to 219) in common, and the carrier detection signal of the carrier detection circuit 22 from the synchronization signal of the carrier signal filtered by the bandpass filter 21. The phase reference signal extraction unit 23 extracts the phase reference signal based on the above and outputs it to the multiplication circuit 24.

Next, the distribution line carrier signal phase modulation / demodulation method according to the present embodiment based on the above configuration will be described together with the operation of the distribution line carrier signal phase modulation / demodulation device. First, as a premise, a plurality of switches 401 are arranged on the distribution line 400, and a transmitter 1 and a receiver 2 are provided on each switch 401 in order to remotely control the plurality of switches 401 from the central monitoring station 500. To be done. In the transmitter 1 and the receiver 2 provided in parallel with each switch 401, a carrier signal as a remote control signal from the central monitoring station 500 propagates through the distribution line 400.

A carrier signal is generated from the transmitter 1 of the central monitoring station 500 in the same manner as in the conventional device shown in FIG. 6 and is propagated to an arbitrary switch 401 via a distribution line 400. As shown in FIG. 2, the propagated carrier signal is modulated and transmitted based on the 0 ° phase reference signal on the transmitting side (and the 90 ° phase reference signal on the transmitting side) obtained by dividing the commercial frequency on the transmitting side. In the process of propagating through the distribution line 400, this carrier signal has a phase difference θ with the carrier signal received by the receiver 2 due to the line distribution constant or the connected load. The phase reference signal of the carrier signal also has a phase difference θ between the transmitting side and the receiving side as shown in FIG.

A receiver 2 receives the transmitted carrier signal, and the receiver 2 filters the carrier signal by a band-pass filter 21 to carry out carrier detection circuit 22 and phase reference signal extraction section 2
3 and the multiplication circuit 24. The phase reference signal extraction unit 23 extracts the phase reference signal of the synchronization signal in the carrier signal on condition that the carrier detection circuit 22 detects the arrival of the carrier signal and outputs the carrier detection signal. This extracted phase reference signal is applied to the multiplication circuit 24.
Is output to the multiplier circuit 24, and the multiplier circuit 24 multiplies and detects the modulated signal in the carrier signal and the phase reference signal.

Since the receiver 2 extracts the phase reference signal from the received carrier signal, the reception side modulation signal and the reception side 0 ° which are multiply detected by the multiplication circuit 24 are detected.
Although the phase reference signal has a phase difference θ with respect to the modulation signal on the transmission side and the 0 ° phase reference signal on the transmission side, the phase difference between the 0 ° phase reference signal and the modulation signal is the same on the transmission side and the reception side. (See FIG. 2). In this way, on the sending side and the receiving side,
Since the phase difference between the 0 ° phase reference signal and the modulation signal is the same, the multiplication detection in the multiplication circuit 24 can be performed quickly and accurately at the same time as the arrival of the carrier signal without providing a phase correction circuit or the like for phase matching. It will be. The multiplication-detected reception side modulation signal is waveform-shaped by the reception filter 25 and then demodulated and output by the demodulation control circuit 26 as reception data.

(Second Embodiment of the Present Invention) Second Embodiment of the Present Invention
The distribution line carrier signal phase modulation / demodulation method according to the embodiment will be described together with the distribution line carrier signal phase modulation / demodulation device based on FIGS. 4 and 5 with reference to FIG. 4 is a circuit block configuration diagram of a transmitter in the distribution line carrier signal phase modulation / demodulation device according to the present embodiment, and FIG. 5 is a detailed block configuration diagram of the phase reference signal extraction circuit shown in FIG.

In each of the drawings, the distribution line carrier signal phase modulator / demodulator according to the present embodiment is the receiver 2 shown in FIG.
Similarly to the above, a bandpass filter 21, a carrier detection circuit 22, a multiplication circuit 24, a reception filter 25, and a demodulation control circuit 26 are provided, and in addition to this configuration, the synchronization signal of the carrier signal filtered by the bandpass filter 21 has multiple signal cycles An integrating circuit 231 for integrating over the entire range, a phase reference signal extracting circuit 232 for extracting a phase reference signal from the integrated synchronizing signal, and a sampling clock signal generating circuit 27 for generating a sampling clock signal from the received commercial frequency. It is the structure provided with.

The phase reference signal extraction circuit 232 is an A / D converter 232a for A / D converting the received carrier signal.
And a buffer memory 232b for storing the phase reference signal of the synchronizing signal in the digitized carrier signal,
A 0 ° phase reading controller 232c for reading the phase reference signal stored in the buffer memory 232b with a phase difference of 0 °;
A 90 ° phase reading controller 232d for reading the phase reference signal stored in the buffer memory 232b with a phase difference of 90 °.
And a configuration including.

The sampling clock signal generation circuit 2
Reference numeral 7 denotes a pulsing circuit 271 for pulsing the commercial frequency of the electric current transmitted through the distribution line 400 into a rectangular wave, and a harmonic generation filter 272 for generating a harmonic of a desired frequency of the pulsed commercial frequency. And a pulsing circuit 273 for pulsing the generated harmonic again, and a multiplier circuit 274 for multiplying the pulsed harmonic to generate a sampling clock.

Next, the distribution line carrier signal phase modulation / demodulation method according to the present embodiment based on the above configuration will be described together with the operation of the distribution line carrier signal phase modulation / demodulation device. As in the case of the first embodiment, the carrier signal propagated from the transmitter 1 via the distribution line 400 is received, and the commercial frequency of the power transmitted via the distribution line 400 is further detected. Based on the detected commercial frequency, the sampling clock signal generation circuit 27 causes the pulse generation circuit 271 to generate a harmonic from the commercial frequency, the harmonic generation filter 272 to generate a harmonic of a desired frequency, and the generated harmonic. The harmonic wave is pulsed again by the pulsing circuit 273, and the pulsed harmonic wave is multiplied by the multiplication circuit 274 to generate a sampling clock signal and output to the integration circuit 231, the phase reference signal extraction circuit 232, and the demodulation control circuit 26. To do. When the carrier detection circuit 22 detects that the received carrier signal has arrived, the carrier signal is output to the phase reference signal extraction circuit 232.

The received carrier signal is an integrating circuit 231.
Are integrated by the integrator circuit 231 over a plurality of frequencies set in advance, and the integrated value is averaged by an averaging circuit (not shown) to output the phase reference signal of the synchronization signal in the carrier signal to the phase reference signal extraction circuit 232. . The phase reference signal extraction circuit 232 performs A / D conversion on the phase reference signal and outputs the digital value of the phase reference signal to the buffer memory 23.
2b is stored by the carrier detection signal of the carrier detection circuit 22.

The phase reference signal stored in the buffer memory 232b is read from the buffer memory 232b in the 0 ° phase by the 0 ° phase read control unit 232c driven by the sampling clock signal output from the multiplication circuit 274, and the phase reference signal is read as 0 °. While outputting the phase reference signal, the 90 ° phase read control unit 232d causes the buffer memory 23 to output the 90 ° phase.
2b is read out and a 90 ° phase reference signal is output. Further, the modulated signal of the received carrier signal is input to the multiplication circuits 241, 242, and is multiplied and detected by the read 0 ° phase reference signal or 90 ° phase reference signal. The modulated signal thus multiplicative detected is received by the reception filter 25.
Waveforms are shaped by 1 and 252 respectively, and the demodulation control circuit 2
6 demodulates and outputs the received data.

As described above, the distribution line carrier signal phase modulation / demodulation method according to the present embodiment generates the sampling clock signal from the commercial frequency of the current detected by the receiver 2 transmitted through the distribution line 400, and at the same time, the distribution line 400. Since the synchronization signal in the carrier signal transmitted by the receiver 2 and detected by the receiver 2 is integrated over a plurality of periods to reliably detect the phase reference signal, the signal between the transmitter 1 and the receiver 2 is distributed between the signals. Even if a phase difference occurs, since the phase difference between the 0 ° phase reference signal and the modulation signal is the same on the transmitting side and the receiving side, the demodulation operation can be executed quickly and reliably, and accurate reception data can be demodulated and output.

[0032]

According to the present invention, the transmitting side generates the phase reference signal from the commercial frequency, and the receiving side receives the information transmitted from the transmitting side by the carrier signal based on this phase reference signal from the synchronizing signal of the carrier signal. Since the signal is extracted and the carrier signal is demodulated based on the extracted phase reference signal to output the information, the phase reference generated at the commercial frequency and the transmission side by the signal transmission line of the distribution line or the load. Even if there is a phase difference with the signal, since there is no phase difference between the phase reference signals on the transmitter side and the receiver side, quick and accurate demodulation can be performed immediately after reception and the circuit configuration on the receiver side is simplified. There is an effect that can be realized.

Further, in the present invention, the phase reference signal is extracted by integrating a plurality of frequencies of the received synchronizing signal, so that more accurate demodulation is possible even when noise or the like is superimposed. Has the effect.

Further, in the present invention, the sampling clock signal used when the phase reference signal is extracted from the synchronizing signal of the carrier signal is generated by the multiplication of the commercial frequency or the frequency division after the multiplication. There is an effect that the demodulation operation can be surely executed with a simple circuit configuration without providing the clock generating circuit.

[Brief description of drawings]

FIG. 1 is an overall block configuration diagram of a distribution line carrier signal phase modulation / demodulation device according to a first embodiment of the present invention.

FIG. 2 is a phase relationship diagram in a transmitter / transmitter of the distribution line carrier signal phase modulator / demodulator shown in FIG.

3 is an arrangement mode diagram in which the distribution line carrier signal phase modulator / demodulator shown in FIG. 1 is installed in a distribution line.

FIG. 4 is an overall block configuration diagram of a distribution line carrier signal phase modulation / demodulation device according to a second embodiment of the present invention.

5 is a detailed block diagram of the phase reference signal extraction circuit shown in FIG. 4. FIG.

FIG. 6 is a block diagram of a conventional distribution line carrier signal phase modulation / demodulation method.

FIG. 7 is a block configuration diagram of another conventional distribution line carrier signal phase modulation / demodulation method.

[Explanation of symbols]

1,100 transmitter 2,200,300 receiver 10,110 coupling circuit 11, 101 Transmission filter 12, 102 Modulation circuit 13, 103 pulse circuit 14, 104 Harmonic generation filter 15, 105 pulse circuit 16, 106, 308 divider circuit 17,107 Phase reference signal filter 18, 108 bandpass filter 19, 109 Transmission amplifier 21,211 bandpass filter 22,212 Carrier detection circuit 23 Phase Reference Signal Extraction Unit 24, 215, 220, 241, 242 Multiplication circuit 25, 221, 251, 252 Reception filter 26, 219 Demodulation control circuit 27 Sampling clock signal generation circuit 213, 271, 273 pulse conversion circuit 214 Harmonic Generation Filter 216, 308 frequency divider 217 Phase reference signal filter 218 Phase control circuit (delay circuit) 231 Integrator circuit 232 Phase reference signal extraction circuit 232a A / D converter 232b buffer memory 232c 0 ° phase readout controller 232d 90 ° phase readout controller 272 Harmonic Generation Filter 274, 307 multiplier circuit 400 distribution line 301,302 Low-pass filter 303 memory circuit 304 complex multiplication circuit 306 Band filter 309 90 ° phase circuit 310, 311 multiplication detection circuit 312 Signal detection circuit 330 circuit memory circuit 340 complex number multiplication circuit 401 switch 500 Central Observatory

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5K004 AA05 FA21 FB04 FH08 FH09                       FK13                 5K046 AA03 BA01 BB05 BB06 CC17                       PS03 PS05 PS31

Claims (3)

[Claims] 1. A distribution line carrier signal in which a distribution line for distributing power of a commercial frequency is used as a signal transmission line, and information is transmitted from the transmission side to the reception side by a phase reference signal based on the commercial frequency via the signal transmission line. In the phase modulation / demodulation method, the transmission side generates a phase reference signal of a carrier signal frequency from the commercial frequency, and transmits the carrier signal phase-modulated by changing the phase of the phase reference signal according to the content of the information, A distribution line carrier characterized in that a receiving side extracts a phase reference signal from a synchronization signal of a carrier signal transmitted via a distribution line, demodulates the carrier signal based on the extracted phase reference signal, and outputs information. Signal phase modulation / demodulation method. 2. The distribution line carrier signal phase modulation / demodulation method according to claim 1, wherein the receiving side integrates a plurality of cycles of the synchronization signal and extracts a phase reference signal from the integrated value. Electric wire carrier signal phase modulation / demodulation method. 3. The distribution line carrier signal phase modulation / demodulation method according to claim 1, wherein the receiving side multiplies or multiplies and divides the commercial frequency to generate a sampling clock signal, and based on the sampling clock signal. A distribution line carrier signal phase modulation / demodulation method characterized in that a phase reference signal is extracted from a carrier signal synchronization signal.