JPS6193745A - Spread spectrum transceiver - Google Patents

Abstract

PURPOSE:To simplify the constitution by using an oscillation signal as a clock for generating pseudo noise and forming a loop to a reception section with a correlation detector, a band pass filter, a voltage controlled oscillator and a pseudo noise generator or the like. CONSTITUTION:The oscillating frequency of the voltage controlled oscillator 21 is changed by an information signal desired to be transmitted, the oscillated output and a pseudo noise generated from a pseudo noise generator 2 apply spectrum spread and the result is transmitted to a lighting line. The signal from the lighting line is subject to automatic gain control 7 at a reception section and its output is multiplied with a correlation detector 17 with an output of a pseudo noise generator 18 in a loop circuit comprising the generator 18, the detector 17, a BPF25, a waveform shaping device 27, a phase comparator 24, the voltage controlled oscillator 15 and a frequency divider 23, an output with in-phase at high level and an output of a different phase at low level are outputted respectively from the detector 17, subject to waveform shaping 27 and inputted to the comparator 24 together with the oscillated signal from the oscillator 15. The oscillated frequency is controlled by the phase difference signal, synchronized with a receiver for demodulation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a spread spectrum transmitter/receiver that transmits or receives various information using spread spectrum.

Conventional configurations and their problems Various communication systems are currently being researched and developed, one of which is known as a spread spectrum communication system.

In this method, the transmitting side spreads the spectrum of a narrowband signal such as data or voice over a wide band using pseudo noise and sends it out, and the receiving side performs correlation detection (despreading) on the signal to reproduce the narrowband signal. It is. This spread spectrum communication system has attracted attention in recent years as a very effective communication system because it not only makes effective use of frequencies, but also is resistant to external interference and noise, and has high confidentiality.

On the other hand, there is a demand for communication by superimposing signals on existing power lines, which are not originally communication lines, because of the simplicity of not requiring new wiring work. An example of this would be a specific frequency (
120 Hz) in synchronization with the power line frequency to control or monitor home appliances, and also transmits FM modulated audio! FM carrier to receive
Turf etc. are being put into practical use.

However, since the above example uses a specific frequency, there are problems such as noise from other devices connected to the same power line (for example, a refrigerator, a vacuum cleaner, etc.) or a drop in impedance at this frequency.

In the case of communication using power lines as a medium, the spread spectrum communication method does not use a specific frequency, so other equipment is connected to the same power line, and this equipment generates noise at a specific frequency. , or even if the impedance of a specific frequency decreases, it is hardly affected, making it a particularly effective means of communication.

When using electric light lines, the frequency range is 1oKHz to 45KHz according to the Radio Law.
Since only the 0 KHz range is available, which is a relatively low frequency band, a baseband spread spectrum method is used. The conventional spread spectrum method using power lines will be described below with reference to the drawings.

FIG. 1 shows the main block configuration of a conventional transmitting/receiving device using a power line spread spectrum system.

In Figure 1, 1 is the clock OK and synchronization signal 5YN
A clock and synchronization signal generator 2 generates GK and a synchronization signal 5YNG generated by the clock and synchronization signal generator 1, and a signal pseudo noise generator that generates wideband pseudo noise such as M series or Gold series. A noise generator 3 is a pseudo noise generator 2 for transmitting an information signal to be transmitted.
A modulator 4 uses a clock GK and a synchronization signal 5YNC generated from a clock and synchronization signal generator 1 to spread the spectrum using pseudo noise for a signal (pseudo noise generated from a signal pseudo noise generator 2). A synchronization pseudo noise generator 4 generates a pseudo noise (such as M sequence or Gold sequence that is synchronized with but different from this); This is an adder that adds the pseudo noise generated by

The above clock and synchronization signal generator 1, signal pseudo-noise generator 2, modulator 3, synchronization pseudo-noise generator 4, and adder 6 form a transmitting section. 6.6' is a coupler composed of a transformer or a capacitor that sends the output of the adder 6 to the power line of the transmission medium or receives it via the power line, and the coupler 6 receives the output of the adder 6 mentioned above. is transmitted to the power line, and the coupler 6' receives the signal superimposed on the power line. 7 is an automatic gain controller that amplifies the signal output from the coupler 6' and automatically controls the gain; 8;
9゜1o is a correlation detector that performs correlation detection by multiplying the output of the automatic gain controller 7 by a pseudo noise generated from a synchronization pseudo noise generator (described later); 11 is a clock GK generated by a voltage controlled oscillator (described later); The synchronization signal is sent out by the synchronization pseudo-noise generator 4 described in the transmitting section, and is necessary to generate three different systems of the same pseudo-noise for one clock while at the same time synchronizing with the signal pseudo-noise generator described later. Signal 5Y
Pseudo-noise generator for synchronization that generates NC, 12, 13゜1
6 is a low-pass filter that passes only the necessary low frequency components of the outputs of the correlation detectors 8 and 10.9, and 14 is a low-pass filter 13 that passes the output of the low-pass filter 12.
16 is a voltage controlled oscillator whose oscillation frequency changes according to the output voltage of the subtracter 14; 18 is a synchronization signal 5YNC generated by the synchronization pseudo noise generator 11;
OK clock generated by voltage controlled oscillator 16 in synchronization with
A signal pseudo-noise generator 17 generates pseudo-noise of the same series as the signal pseudo-noise generator 2 of the transmitter, and the signal pseudo-noise generator 17 generates the output of the automatic gain controller 7 and the signal pseudo-noise generator 18. A correlation detector 19 performs correlation detection by multiplying by pseudo-noise, and a low-pass filter 19 extracts a necessary low-frequency component information signal from the signal despread by the correlation detector 17.

The operation of the transmitting/receiving device configured as described above will be described below.

First, an information signal to be transmitted is generated by a generating means (not shown), and the information signal is sent from the generating means to the modulator 3 of the information signal transmitter. The modulator 3 modulates (spreads) the pseudo noise sent from the signal pseudo noise generator 2, and the adder 6 adds it to the pseudo noise sent from the synchronization pseudo noise generator 4. sent to the line. Here, using the clock GK and synchronization signal 5YNC generated by the clock and synchronization signal generator 1,
The pseudo noises generated by the signal pseudo noise generator 2 and the synchronization pseudo noise generator 4 are synchronized with each other.

Now, the signal and synchronization pseudo noise that have been spread spectrum in the transmitting section and transmitted to the power line are received by the combiner 6' and sent to the automatic gain controller 7. The automatic gain controller 7 amplifies the received signal and automatically controls its gain using the output of a low-pass filter 16 (described later) to maintain a constant level regardless of the input signal level from the coupler 6'. Send a signal. The output of the automatic control gain controller 7 is supplied to the correlation detectors 8, 9, and 10, and the output signal of the synchronization pseudo noise generator 11, which generates the same pseudo noise as the synchronization pseudo noise generator 4 of the transmitter, is supplied to the correlation detectors 8, 9, and 10. ), (b), and ei, respectively, and correlation detection (despreading) is performed.

Here, the pseudo noise output for synchronization (b) is delayed by one clock from the pseudo noise output for synchronization (a), and similarly, the pseudo noise output for synchronization is delayed by one clock from the same (b). Correlation The output of the detector 8 becomes a peak when the pseudo noise sent out from the synchronization pseudo noise generator 4 of the transmitting section and the pseudo noise output (A) of the synchronization pseudo noise generator 11 of the receiving section are in phase. It decreases whether it is fast or slow.Therefore, when the output of the correlation detector 8 is passed through the low-pass filter 12, it becomes a triangular shape whose low side is ±1 clock.Similarly, the output of the correlation detector 10 is passed through the low-pass filter 12. Filter 13
The passed signal has a triangular shape whose lower side is ±1 clock delayed by two clocks from the output of the low-pass filter 12. When the output of the low-pass filter 13 is subtracted by the subtracter 14, the output of the synchronization pseudo-noise generator 11 (b) is the output of the synchronization pseudo-noise generator 4 of the transmitter. If the phase is in phase with , it will be ○, if the phase is leading, there will be a positive peak, and if the phase is lagging, it will be a negative peak. Voltage controlled oscillator 1 with the output of subtracter 14
The clock OK is generated by controlling the oscillation frequency of 5.

This clock GK is used as a clock for generating pseudo noise in the synchronization pseudo noise generator 11.

By using such a loop, the pseudo noise output (b) generated by the synchronization pseudo noise generator 11 becomes in phase with the pseudo noise generated by the synchronization pseudo noise generator 4 of the transmitter. Such a loop is known as a delay-locked loop. In the above delay locked loop, the output (b) of the synchronization pseudo noise generator 11 which is in phase with the pseudo noise of the transmitter synchronization pseudo noise generator 4 is connected to the output of the automatic gain controller 7 and the correlation detector 9. Correlation is detected between the signals, the signal is smoothed by the low-pass filter 16, and the signal is input to the automatic gain controller 7. The automatic gain controller 7 controls the output of the low-pass filter 16 so that it is always constant.

The signal pseudo-noise generator 18 receives the clock GK from the voltage-controlled oscillator 15 and the synchronization signal 5YNG from the synchronization pseudo-noise generator 11, and synchronizes with the synchronization pseudo-noise generator 11. Therefore, as described above, A pseudo noise having the same phase as the pseudo noise generator 2 for the transmitter signal is generated. A correlation detector 17 detects the correlation between the output of the signal pseudo-noise generator 18 and the output of the automatic gain controller 7, and the output is passed through a low-pass filter 19 to remove unnecessary high-frequency signals. Are you able to get a signal?

According to the above configuration, since the signal pseudo noise generator 2゜18 is provided, the information signal can be transmitted and received by spreading it over a wide same frequency band, and it is possible to transmit and receive the information signal by spreading it over a wide frequency band. It is less susceptible to influence, and the information signal cannot be deciphered without knowing the signal pseudo-noise sequence of the transmitter, so it is highly confidential. Further, since the synchronization pseudo noise generator 4.degree. 11 is provided, it has the advantage that transmission and reception can be synchronized without being influenced by information signals.

However, in the above configuration, since the information signal is directly modulated with the pseudo noise of the signal pseudo noise generator 2, the receiving section synchronizes transmission and reception using the pseudo noise of the same signal pseudo noise generator 18. Therefore, the pseudo noise generators 4 and 11 for synchronization are separately required. Also sent/
In order to synchronize reception, in addition to the signal rate, there are also synchronization and automatic gain side (three correlation detectors 8, 9, and 10 are required, totaling 4 correlation detectors are required, etc.). The reception and reception equipment is complicated.Also, as mentioned above, low-pass filters 12, 13, 16, and 19 are required.
In particular, when performing spread spectrum communication using power lines as a medium, there is a low frequency component of the power supply frequency (50H2 or 60Hz) at a large level at the edge compared to the signal, so low-pass filters 12, 13, 16, and 19 are used. enter@
It is necessary to provide a sufficient bypass filter (not shown).

In addition, the low-pass filter has a large DC drift due to temperature and shock noise, compared to a bypass filter or a band-pass filter, and this is especially true for low-pass filters in delay-locked loops for synchronizing transmission and reception. However, it also had the disadvantage of requiring special care.

Purpose of the Invention In view of the above drawbacks, the present invention provides a spread spectrum transmitter/receiver that does not require a synchronization pseudo-noise generator separate from that for signals, is less susceptible to direct current drift, and can greatly simplify the configuration. This is to provide the device.

Structure of the Invention The present invention includes a first oscillator that changes an oscillation frequency according to an information signal to be transmitted, and a first oscillation signal oscillated by the first oscillator to generate a first pseudo-noise as a clock. A transmitter is equipped with a first pseudo-noise generating means, a modulating means for modulating the first oscillation signal with the first pseudo-noise, and an output means for transmitting the output of the modulating means to a transmission medium. and an input means for receiving the output of the output means via the medium, a gain controller for controlling the gain of the received signal received by the input means, and a demodulation means for demodulating the output of the gain controller. a bandpass filter that performs bandpass filtering at a constant frequency on the output of the demodulation means; and an envelope detector that performs envelope detection from the output of the bandpass filter to provide a control signal for the gain controller; A second oscillation signal oscillated by a second oscillator is used as a clock to generate a second pseudo-noise, and the demodulation means demodulates the output of the gain controller according to the second pseudo-noise. a second pseudo-noise generation means for outputting a second pseudo-noise to the demodulation means; and a phase comparison between the output of the second oscillator and the output of the band-pass filter to determine the oscillation frequency of the second oscillator. A receiver is equipped with a phase comparator for controlling the above, and a gain controller, a demodulator, and a bandpass filter on the receiver side.

and an envelope detector to form a first loop circuit, and the gain controller performs automatic gain control, and the demodulation means, a bandpass filter, and a phase comparator.

a second oscillator and a second pseudo-noise generating means;
The above object is achieved by forming a loop circuit to synchronize with the receiver side and performing evening adjustment of the information signal.

The present invention also provides a first oscillator that changes an oscillation frequency according to an information signal to be transmitted, and a first oscillator that generates a first pseudo noise by changing the first oscillation signal oscillated by the first oscillator. 1 pseudo-noise generating means, modulating means for modulating the first oscillation signal with the first pseudo-noise, and output means for transmitting the output of the modulating means to a transmission medium, which are included in the transmitter. Also, an input means for receiving the output of the output means via the medium, a gain controller for controlling the gain of the received signal received by the input means, a first demodulating the output of the gain controller, Second. a third demodulating means; and the first demodulating means. 2nd degree and 1st degree, which perform band M waves of constant frequency on the outputs of the third demodulation means, respectively. Second
．． a third band-pass filter; a second envelope detector that performs envelope detection from the output of the second band-pass filter to provide a control signal for the gain controller;
The first bandpass filter performs envelope detection from the output of the third bandpass filter. a third envelope detector; and a third envelope detector; a subtracter that calculates the difference between the outputs of the third envelope detector; a second oscillator that changes the oscillation frequency according to the output signal of the subtracter; and a second oscillator oscillated by the second oscillator. The oscillation signal of the second, third, . Fourth pseudo-noise (However, the third pseudo-noise is delayed by one clock than the second pseudo-noise, and the fourth pseudo-noise is delayed by one clock than the third pseudo-noise.) are generated, and the first . Second. The receiver is equipped with pseudo noise generating means for outputting so that the third demodulating means demodulates the output of the gain controller, and the gain controller, the second demodulating means, and the second band on the receiver side are provided. The pass filter and the second envelope detector form a first loop circuit, and the gain controller performs automatic gain control, and the first and third demodulating means, the first . A third bandpass filter, a subtracter, a second oscillator, and a second pseudo-noise generating means form a second loop circuit to synchronize with the receiver side and demodulate the information signal. By doing so, the above objective will be achieved.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a block configuration of a spread spectrum transmitter/receiver according to an embodiment of the present invention.

In FIG. 2, 6 is a modulator, 2.18 is a pseudo noise generator, 6.6' is a coupler, 7 is an automatic gain controller, 16 is a voltage controlled oscillator, and 17 is a correlation detector. This is the same configuration as shown in FIG.

On the other hand, 21 is a voltage controlled oscillator, 22.23 is a frequency divider, 2
4 is a phase comparator, 26 is a band pass filter, and 26 is an envelope detector.

The operation of the transmitting/receiving apparatus configured as described above will be explained in detail below with reference to the waveform diagrams shown in FIGS. 2 and 3.

The information signal to be sent as shown in FIG. 3(a) is input to the voltage controlled oscillator 21, and as shown in FIG. 3(b), the frequency f1 is set at the high level of the information signal, and the frequency 12 is set at the low level of the information signal, as shown in FIG. 3(b). generates an oscillation frequency of

(Here, H+72 is set between the transmission bandwidth (10 to 450 KHz in the case of power line transmission).) This oscillation signal is input to the frequency divider 22 and is output as shown in FIG. 3 (C1). The frequency is divided by the necessary frequency division ratio (Fig. 3 shows an example of dividing the frequency by 1/2). This frequency-divided Fig. 3 (Fig. The pseudo noise shown in (d) is generated.The output of the voltage controlled oscillator 2'1 is modulated by the modulator 5 using the pseudo noise generated by the pseudo noise generator 2, and the spectrum is spread. This figure shows an example in which FIG. 3(b) is balanced modulated with dl. In other words, the output of the modulator 6 (FIG. 3(e)) is the output of the pseudo noise generator 2 (the Figure 3 (d))
is high level, the output of the voltage controlled oscillator 21 (third
A signal with the same phase as that shown in Figure (b)) is sent out, and a signal that is in phase with Figure 3 (dl
When BL is at a low level, a signal having the opposite phase to BL (FIG. 3) is sent out.

The output of the modulator 6 is transmitted to the power line through the coupler 6 as described in FIG. 1, and similarly the signal from the power line is received through the coupler 6' and sent to the receiver.

In the receiving section, the automatic gain controller 7 described in FIG. 1 sends out a constant output regardless of the reception level. Although the output of the automatic gain controller 7 has the original waveform shown in FIG. 3 (61), it is actually modified due to the noise on the transmission path or the frequency characteristics of the impedance.Here, for convenience of explanation, the waveform shown in FIG. The pseudo-noise generator 18 is set in advance to generate pseudo-noise of the same series as the pseudo-noise generator 2 of the transmitting section, and is also synchronized by a loop described later. Figure 3 (
The pseudo-noise generator 2 of the transmitting section generates the same pseudo-noise that is in phase with the pseudo-noise (FIG. 3(d)) as shown in FIG. The output of the automatic gain controller 7 (FIG. 3(e)) and the output of the pseudo noise generator 18 (FIG. 3(0)) are the output of the correlation detector 17.
Multiplyed by Figure 3 (when the illusion is at a high level, the same figure (61
When Is is in phase with Is, an output in phase opposite to Is is sent from the correlation detector 17, and this signal is
Frequency f1. explained in the transmitting section. It is a narrowband signal determined by f2 and the transmission speed of the information signal, and is input to a bandpass filter 26 having a frequency bandwidth corresponding to this, and is waveform-shaped by a waveform shaper 27 to produce the signal shown in FIG. This figure 3 (Ship signal and voltage controlled oscillator 16
The oscillation signal of
The oscillation frequency is controlled as shown in Figure 3 (
Form a loop matching g). On the other hand, the output of the voltage controlled oscillator 16 is further set to the same frequency division ratio as the frequency divider 22 of the transmitting section and is supplied to the frequency divider 23, and is clocked to the pseudo noise generator 18 in the same manner as described for the transmitting section. is entered as .

Pseudo noise generator 18 described above. Correlation detector 17, bandpass filter 26. Waveform shaper 27° phase comparator 2
4. By the loop of voltage controlled oscillator 162 frequency divider 23,
The output of the receiving section pseudo noise generator 18 is synchronized with the output of the transmitting section pseudo noise generator 2. The output of the bandpass filter 25 is further supplied to an envelope detector 26, subjected to envelope detection, and input to the automatic gain controller 7. Correlation detector 17. Bandpass filter 26. Due to the loop formed by the envelope detector 26, the output of the envelope detector 26 is constant, so the automatic gain controller 7
The output (FIG. 3(e)) has a constant amplitude.

Due to the action of each loop explained above, the waveform shown in FIG. 3 (hl) is outputted from the phase comparator 24. This is the transmitted information signal shown in FIG. 3 (!L). ,
This information signal has been demodulated.

As described above, according to this embodiment, a pseudo noise generator for synchronization is not used separately from that for signals, and moreover, only one correlation detector can perform synchronization and demodulation of information signals, and the configuration is significantly simplified compared to the conventional one. can do. Furthermore, since the bandpass filter 26 is used in the demodulation loop, a stable system that is not affected by DC drift can be achieved compared to the case where a conventional low-pass filter is used.

FIG. 4 shows a block configuration of a transmitting/receiving device in a second embodiment of the present invention.

In FIG. 4, 6 is a modulator, 2.18 is a pseudo noise generator, 6, 6' is a combiner, 7 is an automatic gain controller, 8, 9 .
10 is a correlation detector, 14 is a subtracter, 16.21 is a voltage controlled oscillator, 22.23 is a frequency divider, 26 is a band pass filter, 26 is an envelope detector, and the above is shown in Figure 2. It is the same as the configuration. On the other hand, 28 and 29 are band pass filters, which have the same performance as the band pass filter 26.

30 and 31 are envelope detectors, which have the same performance as the envelope detector 26.

The operation will be explained below using FIG. 4. Note that the transmitting section has exactly the same configuration as that explained in FIG. 2, so a description thereof will be omitted.

In addition, in the receiving section, the difference in configuration from the conventional Fig. 1 is as follows.
Only one pseudo-noise generator is required, one less correlation detector is required, and band-pass filters 25, 28, 29 and 26 are used instead of the low-pass filters 12, 13, and 16 in FIG.
, 30.31 envelope detectors are provided, a frequency divider 23 having the same configuration as that explained in FIG. Pseudo noise generator 18 (for signals) was set to the same series as (however, the outputs (A) and (1 and H are delayed by 1 clock as explained in Fig. 1). It is a point.

First, the outputs of the correlation detectors 8, 9.10 are outputted by the bandpass filters 2B, 26.29 and the envelope detector 30, respectively.
, 26.31 becomes a correlation strength signal, and outputs a signal equivalent to the low-pass filter 12°16.13 explained in FIG.

Therefore, automatic gain controller 7. Correlation detector9. Bandpass filter 26. The loop of the envelope detector 26 makes the amplitude of the output of the automatic gain controller 7 constant, similar to that explained in FIG. Envelope detectors 30, 31, subtractor 14
, voltage controlled oscillator 161 frequency divider 23. Pseudo noise generator 1
The loop formed by 8 allows the receiver pseudo-noise generator 18 to be synchronized with the transmitter pseudo-noise generator 2, similar to that described in FIG. Therefore, as explained in FIG. 2, the input of the voltage controlled oscillator 16, ie, the output of the subtracter 14, becomes the same information signal as that transmitted and is demodulated. In this case as well, there are effects similar to those of the first embodiment described above.

In addition, in the embodiment explained in FIG. 2 and FIG. 4, the information signal was explained as a binary value as shown in FIG.
Even if I yell at you, I won't let go of my murderous nature.

Further, although the embodiments shown in FIGS. 2 and 4 have been described using the frequency divider 22.degree. 2.3, the case where the frequency division ratio is 1 is also included. In this case, the frequency dividers 22 and 23 can be omitted.

Further, in the embodiments shown in FIGS. 2 and 4, a case has been described in which a power line is used as a transmission medium, but the transmission medium is not limited to a power line, but may also be infrared rays or ultrasonic waves.

Radio waves etc. may also be used.

Furthermore, in the embodiments shown in FIGS. 2 and 4, the input signal of the voltage controlled oscillator is extracted as an information signal, but the output of the bandpass filter 26 is a frequency-modulated signal as described above. However, the information signal can also be demodulated from the output of the bandpass filter 26 using a known frequency demodulator.

Effects of the Invention As described above, the present invention changes the oscillation frequency of a voltage controlled oscillator with an information signal, and uses this oscillation signal as a clock for generating pseudo noise from a pseudo noise generator. By spreading the spectrum and transmitting it, the receiving section forms a loop with a correlation detector, bandpass filter, voltage controlled oscillator, pseudo noise generator, etc.
It has a simpler configuration than the conventional one and is less susceptible to direct current drift, which has great effects.

[Brief explanation of the drawing]

FIG. 1 is a block wiring diagram of a conventional transmitting and receiving device using the spread spectrum method, FIG. 2 is a block wiring diagram of a spread spectrum transmitting and receiving device according to an embodiment of the present invention, FIG. 3 is a timing chart of the same device, and FIG. 4 FIG. 2 is a block diagram of a spread spectrum transmitter/receiver according to another embodiment of the present invention. 1... Clock and synchronization signal generator, 2,4゜11.18... Pseudo noise generator, 3...
・Modulator, 6... Adder, 6.6'...
Combiner, 7... Automatic gain controller, g, 9, 10
．． 17... Correlation detector, 12.13, 16.1
9...Low pass filter, 14...Subtractor,
16, 21... Voltage controlled oscillator, 22.23
... Frequency divider, 24 ... Phase comparator, 26
．． 28, 29...Band pass filter, 26°3
0.31... Envelope detector, 27...
Waveform shaper.

Claims (10)

[Claims] (1) A first oscillator that changes an oscillation frequency according to an information signal to be transmitted, and a first oscillator that oscillates from the first oscillator.
a first pseudo-noise generation means for generating a first pseudo-noise using an oscillation signal of the clock as a clock; a modulation means for modulating the first oscillation signal with the first pseudo-noise; and transmitting the output of the modulation means. A transmitter is equipped with an output means for sending out to a medium, an input means for receiving the output of the output means via the medium, and a gain controller for controlling the gain of the received signal received by the input means. demodulation means for demodulating the output of the gain controller; a bandpass filter for performing bandpass filtering at a constant frequency on the output of the demodulation means; and a bandpass filter for performing envelope detection from the output of the bandpass filter. An envelope detector is used as a control signal for the gain controller, and a second oscillation signal generated by a second oscillator is used as a clock to generate second pseudo-noise, and the demodulation means generates the second pseudo-noise. a second pseudo-noise generation means for outputting the second pseudo-noise to the demodulation means so as to demodulate the output of the gain controller according to the output of the second oscillator and the output of the band-pass filter; The receiver is equipped with a phase comparator that controls the oscillation frequency of the second oscillator by comparing the phases of forms a first loop circuit and performs automatic gain control with the gain controller, and a second A spread spectrum transmitting/receiving device forming a loop circuit to synchronize with the transmitter side and demodulating the information signal. (2) The spread spectrum transmitting/receiving device according to claim 1, wherein the first and second oscillators are voltage controlled oscillators that change their oscillation frequency according to changes in the voltage of the information signal. (3) The first and second pseudo noise generating means each have a first
, comprising a frequency divider that obtains a frequency-divided signal by frequency-dividing the oscillation signal oscillated by the second oscillator, and a pseudo-noise generator that generates pseudo-noise using the frequency-divided signal as a clock signal. A spread spectrum transmitting/receiving device according to claim 1. (4) The spread spectrum transmitting/receiving device according to claim 3, wherein the frequency division ratio of the frequency divider is 1 or less. (5) The spread spectrum transmitting/receiving device according to claim 1, wherein the output means and the input means each include a transformer or a capacitor for transmitting and receiving data via a power line as a medium. (6) a first oscillator that changes an oscillation frequency according to an information signal to be transmitted; and a first oscillator that is oscillated by the first oscillator.
a first pseudo-noise generation means for generating a first pseudo-noise using an oscillation signal of the clock as a clock; a modulation means for modulating the first oscillation signal with the first pseudo-noise; and transmitting the output of the modulation means. A transmitter is equipped with an output means for sending out to a medium, an input means for receiving the output of the output means via the medium, and a gain controller for controlling the gain of the received signal received by the input means. and first, second, and third demodulation means for demodulating the output of the gain controller, and performing bandpass filtering at a constant frequency on the outputs of the first, second, and third demodulation means, respectively. 1st, 2nd, 3rd
a second envelope detector that performs envelope detection from the output of the second band-pass filter to provide a control signal for the gain controller; and the first and third band-pass filters. The first step is to perform envelope detection from the output of
, a third envelope detector, a subtracter that calculates the difference between the outputs of the first and third envelope detectors, and a second envelope detector that changes the oscillation frequency according to the output signal of the subtracter. an oscillator, and second, third, and fourth pseudo noises using the second oscillation signal oscillated by the second oscillator as a clock (however, the third pseudo noise is higher than the second pseudo noise, and the fourth pseudo noise is The first, second, and third demodulation means control the gain control according to each of these pseudo-noises (the pseudo-noises are delayed by one clock each from the third pseudo-noise). The receiver is equipped with pseudo-noise generating means for outputting a signal to demodulate the output of the receiver, and the receiver includes a gain controller, a second demodulating means, a second bandpass filter, and a second envelope. The detector forms a first loop circuit, and the gain controller performs automatic gain control. A spread spectrum transmitting/receiving device which forms a second loop circuit using an oscillator and a second pseudo-noise generating means to synchronize with the receiver side and demodulate the information signal. (7) The spread spectrum transmitting/receiving device according to claim 6, wherein the first and second oscillators are voltage controlled oscillators that change their oscillation frequencies in accordance with changes in the voltage of the information signal. (8) The first and second pseudo noise generating means each have a first
, comprising a frequency divider that obtains a frequency-divided signal by frequency-dividing the oscillation signal oscillated by the second oscillator, and a pseudo-noise generator that generates pseudo-noise using the frequency-divided signal as a clock signal. A spread spectrum transmitting/receiving apparatus according to claim 6. (9) The spread spectrum transmitting/receiving apparatus according to claim 8, wherein the frequency division ratio of the first and second frequency dividers is 1 or less. (10) The spread spectrum transmitting/receiving device according to claim 6, wherein the output means and the input means each include a transformer or a capacitor for transmitting and receiving data through a power line as a medium.