JPH0568017A - Spread spectrum receiver and spread spectrum transmitter and spread spectrum communication system - Google Patents

Abstract

PURPOSE:To implement communication with high quality by using an interference wave display section so as to detect an interference wave from a signal received by a reception section, eliminating the interference wave at the interference wave elimination section based on the result of detection, then applying spread demodulation to the resulting signal, thereby relieving the influence of the interference wave. CONSTITUTION:The system is provided with an antenna 210 inducing a high frequency signal from a radio wave, an interference wave detecting means 230 detecting an interference wave from the high frequency signal induced by the antenna 210, an interference wave eliminating means 240 eliminating the interference wave detected by the interference wave detection means 230 from the high frequency signal, and a spread demodulation means 250 applying spread demodulation to the high frequency signal from which the interference wave is removed by the interference wave elimination means 240. The interference wave elimination means 240 is provided with a signal generating means generating a signal whose frequency, phase and amplitude are almost equal to those of the interference wave detected by the interference wave detecting means 230 and with a signal subtracting means subtracting the signal generated by the signal generating means from the reception signal received by the antenna 210.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum communication system for converting a signal into a signal having a band much wider than the band of this signal.

[0002]

2. Description of the Related Art A spread spectrum system may be used for communication because of its excellent interference resistance and confidentiality.
The spread spectrum communication system is described in detail in "Spread Spectrum Communication System", Science & Technology Publishing Company (1988), but will be briefly described below.

The spread spectrum communication system includes a direct sequence system (DIRECT SEQUENCE) and a frequency hopping system (FREQ).
UENCY HOPPING), but first, the direct diffusion method will be explained.

FIG. 8 is a diagram showing the configuration of a conventional spread spectrum communication. In the figure, 10 is a transmitting station, 20 is a receiving station, and 30 is an interference wave generation source.

In the transmitting station 10, the carrier wave is transmitted by the carrier wave modulating unit 11 as PSK (PHASE SHIFT KEYING), FM.
(FREQUENCY MODULATION), AM (AMPLITUDE MODULATI
After the primary modulation such as ON) is performed, the secondary modulation (spread modulation) is performed by multiplying by the spreading code that is much wider than the transmission data. Then, the spread-modulated signal is power-amplified by the transmitter 13 and radiated as a radio wave from the antenna 14.

On the other hand, in the receiving station 20, the high frequency signal input from the antenna 21 is subjected to high frequency amplification and band limitation in the receiving section 22, and is spread and demodulated in the spreading demodulating section 23.
This spreading demodulation is to demodulate the received signal by multiplying it by the same spreading code as the transmitting side. Then, the carrier demodulator 24 removes the carrier and reproduces the data.

FIG. 9 is a diagram showing a spectrum of a signal of each part in the spread spectrum communication having the configuration shown in FIG.

As shown in FIGS. 1A and 1B, the spectrum of the signal after passing through the spread modulator 12 is much wider than the spectrum of the signal after passing through the carrier modulator 11. As a result, the power density per unit frequency is significantly reduced, and interference with other communications is avoided. Further, when the spreading demodulation unit 23 of the receiving station 20 demodulates using the same spreading code as that used for modulation at the transmitting station, the signal can be reproduced as shown in FIG. When demodulation is performed using a spreading code different from that used for modulation at the station, the information remains spread and cannot be reproduced, as shown in FIG. Therefore, when a plurality of transmission information signals modulated by different spreading codes exist in the same frequency band, by demodulating with the same spreading code at the time of modulation operation of each transmission information, each transmission information is transmitted. Information can be reproduced.

On the other hand, the spread spectrum communication system of the frequency hopping system is a system in which a carrier frequency modulated by information is spread over a wide band by randomly and randomly switching within a given band.

Such a spread spectrum communication system is
Since the signal band is spread, the power density becomes low, and it is difficult to give interference to other communications and at the same time, it is difficult to receive interference from others, and random access multiple communications in the same frequency band are possible. When the value is increased, the quality of the received signal is improved (the ratio of the frequency band B before the information frequency spread and the frequency band W after the information spread is set to the processing gain Gp = W
/ B)).

However, the conventional spread spectrum communication system has the following problems.

Generally, in wireless communication, the influence of interference waves existing in the transmission space is a serious problem. In the spread spectrum communication system, since the signal is spread over a wide band, the transmission space requires a wide frequency band and is affected by all the interference waves in the frequency band of this transmission space. In the spread spectrum communication system, the received signal is multiplied by the spread code at the time of reception, so that the interference wave is spread over a wide band. Therefore, when the power of the interference wave is small, there are few problems. However, when the power of the interference wave is large, the spreading effect also has a large adverse effect and the reception quality is significantly deteriorated.

For example, in recent years, wireless L in the 2.4 GHz band
There is a movement to build an AN, but this band causes a serious problem because the frequency overlaps with a large-amplitude radiated wave from a microwave oven.

[0014]

As described above, in the conventional spread spectrum communication system, the transmission space requires a wide frequency band and is affected by all the interference waves in the frequency band of this transmission space. Especially, when the power of the interference wave is large, the present invention has a problem that the reception quality is remarkably deteriorated. The present invention was devised to solve such a problem. An object of the present invention is to provide a spread spectrum communication system capable of improving quality.

[0015]

In order to achieve the above-mentioned object, the first invention is a spread spectrum receiving apparatus for receiving a radio wave transmitted by spread spectrum for broadening and transmitting a signal to be transmitted. An antenna for inducing a high frequency signal from the radio wave, an interference wave detecting means for detecting an interference wave from the high frequency signal induced by the antenna, and an interference wave detected by the interference wave detecting means for removing from the high frequency signal. A second aspect of the present invention is a spread spectrum receiving apparatus comprising: an interference wave removing means; and a spread demodulation means for performing spread demodulation on a high frequency signal from which the interference wave is removed by the interference wave removing means. In the above, the interference wave removing means has substantially the same frequency, phase, and amplitude as the interference wave when detected by the interference wave detecting means. A spread spectrum receiver comprising a signal generating means for generating a signal and a signal subtracting means for subtracting the signal generated by the signal generating means from the received signal received by the antenna. A third invention is the first invention. In the invention described above, the interference wave removing means substantially matches the frequency of the interference wave detected by the interference wave detecting means with the band stop filter capable of varying the center frequency of the band stop and the center frequency of the band stop filter. A fourth aspect of the present invention is a spread spectrum transmitting apparatus that includes a control means for controlling the spread spectrum transmitting apparatus. Interference wave detecting means for detecting an interference wave in the transmission space, and the transmission space having a predetermined level or more by the interference wave detecting means. A fifth aspect of the present invention is a spread spectrum transmission device comprising a transmission stop means for stopping the transmission of the spread spectrum transmission device when an interference wave exists. A spread spectrum receiving device for receiving the generated radio wave, the interference wave detecting means for detecting an interference wave of the radio wave in the transmission space, and the interference wave of a predetermined level or more in the transmission space by the interference wave detecting means. A spread spectrum receiving device comprising a reception stopping means for stopping the reception of the spread spectrum receiving device in the case of carrying out, and a sixth aspect of the invention is to transmit the signal to be communicated from the transmitting station to the receiving station using radio waves. A spread spectrum system comprising: an interfering wave detecting means for detecting an interfering wave in the transmission space of the radio wave; When the interference wave is detected by the interference wave detecting means in the station, the signal to be communicated is divided into a plurality of signals in a band other than the frequency band of the interference wave, the spectrum is spread and transmitted, and the reception is performed. In the station, when the interference wave is detected by the interference wave detecting means, the spread spectrum demodulation is performed on the signals in the respective bands divided and transmitted from the transmitting station to reproduce the signal to be communicated. A seventh aspect of the invention is a spread spectrum system.
In a sixth aspect of the present invention, the spread spectrum of the transmitting station is a spread spectrum system in which a direct sequence is used to widen a band by multiplying a predetermined code sequence by a signal to be communicated. An eighth aspect of the present invention is the sixth aspect. In the invention, the spread spectrum of the transmitting station is a spread spectrum system which is performed by frequency hopping in which a carrier frequency is varied by a predetermined code string in a band other than the band of the interference wave.

[0016]

In the spread spectrum communication system of the present invention, when an interference wave in the transmission space is detected, the interference wave is removed or a signal is transmitted while avoiding the band of the interference wave.

Therefore, the influence of the interference wave can be reduced and high quality communication can be performed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the spread spectrum communication system of the present invention.

In the figure, 100 is a transmitting station, 200 is a receiving station, and 300 is an interference wave source such as a microwave oven.

The transmitting station 100 uses a carrier wave as the transmission data.
Carrier modulation section 110 that performs the next modulation (PSK, FM, AM, etc.), spread modulation section 120 that performs spread modulation by multiplying the carrier-modulated signal by a predetermined spreading code, and the spread-modulated signal A transmission unit 130 that performs power amplification of
It has an antenna 140 that emits a signal for which power amplification has been performed as a radio wave.

The receiving station 200 includes an antenna 210 for inducing a high frequency signal from an electric wave, an interference wave detecting section 230 for detecting an interference wave mixed in the received signal, and an interference wave detecting section 230.
The interference wave removing unit 240 that removes the interference wave detected in step 1, the spreading demodulation unit 250 that performs spread demodulation on the received signal from which the interference wave is removed, and the carrier wave demodulation on the spread demodulated signal Carrier wave demodulation section 260 for reproducing

Next, the operation of the spread spectrum communication system having the above configuration will be described.

In the transmitting station 100, the carrier modulation unit 110 performs primary modulation such as PSK, FM, and AM on the carrier with transmission data, and then the spreading modulation unit 120 multiplies by a predetermined spreading code to perform secondary modulation ( Spread spectrum modulation) is performed and converted into a signal having a much wider band than the transmission data. The spread-modulated signal is power-amplified by the transmitter 130 and radiated as a radio wave from the antenna 140.

On the other hand, in the receiving station 200, the antenna 210
The high-frequency signal input from the receiver is subjected to high-frequency amplification, band limitation, and the like in the receiving unit 220. And the interference wave detection unit 23
At 0, the presence of the interference wave generated from the interference wave generation source 300 such as a microwave oven and mixed in the received signal is detected. Then, the interference wave removing section 240 removes the interference wave mixed in the received signal. The received signal from which the interference wave has been removed is spread demodulated by being multiplied by the same code sequence as the code sequence at the time of being spread-modulated by the transmitting station in the spreading demodulation unit 250, and is transmitted on the carrier wave demodulated by the carrier wave demodulation unit 260. The data is played.

FIG. 2 is a block diagram showing a detailed configuration of the interference wave detecting section 230 and the interference wave removing section 240, which are characteristic parts of the present invention of the receiving station 200 shown in FIG.

As shown in the figure, the interference wave detector 230
Is a bandpass filter 231 whose center frequency is variable.
And a level detector 232, and detects the interference wave by detecting the signal level at each center frequency while changing the center frequency of the bandpass filter 231 by the control signal.

Further, the interference wave removing section 240 follows the frequency change of the interference wave signal mixed in the received signal and oscillates a signal of the same frequency as the interference wave signal 2
41 and a phase shift circuit 24 for making the phase of the signal oscillated by the phase locked loop circuit 241 and the interference signal the same.
2, a variable gain amplifier 243 that amplifies the signal output from the phase shift circuit 242, a switch 244 that turns on / off the output of the variable gain amplifier 243 according to a signal from the interference wave detection unit 230, and a reception unit 220 A subtraction circuit 245 that takes the difference between the output signal and the output signal of the switch 244;
It has a multiplication circuit 246 that multiplies the output signal of the subtraction circuit 245 and the output signal of the phase shift circuit 242, and an integration circuit 247 that integrates the output signal of the multiplication circuit 246 and extracts only the low frequency component.

Further, a phase locked loop circuit (PLL) 2
41 is a multiplier 241a which is a phase comparator, a loop filter 241b, and a voltage controlled oscillator (VCO) 241c.
Composed of and. The loop filter 241b is composed of, for example, a perfect integration filter. The details of the operation of the PLL are described in, for example, "How to use the PLL-IC (published by the publication)".

Next, the operation of the receiving station having the configuration shown in FIG. 2 will be described.

The signal X (t) of the output signal of the receiver 220 is expressed by the following equation.

X (t) = S (t) + I (t) I (t) = Asin (ω ₀ t + θ) where S (t) is a desired signal and I (t) is a device such as a microwave oven. This is the interference wave emitted from. A indicates the amplitude of the interference wave, ω ₀ indicates the angular frequency of the interference wave, and θ indicates the phase of the interference wave.

The signal X (t) is input to the interference wave detector 230 and the phase locked loop circuit 241. The phase-locked loop circuit 241 synchronizes with the input periodic signal and outputs a signal whose frequency is equal to that of the input and whose noise is suppressed, to the VCO 241.
Output from c.

At this time, the output signal V of the VCO 241c
(T) is shown as follows.

V (t) = cos (ω ₀ t + θ) The phase-locked loop circuit 241 synchronizes with the interference wave I (t),
I (t) and V (t) have a 90-degree phase-shifted relationship. The VCO output V (t) is input to the phase shift circuit 242 and 90
Output signal U (t) of the phase shift circuit 242 when the phase is shifted by 180 degrees.
Is as follows.

U (t) = sin (ω ₀ t + θ) Further, the output signal W (t) of the variable gain amplifier 243 is as follows.

W (t) = Gsin (ω ₀ t + θ) (G
Is the gain of the variable gain amplifier) The output signal W (t) of the variable gain amplifier 243 is the switch 2
44 is input. The switch 244 is off when there is no interference wave, cuts off the signal W (t), is on when there is an interference wave, passes the signal W (t), and inputs it to the subtraction circuit 245. At this time, Y (t) of the output signal of the subtraction circuit 245 is as follows. Y (t) = X (t) −W (t) = S (t) + (A−G) sin (ω ₀ t + θ) Then, the multiplication circuit 246 causes the signal U (t) and the signal Y to be obtained.
(T) is multiplied with the output signal E of the multiplication circuit 246.
(T) is as follows.

E (t) = U (t) .Y (t) = S (t) .sin (ω ₀ t + θ) + (A−G) sin ² (ω ₀ t + θ) = S (t) · sin ( ω ₀ t + θ) + (A−G) (1-cos2 (ω ₀ t + θ)) / 2 Further, when the signal E (t) is input to the integrating circuit 247, the signal E (t ), Only the direct current component of ()) passes, and the output signal e (t) of the integrating circuit 247 is as follows.

E (t) = (A−G) / 2 Further, the gain G of the variable gain amplifier 243 is obtained by the signal e (t).
Is controlled as follows.

When e (t)> 0, that is, A> G, G is increased.

When e (t) <0, that is, when A <G, G is decreased.

By controlling in this way, G is controlled so that e (t) = 0, that is, A = G.

When controlled so that A = G, the output signal Y (t) of the subtraction circuit 245 becomes Y (t) = S (t), the interference wave is removed, and the desired signal S (t) is obtained. Obtainable.

The signal S (t) is input to the spread demodulation section 250 and the carrier demodulation section 260, and is subjected to spread demodulation and carrier demodulation to reproduce data.

In the above-described embodiment, the phase shift circuit 242 has 90
Although the fixed phase shift circuit of phase shift is used as the variable phase shift circuit, it is possible to remove the interference wave with higher accuracy. When there are a plurality of interference waves, a desired characteristic can be obtained by providing a plurality of similar circuits. The interference wave removing unit 240 can be realized by an analog circuit or a digital circuit. Further, the desired signal S (t) is effective not only in a communication system using a wideband signal such as a spread signal in spread spectrum communication but also in a communication system using a narrowband signal. The spread spectrum communication system may be a direct spread system or a frequency hopping system.

FIG. 3 is a diagram showing the configuration of a spread spectrum receiver which is another embodiment of the present invention.

In the figure, 400 is an antenna, and 410
Is a receiving unit that amplifies the high frequency signal induced by the antenna 400, limits the band, etc., 420 is an interference wave frequency detecting unit that detects the frequency of the interference wave signal mixed in the received signal, and 430 is the interference wave frequency detecting unit 420. 7 shows a band elimination filter that attenuates the interference wave by changing the center frequency according to the generated interference wave frequency.

In the embodiment shown in FIG. 2, the output of the phase locked loop circuit 241 is controlled to generate an amplitude signal having the same frequency and phase as the interference wave and subtracted from the received signal to remove the interference wave. Then, the frequency of the interference wave is detected by the interference wave frequency detection unit 420, the center frequency of the band elimination filter 430 is controlled to match the frequency of the interference wave, and the interference wave is removed.

Further, in the embodiment shown in FIGS. 2 and 3, the receiving station detects and removes the interference wave, but when the transmitting station or the receiving station detects the interference wave, the transmission or the reception is stopped. You can

FIG. 4 is a block diagram showing the configuration of a spread spectrum communication system according to still another embodiment of the present invention. In this embodiment, the interference wave is detected on the transmission side or the reception side, and if the interference wave exists, the frequency of the interference wave is detected and the transmission side transmits using a band other than the frequency of the interference wave. In the figure, 500 is a transmitting station,
Reference numeral 600 represents a receiving station.

The transmitting station 500 divides the transmission data into two series of low-speed data strings D1 and D2, and a data dividing section 510.
A carrier modulation section 520 that performs a carrier modulation on the data string D1, a spreading modulation section 530 that performs a spread modulation on the signal modulated by the carrier modulation section 520, and a carrier modulation on the data string D2. Carrier wave modulator 54
0, a spread modulator 550 that performs spread modulation on the signal modulated by the carrier modulator 540, an adder 560 that adds the output signals of the spread modulator 530 and the spread modulator 550, and an adder 560. A transmission unit 570 that performs power amplification of the added signals, an antenna 580 that emits an output signal of the transmission unit 570 as a radio wave, and a duplexer 5 interposed between the transmission unit 570 and the antenna 580.
85 and the interference wave received by the antenna 580 to the duplexer 58.
5 and an interference wave detection unit 590 for detecting the interference wave.

The receiving station 600 includes an antenna 610 for inducing a high frequency signal from a radio wave, a receiving section 620 for performing high frequency amplification and band limitation of the high frequency signal induced by the antenna 610, and a signal output from the receiving section 620. A band pass filter 630 that passes only a specific band of the band,
640, spreading demodulation units 650 and 660 that perform spread demodulation on the reception signals band-limited by the band pass filters 630 and 640, and carrier demodulation that performs carrier demodulation on the signals spread and demodulated by the spreading demodulation units 650 and 660. Units 670 and 680, a data combining unit 690 that reproduces transmission data by combining the data demodulated by the carrier demodulation units 670 and 680, and an interference wave detection unit 695 that detects an interference wave from the reception signal from the reception unit 620. And have.

Next, the operation of the spread spectrum communication having the above configuration will be described.

When the interference wave is not detected by the interference wave detector 590 of the transmitting station 500, the transmitting station 10 shown in FIG.
Data is transmitted using the same configuration as. Receiving station 600
However, if no interference wave is detected by the interference wave detection unit 695, data reception is performed using the same configuration as the reception station 20 shown in FIG. When an interference wave is detected by the interference wave detectors 590 and 695, data transmission / reception is performed using the configuration shown in FIG.

Now, the interference wave detector 590 of the transmitting station 500
When the interference wave is detected by, the data dividing unit 510 first divides the transmission data D into two series of data strings D1 and D2.

FIG. 5 is a diagram showing the transmission data D, the divided data strings D1 and D2, and the spectrum of these data strings.

FIG. 7A shows the transmission data D and its spectrum, and FIG. 8B shows the divided data strings D1 and D2 and their spectra. As shown in these figures, if the frequency bandwidth of the original transmission data D is b0, the bandwidths of the data D1 and data D2, b1 and b2 are b
1 = b2 = b0 / 2.

Next, the carrier wave modulator 520 modulates the carrier wave of frequency f1 by the data string D1. On the other hand, the carrier wave modulator 540 modulates the carrier wave of frequency f2 by the data string D2.

FIG. 6 is a diagram showing the spectrum of the signal after carrier modulation, and f0 shows the frequency of the picture interference wave.

Further, the signals after carrier modulation by the spread modulators 530 and 550 are spread-modulated to widen the band and lower the power density.

FIG. 7 is a diagram showing the spectrum of the signal after the spread modulation. As shown in the figure, by properly selecting the frequencies f1 and f2 of the carrier wave and the data transfer rate with respect to the frequency f0 of the interference wave, it becomes possible to transmit data without overlapping the band of the interference wave. ..

A case where an interference wave is detected by interference wave detecting section 695 in receiving station 600 will be described. In this case, the band pass filter 630 passes the frequency band lower than the frequency f0 of the interference wave, and the band pass filter 640 passes the frequency band higher than the frequency f0 of the interference wave. In the spread modulator 650, the frequency f of the signal that has passed through the bandpass filter 630, that is, the frequency of the interference wave.
Spread demodulation is performed for frequencies lower than 0. Further, in the spread modulator 660, spread demodulation is performed on the signal that has passed through the band pass filter 640, that is, the frequency higher than the frequency f0 of the interference wave, by the same code sequence as used in the transmitting station 500. That is, the spread modulator 650 performs spread demodulation on the data string D1, and the spread modulator 660 performs spread demodulation on the data string D2. Then, carrier demodulation sections 670 and 680 carry out carrier demodulation on the signals spread and demodulated by spread modulation sections 650 and 660, and demodulate data strings D1 and D2, respectively. The data combiner 690 combines the data sequence D1 and the data sequence D2 to reproduce the transmission data D.

The two spreading modulators 5 of the transmitting station 500
The spread code sequences of 30, 550 may be the same or different. Alternatively, the two carrier modulation signals may be combined and then collectively spread-modulated.

In the above-mentioned embodiment, the direct spreading method is used, but a frequency hopping spreading method may be used in which a frequency signal is selected and hopping is performed with a spreading code pattern so as not to overlap the detected interference wave frequency. In the above-described embodiment, the case where there is one interference wave has been described. However, even when there are a plurality of interference waves, data division is performed so as to avoid the frequency band of the interference waves, the carrier frequency is determined, and spread modulation is performed. You can do it. Further, the data division is not limited to two, and the data can be divided into three or more and transmitted.

In the case of the embodiment shown in FIG. 4, for example, a wireless LA
Since the transmitting station and the receiving station are used in a relatively close state such as N, the interference wave from the interference wave generating source 300 is transmitted to the transmitting station 5.
00 and the receiving station 600 are both detected, but when the transmitting station and the receiving station are separated from each other, the transmitting station can detect the interference wave, but the receiving station cannot detect the interference wave. In this way, when the transmitting station and the receiving station are separated from each other, an interference wave detection unit is provided only in the transmitting station, and when the transmitting station detects the interference wave, the receiving station transmits the pilot signal indicating the interference wave detection. When the pilot signal is received, the receiving station 600 shown in FIG. 4 may start receiving.

Furthermore, the transmitting station may transmit using a band other than the frequency of the interference wave, and the interference wave may be removed on the receiving side.

As described above, in the above-described embodiment, the interference wave mixed in the received signal is removed, or the spread-modulated signal is transmitted while avoiding the frequency band of the interference wave. It is difficult to receive, and high quality communication can be performed.

[0068]

According to the spread spectrum communication system of the present invention, when an interference wave in the transmission space is detected, the interference wave is removed or the signal is transmitted while avoiding the band of the interference wave. The influence can be reduced and high quality communication can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a spread spectrum communication system of the present invention.

2 is a block diagram showing a detailed configuration of an interference wave detector and an interference wave remover, which are characteristic parts of the present invention, of the receiving station shown in FIG.

FIG. 3 is a diagram showing a configuration of a spread spectrum receiver which is another embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a spread spectrum communication system according to yet another exemplary embodiment of the present invention.

FIG. 5 shows transmission data D and divided data strings D1 and D
FIG. 2 is a diagram showing spectra of 2 and these data strings.

FIG. 6 is a diagram showing a spectrum of a signal after carrier modulation.

FIG. 7 is a diagram showing a spectrum of a signal after spread modulation.

FIG. 8 is a diagram showing a configuration of conventional spread spectrum communication.

9 is a diagram showing a spectrum of a signal of each unit in the spread spectrum communication having the configuration shown in FIG.

[Explanation of symbols]

 100 ... Transmission station 110 ... Carrier modulation section 120 ... Spread modulation section 130 ... Transmission section 140 ... Antenna 200 ... Reception station 210 ... Antenna 220 ... Reception section 230 ... Interference wave detection section 240 ... Interference wave removal section 250 ... Spread demodulation section 260 … Carrier demodulator 300… Interference wave source

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Nakagawa 3-38-17 Migamioka Nishi, Midori-ku, Yokohama-shi, Kanagawa (72) Inventor Ryuji Kono 1202-9 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa (72) Inventor Shinichi Tachikawa 5154 Katagai-cho, Ojiya-shi, Niigata (72) Inventor Hiroshi Kobayashi 70 Yanagi-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Yanagimachi factory (72) Inventor Shoichiro Yamazaki 70, Yanagi-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Yanagimachi Factory

Claims (8)

[Claims] 1. A spread spectrum receiving apparatus for receiving a radio wave transmitted by spread spectrum for transmitting a signal to be transmitted in a wide band, the antenna for inducing a high frequency signal from the radio wave, and the antenna induced by the antenna. An interference wave detecting means for detecting an interference wave from the high frequency signal, an interference wave removing means for removing the interference wave detected by the interference wave detecting means from the high frequency signal, and a high frequency wave for which the interference wave is removed by the interference wave removing means. A spread spectrum receiver comprising a spread demodulation means for performing spread demodulation on a signal. 2. The interference wave removing means generates a signal having a frequency, a phase, and an amplitude which are substantially equal to those of the interference wave when detected by the interference wave detecting means, and the signal generating means. The spread spectrum receiving apparatus according to claim 1, further comprising signal subtraction means for subtracting a signal from a received signal received by the antenna. 3. The interference wave removing means includes a band stop filter capable of varying the center frequency of the band stop, and the center frequency of the band stop filter substantially coincides with the frequency of the interference wave detected by the interference wave detecting means. 2. The spread spectrum receiving apparatus according to claim 1, further comprising control means for controlling the operation. 4. A spread spectrum transmitter for radiating a signal to be transmitted as a radio wave by spreading-modulating the signal to be spread, and an interference wave detecting means for detecting an interference wave in the transmission space of the radio wave. A spread spectrum transmitter comprising: a transmission stop means for stopping transmission of the spread spectrum transmitter when the interference wave is present in the transmission space by the interference wave detector. 5. A spread spectrum receiver for receiving a radio wave transmitted by spread spectrum, which transmits a signal to be transmitted in a wide band, and an interference wave detecting means for detecting an interference wave in the transmission space of the radio wave. A spread spectrum receiving apparatus comprising: a reception stopping means for stopping the reception of the spread spectrum receiving apparatus by the interference wave detecting means when an interference wave of a predetermined level or more exists in the transmission space. 6. A spread spectrum system for broadening a band of a signal to be communicated and transmitting it from a transmitting station to a receiving station by using a radio wave, comprising an interference wave detecting means for detecting an interference wave in the transmission space of the radio wave. Then, in the transmitting station, when an interference wave is detected by the interference wave detecting means, the signal to be communicated is divided into a plurality of signals in a band other than the frequency band of the interference wave and spread spectrum is transmitted. However, when the receiving station detects an interference wave by the interference wave detecting means, the communication should be performed by performing spread spectrum demodulation on the signals of the respective bands divided and transmitted from the transmitting station. A spread spectrum system that regenerates the signal. 7. The spread spectrum system according to claim 6, wherein said spread spectrum of said transmitting station is performed by a direct sequence for widening the band by multiplying a predetermined code sequence and a signal to be communicated. 8. The spread spectrum system according to claim 6, wherein the spread spectrum of the transmitting station is performed by frequency hopping in which a carrier frequency is varied by a predetermined code string in a band other than the band of the interference wave.