Abstract: A spread-spectrum communication system uses a PN code which ensures that the side lobe of a self-correlation function represents zero on both parts of a sender and a receiver.

Abstract: A correlation pulse generating circuit uses a delay circuit for delaying an output of an absolute value detecting circuit corresponding to an A/D-converted output of a correlation spike, so that amplitude information of a current correlation spike can be used for detection of the correlation spike.

Abstract: A spread spectrum receiver has first and second correlators which each compare a received signal with a respective reference signal. The output of each correlator is routed through a respective band pass filter and a respective AGC amplifier to a respective detector circuit which converts the output of the amplifier into a respective base band signal. The ouput of each detector circuit is supplied to a respective peak value detecting and holding section, which detects and holds for a predetermined time period peak values from the associated detector circuit. Each peak value detecting and holding circuit supplies the peak value currently held therein through a respective low pass filter which serves as an integrator to a data comparing section and to an adding section. The adding section adds the two peak values, and supplies the sum to control inputs of each of the AGC amplifiers for purposes of gain control.

Abstract: A spread spectrum communication (SSC) receiving device is disclosed, in which a received signal consisting of an SSC signal in the SSC signal band and disturbance wave is divided into an upper side band and a lower side band; electric powers of the signal in the upper side band and the signal in the lower side band are compared with each other; and the SSC signal in the upper side band or in the lower side band, where there exists no disturbance wave, is outputted according to the result of the comparison.

Abstract: A correlation pulse generator used in a receiver of a spread spectrum communication system comprises peak hold circuit for holding peak values of positive and negative correlation spikes, threshold setting circuits for generating thresholds based on the peak values, and a comparing circuit for comparing the threshold with a correlation spike to generate a correlation pulse, so that when a level difference exists between positive and negative correlation spike levels of a correlation output, their peaks can be held independently, and thresholds based on the peaks can be generated independently.

Abstract: A spread spectrum receiver is disclosed in which a correlation pulse generating circuit for generating a correlation pulse from a correlation spike outputted by a correlator comprises an A/D converting circuit which A/D-converts said correlation spike; an absolute value detecting circuit for detecting the absolute value of the output of said A/D converting circuit; a peak value detecting circuit for detecting the value corresponding to a peak of the output of said peak value detecting circuit; a threshold value setting circuit for generating a threshold signal based on the output of said peak value detecting circuit; and a comparing circuit for comparing the output of the absolute value detecting circuit with said threshold signal to generate the correlation pulse.

Abstract: An integrating circuit is configured to feed a correlator output to a first integrating and dumping circuit and to a second integrating and dumping circuit and to subsequently add their respective outputs in a composing circuit. The first integrating and dumping circuit and the second integrating and dumping circuit are activated selectively by a switching control switch to perform their integrating and dumping operations.