Abstract

In a pseudo-random communication system, a transmitter-generated encoded signal is to be correlated with a receiver-generated similarly encoded signal for recognizing synchronization of the transmitted and received signals in the presence of undesired received energy. The system comprises a spread-spectrum transmitter including at least two pseudo-noise generators for producing at least two pseudo-noise signals which are related in a predetermined fashion, a mixer for receiving and mixing the two pseudo-noise signals with respective carrier and information signals to produce an output signal, and apparatus for transmitting the output signal. The system also includes a spread-spectrum receiver comprising a correlator and a matched filter coupled in circuit to form a synchronization detector circuit for receiving and detecting the encoded output signal transmitted by the transmitter so as to recover the information therefrom. The correlator includes at least one pseudo-noise generator for producing pseudo-noise signals related in a predetermined fashion to the pseudo-noise signals produced by the transmitter pseudo-noise generators and a mixer for mixing the pseudo-noise signals with the received encoded output signals and coupled in circuit with the matched filter circuit.