SEQUENTIAL CORRELATOR FOR SPREAD SPECTRUM COMMUNICATION SYSTEM

摘要

A spread spectrum communications system includes a spread spectrum encoder wherein the input data signal is combined in an exclusive OR gate with the output of a digital function generator connected in a feedback arrangement which encodes an input data signal with a spreading code sequence. In general, a digital function generator provides an output signal, which after a predetermined time, is a predetermined function of the prior input to the digital function generator. At the receiver, the data is recovered in a spread spectrum correlator using a similar digital function generator and an exclusive OR gate, but connected in a feedforward arrangement. The correlator, using the digital function generator in a feedforward configuration, performs the inverse operation of the encoder, which uses the digital function generator in feedback configuration, in order to recover the data. A spread spectrum system embodying the present invention will synchronize after a predetermined number of chip clocks have elapsed, sufficient to cause the respective digital function generators in the encoder and correlator to each provide an identical predetermined output pattern. DOCKET NO. 1014