4-ary correlator, matched filter, and decoder for coherent, direct sequence, spread spectrum applications

摘要

A system for decoding an IF signal modulated with 4-ary words generated at a known spreading rate (PN code) comprises a receiver in which four known 4-ary words are generated at the same rate. The system then compares the incoming signals modulated with unknown 4-ary words with each of four known 4-ary words. Only one of the known words will be in phase with a received unknown word. The disclosure describes a system which determines which of the four words is in phase, this being the determinant of the identity of the unknown word.