Correlator, synchronizer provided with the correlator, and fast frequency hopping spread spectrum receiver provided with the synchronizer

摘要

A synchronizer of a fast frequency hopping spread spectrum receiver includes a correlator and a peak detection circuit for detecting the peak of the output signal of the correlator and outputting a detection signal. A sampler has the output signal of the correlator pass therethrough when the detection signal is outputted from the synchronizer. A code discriminating circuit discriminates the code of the output signal of the sampler. M pieces of frequency synthesizers of the correlator output M pieces of sinusoidal wave signals having the same frequencies as the frequencies of M pieces of carriers, respectively. A delay line of the correlator includes a plurality of delay elements connected with one another in a cascade, and delays the input signal of the correlator by each delay element and converts the input signal into M pieces of parallel input signals having different delay time, respectively. Besides, the delay time of respective delay elements is defined as a chip period. Each of M pieces of multipliers of the correlator multiplies one of M pieces of parallel signals by one of M pieces of sinusoidal wave signals which has been made to correspond in advance to the one parallel signal. A detection circuit of the correlator detects the output signals of M pieces of multipliers, respectively. An adder of the correlator adds up the output signals of M pieces of detection circuits.