Spread spectrum signal receiver

Abstract

In a spread spectrum signal receiver, a frequency divider circuit divides the frequency of the output signal of a VCO having a phase synchronized with that of the output signal of first multiplier. A first spreading code generating circuit generates a spreading code in response to the output signal of the frequency divider circuit. A second spreading code generating circuit generates first through third spreading codes in response to the spreading code. A selection circuit selects one of the first through third spreading codes. A second multiplier despreads the spectrum using the spreading code output from the selection circuit. A correlation detector circuit detects correlation from the output signal of the second multiplier and a control signal generates a delay or advance control signal in response to the detected correlation. The frequency dividing ratio of the frequency divider circuit is switched according to the delay or advance control signal. The timing of generating a spreading code can be regulated by changing the frequency dividing ratio, and then the timing of the spreading code of the transmitter side and that of the receiver side coincide.