Design of an all digital direct-sequence spread-spectrum receiver

The theory of a fully digital coherent direct-sequence spread-spectrum receiver for microprocessor implementation is described. The receiver samples the input signal at IF and uses a Costas loop for carrier tracking, a delay-lock loop for code tracking, and a serial search acquisition scheme to find the initial code phase. A prototype of the receiver based on the TMS320C25 digital signal processor has been built to prove functional operation.