Direct-sequence spread spectrum acquisition using transform domain processing

This paper describes two transform domain techniques which perform the acquistion of a direct-sequence spread spectrum signal and offer the advantages of lower computational complexity than time-domain methods and the ability to suppress narrowband interference using transform domain excision. For the case where the received signal is distorted by Doppler frequency shift in the carrier frequency and the chip rate, the acquisition circuit is expanded to perform the acquisition search over the range of expected Doppler shifts. The implementation of the system using the Signal Processing WorkSystem by Comdisco Systems, Inc. is discussed and experimental performance results are presented. These experimental results are compared with analytical results