Parallel correlator for a spread spectrum receiver

摘要

A direct sequence spread spectrum receiver samples an incoming signal and stores the sample in memory. The signal sample is read from memory as necessary to process the signal without further signal acquisition. The correlator calculates an inner product by simultaneously correlating each bit of the sample with a corresponding bit of a replica signal. If the inner product does not exceed a threshold value the correlator calculates another inner product between the same signal sample and another replica signal. This occurs until all available signals are identified. In one embodiment, memory is segmented and each segment is read by a separate correlator allowing faster identification of one signal or multiple signals to be acquired simultaneously. Such a receiver is useful in global positioning satellite (GPS) signal processing where the incoming signal contains several satellite transmissions encoded with CDMA encoding.