Optimal and suboptimal noncoherent detectors for PN code acquisition in the presence of data modulation

Noncoherent detectors for use in acquiring data-modulated direct-sequence spread-spectrum (DS/SS) signals are considered in this paper. Taking data modulation into account, we examine maximum likelihood (ML) and generalized maximum likelihood (GML) detection structures and then derive suboptimal detectors. We call one of the suboptimal detector as noncoherent partially matched filter (PMF) as it matches only part of the family of legitimate data patterns. We compare the detector operating characteristic (DOC) performance of the PM filter and that of the noncoherent combining (NC) detector that had been proposed to serve the same need. Although the PM filter requires a little more computing it does give better performance