Noncoherent detectors for PN code acquisition in the presence of data modulation

Noncoherent detectors for use in acquiring data-modulated direct-sequence s pread-spectrum (DS/SS) signals are considered in this paper. Taking data mo dulation and timing uncertainty into account and using the generalized maxi mum likelihood (GML) or maximum likelihood (ML) detection approaches, we de rive optimal detectors in the sense of Bayes or Neyman-Pearson and propose various suboptimal detectors. A simple systematic means for their realizati on is suggested and the numerical performance of these detectors is present ed. We also compare their performance with that of the noncoherent combinin g (NC1) detector that had been proposed to serve the same need. Numerical r esults show that even the proposed suboptimal detectors can outperform the NC1 detector in most cases of interest.