ANALYSIS OF NONCOHERENT CORRELATION IN DS BPSK SPREAD-SPECTRUM ACQUISITION/

Non-coherent detectors for initial code synchronization (acquisition) of BPSK direct sequence spread spectrum signals on an AWGN channel are analyzed. In addition to the thermal noise, in many applications such detectors are faced with the ''self-noise'', due to the partial perio d correlations. Under the random code sequences assumption, in this pa per an exact analysis of the non-coherent correlator's detection perfo rmance is carried out by using the theory of circularly symmetric rand om variables. The exact analysis shows that the familiar Gaussian appr oximation to the distribution function of the code self-noise is justi fied for all cases of practical interest. Furthermore, the overall det ection performance was found to be determined asymptotically by the su m of the thermal and correlator's self-noise. In most cases of practic al interest, this asymptotic result provides a very good approximation to the actual detection performance of a non-coherent correlator, imp roving tile approximations devised previously.