Acquisition of spread spectrum signals by an adaptive array

Discrete-time processing techniques are discussed for the acquisition of direct-sequence spread-spectrum signals by an antenna array. Both constant data and random data modulation of the code are considered. The maximum-likelihood (ML) procedures for estimating the received code lag are described, assuming an unknown channel and interference signal of either known or unknown covariance. Analytic and simulation results for performance of the optimum estimators are presented. Simulation results for the ML data estimators are shown to be close to analytical predictions of bit error rate (BER) performance. The ML procedure for data demodulation is also described