A decision directed adaptive correlator for a direct sequence spread spectrum receiver

An adaptive correlator is presented as the data detector in a direct sequence spread spectrum communication system. The adaptive correlator has the same structure as an least-mean-square (LMS) adaptive filter, but the tapped delay line of the filter is shifted multiple times between each adaptation. This method implements an LMMSE estimator of the transmitted data based on the received samples. The tap weight behavior is predicted for such an estimator in the presence of single tone interference and multipath propagation, and the resulting receiver is simulated to verify convergence. A decision directed receiver using this detector is simulated and is shown to be effective at removing both interference and multipath effects. An efficient serial method for implementing the receiver is also presented