Gradient Adaptive Lattice Algorithm for MMSE Receivers in DS-CDMA Systems

This paper considers a minimum mean-squared error (MMSE) single user adaptive receiver for the asynchronous direct-sequence code-division multiple-access (DS-CDMA) system, based on a gradient adaptive lattice (GAL) algorithm. Since the lattice predictor orthogonalizes the input signals this algorithm achieves a faster convergence rate than the transversal least-mean-square (LMS) algorithm. Moreover, a parallel interference cancellation (PIC) procedure is developed in order to increase the convergence performance, which further reduces the overhead introduced during the receiver´s training period.