Convergence and Stability Analysis of a Synchronous Adaptive CDMA Receiver

A thorough investigation on the convergence and stability of a recently proposed adaptive synchronous CDMA receiver is presented in this paper. The receiver consists of a decorrelator at the first stage and an adaptive interference canceler at the second stage. By using a steepest descent algorithm that minimizes the output signal energy to adaptively control the weights, neither the knowledge of the users' received amplitudes nor the use of training sequences is required. The system is near-far resistant, and its error performance approaches the single-user bound when the interferers' SNR's are high. Sufficient conditions for the receiver to achieve convergence are derived, and their properties are analyzed.