Subspace-based interference suppression technique for long-code downlink CDMA adaptive receiver

This paper presents a novel combination of subspace method and linear adaptive step-size LMS receiver for multiuser detection (MUD) in synchronous long-code downlink DS-CDMA systems. The receiver can be operated in multipath environments with the presence of multiple access interference (MAI) and near-far problem. Simulations show that the proposed receiver is capable of MAI suppression and multipath mitigation. Specifically, the proposed receiver improves performance of the linear adaptive LMS receiver in terms of convergence speed and SINK in static environment and dynamic environment where the number of interferers are time varying.