Adaptive Iterative Receiver for CDMA Systems in Rayleigh Fading Channels

An adaptive iterative receiver for a Layered Space-Time Coded CDMA (LSTC-CDMA) system has been proposed in this paper. The LSTC-CDMA system, based on a joint adaptive iterative detection and decoding algorithm, adaptively cancels Co-Channel Interference (CCI) and mitigates Multiple Access Interference (MAI). The Least Means Square (LMS) algorithm is used for both feed-forward filter and feedback filter in the adaptive detection. A Partially Filtered Gradient LMS (PFGLMS) algorithm is also proposed to improve the convergence speed of the adaptive detector. The performance results show that the receiver, based on PFGLMS algorithm, yields much faster convergence speed and tracking ability with a slightly increase in complexity. The proposed receiver is analyzed in the slow and fast Rayleigh fading channels.