Iterative group blind multiuser detection and decoding for asynchronous CDMA systems

A turbo multiuser receiver is proposed for uplink channel-coded, code division multiple access (CDMA) systems with unknown interferences. The proposed receiver consists of a first stage of soft interference cancellation, and a group blind linear minimum mean-square error filtering, followed by a second stage that performs the channel decoding. A receiver suitable for suppressing high intercell interference is obtained. By exchanging soft information between the first and second stages, the receiver performance is improved via iteration. Simulation results show that the proposed group blind receiver significantly outperforms the conventional turbo multiuser detector in the presence of intercell interferences.