Turbo multiuser detection for asynchronous coded CDMA systems in the presence of intercell interference

A turbo multiuser receiver is proposed for the uplink of coded code-division multiple-access (CDMA) systems when intercell interference is present. 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 through iteration. Simulation results show the proposed group-blind receiver significantly outperforms the conventional turbo multiuser detector in the presence of intercell interference.