Space-time multiuser detection in multipath CDMA channels

The problem of multiuser detection in multipath CDMA channels with receiver antenna array is considered. The optimal space-time multiuser receiver structure is first derived, followed by linear space-time multiuser detection methods based on iterative interference cancellation. Blind adaptive space-time multiuser detection techniques are then proposed, which require prior knowledge of only the spreading waveform and the timing of the desired user's signal. Single-user-based space-time processing methods are also considered and are compared with the multiuser approach. It is seen that the proposed multiuser space-time processing techniques offer substantial performance gains over the single-user-based methods, especially in a near-far situation.