Space-time multiuser detection with alternating soft interference cancellation in highly loaded CDMA systems

This paper presents an iterative, yet effective minimum mean square error (MMSE) space-time multiuser detector (MUD) with the assistance of soft interference to enhance the performance in the multipath code division multiple access (CDMA) systems. The proposed space-time MUD is of rank one and comprises of a spatial filter and a temporal filter. To offset the performance loss due to such a constraint, the new MUD alternatively updates the spatial filter or the temporal filter with the soft interference cancellation in between so as to refine the received signal. Computer simulations show that the new MUD can drastically enhance the performance compared to previous works with modest computations, especially in highly loaded scenarios.