A group oriented multiuser detection with beamforming for multicarrier CDMA systems

The capacity of MC-CDMA communication systems can be significantly enhanced by employing multiuser detection (MUD) techniques. A group oriented MUD based on the combination of smart antennas and multiuser or joint detection is presented. The proposed method is featured as a novel technique for further increasing the system capacity and performance. In this method, all the users are first divided into several groups according to their impinging direction of arrivals (DOA). All users with similar DOAs are classified into the same group and then MUD is employed in each group in parallel. Because spatial filtering cannot suppress all the interference between the groups, interference cancellation among groups is used prior to MUD within the groups. It is shown that the proposed group oriented MUD algorithm can significantly reduce the computational complexity and processing time delay compared with the conventional MUD schemes. Furthermore, it is demonstrated that significant performance improvement can be achieved.