Downlink beamforming for DS-CDMA mobile radio with multimedia services

Downlink beamforming is a promising technique for DS-CDMA systems with multimedia services to effectively reduce strong interferences induced by high data rate users. In this paper, we first proposed a new downlink beamforming algorithm which converts the downlink beamforming problem to a virtual uplink one and takes into account the data rate information of all users. Since the main complexity of this algorithm is due to existence of the multipath effect, a simplified algorithm is suggested using an equivalent one-path channel vector (EOCV) to replace multipath channel vectors. Computer simulation results are given to evaluate downlink capacity of DS-CDMA systems using a base station antenna array and the new algorithms proposed in this paper.