Downlink beamforming for DS-CDMA mobile radio with multimedia services
Downlink beamforming is a promising technique for direct-sequence code-division multiple-access (DS-CDMA) systems with multimedia services to effectively reduce strong interference induced by high data rate users. A new downlink beamforming technique is proposed that converts the downlink beamforming problem into a virtual uplink one and takes into account the data rate information of all users. Since the main complexity of this method is due to the existence of multidelay paths, two simplified algorithms are suggested using an equivalent one-path channel vector to replace multipath channel vectors. Computer simulation results are given to evaluate the downlink capacity of DS-CDMA systems using a base station antenna array and the new algorithms proposed.