CDMA pre-RAKE diversity system with base station transmit diversity

In recent years, there has been significant research and development efforts for third-generation or 3G wireless and cellular mobile communication systems. Among the various technologies, wideband direct-sequence (DS) CDMA has emerged as the main candidate under consideration for UMTS and IMT-2000. Antenna arrays at the base-station have been shown to mitigate the multipath fading effect and suppress co-channel interference, thereby, improving the transmission quality and increasing the system capacity. In this paper, we introduce a system which combines pre-RAKE diversity and space transmit antenna diversity, along with a simplified receiver structure for downlink DS/CDMA systems. Both simulation results and analysis are provided and demonstrate the potential of the system, which can improve the system performance or increase the system capacity significantly as the number of transmit antenna increases