Wcdma System Transmit Diversity And The Base Station Receiver Hardware Implementation

In 3G systems, the capacity of uplink can be increased by some techniques such as antenna array diversity and MUD. On the other hand, the capacity of downlink can be increased by transmission diversity. Transmission diversity can achieve a considerable performance gain especially in the channel that lacks of available paths. Thus, some open-loop and closed-loop transmission diversity methods have been used in WCDMA system. Furthermore, many transmission diversity schemes using more than 2 antennas are proposed and discussed.Firstly the transmission diversity schemes used in WCDMA are described in this thesis. We focus on the closed-loop transmission diversity and the comparison of two transmission diversity modes. A feasible scheme that can be implemented on hardware is also discussed. Secondly some transmission diversity methods proposed in 3GPP, which use more than 2 antennas, are studied and analyzed. Simulation results are given and conclusions are drawn. Finally the hardware implement of RAKE receiver and TRCHs-demultiplexing in uplink is described in detail. The whole design has been verified on the FPGA platform.