Performance Analysis of Space-Time Transmit Diversity for WCDMA

： There are two modes of transmit diversity for the third generation mobile communication system WCDMA: open-loop mode and the close-loop mode. In the open-loop mode, STTD (Space Time Transmit Diversity) is employed. For the STTD , an algorithm using common pilot channel to estimate channel parameters is proposed. Algorithm used for coherent RAKE reception as well as its performance analysis and simulation results are also given. Simulation results demonstrate that for the same total transmitted bit-energy, performance of STTD RAKE receiver is superior to that of single antenna RAKE receiver. It is more evident when the receiver moves slowly. The same advantage can not be seen in STTD mode when the receiver is in high speed moving.