Abstract: Space-time spreading (STS) is considered as a transmit diversity scheme in the current cdma2000 standard. Space-time transmit diversity (STTD) has been adopted in the current WCDMA standard. In this paper, the performance of STS and STTD have been compared and simulated in forward link cdma2000 systems. The performance analysis and simulation results show that these two schemes have approximately the same performance on the frame error ratio in the multipath fading channel even with imperfect channel estimation. However, compared with STTD, STS has more implementation complexity and higher peak to average power ratio.

Key words: cdma2000, peak to average power ratio, space-time spreading, space-time transmit diversity