On the impact of imperfect multipath detection on the performance of CDMA systems with space-time spreading

We investigate the impact of imperfect multipath detection on the performance of CDMA systems employing space-time spreading. Conventionally, multipath components are detected and assigned to the RAKE fingers based on their average energy content. It is shown that the errors produced by the conventional scheme in detecting the potential multipath components severely impact the performance of the receiver. To boost the performance, we introduce an improved multipath detection scheme based on estimating the interference power in the resolved paths. Our results show that the proposed scheme not only improves the bit error rate performance significantly, but also utilizes the pilot power much more efficiently.