Performance of UWB RAKE receivers with imperfect tap weights

In this paper, we develop an analytical framework to quantify the effects of the channel estimation error on ultra-wideband systems operating in dense multipath environments in terms of the receiver performance, the receiver complexity and the channel estimation measurement. The focus of the paper is to characterize the SEP performance using the saddle-point approximation. We find that the performance of P-RAKE with a limited number of fingers degrades much less than the A-RAKE with imperfect channel estimation. And channel estimation by averaging two channel measurements greatly improves the performance with a small rate loss. Furthermore, the performance of the P-RAKE receiver with greater than four fingers is similar to that achievable by using a S-RAKE with the same number of fingers in the presence of channel estimation error.