Exact BER analysis and design of Prerake combining schemes for direct sequence ultra-wideband multiple access systems

Abstract

We study two important aspects of DS UWB communication systems: The first one is to exactly evaluate the bit error rate (BER) performance of DS UWB multiple access systems. The second one is to effectively capture energy using Prerake combining schemes. Validity of the GA method in BER evaluation is found to be questionable. Hence we propose to use a novel method based on characteristic function (CF) to compute BER values. Results show that the CF method outperforms the GA method in both additive white Gaussian noise (AWGN) channels and lognormal multipath fading channels. We propose to use the Prerake combining to effectively capture energy with a simple correlation receiver. We consider imperfect channel estimation and highlight the tradeoff between data rate and system performance. A high data rate (HDR) Prerake DS UWB system is proposed and the CF method is employed to analyze its performance.