Channel shortening through bit error rate minimization for UWB systems

Abstract

Ultra wideband (UWB) communication systems occupy huge bandwidths with very low power spectral densities. This feature make the UWB channels highly rich in resolvable multipaths. To exploit the temporal diversity, the receiver is commonly implemented through a rake. The aim to capture enough signal energy to maintain an acceptable output signal to noise ratio (SNR) dictates a very complicated rake structure with a large number of fingers. Channel shortening or time domain equalizer (TEQ) can simplify the rake receiver design by reducing the number of significant taps in the effective channel. In this paper, we present a TEQ design which minimizes the bit error rate (BER) of the system to perform efficient channel shortening in UWB systems. The performance of the proposed algorithm is compared with a generic TEQ design and other rake structures in UWB channels. It is shown that the proposed algorithm maintains a lower BER along with efficiently shortening the channel.