EURASIP Journal on Wireless Communications and Networking
Volume 2009 (2009), Article ID 786291, 11 pages
doi:10.1155/2009/786291
Research Article

Time Domain Equalizer Design Using Bit Error Rate Minimization for UWB Systems

Syed Imtiaz Husain,1 Jinhong Yuan,1 Jian Zhang,2,3 and R. K. Martin4

1School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW 2052, Australia
2Australian National University, Canberra, ACT 0200, Australia
3Canberra Research Laboratories, National ICT Australia (NICTA), Canberra, ACT 2601, Australia
4The Air Force Institute of Technology, Kettering, OH-45433, USA

Received 28 January 2009; Accepted 27 March 2009

Academic Editor: Steve McLaughlin

Copyright © 2009 Syed Imtiaz Husain et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ultra-wideband (UWB) communication systems occupy huge bandwidths with very low power spectral densities. This feature makes 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 first derive the bit error rate (BER) of a multiuser and multipath UWB system in the presence of a TEQ at the receiver front end. This BER is then written in a form suitable for traditional optimization. We then present a TEQ design which minimizes the BER of the system to perform efficient channel shortening. The performance of the proposed algorithm is compared with some generic TEQ designs and other Rake structures in UWB channels. It is shown that the proposed algorithm maintains a lower BER along with efficiently shortening the channel.