Diversity of MRC frequency domain equalizer for single carrier UWB block transmission with direct sequence spreading

Ultra Wideband (UWB) technology has become an ideal candidate for wireless personal area network (WPAN). UWB channel is featured by rich multipath components, which means both serious inter-symbol interference (ISI) and great multipath diversity for high data rate communications. Single carrier block transmission with frequency domain equalization is an effective way to combat frequency selective channels. However linear equalization methods are hardly to achieve full diversity. And nonlinear equalization methods are usually much more complicated. Direct sequence spreading in time domain leads to repetition and interleaving in frequency domain. In this article, a direct sequence spreading frequency domain equalizer with maximal ratio combining (DS-MRC-FDE) is proposed for block transmission UWB systems. Both theoretical analysis and simulation results show that full diversity could be achieved by linear equalization complexity.