Genetic algorithm assisted DS-UWB BPSK MMSE receiver

Abstract

Ultra Wide-band (UWB) in recent times draws much consideration as an indoor short range high-speed wireless communication technology for future networks. Direct sequence spread ultra-wide-band (DS-UWB) systems uses extremely short pulses and has the advantage of high path resolution and can get multi-path diversity. Mainly it is useful for indoor communication, which generates many multipaths. The effect of multipath components can be positively used, if rake structured receivers such as selective rake (S-rake) receiver is used. Unfortunately inter-symbol interference (ISI) will become a significant performance limitation when data rate is high. Adaptive algorithms such as Least-Mean-Square (LMS) based channel equalizer aim to minimize the Inter symbol Interference (ISI) present in the transmission channel. However the adaptive algorithms suffer from long training time and undesirable local minima during training mode.A new adaptive channel equalizer using genetic algorithm (GA) is proposed here. This algorithm is suitably used to select the LMS convergence factor of the equalizer. The performance of the proposed channel equalizer is evaluated in terms of mean square error (MSE) and convergence rate and compared with analytical method.