Nonlinear channel blind equalization using hybrid genetic algorithm with simulated annealing

K e y w o r d s N o n l i n e a r channel, Blind equalization, Genetic algorithm, Simulated annealing. 1. I N T R O D U C T I O N In digital communication systems, data symbols are transmitted at regular intervals. Time dispersion caused by nonideal channel frequency response characteristics, or by multipath transmission, may create inter-symbol interference (ISI), and it has become a limiting factor in many communication environments. Furthermore, the nonlinear ISI that often arises in high-speed communication channels degrades the performance of the overall communication system [1]. To overcome the effects of nonlinear ISI and to achieve high-speed reliable communication, nonlinear channel equalization is necessary. The conventional approach to linear or nonlinear channel equalization requires an initial training period, with a known data sequence, to learn the channel characteristics. In contrast to standard equalization methods, the so-called blind (or self-recovering) equalization methods operate without a training sequence [2]. Because of its superiority, the blind equalization method 0895-7177/05/$ see front matter ~) 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.mcm.2004.05.006 Typeset by .A.A4S-TEX