Improved Fractionally Spaced Constant Modulus Blind Equalization Algorithm
Jing Zhou Lu · Jisuanji fangzhen · 2012
To improve the robustness and achieve lower residual mean square error of the constant modulus algorithm(CMA) in underwater acoustic channels,an improved fractionally-spaced constant modulus algorithm(IFSE-CMA) was proposed.The new algorithm employed T/2 spaced sampling.The error function of CMA was replaced by a new one.The new error function was specifically designed for the low signal to noise ratio(SNR) which is commonly encountered in the underwater acoustic communication.Computer simulations based on a shallow water acoustic channel demonstrate that the new algorithm has the advantages of robustness under low SNR,over perform baud-spaced CMA(BSE-CMA) and fractionally-spaced CMA(FSE-CMA) in aspect of residual mean square error,and has fast convergence rate.The improved algorithm is suitable for shallow water acoustic channel which has lower SNR.