A novel variable step size soft decision feedback blind equalizer

The use of soft decisions to mitigate error propagation in a conventional decision feedback equalizer (DFE) is considered for application to blind equalization in this paper. A novel variable step size adjustment method has been proposed to improve the performance of the most commonly used blind equalization technique, constant modulus algorithm (CMA) in this study. Experimental studies have been performed to verify the performance of the proposed method using WiMAX (IEEE 802.16-2004) standard in 3.5 GHz frequency region. The obtained experimental simulation results have demonstrated that the proposed VSS-CMA algorithm with soft decision feedback has considerably better performance than conventional CMA, normalized CMA (N-CMA) and the other VSS-CMA algorithms.