A novel approach for blind channel equalization

Abstract

The Constant Modulus Algorithm (CMA), while the most commonly used blind equalization technique, converges very slowly. The convergence rate of the CMA is quite sensitive to the adjustment of the step size parameter used in the update equation as in the Least Mean Squares (LMS) algorithm. A novel approach in adjusting the step size of the CMA using the fuzzy logic based outer loop controller is presented in this paper. It also presents a computational study and simulation results of this newly proposed algorithm compared to other variable step size CMA such as conventional CMA, Normalized CMA (N-CMA) [1], Modified CMA (M-CMA) [2], CMA-Soft Decision Directed (CMA-SDD) [3]. The simulation results have demonstrated that the proposed algorithm has considerably better performance than others. © 2008 Springer-Verlag Berlin Heidelberg.