A Hybrid Variable Step-Size MCMA Blind Equalizer Algorithm for QAM Signals

Abstract

Abstract: Blind equalization is a technique for adaptive equalization of a communication channel without the aid of the usual training sequence. The Modified Constant Modulus Algorithm (MCMA) is one of adaptive blind equalization algorithms. The step size in (MCMA) must be selected to get balancing between convergence rate and final accuracy (maladjustment). This paper proposes an enhanced technique based on an absolute difference error and iteration number to adjust a step size which is used in modified constant modulus algorithm (MCMA). The new proposed algorithm is called Combined Iteration and Absolute Error MCMA (CIAE-MCMA). It is observed from the simulation results that the proposed algorithm can speed up convergence rate and decreases steady state mean square error and performs significantly better than the conventional fixed-step size MCMA and other variable step size algorithms (VSS-MCMA).