Variable Step Size Normalized Least Mean Square Algorithm for Mobile Communication

This paper describes a robust variable step size normalized least mean square algorithm (VSSNLMSS) to enhance interference suppression in smart antenna system. The fixed step size normalized least mean square (NLMS) will result in a trade-off issue between convergence rate and steady-state mean square error (MSE) of NLMS algorithm. The purpose of a variable step-size normalized LMS algorithm is to solve the dilemma of fast convergence rate and low MSE. The proposed VSSNLMS algorithm reduces the MSE and shows faster convergence rate when compared to the conventional LMS and NLMS. Moreover, the enhanced performance of the new VSSNLMS algorithm is validated from the output beam pattern.