Performance analysis of adaptive beamforming algorithm for smart antenna system

Adaptive array antenna systems are currently the subject of intense research interest for radar and communications applications. In addition, algorithms that follow the steepest descent method for adaptive beamforming are widely used in practice and popular for their computational simplicity. In this paper, the authors investigate the Least Mean Square (LMS) and Normalized Least Mean Square (NLMS) algorithms and proposea new scheme to overcome the shortcomings of existing algorithms for a robust smart antenna system. Simulations demonstrate that Active Tap Detection-Normalized Least Mean Square (ATD-NLMS) has the highest convergence rate as it estimates only the active taps for the beamformer. The beamwidth is significantly narrower with higher gain and almost no side lobes in comparison to the other two existing algorithms which lead to a better system efficiency of smart antenna system.