The research on new adaptive beamforming algorithms

In this paper, we propose a novel semi-blind algorithm and a novel transform domain algorithm. The feasibility, stability, complexity and other characteristics of the semi-blind algorithm were analyzed. The novel semi-blind algorithm integrates LMS (Least mean square) and CMA (Constant modulus algorithm). It uses the LMS algorithm, which is simple to implement and not computationally intensive, but with CMA initialization in order to ensure desirable robustness properties. Then the new transform domain least mean-square adaptive algorithm employing a new adaptive step size control technique is proposed. The variable step size approximates a theoretical optimal one based on a proposed cost function. As a result, considerable improvement in convergence speed is attained in early stages of convergence with small misadjustment near the optimum. Simulation experiments clearly demonstrate the enhanced convergence characteristics of the proposed algorithm.