A Novel Minimax Algorithm for Multi-channel Active Noise Control System

Global active noise control (ANC) employs multichannel filtered-x least mean square (MCFxLMS) algorithm as it is more suitable algorithm to obtain large quiet zone. Minimax algorithm was proposed to counter the higher computational complexity faced in MCFxLMS based ANC by minimizing the square of the maximum of the absolute values of residual noise at the error microphones. However, the minimax approach leads to inferior performance in terms of convergence as well as noise reduction. Also, the classical minimax approach offers little flexibility in adjusting the ANC performance. In this paper, a novel minimax algorithm is proposed in order to tackle these shortcomings of conventional minimax algorithm at a cost of increase in computational complexity as compared to conventional minimax algorithm. The performance of the proposed approach is evaluated and compared with classical minimax for global noise reduction in a 2-dimensional quiet zone of size 1 m x 1 m in a 3-dimensional reverberant room. The proposed scheme is able to improve the performance with much reduced computational complexity as compared to MCFxLMS though with increased computational complexity as compared to classical minimax approach.