Unbiased plain gradient adaptive IIR notch filter for echo cancellation

An adaptive echo canceller based on adaptive IIR notch filter with unbiased plain gradient algorithm is proposed, for the echo cancellation in telephone network. The unbiased plain gradient algorithm employs the bias removal techniques to remove the bias existing in the estimated parameter, resulting in obtaining good estimate of parameter for the echo canceller. Simulation results show that the proposed canceller outperforms the canceller with the classical LMS algorithm in terms of echo return loss enhancement (ERLE).