Practical variable step-size adaptive algorithms for echo cancellation

The most common algorithms used for echo cancellation are the normalized least-mean-square (NLMS) and the affine projection (AP). The classical versions of these algorithms use a constant step-size parameter and need to establish a tradeoff between several performance criteria e.g., high convergence rate versus low misadjustment. In this paper, we present a class of variable step-size NLMS and AP algorithms, which are designed to recover the near-end signal from the error of the adaptive filter. The simulation results indicate a robust behavior of these algorithms against the presence of the near-end signal.