Recursive cost function adaptation for echo cancellation

The goal of this paper is to introduce the RCFA (recursive cost function adaptation) algorithm. The derivation of the new algorithm does not use an estimator of the instantaneous error as the previous CFA (cost function adaptation) algorithms did. In the RCFA case, the new error power is computing from the previous error power using an usual LMS recursive equation. The proposed method improves the sensitivity of the error power with respect to the noisy error, while the other benefits of the CFA algorithms in terms of the convergence speed and residual error remain. The properties of the new algorithm will be compared, using computer simulations, to standard LMS and least mean fourth (LMF). The effect of the parameters involved in the design of the error power adaptive subsystem is also discussed