Efficient RLS Algorithms with Line Search Methods for Stereophonic Acoustic Echo Cancellation

The classical stereophonic acoustic echo cancellation (SAEC) setup requires the estimation of four acoustic impulse responses using four adaptive filters. The widely linear (WL) model was used in the past to simplify the manipulation of the SAEC scenarios, and allows the use of a single adaptive filter working with fewer complex valued signals and coefficients, requiring the same overall arithmetic resources. This paper compares the performances of the recursive least-squares (RLS) algorithm combined with several line search methods (LSMs) working within the WL framework. Simulation results are shown in order to demonstrate the performances of the proposed methods, and numerical estimations are presented regarding arithmetic complexities, with respect to practical applications and possible future developments.