EFFECTS OF HARMONIC COMPONENTS GENERATED BY POLYNOMIAL PREPROCESSOR IN ACOUSTIC ECHO CONTROL

The aliasing problem in adaptive polynomial flltering is described and two difierent approaches to overcome it are proposed. The polynomial model considered is the separable homogeneous Volterra fllter, which is a cascade of polynomial preprocessor and a linear fllter. The polynomial preprocessor produces higher order harmonics to the output and they are aliased to lower frequencies. It is shown that if the aliasing is taken into account the performance of acoustic echo cancelers can be improved by 1{2 dB.