Comparison of Hammerstein and Wiener systems for nonlinear acoustic echo cancelers in reverberant environments

The aim of this paper is the presentation of a comparative analysis of Hammerstein and Wiener systems used for the problem of compensation of the nonlinear distortion due to non-ideality of amplifiers and loudspeakers in acoustic echo cancellation. The proposed solutions consist in a cascade of a flexible nonlinear function, whose shape can be modified during the learning process, and a linear adaptive filter in different order, respectively. Two different type of flexible nonlinearities are tested. Some numerical results show the effectiveness of the proposed approaches and underline that the Hammerstein system has better performances than the Wiener one.