Nonlinear acoustic echo canceller with DABNET + FIR structure

This work proposes a general nonlinear digital filter structure for nonlinear acoustic echo cancellation applications. It is constructed under the assumption that the nonlinearity in typical hands-free speakerphones is of a localized nature then followed by a linear room impulse response. By doing so, the proposed structure is made upon of a nonlinear discrete dynamic model cascaded with a FIR filter. The DABNet model is able to approximate the nonlinearity present in the system to any extent, while the FIR deals with the room impulse response. Comparisons of the echo canceller implemented with the DABNet + FIR show a significative performance improvement against the linear FIR echo canceller.