Realization of Nonlinear Acoustic Echo Cancellation by Subband Parallel Cascade Volterra Filter

In this paper, we propose low complexity realization of nonlinear acoustic echo cancellation. Generally, it is assumed that the acoustic echo path in hands free telecommunication systems is a linear system. However, the acoustic echo path in modern cellular phones has nonlinearity because the influence of nonlinear distortions of the low cost audio equipment is very large. In order to solve this problem, the nonlinear echo cancellation that includes the linearization system has been proposed. However, there is a problem of having huge computational complexity for convolution between the input signal and the 2nd-order Volterra kernel. Therefore, we propose a nonlinear echo cancellation which consists of subband parallel cascade realization of the 2nd-order Volterra kernel, and examine the validity through simulation results. Simulation results demonstrate that the proposed realization can substantially reduce the computational complexity while maintaining the same echo return loss enhancement as the conventional one.