Nonlinear line echo cancellation using a simplified second order Volterra filter

This paper deals with nonlinearities in line echo cancellation. If a high attenuation of the echo signal is required, the nonlinear behaviour of the actual echo path has to be taken into account. As the echo path inherently has memory, the nonlinear approaches have to be capable to model nonlinear systems with memory. Adaptive Volterra filters represent a common method to deal with such systems. Unfortunately, they suffer from a high computational complexity. Therefore, we propose an adaptive structure representing a simplified realization of a special second order Volterra filter (SVF) and provide an efficient step-size control for speech input. For the given application this structure achieves the same performance as second order Volterra filters at remarkably reduced computational cost.