Design of nonlinear inverse systems by means of adaptive Volterra filters

A conventional linear filter increases nonlinear distortion when it is applied to the elimination of linear distortion of a system. This paper proposes an off-line design method of an adaptive Volterra filter that eliminates linear and nonlinear distortions at the same time. This paper analyzes, by using the Volterra theory, the mechanism of increase of nonlinear distortion due to the elimination of linear distortion. This paper also analyzes, again using the Volterra theory, a signal component caused by the tandem connection of a nonlinear system and gives a design method for a nonlinear inverse system that eliminates nonlinear distortion. The proposed method reduces the nonlinear distortions by as much as 70 dB. The design time of the method is much shorter than that of existing conventional methods. (C) 1997 Scripta Technica, Inc.