An Elimination Method of the Nonlinear Distortion in Frequency Domain by the Volterra Filter

There are two types of distortion of the loudspeaker system, the linear and the nonlinear distortions. We have tried to eliminate the linear distortion by digital filters. However, the more quantity of the elimination of the linear distortion, results in the more quantity of the nonlinear distortion. Therefore in order to make a high quality audio system we need to eliminate both the linear and the nonlinear distortions at the same time. First, we have identified the loudspeaker system by the Volterra expansion which expresses the relationship between input and output signals, and then proposed the design method of the inverse system. The result of simulation shows that a decrease of the nonlinear distortion of about 100dB can be obtained by using the design method proposed here.