A nonlinear adaptive noise canceller

The purpose of this paper is to describe a nonlinear system structure that can be used to perform adaptive interference cancellation. It is shown that a nonlinear extension of the conventional tapped delay line filter is amenable to adaptation with the LMS algorithm, and can be used to represent a class of nonlinear systems. Experimental results are presented illustrating cases where nonlinear interference cancelling is superior to conventional linear cancelling. The generalization of the conventional linear structure to the nonlinear one described appears to provide a significant performance advantage in certain cases. At the same time, the complicated analyses usually associated with optimal nonlinear systems and the requirement to measure higher-order statistical parameters are avoided by virtue of the LMS algorithm.