Linearization of Time-Varying Nonlinear Systems Using A Modified Linear Iterative Method

TL;DR

This paper introduces a real-time capable linearization method for time-varying nonlinear systems using a modified linear iterative approach, improving signal distortion correction and robustness.

Contribution

It presents a novel linearization technique based on a modified iterative method for Volterra series, with convergence conditions and practical demonstration.

Findings

Effective linearization of a nonlinear amplifier with distorted signals

Demonstrates advantageous convergence and robustness

Applicable to time-varying nonlinear systems

Abstract

The linearization of nonlinear systems is an important digital enhancement technique. In this paper, a real-time capable post- and pre-linearization method for the widely applicable time-varying discrete-time Volterra series is presented. To this end, an alternative view on the Volterra series is established, which enables the utilization of certain modified linear iterative methods for linearization. For one particular linear iterative method, the Richardson iteration, the corresponding post- and pre-linearizers are discussed in detail. It is motivated that the resulting algorithm can be regarded as a generalization of some existing methods. Furthermore, a simply verifiable condition for convergence is presented, which allows the straightforward evaluation of applicability. The proposed method is demonstrated by means of the linearization of a time-varying nonlinear amplifier, which highlights its capability of linearizing significantly distorted signals, illustrates the advantageous convergence behavior, and depicts its robustness against modeling errors.