Excitation signal and radial basis function methods for use in extraction of nonlinear black-box behavioral models

Abstract

A method utilizes time-domain measurements of a nonlinear device to produce or extract a behavioral model from embeddings of these measurements. The resulting behavioral model of the nonlinear device is a black-box model that accommodates nonlinear devices with one or more input ports and one or more output ports. The black-box model is a functional form that is a closed form function of input variables that produces an output as opposed to a structural form. The method of producing a behavioral model comprises the steps of applying an input signal to the nonlinear device, sampling the input signal to produce input data, measuring a response of the device to produce output data, creating an embedded data set, fitting a function to the embedded data set, and verifying the fitted function. The method may apply a CDMA type input signal in the step of applying, and/or may fit a novel radial basis function in the step of fitting a function. The input signal is constructed from a single CDMA signal representation. The method of constructing is not dependent on knowledge of the behavioral model of the nonlinear device. The novel radial basis function may be determined using a modified gaussian function.