IDENTIFICATION OF POLYPERIODIC NONLINEAR SYSTEMSS

A method for identifying the Fourier-Volterra kernels of polyperiodic nonlinear systems by crosscorrelating the system output with prescribe d nonlinear transformations of a prescribed random input is introduced . A frequency-domain counterpart of this method, which can utilize a c omputationally efficient FFT algorithm to compute cross-spectra of the system output and prescribed nonlinear transformations of the input, is also introduced. With complex inputs, the methods apply to infinite -order systems with infinite memory. For real inputs, they apply only to finite-order systems.