Estimation of second-order harmonic and intermodulation distortions using higher order spectra

A new higher-order spectral method for estimating second-order harmonic and intermodulation distortions of a nonlinear system, which can be described by a second-order Volterra series, is presented in this paper. The conventional higher-order spectral method, due to its embedded error, exhibits poor performance when the available data for estimating the second-order distortions are limited. By removing the embedded error, we show that, the new method is able to achieve better distortion estimates using significantly less amount of data. Nonlinear electronics components whose distortions need to be identified and measured can benefit from the new method.