On retrieval of intermodulated sinusoids

As intermodulated sinusoids are generated when a nonlinear system is subject to multiple fundamental frequencies, an approach is proposed in this paper to detect and to estimate, or simply to retrieve the intermodulated sinusoids. It is shown that both detection and estimation performance are improved by using the intermodulation relationship as an additional constraint. Although the periodogram method is used here, the approach can be readily modified to accommodate other frequency retrieval techniques. The implementation and the performance of this approach are demonstrated by simulation examples.