The application of slice polyspectra in nonlinear coupled harmonics analysis

For the nonstationary property of the mixed processes, Fourier series polyspectra and scaled polyperiodograms are introduced. We propose a method to estimate frequencies of cubic coupling harmonics in multiplicative noise with nonzero mean. Coupled frequencies can be obtained only by single record data and additive stationary noise is restrained without assumption of noise color and distribution. This approach is also adapted to the cases of kth-order coupled harmonics. Finally, the simulation results are given