A new frequency-domain analysis framework for nonlinear time-varying systems is introduced based on parametric time-varying nonlinear autoregressive with exogenous input models. It is shown how the time-varying effects can be mapped to the generalized frequency response functions (FRFs) to track nonlinear features in frequency, such as intermodulation and energy transfer effects. A new mapping to the nonlinear output FRF is also introduced. A simulated example and the application to intracranial electroencephalogram data are used to illustrate the theoretical results.
- Frequency response functions (FRFs)
- nonlinear and nonstationary systems
- spectral analysis
- system identification
- time-varying systems
ASJC Scopus subject areas
- Biomedical Engineering