Aliasing effects on estimating transfer functions of quadratically nonlinear systems

Previous methods developed for estimating transfer functions in the frequency domain with stochastic inputs failed to completely establish the link between the frequency domain estimates and the true system coefficients. By taking aliasing effects into consideration, the authors develop a robust scheme to estimate the time domain system coefficients of a discrete-time linear-quadratic system via a frequency domain method. Furthermore, the estimation errors can be greatly reduced by eliminating the time-aliasing effect. The robustness of this method has been tested as well