Reference tracking of nonlinear dynamic systems over AWGN channel using the describing function

This paper presents a new technique for mean square asymptotic reference tracking of nonlinear dynamic systems over Additive White Gaussian Noise (AWGN) channel. The nonlinear dynamic system has periodic outputs to sinusoidal inputs and is cascaded with a bandpass filter acting as encoder. Using the describing function method, the nonlinear dynamic system is represented by an equivalent linear dynamic system. Then, for this system, a mean square asymptotic reference tracking technique including an encoder, decoder and a controller is presented. It is shown that the proposed reference tracking technique results in mean square asymptotic reference tracking of nonlinear dynamic systems over AWGN channel. The satisfactory performance of the proposed reference tracking technique is illustrated using practical example simulations.