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 nonlineardynamic systems over Additive White Gaussian Noise (AWGN) channel. The nonlinear dynamic systemhas 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 equivalentlinear dynamic system. Then, for this system, a mean square asymptotic reference tracking techniqueincluding an encoder, decoder and a controller is presented. It is shown that the proposed referencetracking technique results in mean square asymptotic reference tracking of nonlinear dynamic systemsover AWGN channel. The satisfactory performance of the proposed reference tracking technique isillustrated using practical example simulations.