Stabilization and performance over singal-to-noise ratio constrained channels for NCSs with a disturbance observer

In this paper, a signal-to-noise ratio (SNR) method is used to deal with the stability and performance of the NCSs. Based on spectral factorization methods, we obtained a disturbance observer for the internal stability of the NCSs. The infimal SNR required for the NCSs is also given. A four-step iterative design procedure is proposed for the performance of the NCSs. Through iteration method, we obtained not only the optimal encoder and controller, but also the lower bound of SNR, despite the presence of uncertainties and square integrable noise. The results are illustrated through a numerical example.