Stability analysis of quantized feedback systems including optimal dynamic quantizers

This paper characterizes the stability of quantized feedback systems which contains optimal dynamic quantizers recently proposed by the authors. First, it is shown that the separation property of the quantizer-controller design, which is similar to the well-known separation property of the observer-controller design, holds in the quantized feedback systems. Next, based on this property, a necessary and sufficient condition for the stability is derived, where the stability is characterized by the poles/zeros of a linear feedback system to be quantized. Finally, we present suboptimal dynamic quantizers for which the resulting quantized feedback systems are always stable.