I. Introduction
Quantized feedback control has drawn considerable attention due to limited capacity or security constraints on the networked control systems [1]– [5]. The coarsest quantizer that quadratically stabilises a linear time-invariant system was given in [1]. The coarsest quantization densities for the stabilization of a multivariable system was derived in [2]. The adaptive state feedback control for uncertain nonlinear systems with input quantized was investigated in [4], while the adaptive output feedback quantized control was addressed in [5].