Almostallcontrolsystemsarerealizedusingdiscretized(discrete-timeanddiscrete-value,i.e.,digital)signals.However,analysisanddesignmethodsfordiscretized/quantizedcontrolsystemsarenotalwaysestablished.Theanalyticaltreatmentoflineardiscrete-time(sampled-data)controlsystemswasdevelopedinthe1950san