Multirate sampled-data systems: All H-infinity suboptimal controllers and the minimum entropy controller

For a general multirate sampled-data (SD) system, the authors characterize explicitly the set of all causal, stabilizing controllers that achieve a ce rtain H-infinity norm bound;:moreover, they give explicitly a particular co ntroller that further minimizes an entropy function for the SD system. The characterization lays the groundwork for synthesizing multirate control sys tems with multiple/mixed control specifications.