Characterization of the solution to the optimal H∞ model reduction problem

Abstract

In this paper the H ∞ norm approximation of a given stable, proper, rational transfer function by a lower order stable proper rational transfer function is studied. The solution method is based on the authors observation that the H ∞ model reduction problem can be converted into a Hankel norm model reduction problem. A simple characterization of the solution to the optimal H ∞ model reduction problem is developed.