A POLYNOMIAL SOLUTION TO THE SCALAR 4-BLOCK H-INFINITY GENERAL DISTANCE PROBLEM

The H-infinity mixed sensitivity with measurement noise problem is con sidered for the scalar case using a polynomial description. The proble m results in a 4-block general distance scalar problem which is solved in a general way by using a polynomial equation approach. As an examp le, the solution is then applied to the mixed sensitivity with measure ment noise problem where all relevant simplifications are carried out. The solution requires solving two spectral factorization problems and one linear polynomial equation. Further, new insight into the connect ions with the Nehari problem is provided.