On normalized Bezout fractions of distributed LTI systems

The Hardy space H/sub infinity / and Bezout fractions are introduced. Some properties of transfer function matrices with entries in the Nevanlinna class are discussed. Shift-invariant subspaces in the Hardy space H/sub 2//sup k /are introduced, and the existence of normalized right Bezout fractions is proven. The existence of normalized left Bezout fractions and normalized Bezout fractions of discrete linear time-invariant (LTI) systems are considered. It is shown that if a transfer matrix with entries in the Nevanlinna class has a Bezout fraction, then it has a normalized one. This means that the full power of the theories developed by using normalized Bezout fractions can be applied to the transfer matrices with entries in the Nevanlinna class.<
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