State - space solution to the periodic multirate H 1 control problem :

A state-space solution to the H 1 control problem for periodic multirate systems is presented. The solution is based on the lifting method, where an equivalent time-invariant system description is derived for the original periodic multirate problem. The H 1-optimal controller for the multirate system is expressed in terms of two algebraic Riccati equations. The so-called causality constraints are represented by a set of positive deenite-ness conditions and coupling criteria.