/spl Hscr//sub /spl infin// optimal interconnections and system design

In this paper, a behavioral version of the /spl Hscr//sub /spl infin// problem for continuous time, linear time invariant systems is formulated and solved. This general formulation, of which standard /spl Hscr//sub /spl infin// is a special case, provides added freedom in the design of optimal controllers, and can in fact be viewed as a means of designing optimal systems. In particular, the formulation presented allows for singular interconnections, which naturally occur when interconnecting systems.<>