Abstract
This paper provides an analytical expression of the discrete-time H2performance limit based on state space representation. The obtained formula, similarly to its continuous-time counterpart, clarifies performance degradation caused by non-minimum phase properties of the plant. The derivation is not so strainghforward because of the theoretical difficulty arising from the definition of H2-space on the unit disc. The result can be interpreted intuitively by introducing the class of strictly causal controllers.
