  The paper considers the suboptimal H-infinity control problem for a general
discrete-time system (whose transfer function matrix is allowed to be improper
or polynomial). The parametrization of output feedback controllers is given in
a realization-based setting, involves two generalized algebraic Riccati
equations, and features the same elegant simplicity of the standard (proper)
case. A relevant real-life numerical example proves the effectiveness of our
approach.
