A new condition for output feedback decoupling of multivariable systems

A new rank condition for decoupling linear time-invariant multivariable systems is presented in this communication. The development of this condition is based on a one-to-one correspondence between state and output feedback decoupling control laws. This new criterion is expressed in terms of the open-loop parameters of the system, and does not require computation of the state feedback decoupling matrix, nor does it need any coordinate transformation.