Parametrization of all optimal solutions for 2-block H∞ control problem

All optimal solutions of the 2-block H^∞ control problem are parametrized by an alternative approach in this paper. The diagonalizing matrix pair is used to connect the successive layers as well as to characterize the sub-layers. The parameter which is one of the suboptimal solutions of the sub-layers parametrizes all optimal solutions. It reflects the performance of the sub-layers simultaneously. The concept in synthesis of the sub-layers becomes implementable in computation.