Identification of nearly paraunitary filter banks by the method of steepest descent

A method of designing nearly paraunitary filter banks in a subband domain Wiener filtering system is proposed. The design is based on the method of steepest descent and the paraunitary constraint which is imperative in filter bank design is imposed by suitable penalty functions. In spite of the fact that the resulting system is only nearly optimal, the proposed method is much simpler than previously proposed ones which impose the paraunitary constraint structurally