Ladder scheme for perfect reconstruction modulated filter banks

A product form of the polyphase filter matrix with adjustable overall delay which allows perfect reconstruction, is given for orthogonal and biorthogonal modulated filter banks. The lifting scheme has been used, yielding to simpler implementation and allowing for in-place computations, i.e. the transform can be calculated without allocating auxiliary memory. The modulated filter bank system is decomposed into small subsystems in a ladder module configuration, which is profitable for many applications and easies the hardware implementation.