Novel approach to exact design of digital LDI allpass networks

A novel approach is proposed for the direct z-domain design and synthesis of arbitrary-order digital LDI allpass networks. This leads to the development of two LDI allpass network structures, one of which is completely new whereas the other has recently been derived indirectly by using the bilinear LDI design technique. Both structures lend themselves to fast two-cycle operation independent of the order of the corresponding transfer function. In addition, they are minimal in the number of digital multipliers and require only one unit-delay more than the minimum number possible.