Hardware sharing in tree-structure QMF banks

In this paper, a hardware sharing method for multirate systems is presented. Using the proposed method, we successfully designed the architecture of a tree-structured quadrature mirror filter (QMF) bank, which can also be used to implement discrete wavelet transforms. The features of the resulted shared architectures are that they keep the same topology of the original non-shared one and requires less power for delay registers. Moreover, 100% utilization can also be achieved, if the input rate of the system is not required to be constant. Several techniques are used in the sharing method. The techniques include a parallel register duplication scheme, switch timing mapping and interconnection arrangement.