Scalable VLSI architectures for lattice structure-based discrete wavelet transform

In this paper, we develop a scalable VLSI architecture employing a two-channel quadrature mirror filter (QMF) lattice for the one-dimensional (1-D) discrete wavelet transform (DWT). We begin with the development of systematic scheduling, which determines the filtering instants of each resolution level, on the basis of a binary tree. Then input-output relation between lattices of the QMF bank is derived, and a new structure for the data format converter (DFC) which controls the data transfer between resolution levels is proposed. In addition, implementation of a delay control unit (DCU) that controls the delay between lattices of the QMF is proposed. The structures for the DFC and DCU are regular, scalable, and require a minimum number of registers, and thereby lead to an efficient and scalable architecture for the DWT. A scalable architecture for the inverse DWT is also developed in a similar manner. Finally, pipelining of the proposed architecture is considered.