Architectures for lattice structure based orthonormal discrete wavelet transforms

This paper presents efficient single-rate architectures for the orthonormal discrete wavelet transform (DWT). Folded and digit-serial architectures are derived from an efficient lattice implementation of two-channel FIR paraunitary systems known as the quadrature mirror filter (QMF) lattice. Folded architectures are derived by applying systematic folding techniques to multirate systems. For digit-serial architectures, we show that any two-channel subband system can be implemented using digit-serial processing techniques by utilizing the polyphase decomposition. Using this result, we describe an orthonormal DWT architecture which uses the QMF lattice structure and digit-serial processing techniques. The number of multipliers and adders required for both the folded and digit-serial lattice-based architectures approaches one-half the number required to implement similar systems based on direct-form filter implementations as the order of the FIR filters becomes large. This makes folded and digit-serial QMF lattice structures attractive choices for applications of the orthonormal DWT which require low area and low power dissipation