Application specific efficient VLSI architectures for orthogonal single- and multiwavelet transforms

In this paper, efficient VLSI architectures for orthogonal wavelet transfor ms with respect to common applications are presented. One class of orthogon al wavelet transforms is the singlewavelet transform which is based on one scaling and one wavelet function. An important application of this transfor m is signal denoising for which an efficient VLSI implementation and layout is derived in this paper. Contrary to singlewavelets, orthogonal multiwave lets are based on several scaling and wavelet functions. Since they allow p roperties like compact support, regularity, orthogonality and symmetry, sim ultaneously, being impossible in the singlewavelet case, multiwavelets are well suited bases for image compression applications. With respect to an ef ficient implementation of these orthogonal wavelet transforms, approximatio ns of the exact rotation angles of the corresponding wavelet lattice filter s are used. The approximations are realized by elementary CORDIC rotations. This method reduces the number of shift and add operations significantly w ith no influence on the good performance of the transforms. VLSI architectu res for the computationally cheap transforms and related implementation asp ects are discussed and design examples from architectural level down to lay out are given.