Oversampled Wilson-type cosine modulated filter banks with linear phase
AuthorsHelmut Bölcskei and Franz Hlawatsch
ReferenceAsilomar Conf. on Signals, Systems, and Computers, Pacific Grove (CA), pp. 998-1002, Nov. 1996.
AbstractWe introduce Wilson filter banks (WFBs) as a new type of cosine modulated filter banks (CMFBs) corresponding to the discrete-time Wilson expansion. WFBs allow linear phase filters in all channels. We formulate perfect reconstruction (PR) conditions for oversampled and critically sampled WFBs and show that PR WFBs correspond to PR DFT filter banks with twice the oversampling factor. Generalizing WFBs, we then propose the new family of "even-stacked'' CMFBs allowing both PR and linear phase filters in all channels. This CMFB family contains WFBs as well as CMFBs recently introduced by Lin and Vaidyanathan. Finally, after extending conventional ("odd-stacked'') CMFBs to the oversampled case, we formulate unified PR conditions for both even- and odd-stacked, oversampled and critically sampled CMFBs. We show that PR CMFBs are always related to PR DFT filter banks of the same stacking type and with twice the oversampling factor.
KeywordsWilson expansion, cosine modulated filter bank, oversampling, linear phase, DFT, DCT
Download this document:
Copyright Notice: © 1996 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.