A class of two-channel IIR/FIR filter banks
2000 (English)In: European Signal Processing Conference,2000, 2000, 1897-1900 p.Conference paper (Refereed)
A class of digital filter banks is introduced, in which the anal-ysis filters are half band IIR filters and the synthesis filters are FIR filters. The proposed filter bank satisfy approximately perfect reconstruction and has an exact linear phase. Further, it is suitable for applications where a very low complexity analysis filter bank is required. 1 INTRODUCTION This paper introduces a class of two-channel digital filter banks. This class belongs to the general class of two-channel maximally decimated filter banks shown in Fig. 1. It consists of an analysis filter bank, formed by the analysis filters H 0 (z) and H 1 (z), and a synthesis filter bank, formed by the synthesis filters G 0 (z) and G 1 (z). Downsamplers and upsamplers are present between the analysis and synthesis filter banks in order to reduce the computational workload. In the filter banks that have been proposed during the past decades, the analysis and synthesis filters have equal complexities , . This holds true for both IIR and FIR filter banks. In this paper, we propose a filter bank in which the analy-sis filters are half-band IIR filters whereas the synthesis filters are FIR filters. The complexity of the analysis filter bank is then very low whereas that of the synthesis filter bank is higher. However, the overall complexity is comparable to that of conventional filter banks. Such filter banks are of interest in applications where it is important to have a very low com-plexity for the analysis filter bank, and where one can afford a higher complexity in the synthesis filter bank. One is mixed discrete-time and digital filter banks for A/D-conversion, where the analysis filters are discrete-time filters, such as SC-filters. Here filter banks are used to reduce the distortion caused by gain-and phase mismatch errors which is inherent in parallel A/D converters. Since it is more difficult to imple-ment high-resolution discrete-time filters than digital filters, it is essential to use low-order analysis filters. The proposed class of filter banks are approximately per-fect reconstruction filter banks. They have magnitude distor-tion, but no phase distortion. Further, the aliasing can be made either exactly zero or approximately zero. In this paper we only consider the case in which the analysis filters have low complexity. Naturally, it is possible to let the synthesis filters be the low-complexity filters by simply interchanging the analysis and synthesis filters.
Place, publisher, year, edition, pages
2000. 1897-1900 p.
LiTH-ISY-R, ISSN 1400-3902 ; 2286
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-34416Local ID: 21425ISBN: 9521504471ISBN: 9521504439OAI: oai:DiVA.org:liu-34416DiVA: diva2:255264
European signal processing conference, 2000, Tampere, Finland