Perfect reconstruction nonuniform filter banks with linear phase

A nonuniform filter bank divides the band nonuniformly according to the pro perties of the signal, which is expected to be more effective than a unifor m division filter bank in applications such as subband coding. The structur e of the nonuniform filter bank, however, is complex. In particular, no inv estigation has been made of the linear-phase nonuniform filter bank. From s uch a viewpoint, this paper considers a perfect reconstruction nonuniform f ilter bank with linear phase, and derives the necessary and sufficient cond itions for a perfect reconstruction system as well as for a linear-phase fi lter. Then, a design method is presented based on the amplitude distortion in the frequency domain and the elimination of aliasing. By the proposed me thod, the nonuniform filter bank can be designed directly without using the equivalent transformation to the uniform filter bank. (C) 2000 Scripta Tec hnica, Electron Comm Jpn Pt 3, 83(8): 103-114, 2000.