Uniform filter banks with nonuniform bands: post-processing design

In this paper, uniform, critically decimated lter banks are used to approximate nonuniform lter banks wherein di erent lters have approximately the same magnitude response, but di erent phase, thus forming a linear periodically timevarying lter whose characteristics are similar to those of a nonuniform bank. This is done by post-processing a number of selected subbands of a uniform bank using a special synthesis lter bank, which combines the selected bands into one. Design methods for the post-processing stage are discussed and design examples are presented.