Uniform filter banks with nonuniform bands: post-processing design

In this paper, uniform, critically decimated filter banks are used to approximate nonuniform filter banks wherein different filters have approximately the same magnitude response, but different phase, thus forming a linear periodically time-varying filter 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 filter bank, which combines the selected bands into one. Design methods for the post-processing stage are discussed and design examples are presented.