Frequency band characteristics of tree-structuredfilterbanks
Ömer Nezih Gerek, Metin N. Gürcan, A. Enis Çetin · Electronics Letters · 1996
A sub-band decomposition filter bank can be recursively used in a tree structure to divide the frequency domain into various subfrequency bands. The frequency bands of the sub-band signals have a counter intuitive order in such a decomposition. The authors show that the relationship between the frequency content and the index of a sub-band signal can be expressed by an extension of the Gray code.