Two-channel QMF bank without checkerboard effect and its lattice structure.

Filter banks are usually designed so that the perfect reconstruction condition is satisfied. This condition, however, is not always satisfied in actual applications. In such a case, the filter bank operates as a time-varying system, and checkerboard distortion is produced by the time-varying effect. This paper discusses the checkerboard effect in a two-channel filter bank, including the effect of finite word length implementation and the case in which the perfect reconstruction condition is not satisfied. The general condition for avoiding the checkerboard effect is formulated. A design procedure for a paraunitary QMF bank satisfying that condition, as well as an implementation by the lattice configuration, are shown. It is furthermore shown that the checkerboard effect can be minimized in a finite word length implementation by employing the proposed lattice configuration and adding a correction to the rotation angle. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 82(11): 74–85, 1999 [ABSTRACT FROM AUTHOR]