Oversampled filter banks based on polyphase submatrices
Hitoshi Kiya, Hiroyuki Kobayashi · Electronics and Communications in Japan (Part III Fundamental Electronic Science) · 1999
In many applications of the filter bank, often maximum thinning cannot be used. However, in comparison with maximally thinned filter banks, oversampled filter banks have not been studied very extensively. In this paper, the polyphase submatrix is defined. Based on this matrix representation, the perfect reconstruction condition for oversampled filter banks is provided. Based on this representation, the relationship to maximally thinned filter banks, the degrees of freedom in the design of oversampled filter banks, and the design condition for low-delay filter banks are given. Also, the representation of the DFT filter bank is extended. It is shown that a perfect reconstruction FIR DFT filter bank can be designed, which cannot be accomplished in the maximally thinned case. Finally, a design example confirms the effectiveness of the present method. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 82(6): 55–65, 1999