Synthesis of QMF Bank Using a New Window Family

A new combinational window family for the design of prototype FIR filter of two-channel Quadrature Mirror Filter (QMF) bank is introduced. One variable window, viz., Kaiser Window is also used to design prototype filters. The design equations of variable window function based filter banks is also given in this article. Reconstruction error, which is used as an objective function, is minimized by optimizing the cutoff frequency of designed prototype filters. The Gradient based iterative optimization algorithm is used. The performances of filter banks designed with these window functions are compared on the basis of reconstruction error. The proposed combinational window provides the QMF bank with better reconstruction error.