Design and performance analysis of adjustable window functions based cosine modulated filter banks

In this paper, design and comparative analysis of adjustable window functions based cosine modulated filter banks are analyzed. Four adjustable windows, viz., Kaiser window, Saramäki window, ultraspherical windows and Roarkʼs transitional window are used to design prototype filters. 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. These optimized filters are later cosine modulated to obtain filter banks. The performances of filter banks are compared on the basis of reconstruction error and aliasing error.