Non-uniform DFT filter banks design with semi-definite programming

The uniform DFT filter banks are well studied but they are not always suitable for applications with non-uniform time frequency representations such as speech and image processing. Using an all-pass transformation, non-uniform spacings between the frequency subbands can be obtained. However, this introduces an additional aliasing due to non-linear phase distortions. This paper considers the design of non-uniform DFT filter banks with a specified group delay by minimising the aliasing whilst constraining the magnitude and phase distortions to a prescribed tolerance.