Efficient Implementation of 2<tex>$times$</tex>Oversampled Exponentially Modulated Filter Banks

Abstract

This paper studies 2times oversampled exponentially modulated filter banks because they can be a useful solution for various communications signal processing problems. At first, the perfect reconstruction (PR) property of this kind of 2M-channel complex modulated filter bank is proven by using the results of M-channel PR cosine-/sine-modulated filter banks (CMFBs/SMFBs). Then, two efficient implementation structures are developed. The computational complexities of CMFB/SMFB-based and discrete Fourier transform (DFT)-based realizations are practically the same when comparing the required number of multiplications and additions. However, the DFT-based structures can be further simplified by using an intuitive spectral interpretation. This results in the modified filter bank part that requires less arithmetic operations than the original one