Oversampled Cosine Modulated Fi ter Banks with Linear Phase'"

Abstract- We introduce oversampled cosine modulated fil-ter banks (CMFBs) and a new classification of (oversam-pled or critically sampled) CMFBs as odd-stacked and even-stacked. We propose the new class of even-stacked CMFBs which allows both perfect reconstruction (PR) and linear phase filters in all channels. We formulate conditions for PR and show that any PR CMFB corresponds to a PR DFT fil-ter bank with twice the oversampling factor. We also show that the frame-theoretic properties of a CMFB and of the corresponding DFT filter bank are closely related. I