Biorthogonal Cosine-Modulated Filter Banks without DC leakage

In this paper, we present a structure for implementing the polyphase filters of biorthogonal modulated filter banks that automatically guarantees perfect reconstruction (PR) of the filter bank and furthermore allows to specify the values of the filters' frequency responses at certain frequencies. Thus, modulated filter banks without DC leakage can be designed. The new structure is based on lifting schemes for the polyphase filters and DC leakage can be avoided very easily when reducing the number of lifting coefficients that can be freely chosen and used for filter optimization. The great advantage of the new method is that we do not have to take constraints into consideration when optimizing the prototype filter, but PR and specified zeros are structure inherent.