Linear-Phase Cosine-Modulated Filter Banks without DC leakage

In this paper, we present a new class of linear-phase cosinemodulated filter banks. In contrast to the 2M band structure of the linear-phase DCT-II filter bank derived by Lin and Vaidyanathan, our filter bank has M bands and requires different prototype filters for the analysis and synthesis. Given the PR constraints of the bank, we derive a non-orthogonal lattice structure for implementing the polyphase components of the prototype filters. This structure shares similarities with the one of DCT-IV filter banks and automatically guarantees perfect reconstruction of the bank. It furthermore allows to specify the values of the filters’ frequency responses at certain frequencies, thus allowing the design of linearphase cosine-modulated filter banks without DC leakage. Since analysis and synthesis prototype filters are different, we investigate several cost functions for their design.