M-Channel Linear Phase Cosine Modulated Filter Banks with Perfect Reconstruction

A class of cosine modulated filter banks in which all the sub-band filters have linear phase is presented. It has only M bands compared to the M 2 channel structures so far reported in the literature. The filter bank uses only one prototype filter for both analysis and synthesis side and structurally guarantee perfect reconstruction property. The formulation is based on DCT-II. The necessary and sufficient conditions for the perfect reconstruction and linear phase are derived. Key-Words: Filter bank; Cosine modulation; Linear phase; Perfect reconstruction; Discrete cosine transform