A new implementation of arbitrary-length cosine-modulated filter bank

In this paper, the fast implementation of cosine-modulated filter bank (CMFB) is revisited. A class of paraunitary CMFBs with arbitrary length is considered. By further reorganizing of the polyphase component matrix and using the linear-phase property of the prototype filter, we obtain a more efficient implementation structure for the CMFB, in which we use 2/spl times/2 lossless matrices instead of 2/spl times/1 ones. In the new implementation, the number of two-channel lossless lattices is reduced by a factor of two.