A Recursive Fast Fourier Transformation Algorithm

In this letter a new composite filter-bank structure is presented for the efficient implementation of the recursive discrete transformation. This structure is based on a proper combination of the concepts of polyphase filtering and the last fourier transformation (FFT) algorithm. Its computational complexity is in direct correspondence with the FFT, and can be operated both in sliding and block-oriented modes. The inherent parallelism of this structure enables very high speed in practical implementations.