Efficient methods for FFT calculations using prime factor algorithm
N. Kalaiarasi, A. Rathinam · 2011
FFT algorithms are mainly used for the calculation of DFT because they are preferred due to their increased speed and higher efficiency, which arises due to the fact that for the calculation of an N-pt DFT, the sequence is broken into several segments and the DFT for each segment is calculated. However, for this many redundant memory spaces and the Butterfly structures are required for DFT calculations. Grouping the identical twiddle factors of different stages together reduces the number of memory references and the storage space due to twiddle factors, therein reducing the number of clock cycles needed for the complete implementation of the algorithm. For further reduction combine the DIT at the initial stage and DIF at the final stage. This technique is referred as DITF. It combines both the benefits of DIT and DIF and thus reducing the memory reference. The DITF algorithm reduces the number of the complex additions and multiplications in the calculation and hence in turn reduces the computational time.