TWIDDLE FACTOR MERGED FREQUENCY-DECIMAL FFT ALGORITHM——A NEW EXPLANATION OF THE RCFA

Twiddle factor merged frequency-decimal FFT algorithm—A new explanation of the RCFA

Merging the twiddle factors in two neighbouring stages for the frequency-decimal FFT algorithm, we can obtain the twiddle factor merged frequency-decimal FFT algorithm. The result is exactly the same as that of the Recursive Cyclotomic Factorization Algorithm (RCFA) derived by Martens (1984) by use of the theory of polynomial algebra. So it has the advantages of simple sturcture and high efficiency in computation. It is much easier to be understood and implemented by engineers than RCFA, and it is also easy to be generalized to the case of time-decimal FFT.