Bit reverse unscrambling for a radix-2MFFT

The traditional Cooley-Tukey and the prime factor FFT algorithms either produce the output in scrambled order or the input data order must be prescrambled. Several methods for scrambling and unscrambling the DFT are presented. The new result in this paper is the observation that the radix-4, radix-8, or any radix-2^mFFT can be modified to give the output in the same bit-reversed order as the radix-2 FFT.