Study on the operation time of FFT permutation algorithm

The input data need to be sorted before the in-situ operation of FFT(Fast Fourier Transform). The main methods include calculating the reversed data serial number according to the positive data serial number, calculating the reversed data serial number based on the previous reversed data serial number, and table look-up. Through the simulation on IAR and KEIL platforms, this paper studies the operation time of various algorithms. The experimental results are highly consistent on two platforms. The results show that the most direct and simplest table look-up method is obviously better than the other two methods in terms of the operation time.