Introduction - If you have any usage issues, please Google them yourself
DSP programming code, the FFT algorithm, classic! ! FFT an experimental and theoretical : formula (1) FFT formula FFT is not a new transformation, it is the discrete Fourier transform (DFT), a fast algorithm. As in the calculation of DFT at the complex multiplication required a four real multiplication and secondary real Adder; Adder required a complex real Adder II. Each Operational an X (k) needs time 4N complex multiplication and 2N 2 (N-1) = 2 (2N-1) Real Adder. Therefore, the whole operation would need a total DFT 4N ^ 2 times the actual amount of multiplication and N* 2 (2N-1) = 2N (2N-1 ) times the actual amount of additive. So, when calculating the number of multiplication and addition are the number and proportion of N ^ 2, when the big N, Operational capacity is substantial and