Fft calculation example

1. How do you calculate FFT?
2. How many computations are in a FFT?
3. What is FFT in simple terms?

How do you calculate FFT?

Signal Processing, Digital

In the FFT formula, the DFT equation X(k) = ∑x(n)W_N^nk is decomposed into a number of short transforms and then recombined. The basic FFT formulas are called radix-2 or radix-4 although other radix-r forms can be found for r = 2^k, r > 4.

How many computations are in a FFT?

Each pair requires 4 additions and 4 multiplications, giving a total number of computations equaling 8N4=N2. This number of computations does not change from stage to stage. Because the number of stages, the number of times the length can be divided by two, equals log2N, the complexity of the FFT is O(NlogN).

What is FFT in simple terms?

The "Fast Fourier Transform" (FFT) is an important measurement method in the science of audio and acoustics measurement. It converts a signal into individual spectral components and thereby provides frequency information about the signal.