Howtosignalprocessing
- What is length of signal in FFT?
- What are the outputs of FFT?
- Why is FFT divided by length?
- What units does FFT return?
What is length of signal in FFT?
The correct size of the FFT lengths for a linear convolution, is Nfft=Lx+Ly−1, where obviously those lengths correspond to the length of your signals x and y.
What are the outputs of FFT?
These frequencies actually represent the frequencies of the two sine waves which generated the signal. The output of the Fourier transform is nothing more than a frequency domain view of the original time domain signal.
Why is FFT divided by length?
Accepted Answer
The Fourier transform is a sum-of-sines (and cosines), so to normalise the coefficients, divide by the integration time or length of the summation.
What units does FFT return?
If you take the Fourier transform of x(t) to get X(jw) , then the units of X(jw) are C*sec or C/Hz (according to the Fourier transform integral). If you use (abs(X(jw)))^2 , then the units are C^2*sec^2=C^2*sec/Hz .
