Howtosignalprocessing
- How does the length of a signal affect the DFT?
- How does FFT length affect the spectrum?
- What is signal length FFT?
- What is Nfft in spectrogram?
How does the length of a signal affect the DFT?
The length N of the DFT is the number of frequency points that will result in the DFT output. Zero padding will result in more frequency samples, however this does not increase frequency resolution, it just interpolates samples in the DTFT.
How does FFT length affect the spectrum?
The selected FFT size directly affects the resolution of the resulting spectra. The number of spectral lines is always 1/2 of the selected FFT size. Thus a 1024 point FFT produces 512 output spectral lines. The frequency resolution of each spectral line is equal to the Sampling Rate divided by the FFT size.
What is signal length 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 is Nfft in spectrogram?
nfft tells you how many FFT points are desired to be computed per chunk. The default number of points is the largest of either 256, or floor(log2(N)) where N is the length of the signal. nfft also gives a measure of how fine-grained the frequency resolution will be.
