Interpolation by zero padding FFT

1. What does zero padding do to FFT?
2. How do you interpolate FFT?
3. What is the effect of zero padding in frequency domain?
4. How does zero padding increase frequency resolution?

What does zero padding do to FFT?

In addition to making the total number of samples a power of two so that faster computation is made possible by using the fast Fourier transform (FFT), zero padding can lead to an interpolated FFT result, which can produce a higher display resolution.

How do you interpolate FFT?

The fastest way to compute a single interpolated FFT spectral sample at frequency k is to merely compute a brute force N‑point DFT of the original x(n) time samples using: where, again, 0 ≤ k ≤ N‑1, and k is not an integer. Assuming the x(n) input in Eq. (6) is real-only, the computational workload comparison of Eq.

What is the effect of zero padding in frequency domain?

In this case, we can say “zero padding in the frequency domain results in an increased sampling rate in the time domain”.

How does zero padding increase frequency resolution?

In summary, the use of zero-padding corresponds to the time-limited assumption for the data frame, and more zero-padding yields denser interpolation of the frequency samples around the unit circle. Sometimes people will say that zero-padding in the time domain yields higher spectral resolution in the frequency domain.