Zero-padding the middle of a signal

1. What does zero padding do to a signal?
2. What does zero padding do in FFT?
3. Does zero padding reduce spectral leakage?
4. Why should I zero pad a signal before taking the Fourier transform?
5. Does zero padding increase frequency resolution?

What does zero padding do to a signal?

Zero padding enables you to obtain more accurate amplitude estimates of resolvable signal components. On the other hand, zero padding does not improve the spectral (frequency) resolution of the DFT. The resolution is determined by the number of samples and the sample rate.

What does zero padding do in FFT?

``Zero-padding'' means adding additional zeros to a sample of data (after the data has been windowed, if applicable). For example, you may have 1023 data points, but you might want to run a 1024 point FFT or even a 2048 point FFT.

Does zero padding reduce spectral leakage?

Zero-padding a signal does not reveal more information about the spectrum, but it only interpolates between the frequency bins that would occur when no zero-padding is applied. In particular, zero-padding does not increase the spectral resolution.

Why should I zero pad a signal before taking the Fourier transform?

Zero padding allows one to use a longer FFT, which will produce a longer FFT result vector. A longer FFT result has more frequency bins that are more closely spaced in frequency.

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.