DFT zero-padding of signals starting before n=0

1. How does zero padding affect the DFT?
2. Why should I zero pad a signal before taking the Fourier transform?
3. How does zero padding work?
4. What is the effect of zero padding in frequency domain?

How does zero padding affect the DFT?

You can interpolate the DFT by zero padding. 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.

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.

How does zero padding work?

In zero padding, you add zeros to the end of the input sequence so that the total number of samples is equal to the next higher power of two. For example, if you have 10 samples of a signal, you can add six zeros to make the total number of samples equal to 16, or 32, which is a power of two.

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”.