Upsampling zero padding

1. What is padding with zeros?
2. What is the use for zero padding in DFT?
3. What is the effect of zero padding in frequency domain?
4. What happens in upsampling?

What is padding with zeros?

Zero padding is a technique typically employed to make the size of the input sequence equal to a power of two. 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.

What is the use for zero padding in DFT?

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 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”.

What happens in upsampling?

Upsampling is the process of inserting zero-valued samples between original samples to increase the sampling rate. (This is sometimes called “zero-stuffing”.) This kind of upsampling adds undesired spectral images to the original signal, which are centered on multiples of the original sampling rate.