upsampling
Interpolation
3.1 Basics
3.1.1 What are "upsampling" and "interpolation"?
"Upsampling" is the process of inserting zero-valued samples between original samples to increase the sampling rate. (This is called "zero-stuffing".) Upsampling adds to the original signal undesired spectral images which are centered on multiples of the original sampling rate.
