Upsampling

The term up-sampling or up-sampling, within the context of digital signal processing implementation of a digital signal with a low sampling rate to a digital signal having a higher sampling rate, the signal information is preserved completely and unchanged. Upsampling is the reverse process of the down-sampling, and provides a shape of the sample rate conversion is that based on the mathematical function of the interpolation.

Method

Special case Integer interpolation

Upsampling indicated by the integer interpolation factor L, which expresses the ratio of the higher sampling rate of the sequence, y [ n] to the lower sampling rate of the input sequence x [n] at the output. The process is in two stages, as shown graphically in the illustration on the basis of an exemplary waveform:

Special case Rational Interpolation

In a non- integer interpolation factor, which can be expressed in the form, ie as a rational number, in the simplest case first upsampled by a factor of L, followed by a downsampling by a factor of M.

Any interpolation

From a mathematical point of view, all resampling problems to Interpolationsprobleme of numerical mathematics for which it provides various methods, eg Nearest neighbor, linear or spline interpolation.