**<< Previous page TOC INDEX Next page >>**

Stretch OperatorUnlike all previous operators, the operator maps a length signal to a length signal, where and are integers. We use “” instead of “” as the time index to underscore this fact.

Definition:Astretch by factoris defined by

Thus, to stretch a signal by the factor , insert zeros between each pair of samples. An example of a stretch by factor three is shown in Fig. 8.4. The example isThe stretch operator is used to describe and analyze

upsampling, i.e., increasing the sampling rate by an integer factor.