# sampling a signal below nyquist rate

This question is for people working in multi rate signal processing. Using compressive sensing techniques, we can still recover a signal by sampling below nyquist rate(by decimating the signal). How is that possible, can you explain?

There are some answers available on the web , but I want to hear it from SE group.

phani tej

• Here's a brief, intuitive explanation. A signal with bandwidth $B$ can be represented by a stream of samples at rate $2B$. In general, these samples are uncorrelated: one sample doesn't tell you anything about the others. When the samples are correlated, you don't need so many samples. This is what is meant by a signal that has a lower dimensionality than a general signal of bandwidth $B$.
– MBaz
Jan 10 '15 at 15:24