[salty_biscuits]

The biggest one I have run into is that the bandwith doesn't need to be contiguous. If you know the the important bits of the signal are contained in certain frequency bands then you can get much lower sampling rates. Basically why things like l1 reconstruction work.

[mwbajor]

Bandpass sampling is a regular technique used in the RF world to mix down a signal to its final IF or baseband frequency, digitally. In this case, you are undersampling but using a well defined signal that you have apriori knowledge of where it is before and after sampling.

https://en.wikipedia.org/wiki/Undersampling#:~:text=In%20sig....