[giomasce]

Link to the proof? Or at least, does the theorem has a well-known name?

[tripletao]

The Shannon–Hartley theorem. It assumes additive white Gaussian noise (which is a good model for most kinds of thermal-ish noise), and provides a bound on the channel capacity that practical codes closely approach.

https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...