Put the input and the output of a Schmidt on an oscilloscope some time and tune across an HF band for weak digital (RTTY) signals. Then try adding crap to the input.
They'll pull perfect (digital, lossless) copy so far down in the (analog) noise that it can barely be heard. I'm sure there's better stuff these days (been a while).
Some casual reading of modern mobile phone signaling can make one's head spin. Best I could tell, every phone talk on top of each other and still the base is able to pick out individual data streams from the resulting soup.
The reason the base station and your phone need to know their distance is so the phone can transmit at the right time so its signal arrives at the base during the phones time slot and vice versa. That way the base can listen to other phones outside of that slot and the phone can not listen, saving energy, outside of the slot.
Put the input and the output of a Schmidt on an oscilloscope some time and tune across an HF band for weak digital (RTTY) signals. Then try adding crap to the input.
They'll pull perfect (digital, lossless) copy so far down in the (analog) noise that it can barely be heard. I'm sure there's better stuff these days (been a while).