Comment by jasonwatkinspdx

All RF protocols have some provision for signal acquisition. It can take a bunch of forms but what it nets out to is the oscillator in the receiver can acquire the signal from the sender. A simple example of this is "pilot" signals or prefixes that have an easily recognizable structure and allow the receiver to align to the sender in the clock recovery sense. So the receiver needs a little extra tunable bandwidth and to run the messy intermediates through something like a convolution filter, but it can latch on easily. This is early days of radio technology, like mid century post war.