Consider two Manchester bits "00" = "0101" symbols as the preamble. Binary FSK modulation. When there is no signal (i.e. only noise on the channel) I envision the average sub-GHz receiver to immediately detect such preamble, because white noise will only yield 0/1 sequences of various lengths.
But this does not happen, no receiver detects such preambles from white noise. So how do they do it ?
But this does not happen, no receiver detects such preambles from white noise. So how do they do it ?