Recently, ultra-wideband technology has been in the news again. From the Wikipedia article:
UWB transmissions transmit information by generating radio energy at specific time intervals and occupying a large bandwidth, thus enabling pulse-position or time modulation.
From other reading I've done, I've gotten the impression that UWB signals can be used in a way quite similar to radar which makes sense. (In that it seems relatively plausible that one could send out a known broad-spectrum signal and look for reflected returns that correlate well to what was sent.)
But how would UWB work for transmitting data between two transceivers? My impression is that the transmit power is weak enough and spread out enough that these devices are allowed by the FCC as ± a Part 15 unintentional radiator. Without sharing an exact timebase [at least, not initially?] how would a receiver discern signal pulses it should be interested in, versus other random broad-spectrum noise? And how many devices could be communicating simultaneously in a given area before the strategy falls apart?