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by smegsicle 1614 days ago
yeah- they call it time-domain-multiplex (or something) when you have different phones subscribing to listen at different points in time. Traditionally only the closest station would broadcast to each phone, because multiple stations broadcasting the same frequency leads to a mushy signal (on average). BUT, if all the stations are synced, they can align the phases of their signals so that they 'constructively interfere' into a brighter signal where the target phone is. The appropriate phase difference will be different for each phone, so each time slice signal is indeed tailored to each device-- they also need to track device movement, to best target the signal while it drives/walks around.

'beamforming' is a kind of confusing term, based on how a bunch of antennas in a tight group can time their phases into a cone of signal-- functionally aiming the antenna, but without anything physically moving. When the involved antennas are not in a tight group, the 'beam' that is formed starts to look less like a cone, and more like a target 'bean'... beanforming ....

anyway this demo page can show some of how it works, ui is kind of weird, type a number and click to add/move an antenna, hit 'r' and click to place the receiving device, 'o' to align the phases for best signal.. https://apenwarr.ca/beamlab/