Comment by Sesse__
5 months ago
Indeed. The output of the beamforming algorithm is something like four (complex) numbers that you use to tell which of your radios to shout the loudest (and with what delay), which magically makes the signal become the strongest possible at wherever the device was last heard. And at an infinite amount of other places.
If you have MIMO, i.e., multiple signal streams, it will be more like an 4x4 matrix instead (how loud should radio X shout signal Y), and you'll not only optimize for “signal 1 should be the loudest possible at receiver 1” but _also_ “signal 1 should be at the _most quiet_ possible at receiver 2”.
The fact that cheap consumer devices are able to do this fairly reliably (one could even say it's pedestrian) at near-gigabit speeds says something about how insane our level of technology is.
I think it is the same kind of magic thinking about 5G that causes people to believe that those base stations somehow mysteriously know to within a couple of feet where a handset is located. That's just not how it works, at all. At best you could say that the interference pattern caused by a particular engagement of the radios has a local peak that - hopefully - coincides with the location of a particular handset. But there are countless such interference patterns and no single one will stand out to say 'that's the one', besides the impossibility of actually calculating the patterns because of the lack of knowledge about the environment.
It's also amusing to see lots of people state with great authority how simple it is to track down a transmitter, when in fact they've probably never so much as participated in a fox hunt, which can get quite interesting at higher frequencies and when not in open field.