GeoffreyM
Re:Artemis is building a 4G network in SF to prove its pCell tech works
on Tuesday February 24, 2015 @11:02AM (#9101379)
"Constructive and destructive interference from distributed transmitters" is basically the definition of a sparse phased array... and it suffers from the Thinned Array Curse. Every radio engineer sooner or later re-discovers this classic "curse" :)
Re:Artemis is building a 4G network in SF to prove its pCell tech works
on Tuesday February 24, 2015 @10:03AM (#9100871)
It's still snake oil. What they're designing is called a thinned phased array, or sparse phased array, see figure 19 in the white paper. Such design suffers from a major flaw known to any radar engineer: The Thinned Array curse. It even has a wikipedia article:
https://en.wikipedia.org/wiki/Thinned-array_curse
In layman terms, >99% of the power transmitted is lost to sidelobes and doesn't reach the intended users (1-a/A power is lost, if you want to get technical). Such design can carry a small number of users, operating very close to the environment noise floor. The maximum allowed number of users is approximately proportional to the number of transmitters. Each user added above this limit decrease the SNR for all users in the system, killing the communication for everyone. Not a sound design for a cellular system.
Phased-array design is complex and not always intuitive. Whoever invested in this company hasn't done proper due diligence.