Initially I was excited, because by coincidence I have to work on the exact same problem. Enhancing the precision, to enable gesture recognition without having to carry a device. My plan was to use WiFi and rebuild this project: http://www.washington.edu/news/2013/06/04/wi-fi-signals-enab...

We have built an Indoor-Navigation-System with a POI-Editor for OSM and Route-Planning algorithms and more.

The article is disappointing, because it doesn't tell much more than you already know by reading the title. Here's the original article: https://wncg.org/research/briefs/centimeter-accurate-low-pow...

Then there is also an even greater TED Talk by Todd Humphrey: http://www.ted.com/talks/todd_humphreys_how_to_fool_a_gps

You can find more about their plans for the VR-Application here: http://radionavlab.ae.utexas.edu/videos/280-precise-augmente...