Deepak Vashisht (MIT), Swarun Kumar (CMU), Dina Katabi (MIT); Decimeter-Level Localization with a Single WiFi Access Point; In Proceedings of the 13th USENIX Symposium on Networked Systems Design and Implementation (NSDI ’16); 2016-03-16; 15 pages; landing.
Slides: Decimeter-Level Localization with a Single WiFi Access Point; 52 slides.
We present Chronos, a system that enables a single WiFi access point to localize clients to within tens of centimeters. Such a system can bring indoor position- ing to homes and small businesses which typically have a single access point.
The key enabler underlying Chronos is a novel algorithm that can compute sub-nanosecond time-of-flight using commodity WiFi cards. By multiplying the time-of-flight with the speed of light, a MIMO access point computes the distance between each of its antennas and the client, hence localizing it. Our implementation on commodity WiFi cards demonstrates that Chronos’s accuracy is comparable to state-of-the-art localization systems, which use four or five access points.
- AscTec Quadrotor, a drone
- Intel 5300 WiFi card
- Concept: Emulate a wideband radio by transmitting packets on different frequencies
- Angle of Arrival (AoA)
- Channel State Information (CSI)
- Non-uniform Discrete Fourier Transform (NDFT)