xD-Track: Leveraging multi-dimensional information for passive Wi-Fi tracking

Yaxiong Xie, Jie Xiong, Mo Li, Kyle Jamieson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

39 Scopus citations


We describe the design and implementation of xD-Track, the first practical Wi-Fi based device-free localization system that employs a simultaneous and joint estimation of time-of-flight, angle-of-arrival, angle-of-departure, and Doppler shift to fully characterize the wireless channel between a sender and receiver. Using this full characterization, xD-Track introduces novel methods to measure and isolate the signal path that reflects off a person of interest, allowing it to localize a human with just a single pair of access points, or a single client-access point pair. Searching the multiple dimensions to accomplish the above is highly computationally burdensome, so xD-Track introduces novel methods to prune computational requirements, making our approach suitable for real-time person tracking. We implement xD-Track on the WARP software-defined radio platform and evaluate in a cluttered office environment. Experiments tracking people moving indoors demonstrate a 230% angle-of-arrival accuracy improvement and a 98% end-to-end tracking accuracy improvement over the state of the art localization scheme SpotFi, adapted for device-free localization. The general platform we propose can be easily extended for other applications including gesture recognition and Wi-Fi imaging to significantly improve performance.

Original languageEnglish (US)
Title of host publicationProceedings of the 3rd Workshop on Hot Topics in Wireless, HotWireless 2016
PublisherAssociation for Computing Machinery
Number of pages5
ISBN (Print)9781450342513
StatePublished - Oct 3 2016
Event3rd ACM Workshop on Hot Topics in Wireless, HotWireless 2016 - New York, United States
Duration: Oct 3 2016Oct 7 2016

Publication series

NameProceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM


Other3rd ACM Workshop on Hot Topics in Wireless, HotWireless 2016
Country/TerritoryUnited States
CityNew York

All Science Journal Classification (ASJC) codes

  • Computer Networks and Communications
  • Hardware and Architecture
  • Software


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