Passive Wireless Sensing

Other Videos: [Walking] (need to download) [Body Swing] [Breathing] [Hand Gesture 1] [Hand Gesture 2] (AirGest)

Technology

The Passive Wireless Detection System uses software defined radio architecture, which includes proprietary signal processing and a graphic user interface. The hardware consists of a reference antennas and a surveillance antenna, the computing and display unit. The system detects the change if frequency of radio waves reflected off a moving object (Doppler effect).

Because WiFi signals (and other radio waves) propagate through walls, the system can be used to detect movement behind walls up to one foot thick. Detection is passive as there is no dedicated transmitter or emitted radiation from the unit itself resulting in a system that is covert and undetectable, small size and low power. In addition, there is no need for a spectrum license fee. The detection system offers great flexibility as the operational parameters can be changed and adjusted through a software update or a simple hardware plug-in. Currently, a demonstrator unit exists which has been successfully deployed in a normal urban environment to detect the presence and movement of a person behind a wall.

Patent

  • B. Tan, K. Woodbridge, and K. Chetty, P102447GB Passive Wi-Fi Sensing, filed in 2013, approved in 2015, UK and US, Referenced by Qualcomm. [Available online], For Biz Development

Publications

  1. W. Li, B. Tan, Y. Xu, R. Piechocki, "Log-likelihood Clustering Enabled Passive RF Sensing for Residential Activity Recognition", Submitted to IEEE Sensor Journal
  2. W. Li, Y. Xu, B. Tan, R. Piechocki, "Unsupervised Classification of Human Activity Using Passive Radar With Hidden Markov Models", to appear iWCMC 2017
  3. W. Li, B. Tan, R. Piechocki, "Passive Radar for Opportunistic Monitoring in e-Health Applications", IEEE Journal of Translational Engineering in Health and Medicine, 1st revision
  4. B. Tan, Q. Chen, K. Chetty, K. Woodbridge, "Combining Passive WiFi Sensing and Machine Learning Systems to Monitor Health, Activity, and Well-Being Within Nursing Homes" National Instruments Case Study, [Online]
  5. B. Tan, Q. Chen, W, Li, K. Chetty, K. Woodbridge, R. Piechocki, "Exploiting WiFi Channel State Information for Residential Healthcare Informatics" IEEE Communications Magazine, 2nd revision, 2017
  6. B. Tan, Q. Chen, K. Woodbridge, K. Chetty "AirGest – A New Interaction Modality for WiFi Devices" Ready for submitting
  7. Q. Chen, B. Tan, K. Woodbridge, K. Chetty "Activity Recognition Based on Micro-Doppler Signature with In-Home Wi-Fi" Healthcom 2016 [PDF]
  8. Q. Chen, K. Chetty, K. Woodbridge, B. Tan, "Signs of Life Detection using Wireless Passive Radar", for IEEE Radar Conference 2016 [PDF]
  9. B. Tan, K. Woodbridge, K. Chetty, "A Wireless Passive Radar System for Real Time Through-Wall Movement Detection", IEEE Transactions on Aerospace and Electronic Systems, 2016 [PDF]
  10. W. Li, B. Tan, R. Piechocki, I. Craddock "Opportunistic Physical Activity Monitoring Via Passive WiFi Radar", IEEE Healthcom 2016 [PDF]
  11. W. Li, B. Tan, R. Piechocki "Non-Contact Breathing Detection Using Passive Radar", in ICC 2016 [PDF]
  12. B. Tan, A. Burrows, R. Piechocki, I. Craddock, Q. Chen, K. Woodbridge, K. Chetty "Wi-Fi Based Passive Human Motion Sensing for In-Home Healthcare Applications", IEEE World Forum on Internet of Things, 2015 [PDF]
  13. Q. Chen, B. Tan, K. Woodbridge, K. Chetty, "Indoor Target Tracking Using High Doppler Resolution Passive Wi-Fi Radar", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) 2015 [PDF]
  14. B. Tan, "Tracking WiFi Signals to Passively See Through Walls Using NI USRP and LabVIEW", National Instrument Case Study, 2014 [Link]
  15. B. Tan, K. Woodbridge K. Chetty, "A Real-Time High Resolution Passive WiFi Doppler Radar and Its Applications" International Radar Conference 2014 [PDF]
  16. K. Chetty, B. Tan, K. Woodbridge, "A Real-Time Software Defined Wireless Passive Radar" IEEE Radar Conference 2014 [PDF]
  17. K. Chetty, G. E. Smith and K. Woodbridge, "Through-the-Wall Sensing of Personnel Using Passive Bistatic WiFi Radar at Standoff Distances," IEEE Transaction on Geoscience and Remote Sensing, 2012

Awards

  • National Instrument Engineering Impact Awards nominated in Biomedical (Global, 2015),
  • National Instrument Engineering Impact Awards winner in RF and Communications (Global, 2015), [Link]
  • National Instrument Engineering Impact Awards winner in Advanced Research (UK & Ireland, 2014), [Link]

People

Prof. Karl Woodbridge (UCL, Dept of Electronics and Electrical Engineering)

Dr. Kevin Chetty (UCL, Dept of Security and Crime Science)

Dr. Bo Tan (Coventry University, School of Computing, Electronics and Mathematics. UCL, Dept of Electronics and Electrical Engineering)

Mr. Qingchao Chen (UCL, Dept of Security and Crime Science)