Through the wall sensing of personnel using passive bistatic wifi radar at standoff distances

• In this paper,we investigate the feasibility of incooperatively and covertly detecting people moving behind walls using passive bistatic Wi-Fi radar at standoff distances.A series of experiments was conducted in MATLAB which involved creating personnel targets that are supposed to move inside a building within the coverage area of a Wi-Fi access point.These targets were monitored using a passive multistatic receiver, and the data were processed to yield range and Doppler information.

• The results presented show the through-the-wall (TTW) detections of moving personnel using passive Wi-Fi radar.The measured Doppler shifts agree with those predicted by bistatic theory.Further analysis of the data revealed that the system is limited by the signal-to-interference ratio(SIR) and not the signal-to-noise ratio.We have also used a matched filter as an interference suppression technique that can improve the SIR by approximately 19 dB.These encouraging initial findings demonstrate the potential for using passive.