par Yildirim, Hasan Can ;Storrer, Laurent ;Van Eeckhaute, Mathieu ;Desset, Claude;Louveaux, Jérôme;Horlin, François
Référence (02-04 October, 2019: Paris, France), Proc. of the 16th European Radar Conference, EuRAD
Publication Publié, 2019-10
Publication dans des actes
Résumé : Passive radars opportunistically capture communications signals to detect and track targets in the environment. Since Wi-Fi signals are widely available today and have a limited coverage, interestingly they can be used by passive radars in local areas. Until now, passive radars based on Wi-Fi signals have only been designed for 11a/b/n signals, which makes the radar range accuracy insufficient for object detection because of the limited signal bandwidth (20-40 MHz). This paper investigates the use of the recent 11ac signals of much wider bandwidth (80-160 MHz) to significantly improve the range accuracy. The radar works by observing the 11ac preamble transmitted at the beginning of each data burst by the Wi-Fi access point and applies either a two-dimensional cross-correlation or a frequency/time domain channel estimation to build range/Doppler maps of the radar scene. It is shown by simulations that radar processing based on time-domain channel estimation is the only viable solution due to the frequency guard bands introduced in the signal that cause significant sidelobes in the range/Doppler map. Experimental results held in our research lab confirm that the radar is capable of separating objects of small size in an indoor environment (a fan and an electric train in our experiments).