NSF-funded research is designed to help improve security, safety and other vital activities by enabling the location of objects that don’t have radio frequency devices

Hongbin Li, professor in the Department of Electrical and Computer Engineering at Stevens Institute of Technology, is actively working to enable passive radio frequency (RF) sensing, using existing wireless signals to locate objects that don’t have their own RF devices. To that end, Li has been granted a $360,000 award from the National Science Foundation for his research study, “Leveraging Bandwidth-Rich Wireless Signals for Passive Localization of RF-Silent Mobile Objects.”

Assistant Professor Hongbin LiThe world is already full of wireless radio frequency signals from WiFi, cellular, radio, television and satellites. These signals, designed for communication with RF-equipped devices, also have the potential to support passive RF sensing for tracking, monitoring heart and breathing rate, detecting falls, and other activities involving “RF-silent” objects that are not equipped to communicate through radio frequencies. 

Through this project, Li will work to develop techniques to locate passive RF-silent mobile objects in complex indoor and outdoor settings through harnessing bandwidth-rich wireless signals such as 5G/6G cellular and WiFi-6/7, multi-static sensing geometry and new graph-theoretic techniques. The results of his research may support improved security and surveillance, indoor or outdoor traffic monitoring, search and rescue operations, location-based services and health and wellness. 

"Passive radio frequency sensing is environmentally green since it does not require dedicated RF transmitters,” Li said. “It is non-intrusive and economical. Research outcomes can potentially be integrated with existing wireless networks, enabling service providers to offer both wireless communication and RF sensing services to their customers."