Feasibility and Limits of Wi-Fi Imaging

We explore the feasibility of achieving computational imaging using Wi-Fi signals. To achieve this, we leverage multi-path propagation that results in wireless signals bounc-ing off of objects before arriving at the receiver. These re-flections effectively light up the objects, which we use to per-form imaging. Our algorithms separate the multi-path reflec-tions from different objects into an image. They can also ex-tract depth information where objects in the same direction, but at different distances to the receiver, can be identified. We implement a prototype wireless receiver using USRP-N210s at 2.4 GHz and demonstrate that it can image objects such as leather couches and metallic shapes in line-of-sight and non-line-of-sight scenarios. We also demonstrate proof-of-concept applications including localization of static hu-mans and objects, without the need for tagging them with RF devices. Our results show that we can localize static hu-man subjects and metallic objects with a median accuracy of 26 and 15 cm respectively. Finally, we discuss the limits of our Wi-Fi based approach to imaging