Through‐the‐wall imaging using Wi‐Fi signals

In this work, the authors experimentally investigate the high‐resolution three‐dimensional through‐the‐wall imaging exploiting commodity Wi‐Fi signals in an indoor environment. The authors also provide physical insights into this novel imaging strategy, which has been derived from the Huygens' principle. In the authors’ experiments, a pair of antennas are used to acquire the Wi‐Fi signals reflected from the scene in a synthetic aperture mode. The classical filtered back propagation (FBP) algorithm is then used to form the image based on these signals. The authors use an IEEE 802.11n protocol wireless router working at 2.4 GHz with bandwidth of 20 MHz. It can be faithfully expected that such imaging technique can open an exciting new door for various practical applications including safety screening and others.