A Dynamic Differential Phase Analysis Method for Wireless Sensing

Wireless sensing is an emerging technique, which could enable a receiver to sense surrounding target information, such as location, angle of arrival, activity, gesture, speed, and vital signs, by analyzing the influence of the target on the received signals. It empowers wireless receivers with the additional sensing ability and could provide rich context information for intelligent applications. Intuitively, if we can understand the variation law of the influenced signal and better observe it, we will definitely achieve better sensing performance. Unfortunately, as a fundamental issue, this problem has not yet been extensively explored. In this paper, we propose a dynamic differential phase analysis method to solve this issue. Specifically, we design a differential phase change rate metric to characterize the degree of target influence in the vicinity of the receiver, propose to utilize the dynamic differential phase as the observation to realize wireless sensing, and develop a scale-variable scheme to enlarge the influenced signals by changing the distance between adjacent receiving antennas. Experimental results in three typical wireless sensing systems confirm that the proposed method could not only guide us to achieve better sensing performance, but also strengthen our understanding on the nature of wireless sensing.