Relative localization without beacon nodes based on TDOA distance measurement

In the scenarios of MICE (Meetings, Incentives, Conventions and Exhibitions) and other on-site face-to-face communications, one requirement is to conveniently discover surrounding PoI (People-of-Interest). In this paper, one relative localization method is proposed to accurately obtain the distances and azimuths from any person (one node) to his/her PoI (another node) in proximity. Specifically, the distances are firstly measured based on TDOA (Time Difference of Arrival), and the azimuths among nodes are calculated subsequently. Using the proposed method, the relative locations (distances and azimuths) of PoI can be derived for all individual PoI in the system, without using pre-deployed beacons or fixed infrastructures with known coordinates. Finally, the performances are evaluated via a field test in office environment with obstacles, moving-around people and random noises, which demonstrates a relative localization error within 20cm.