The design of indoor positioning prototype based on Wi-Fi

Indoor positioning has wide prospects in emergency positioning, public safety, and exhibition services and has become a research focus. This paper presents a 2D indoor positioning system based on Wi-Fi and TDOA on USRP platform. Meanwhile, the sending and receiving of Wi-Fi signal are implemented for measurement and the algorithm of frequency offset estimation, initial phase estimation and the cross correlation method are introduced. At last, experiments show that it could work and display correctly and reach an accuracy and precision of 0.3 m.