Abstract: TDOA(Time Difference of Arrival) and AOA(Angel of Arrival) methods require additional sensing mechanisms and have poor positioning accuracy used in WiFi environment, so a novel TDOAAOE hybrid positioning algorithm was proposed. The proposed algorithm used the AOE (Angle of Emission) information instead of AOA information to estimate the position of a WiFi-based mobile terminal. In this method, access points emitted signals with angle information encoded in beacon packets through directional antennas; which was rotated by motors. WiFi-based mobile devices estimated angles of the access points by receiving and decoding these beacon packets, which calculated the position themselves. This method integrated time-difference idea of TDOA method to decrease the angular measuring error without any additional sensors. Simulation results indicate that the proposed hybrid algorithm performs much better than TDOA and AOA method in terms of positioning accuracy and deployment costs.

Key words: WiFi, TDOA algorithm, AOE algorithm, positioning technique