Power compensation in WLAN positioning using a smartphone

In regard to achieving accurate WLAN positioning, a model of the power absorption by a person was experimentally devised. Parameters of the model are estimated using maximum likelihood estimation (MLE), and the angle of power absorption is measured by a magnetic sensor built into a smartphone. On the basis of the measured angle, the proposed method compensates the power absorption and the influence of multipath fading. According to evaluations by experiment and simulation, positioning error of the proposed method is 28% to 32% lower than that of the conventional method, and the proposed method achieves RMSE of 2.26 m for sparse deployment of access points.