Differential access points for indoor location estimation

Location positioning systems using Wi-Fi infrastructure are considered cost effective and practical solutions for indoor location tracking and estimation. However, accuracy deterioration due to environmental factors and the need for manual offline calibration limit the application of these systems. In this paper, a new method based on differential operation access points is proposed to eliminate the adverse effects of environmental factors on location estimation using Wi-Fi based systems. Experimental measurement results indicate that the proposed method can effectively reduce the positioning errors introduced by path loss variation over time due to changes in environmental dynamics.