Research On Indoor Positioning System Based On RFID Technology

Growing convergence among mobile computing devices and embedded technology sparks the development and deployment of location—aware applications. The LANDMARC approach,which presented the concept of reference tags,is the most typical indoor positioning system based on RFID.It was also the first attempt using active RFID for indoor localization with gratifying results.Moreover, with reference tags adopted, the LANDMARC system does not need a large number of RFID readers which are expensive and makes RFID technology cost-effective for indoor location sensing.In LANDMARC system, positioning accuracy is subject to the reference label layout density and the number selected values of the nearest neighbor reference tag. Therefore, on the basis of RFID localization algorithm in-depth study on the detailed analysis of the performance of the algorithm LANDMARC system, seeking an optimal reference label deployment density distribution and select the optimal number of values adjacent to the reference label.This article also describes the VIRE indoor positioning systems which use virtual reference tags, and do a simulation about the Virtual Reference label insert number N and the Select of threshold in similar map impact on system performance orientation. The advantage of VIRE system is can obtain better performance than LANDMARC system without increasing hardware conditions. However, in an indoor environment, the signal strength value and a tag from the tag reader to the complex curves showing the relationship between, and VIRE algorithm uses linear interpolation to estimate the reception intensity value of a virtual reference tag is obviously inadequate.Based on the way VIRE linear interpolation algorithm error analysis gives an alternative way of using the Lagrange interpolation linear interpolation to approximate the signal strength value virtual label. The results show that the performance-based indoor positioning system location Lagrange interpolation method is better than the original linear interpolation VIRE system 14%.