Abstract: The accuracy of location decreases seriously due to increasing of ranging errors when the Monte Carlo location algorithm is used to keep track of tag in Radio Frequency Identification（RFID） indoor location system. In this paper, the diffusion function is introduced into the Monte Carlo location algorithm, in order to research the relation between the accuracy of location and ranging error. Simulation results show that the accuracy of location is influenced not only by the value of ranging error, but also by the direction of tag’s movement. For the same ranging error, the location is most accurate, when the direction of tag’s movement is perpendicular or parallel to the line from tag to reader.

Key words: Radio Frequency Identification（RFID）, indoor location, diffusion function

摘要： Monte Carlo定位算法用于室内射频标签定位时，测量误差的增加导致定位精度严重下降。提出将扩散方程用于Monte Carlo定位算法，研究测量误差与标签定位精度之间的联系。仿真结果表明，定位的精度不仅受到测量误差大小影响，而且与标签的运动方向密切相关。测量误差相同时，当标签移动的方向与标签到阅读器的直线垂直或平行时，定位精度最高。

关键词: 射频识别, 室内定位, 扩散方程