中文摘要：

本文研究了无线电波的传输特性,建立起传感器节点的定位模型,在该模型的基础上推导了二维平面的节点定位公式。现存的定位算法,都是假设信标节点不存在位置误差,这和实际情况不符。文中提出定位偏差参数的概念,以此作为信标节点选择的依据,设计出信标优化选择定位算法（OBS）,OBS通过减小定位过程中的误差传递来提高定位精度。试验和仿真数据表明,通过合理选择权值,本方法可以达到较高定位精度,相对于最大似然法和质心算法,本方法定位效果更好。

英文摘要：

In this paper, the transmission character of radio wave is studied and the location model of wireless sensor nodes is set up. From this model,2-D localization equations are deduced. Beacon may have position error, but existing algorithms pay no attention to this aspect. In order to select the best beacons for localization, the concept of location error parameter is launched. Based on this concept, OBS （ optimal beacon selection） algorithm has been designed, which can minimize the transfer error in the location process. Experiment and simulation results show that OBS can achieve high localization precision by choosing weight properly. Compared with ML and centroid algorithms, OBS has better performance.