Abstract: According to the structural characteristics of Wireless Sensor Network（WSN），a novel range-free and distributed positioning algorithm（PBSAO） is proposed based on anchor’s sectored antenna and sensor’s omnidirectional antenna.In PBSAO algorithm，the information about the different sectored communication regions of anchors is broadcasted to the neighbor sensors using the anchor’s sectored antenna and power control.Then the positions of sensors are extracted through computing the overlapping region of the information.In order to improve the coverage rate of positioning，the located sensors work as anchors and also broadcast positioning information to neighbor sensors using omnidirectional antenna.Results of simulation show that the positioning precision of LBSAO is superior to that of other typical positioning algorithm，as well as the scalability and robustness，which can meet the requirements of positioning in large-scale WSN.

Key words: Wireless Sensor Network（WSN）, positioning, sectored antenna, omnidirectional antenna

摘要： 基于锚节点装配的扇区天线和普通节点装配的全向天线，提出了一种非测距分布式节点定位算法（PBSAO）。在PBSAO算法中，锚节点通过功率控制扇区天线为不同扇区内的邻居节点提供角度信息和位置信息，未知节点通过计算锚节点定位信息的重叠区域确定自身位置。为了提高定位覆盖率，已定位节点升级为锚节点，利用装配的全向天线为未定位的邻居节点提供定位信息。仿真结果表明，与其它典型非测距定位算法相比，PBSAO算法具有较高的定位精度及较好的扩展性、鲁棒性，在大规模无线传感器网络定位中有广阔的应用前景。

关键词: 无线传感器网络, 定位, 扇区天线, 全向天线