NLOS环境下无线传感器网络TOA定位算法

摘要

针对现有定位算法定位精度低、适用场景少的问题，提出一种非视距传播(NLOS)环境下的无线传感器网络电波到达时间(TOA)定位算法。对未知节点位置进行初步估计，将该估计值作为初始迭代参考点，利用泰勒级数展开法进行迭代计算，得到未知节点位置的二次估计值。使用二次估计值反推得到未知节点与各传感器锚节点的近似距离，将原始TOA测量距离与该近似距离之差作为非视距传播误差值，从而剔除NLOS误差较大的TOA测量组，利用误差修正后的TOA测量组再次进行泰勒级数迭代处理，实现未知节点的精确定位。仿真结果表明，该算法可有效抑制NLOS误差，相比传统定位算法，其定位误差小、定位精度高。%Aiming at the existing localization algorithms have the problem of low positioning accuracy and less applicable scenario, under the Non-Line-of-Sight(NLOS) environments, a localization algorithm based on Time of Arrival(TOA) in Wireless Sensor Network(WSN) is proposed in this paper. It uses the initial estimation of the unknown node as the reference point, the Taylor series expansion method is used to calculate the second estimation iteratively. The second estimation value is used to calculate the approximate distance between the unknown node and the anchor nodes. And this distance can be modified with the original TOA distance to determine the NLOS errors. The TOA measurement groups which are seen as containing the large NLOS error can be removed. The Taylor method is used to get the precise position of the unknown node based on the rest of the TOA measurements after correction processing. Simulation results show that the proposed location algorithm can restrain NLOS error effectively, and has better location accuracy than the traditional location algorithms.