基于角度重构和差分飞行时间的室外多站定位

针对当前室外定位基站和目标之间的信号收发不同步,以及非视距(Non-Line of Sight,NLOS)环境下定位困难的问题,提出了一种基于角度重构和差分飞行时间(Time of Flight,TOF)的室外NLOS多站定位方法。首先,基于单次散射模型给出了一种关于散射体波达角(Angle of Arrival,AOA)的粗略重构方法,再利用多径信号的差分TOF并结合模型中目标、散射体、基站之间的几何位置关系构建定位方程;然后,结合先验信息添加约束区间并结合定位方程将定位问题转化为最小二乘优化问题,并利用列文伯格-马奈尔特法(Levenberg Marquardt,LM)算法进行初始解算得到基站到目标的初始估计距离;最后,将每个基站的距离估计结果进行联合多边定位得到最终目标位置。仿真结果表明,该方法利用多个基站能在室外NLOS环境中实现较高定位精度。

Outdoor multi-station positioning based on angle reconstruction and differential time of flight

In order to solve the problem that the signal transmission between base station and the target is not synchronized,and the positioning is difficult in non-line of sight(NLOS) environment,an outdoor NLOS multi-station positioning method based on angle reconstruction and differential time of flight(TOF) is proposed.Firstly,a rough reconstruction method for the angle of arrival(AOA) of the scatterer based on the single-scattering model is proposed.Then,the differential TOF of multipath signals is combined with the geometric position relationship between the target,the scatterer,and the base station in the model to construct a positioning equation.Moreover,the positioning problem is transformed into a least square optimization problem according to the constraint interval of the target.The initially-estimated distance from the base station to the target is obtained by using the Levenberg-Marquardt(LM) algorithm.Finally,the final target position can be obtained by utilizing the initially-estimated distance of each base station for multilateral positioning.Simulation results show that the proposed method can achieve higher positioning accuracy in outdoor NLOS environment by using multiple base station.