基于无人机5G高空基站的低成本应急定位方法  

Low-cost Emergency Positioning Method Based on 5G High-altitudeBase Station of UAV

作　　者：郑迪 谢亚琴[1] 谷天园 ZHENG Di;XIE Yaqin;GU Tianyuan(School of Electronic and Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044

出　　处：《无线电工程》2023年第11期2607-2618,共12页Radio Engineering

基　　金：国家自然科学基金(62001238)。

摘　　要：当由于台风、塌方和地震等极端灾害导致地面固定基站损毁时,可以利用无人机搭载5G高空基站来为待测用户(User Under Test,UT)提供应急定位服务。要获得目标的三维位置信息,至少需要4个基站。针对如何降低极端条件下待测目标的定位成本,减少对无人机基站数量的要求,提出了一种基于无人机5G高空基站的低成本应急定位方法。利用最小二乘(Least Square,LS)算法来估计UT的初始位置,并将该初始位置作为虚拟移动基站加入初始基站集合。基于新的基站集,利用二次LS算法对UT的位置进行迭代估计,并将得到的一系列待测目标估计值作为虚拟基站集,随后基于高程精度因子(Vertical Dilution of Precision,VDOP)最小从虚拟基站集中选取一个最佳的虚拟移动基站,并以此作为UT的位置更新。将位于三维空间的无人机基站投影到水平面,联合到达时间差(Time Difference of Arrival,TDOA)和方位角测量值,采用一次加权最小二乘(Weighted LS,WLS)算法求解待测目标的水平位置。利用初始解分量之间的相关性,通过二次WLS算法对目标的水平位置进行修正,获得UT的最终位置估计。仿真结果表明,与现有的定位算法相比,提出的定位算法能以较低的成本获得较高精度的定位信息。When the ground fixed base stations are damaged due to extreme disasters such as typhoons,landslides,and earthquakes,UAV can be used to carry 5G high-altitude base stations to provide emergency positioning services for Users Under Test(UT).However,to obtain three-dimensional location information of the target,at least four base stations are required.In order to reduce the positioning cost of the target under extreme conditions and reduce the requirement on the number of UAV base stations,a low-cost emergency positioning method based on 5G high-altitude base stations of UAV is proposed.Firstly,the Least Square(LS)algorithm is used to estimate the initial position of UT,and the initial position is then added to the initial base station set as a virtual mobile base station.Secondly,based on the new base station set,the position of UT is iteratively estimated using the quadratic LS algorithm and a series of estimated values of the target to be measured are taken as the virtual base station set.And then,based on the Vertical Dilution of Precision(VDOP)min,an optimal virtual mobile base station is selected from the virtual base station set and used as the UT position update.Thirdly,the UAV base station located in the three-dimensional space is projected onto the horizontal plane,and combined with the measured Time Difference of Arrival(TDOA)and azimuth angle,the Weighted Least Squares(WLS)algorithm is used to solve the horizontal position of the target to be measured.Finally,using the correlation between the initial solution components,the horizontal position of the target is corrected by the quadratic WLS algorithm,and the final position estimation of UT is obtained.The simulation results show that compared with the existing positioning algorithms,the proposed algorithm can obtain localization information with higher precision at a lower cost.

关 键 词：无人机 5G高空基站 应急定位 虚拟移动基站 

分 类 号：TN92[电子电信—通信与信息系统]