LEO卫星通信终端的RTT定位技术  

RTT positioning technology of LEO satellite communication terminal

作　　者：屈德新 冯健锋 张更新 QU Dexin;FENG Jianfeng;ZHANG Gengxin(School of Communications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,江苏南京210003

出　　处：《南京邮电大学学报（自然科学版）》2024年第1期20-27,共8页Journal of Nanjing University of Posts and Telecommunications：Natural Science Edition

基　　金：国家自然科学基金(U21A20450)资助项目。

摘　　要：低地球轨道(LEO)卫星通信互联网是未来满足万物智联、天空地一体化网络连接的6G移动通信网络重要组成部分。LEO卫星通信终端的移动性管理是LEO卫星网络运行管理的基本功能,而获取卫星终端的位置是实现移动性管理的基础。目前,全球卫星导航系统(GNSS)能够提供比较高的定位精度,但是当GNSS位置服务在受到环境遮蔽、外部干扰时可能失效,因此卫星通信终端需要一种独立于外部GNSS服务的自主定位方案。以未来LEO卫星互联网的通信信号为背景,提出一种基于往返时延(Round Trip Time,RTT)测量的LEO卫星通信终端自主定位体制,对OFDM卫星互联网信号的时延估计算法精度以及定位误差进行了理论计算和数字仿真,获得了本定位方案的均方根误差(RMSE)和几何稀度因子(GDOP),计算结果表明可以实现百米量级的快速定位,满足了移动性管理所需的千米量级位置信息的应用需求。The low earth orbit(LEO)satellite communication network is an important part of the 6G mobile communication network that will meet the requirements of the future connection of all things and the sky-earth integration network.The mobility management of LEO satellite communication terminals is the basic function of LEO satellite network operation management,and obtaining the location of satellite terminals is the base of the mobility management.At present,the global navigation satellite system(GNSS)can provide relatively high positioning accuracy,but it may fail when its location service is shielded by the environment and external interference.Therefore,the satellite communication terminals need a novel positioning scheme independent from the external GNSS service.Targeting the communication signals of future LEO satellite Internet,we propose a LEO satellite communication terminal autonomous positioning system based on the measurement of round trip time(RTT).The theoretical calculation and digital simulation are conducted for the orthogonal frequency division multiplexing(OFDM)satellite Internet signals,including the accuracy of the time delay estimation algorithm and the positioning error,and the root mean square error(RMSE)and geometric dilution of precision(GDOP)of this positioning scheme are obtained.The calculation results show that the proposed method can realize fast positioning at the level of 100 m and meet the mobility managements practical requirements of kilometer-level location information.

关 键 词：低轨卫星 终端自主定位 波达时间 移动性管理 往返时间 几何稀度因子 

分 类 号：TN971[电子电信—信号与信息处理]