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 management's 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
Key words
low earth orbit(LEO)satellite/self-positioning of terminal/time of arrival(TOA)/mobility management/round trip time(RTT)/geometric dilution of precision(GDOP)
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