一种低轨卫星高灵敏度辅助定位服务系统

本文针对全球导航卫星系统(GNSS)接收机低信噪比环境下的快速定位需求，在充分分析扩频信号相干积分关键影响要素的基础上，设计了一种低轨卫星高灵敏度辅助定位服务系统。针对空间段信号发射机低相噪信号生成技术所需的参考源、时钟树给出了详细设计及指标分析，通过发射信号误差向量幅度EVM对比测试，所设计的发射信号(EVM)指标可控制在优于1.19%。针对系统服务能力进行了星地一体化性能测试，实验结果表明，该系统可有效实现终端在灵敏度提升12 dB前提下有效定位且辅助定位时间优于3.5分钟。

A High Sensitivity Auxiliary Positioning Service System Using LEO Satellites

Based on the analysis of the key factors affecting the coherent integration of spread spectrum signals, a novel high sensitivity auxiliary positioning service system for LEO satellite is proposed to address the fast positioning requirement of global navigation satellite system (GNSS) receivers under low signal to noise ratio environment. Detailed design and index analysis are given according to the reference source and clock tree for low phase noise signal generation technology in space segment signal transmitter. Error vector magnitude (EVM) comparison tests of the transmitted signal show that the EVM index can be controlled to be better than 1.19%. Furthermore, the satellite ground integration performance test is carried out in allusion to the system service capability, which shows the system can effectively realize the terminal positioning with the sensitivity increased by 12 dB, and the auxiliary positioning time is less than 3.5 minutes.