多体制卫星导航闭环测试系统关键技术研究

Satellite navigation signal simulator is a important and indispensable test equipment for satellite navigation system, signal structure design, receiver development and performance assessment, the navigation terminal batch testing. It has a wide range of applications in various fields of military and civilian, and it have important academic value and it is a hot research point in the field of satellite navigation. Traditional simulator and receiver are independent of each other, the simulator indicators often can not evaluation, and is unconvincing. The project study the high-precision satellite signal propagation effects of space environment simulation, and technique for generation multi navigation system signals with high accuracy, BD /GPS/ GLONASS multi-system space and time synchronization, precise orbit simulation of the constellation model theory and technology. The project will solve the sub-centimeter-level navigation signal generation technology based on the study, and with combinations of high-performance receiver technology, the whole system will measure the generated signal and the measured information at the configured epoch with synchronization closed loop. The simulator - receiver real-time closed-loop test system will measure the problem from a broader, more micro perspective in the assessment of satellite navigation. Through the above research, the project will develop of multi-system satellite signal simulator with the international advanced level prototypes and the closed-loop test system

卫星导航信号模拟器是卫星导航系统建设、信号体制设计、接收机研发与性能指标评估、导航终端批量检测不可缺少的重要测试设备，是当前卫星导航领域的热点方向之一。传统模拟器和接收机彼此独立，模拟器的自身指标往往不能评测。本项目在进行高精度卫星信号空间环境传播效应模拟、多种导航信号体制信号精确生成、中国BD/GPS/GLONASS多系统的空间和时间同步、多种星座模式的精密轨道仿真等理论与技术的研究基础上，解决亚厘米级导航信号生成技术，不仅解决高精度、多系统的卫星导航信号模拟器关键技术，并组合高性能接收机技术，使整个系统测量历元可配置，以实现信号生成信息和测量信息同步闭环比对，构建模拟器－接收机实时闭环测试系统，可以从更广泛、更微观的视角评估卫星导航中的问题。通过以上研究，研制具有国际先进水平的多系统卫星信号模拟器闭环测试设备。

本项目致力于导航系统原理分析平台研究，分为三部分：首先通过分析接收机测量误差来源及影响，给出了闭环测试系统总体结构及工作原理。其次详细的介绍了系统模拟器DSP算法设计以及FPGA数字基带生成，其中DPS算法设计包括：轨迹生成、可见星的判断、伪距计算、频率控制字计算，FPGA基带生成包括：信号调制，多路径信号生成，反SINC滤波器的设计。最后通过闭环测试电离层和对流层延迟、多路径以及星座分布对定位结果的影响,其中电离层误差是接收机的主要误差来源，深入研究了电离层模型并在接收机端加入电离层模型后定位精度有了明显改善。在GNSS模拟器中加入电离层、对流层误差模型后，定位精度得到很大的提高，卫星的伪距测量误差比较小。参与定位的每颗卫星都存在一定的伪距误差，根据分析，传播误差是主要测量误差，使用闭环数据定位误差基本为零，出现的定位波动现象主要是因为接收机软件计算数据截位造成的误差。. 项目基本完成了预期研究内容，申请专利16项，获授权7项；发表论文10篇，其中SCI收录1篇，中文核心9篇；软件著作权10项；获得科技奖励共2项，2014年度卫星导航定位科技进步奖二等奖，2016年度广西技术发明一等奖。