基于Chirp的新体制卫星导航信号设计及处理方法研究

Satellite navigation system, which is used to correct errors and provide absolute positioning information for inertial sensor, is an important part of the integrated navigation system of high dynamic vehicles such as hypersonic vehicle and supersonic cruise missile. The traditional satellite navigation system with DSSS signals has to perform a long-time two-dimensional search to acquire navigation signals in high dynamic conditions, and can hardly estimate the carrier phase to achieve high precision positioning. As a result, the positioning speed and accuracy of the traditional satellite navigation cannot match the inertial sensor. This project intends to propose a novel navigation signal, which possesses the properties of large Doppler tolerance, multiple-access, and physical-layer security. With the new signal, the acquisition process of the satellite navigation will be simplified as a process of time-domain search, and the acquisition time will be reduced to the length of time-domain search range. The estimation performance of the carrier phase will also be enhanced. This project intends to study: (1) A pseudo-random Chirp based multi-access signal and physical-layer secure transmission method; (2) The fast acquisition algorithm based on time-domain search and tracking loop design; (3) The robust carrier phase estimation algorithm in high dynamic conditions. This project strives to provide a new technical reserve for the future development of Chinese military satellite navigation system.

卫星导航是高超音速飞行器、超音速巡航导弹等高动态载体组合导航系统的重要组成部分，其作用是为惯性传感器提供误差修正和绝对定位信息。传统直扩信号体制的卫星导航接收机在高动态下必须经过长时间的时延-频偏二维搜索才能捕获导航信号，并且难以估计用于高精度定位的载波相位，因此很难与惯性传感器初始对准的速度和精度相匹配。本项目拟提出一种兼具大多普勒容限、多址接入和物理层安全性的新体制卫星导航信号设计及处理方法，从根本上将卫星导航捕获过程降维成时域一维搜索，捕获时间降低至与时域搜索长度相当，同时解决高动态导致的载波相位失锁周跳问题，提升相位估计的动态应力。本项目拟研究：（1）基于伪随机Chirp的多址接入信号设计及物理层保密传输方法；（2）基于时域宽步长搜索的快速捕获算法及无牵引跟踪环路设计方法；（3）高动态载波相位稳定估计算法。研究成果力争为我国军用卫星导航系统的未来发展提供技术储备。

卫星导航是高超音速飞行器、超音速巡航导弹等高动态载体组合导航系统的重要组成部分，其作用是为惯性传感器提供误差修正和绝对定位信息。传统直扩信号体制的卫星导航接收机在高动态下必须经过长时间的时延-频偏二维搜索才能捕获导航信号，并且难以估计用于高精度定位的载波相位，因此很难与惯性传感器初始对准的速度和精度相匹配。本项目提出了一种兼具大多普勒容限、多址接入和物理层安全性的新体制卫星导航信号设计及处理方法，从根本上将卫星导航捕获过程降维成时域一维搜索，捕获时间降低至与时域搜索长度相当，同时解决了高动态导致的载波相位失锁周跳问题，提升了相位估计的动态应力。本项目主要研究内容和研究成果包括：（1）基于伪随机Chirp的多址接入信号设计及物理层保密传输方法；（2）基于时域宽步长搜索的快速捕获算法及无牵引跟踪环路设计方法；（3）高动态载波相位稳定估计算法。研究成果有望为我国军用卫星导航系统的未来发展提供技术储备。