基于锁相环的GNSS授时接收机钟差校准算法

GNSS(全球卫星导航系统)授时接收机利用卫星导航信号获取钟差并校准本地时钟,从而与GNSS系统时间同步。提出了全新的基于锁相环的GNSS授时接收机钟差校准算法,将钟差校准过程等效为传统的锁相环模型,鉴相器的功能由PVT(位置、速度与时间)解算实现,压控振荡器的功能由本地时间调整接口实现,环路将本地秒相位与GNSS系统的秒相位锁定。分析了环路总误差的组成,以及环路参数与各误差项的关系,给出了误差最小的环路优化设计准则。在北斗二号卫星导航接收机平台上进行了对比实验,验证了算法的有效性。

A clock error calibration algorithm based on phase lock loop in GNSS time synchronization receiver

GNSS receiver synchronizes local clock by calibrating clock error obtained from GNSS satellite signal. A novel local clock error calibration algorithm is developed. The time synchronization procedure was considered as a PLL model. In this model, phase detector was achieved by PVT solution, VCO was achieved by local clock adjusting interface, and the PLL lock the phase of local clock and GNSS clock. The total PLL time synchronization loop errors were analyzed, the relationship of each error item and parameters of PLL was analyzed, and the best PLL design criteria were developed. Finally, the time synchronization algorithm was tested on a COMPASS navigation receiver.