一种新型GPS冗余授时方法

大量采用GPS授时的网络存在安全隐患,而采用其它授时方法则难以在现有设备增加外部时钟接口.介绍了基于GPS射频信号模拟的外部授时方法,对原有设备无需作任何改动,从外部授时模块中获得外部同步的1 pps(pulses per second)和时间信息,仿真产生固定点接收到GPS信号的导航电文和观测数据,并将GPS导航电文的时间信息实时修改;GPS射频信号基于仿真数据产生,使设备内嵌的GPS接收机正常定位授时,恢复出外部同步的1 pps,从而实现外部授时.论文介绍了采用大规模FPGA的实现方法,实验结果验证了对于固定位置该授时方法的有效性.

A Novel Redundancy Method of GPS Timing

It's unsafe for so many networks timed by GPS,but it's hard to add redundancy clock interface by adopting other timing methods.This paper proposes time transfer approach based on the simulated GPS RF signal,and no change is done to original network.GPS RF signal is simulated based on outer time standard.GPS navigation and observation data such as pseudo-range of fixed point are simulated.Time information of GPS navigation data is modified to outer time standard.The GPS RF signal is generated based on the simulated data.The GPS receiver embedded in the device gets the RF signal and recovers the outer time standard and realizes the time distribution.A FPGA-based prototype can realize the above simulation procedure and the experiment shows the effectivity of this method.