基于卡尔曼滤波的Link-22数据链网络时间同步算法

Clock synchronization algorithm in Link-22 datalink network based on Kalman filter

为了维持网络正常运行,Link-22数据链所采用的时分多址接入协议必须要求高精度的网络时间同步,传统的RTT算法降低了系统的实时性,PTP算法增大了系统的网络负担,且2种算法都忽略了延迟抖动以及获取时间戳带来的误差,导致时间同步精度低。基于此,文中提出了一种基于卡尔曼滤波的RTT-PTP算法,该算法在不影响系统的实时性以及不增加网络开销的情况下,利用卡尔曼滤波有效地降低延迟抖动以及不同时间戳精度带来的误差。最后通过仿真验证新算法能够有效地提高系统的时钟精度。

In order to maintain the normal operation of the network,Time Division Multiple Access（ TDMA） Protocol used in Link-22 datalink must require high precision network time synchronization. Traditional round trip timing（ RTT） algorithm reduces the system＇s real time,and the PTP algorithm increases the network burden on the system. In addition,both RTT and PTP algorithms ignore the delay jitter and the error when get the timestamp,leading a low time synchronization accuracy. For these problems,this paper presents RTT-PTP algorithm based on Kalman Filter. The new algorithm does not affect the system in real time and without increasing network overhead,and it effectively reduces delay jitter and the timestamp＇s error using Kalman Filter. At last,through a simulation verification the new algorithm can effectively improve the system clock accuracy.