一种改进PBS的无线传感器网络时钟同步方法SCRT

An improved PBS based clock synchronization method SCRT for wireless sensor networks

针对无线传感器网络使用PBS方法进行时钟同步时传感器节点同步范围受限的问题,提出一种改进PBS的无线传感网络时钟同步方法 SCRT。该方法结合发送者-接收者(SR)和仅接收者(RO)两种同步,使得分组成簇网络中簇头节点通过与参考节点交换时钟消息、成员节点根据簇头发送和接收时钟消息内携带的参考时间戳调节本地时钟,从而达到时钟同步。时钟偏移估计、频率偏移估计与计算出的克拉美罗界通过Matlab钟同步方法与PBS方案相比,增大了节点的同步范围、显著降低了整个网络的同步误差且提高了同步效率。

In allusion to the problem that the synchronization range of sensor nodes is limited when the pairwise broadcast synchronization(PBS)method is used to conduct clock synchronization for wireless sensor networks(WSNs),an improved PBS based clock synchronization method SCRT is proposed for WSNs.In the method,the sender-receiver(SR)synchronization and receiver-only(RO)synchronization are combined.The cluster head nodes in the packet clustered network exchange the clock information with the reference nodes,and the member nodes adjust the local clock according to the reference time stamps carried in the cluster head sending and receiving clock messages,so as to achieve clock synchronization.It is found that the clock offset estimation and frequency offset estimation are optimal in the comparison with the calculated Cramer-Rao Lower Bound(CRLB)in the Matlab simulation.The experimental results show that in comparison with the PBS scheme,the clock synchronization method can increase the synchronization range of the nodes,significantly reduce the synchronization errors of the entire network,and improve the synchronization efficiency.