针对多跳网络分层或分簇同步算法中的误差随跳距累积、临近同步状态时同步交互消息数量急剧增加、信道争用加剧等问题,提出一种基于自适应阈值处理的WSN协作时间同步算法。该算法采用空间平均,解决了分层或分簇算法中的误差累积;采用随机退避策略发送同步脉冲,并对脉冲的接收时间作自适应阈值处理,从而调整节点同步脉冲的发送次数,减小信道的争用率,节省了网络同步开销。应用统计信号估计理论对该同步算法的性能进行了仿真,仿真结果表明,本算法在保证协作同步算法精度的前提下,降低了能耗。
A novel algorithm based on the adaptive thresholding cooperative time synchronization(ATCTS)is proposed to achieve accurate time synchronization in multihop wireless sensor networks.Synchronization error accumulation is solved by the proposed algorithm,the number of the messages and channel connection is dramatically increased.By using the spatial average and the random back-off strategy,the synchronization overhead and the channel contention are reduced.And the performance is verified by the signal estimation theory.Simulation results show that the energy efficiency is improved.Moreover,the proposed algorithm ensures the performance of synchronization.