多普勒辅助水下传感器网络时间同步机制研究

摘要

Time synchronization problem in underwater acoustic sensor networks (UWSN) was studied. Due to the propagation of acoustic signals in underwater environment and nodes movement bring some problems to time synchroni-zation. A distributed time synchronization algorithm was proposed based on Doppler method, called NU-Sync. NU-Sync solved the problem of uncertainty propagation delay caused by nodes movement through calculating relative velocity. And autonomous underwater vehicle (AUV) was used as beacon node which can save energy consumption in the process of calculation clock skew. Simulation resulted show NU-Sync achieves high level time synchronization precision.%研究了水下传感器网络(UWSN)时间同步算法.针对水下环境中声信号传播时延长、节点移动性等特点给时间同步带来的问题,基于多普勒原理提出了一种分布式时间同步算法(NU-Sync),通过计算相对速度解决由节点移动导致传播时延不确定的问题,利用自主式水下潜器作为信标节点,通过不断广播时间信息的方式计算时钟频率偏斜,节省网络的能量消耗.仿真实验表明,与现有算法相比,NU-Sync能够实现较高的同步精度.