Abstract: In order to alleviate the effects of transmission delay and inaccurate receiving time on the time synchronization of the Wireless Sensor Network(WSN), based on the sender-receiver time synchronization algorithm, this paper proposes an improved time synchronization method, which uses the maximum likelihood estimation to estimate the value of each receiving node and to approximate its real value. Then it gets the system clock deviation from the clock deviation of each nodes’ receiving data, obtaining more accurate synchronization time offset. Simulation results show that, without changing the synchronization mechanism, the proposed method can improve the precision of synchronization.

Key words: Wireless Sensor Network(WSN), time synchronization, maximum likelihood estimation, exponential distribution, consistent estimation

摘要： 信息传输延迟和接收时间不精确会影响无线传感器网络的时间同步。针对该问题，基于发送者-接收者同步模型的时间同步算法，提出一种改进的时间同步算法。对每个接收节点的时间值做最大似然估计，从而最接近原始时间值，根据每个节点接收数据时的时钟误差，得到系统的时钟误差，以获得更精确的同步时钟偏移量。仿真结果表明，该算法在不改变原有同步机制、不增加较大能耗的情况下，能够提高同步精度。

关键词: 无线传感器网络, 时间同步, 最大似然估计, 指数分布, 相合估计

CLC Number: 

• TP393