关键词: 无线传感器网络, 时间同步算法, 同步精度, 贝叶斯估计

Abstract: The applications of Wireless Sensor Network need clock of sensors nodes to be synchronized. Due to the impact of node clock skew and the delay in information transmission, the receipt time of commonly used classic time synchronization algorithm is inaccurate, which will reduce the time synchronization accuracy to a certain extent. In order to improve time synchronization precision and balance node energy consumption of the network, this paper proposes an improved hierarchy referencing time synchronization algorithm, which is based on the time characteristics of each node in the hierarchy having the unique physical location. This paper uses Bayesian estimation methods to compute the receipt time of each node, narrows the error scope of time deviation, and finally obtains more precise synchronization time offset. It adopts wireless channel broadcast nature and bi-directional synchronization mechanisms, minimizes communication load and balances node energy consumption. The simulation results show that the use of Bayesian estimation method can significantly improve the accuracy of synchronization algorithm and balance node energy consumption.

Key words: Wireless Sensor Networks（WSN）, time synchronization, synchronization precision, Bayesian estimation