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IEEE

(上接第1172页)

如果单跳误差独立同分布E~N(0,R2),经过n跳后的累积误差的均方差等于。目前的算法如RBS、TPSN、DMTS和FTSP都采用提高单跳同步精度、采用最短路径同步以减少跳数,降低多跳误差累积。却没有充分利用周围节点的时钟信息以降低误差随跳数累积的速度。

时钟精度实质是对时钟值不确定性的表征,根据信息论的观点,信息作为一种负熵,可以降低不确定度。节点可以利用的信息包括临近节点的时钟信息以及自身的时间记录,在实际应用中,结合极大似然估计、贝叶斯后验估计进行数据融

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4 结语

时钟同步是无线传感器网络的一项重要支撑技术,它对

网络的运行以及应用的开展意义重大。本文分析了时钟同步在传感器网络的应用及其对时钟同步算法的特殊需求,阐述了时钟同步的一般原理,分类综述了现有的三大类同步算法,最后给出了未来研究的几个领域。参考文献:

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