【作者】 杨延华；

【导师】 杨克虎；

【作者基本信息】 西安电子科技大学 ， 信号与信息处理， 2007， 硕士

【摘要】 无线传感器网络的时间同步和节点定位是利用无线传感器网络进行目标探测与跟踪中的两个重要的问题。本论文提出一种新的实现无线传感器网络时间同步的方法,该方法通过估计两个节点的本地时钟的相对频偏和目标节点的本地时钟的时间偏移对目标节点的本地时钟进行调整,估计相对频偏和时间偏移时所用到的时间信息是通过在节点间按一定的机制发射超宽带信号并用各自的本地时钟记录发射时刻获得的。在时间同步的基础上,提出利用超宽带信号和信标节点实现节点定位的方法,超宽带信号用来测量未知节点到各个信标节点的距离。我们用matlab Simulink建立了时间同步和节点定位的动态模型,性能分析和仿真结果均表明本文所提方法的有效性。本文还对无线传感器网络中单个低飞声目标的定位和跟踪进行了研究,通过建立动目标飞行的状态模型和观测模型,利用粒子滤波器和各个节点上的均匀线性麦克风阵列接收的信号,对声音目标飞行时的状态进行估计和跟踪,得到了无线传感器网络中单个低飞声目标的航迹曲线,仿真结果表明粒子滤波算法在实现无线传感器网络目标跟踪问题的有效性。更多还原

【Abstract】 Time synchronization and node localization are known to be two important problems of wireless sensor networks (WSN) for target detection and tracking. In this thesis we propose a new time synchronization method for WSN using ultra-wideband (UWB) signals. In the proposed method, the synchronization is performed by two steps of estimating the relative drift and the offset of the two local clocks and aligning the local clocks, where the time information employed in the estimation steps is obtained by transmitting reference UWB signals at physical layer between pair of nodes and recording the local time instant of transmission using the local clocks. A new method of node localization is proposed on the basis of the proposed time synchronization method. UWB signal is employed to estimate the distance between the unknown node and each beacon node. The dynamic system models are established and the computer simulations are performed using matlab Simulink. The analysis and the simulation results confirm the effectiveness of the proposed methods. Furthermore, the problem of the tracking of the single acoustic target in the WSN is discussed in this paper. The target dynamics and data likelihood are established. The track curves of target are obtained by processing the array data using particle filter. The simulation results confirm the effectiveness of the particle filter dealing with the problem of the target tracking of WSN.更多还原