【作者】 龙承志；

【导师】 吴伟陵；

【作者基本信息】 北京邮电大学 ， 信号与信息处理， 2009， 博士

【摘要】 近几年,随着微机电系统技术、数字信号处理技术、无线通信技术和计算技术的发展,无线传感器网络(Wireless Sensor Network,WSN)应运而生。它是由集感知、计算和通信能力的微型传感器节点,以Ad hoc方式构成的无线通信网络。这种网络的快速布署、多跳路由、动态拓扑、健壮性、以数据为中心和面向应用等特性,使得它在环境监测、医疗卫生、智能家居、军事等领域有着广泛的应用前景。在大规模部署的网络中,如何有效延长网络的生命周期,提升网络数据传输的吞吐量以提高网络整体性能,始终是WSN的研究重点。本文围绕这个重点,在传感器网络的拓扑控制、休眠机制、节点协作、确定性覆盖方面,展开了相应的研究,主要成果有:分别在频率平坦信道与频率选择信道条件下构建了分簇传感器网络簇间协作通信模型,并做了较详细分析。针对衰落信道,对传感器网络簇间通信信道容量进行了分析,并给出相应的理论表达式。在分簇拓扑方案基础上对VMIMO在WSN中的应用进行了更进一步的分析研究。考虑了利用选择分集及最大比合并的方式,选择性能更好的信道进行数据传输,在发射簇利用空时分组码对协作节点进行空时编码,在接收簇利用最大似然译码算法对协作节点接收的信号进行联合译码。本文提出的N S节点优化选择算法除在比不考虑节点选择有更好的节能性能之外,还比chernoff性能界对系统的能耗描述有更好的精确度,因此更适合系统模型的分析。同时,它并不随节点数的增加而降低发送数据率或增加系统电路模块的能量消耗,非常适合大量节点协作的场合,也适用于网络拓扑动态变化的场景。在考虑传感器节点异质性的前提下,提出了一种结合节点异质性,基于簇间节点协作通信的传感器网络通信传输方案。在已有簇头节点概念的基础上,本文提出虚拟簇头节点的概念,把整个传感器网络通信过程划分为两个阶段,簇内通信阶段与簇间通信阶段。对各类型节点的数据传输时的能量消耗模型进行了相应的建模,并做了理论分析与计算机仿真,验证了新的通信传输方案在能量有效性方面的优势。为尽可能地延长无线传感器网络生存时间,增加网络吞吐量,提出一种考虑无线传感器网络节点异质性和冗余性的拓扑算法SEA(Sleep-scheduling & Energy-efficientAlgorithm)。与现有相关研究相比,SEA能更好地解决节点异质问题,并充分利用了节点冗余性。仿真结果证明,此算法可有效地延长网络稳定周期和提高网络吞吐量。构建了一个基于目标追踪的传感器网络覆盖模型,利用超声波的传输特性及测距原理,结合三维定位原理,提出定位网络基本单元概念,并对这个定位网络基本单元进行了分析,在这基础上进行了定位单元的扩展和延伸,提出一种最优节点传感器网络覆盖模型,并分析了可行性。更多还原

【Abstract】 In recent years, progress in micro-electro-mechanism system (MEMS), digital signals process, wireless communications and computation has enabled the development of low-cost, self-organized, multi-functional wireless sensor nodes with short communication range. Compared with traditional networks, wireless sensor networks (WSN) have unqiue characteristics, such as rapid deployment, source constraint, multi-hop, dynamic topology, fault tolerance, data-centric and application-based. These features enable WSN to conduct many special applications, such as environmental surveillance, medical treatment, smart homing and military application.To enhance the performance of the whole network and extend network lifetime, ensuring its easy usage and the effectiveness of its data transmitssion is an important issue for wireless sensor network. This dissertation focuses on energy-efficient algorithms and protocols, including topology control algorithms, nodes collaboration, sleep-scheduling and so on.The main contributions of the thesis are as follows:The dissertation constructs a cooperated communication model between the clusters in frequency flat channel and frequency selective channel of WSN. And the model is analysed in detail. The capacity of fading channel between the clusters in WSN is proposed with expression of theory.Based on the topology of hierachical clusters, it analyses the further application of the virtual multiple-input multiple-output (VMIMO) systems in WSN. Considered selecting diversity and maximum ratio combining, a scheme is proposed to transmit data with the best channel in WSN. Space-time block coding is applied in cooporation nodes in transmitting cluster, and the maximum likelihood decoding is applied in cooperation nodes in receiving cluster. Compared with Chernoff bound, not only does the N_S algorithm put forward in this dissertation have the excellent performance in saving energy, but also has more precise function to describe the communication model between clusters. At the same time, neither does the algorithm reduce the total of transmitting data between clusters, nor increases energy consumption in circuit block. This algorithm quite suits to the situation with mass nodes as well as dynamic topology network. In the dissertation, considered the feature with heterogeneous nodes in WSN, it brings forward the whole communication scheme in network based on the model between clusters. Moreover, the conception of virtual head cluster is proposed, and WSN communication is divided into two stages. And the two stages are the communication in one cluster and between clusters. The energy consumption model is set up for different type nodes. Analyzed by theory and the simulation in matlab, the advantages of new scheme are proved in chapter 5.In order to prolong the lifetime of network and increase the throughput of efficient data in WSN, SEA (Sleep-scheduling&Energy-efficient Algorithm) is proposed in chapter 6, considering the characteristics with heterogeneous and redundancy in WSN. Compared with the correlation study, the SEA could effectively prolong the lifetime of network and increase data throughput after being proved by theory and simulation with matlab.A coverage model is proposed in chapter 7 based on the application with tracing object. Firstly, a concept of basic cell to localization is put forward using the principle of measuring distance with ultrasonic. Secondly, an excellent coverage model based on the basic cell in WSN is brought forward and analyzed in chapter 7.更多还原