【作者】 苏家勇；

【导师】 田逢春；

【作者基本信息】 重庆大学 ， 通信与信息系统， 2009， 硕士

【摘要】 可用的频谱资源是无线网络容量提升的主要瓶颈。有效的频谱资源分配策略可以减小信道之间干扰、提高频谱资源利用率,从而增加网络容量。无线mesh网络(Wireless Mesh Network,WMN)是一种新型宽带无线网络,由于其复杂的组网模式,使其核心技术研究面临诸多理论和实践的挑战,而频谱资源分配和多信道技术也成为影响无线Mesh网络性能的关键问题。本文阐述了无线网络中频谱资源分配的基本概念和研究现状,具体分析了信道分配问题中的图着色理论,以及固定信道分配方案中在优化目标不同时的具体分类,并给出了相应的数学描述和定义。探讨了信道分配问题在无线蜂窝网络中的应用,包括蜂窝网络中静态信道分配、动态信道分配以及混合信道分配问题。进一步分析了不同着色模型下的蜂窝网络信道分配算法。本文重点研究了无线mesh网络中的信道分配问题。在分析mesh网络现有主要信道分配方案的基础上,针对863课题中虚拟层次化无线mesh网络架构提出了一种无线信道资源分配的实现方案。方案针对虚拟层次小区所构成的网络拓扑,提出了利用射频防卫度作为信道分配的指标的一种广义集合T-coloring模型,其能够很好的适用于课题中的虚拟层次化网络环境,从而获得了保持网络的连通性、控制无线信道干扰的资源分配的良好效果。本文进一步开展了多接口-多信道无线mesh网络中信道分配的理论研究,分析了其现状和数学模型,探讨了节点接口数充足的理想状态下无线mesh网络中的信道分配问题。在此基础上提出了一种多接口-多信道无线mesh网络中基于图分解的时隙信道分配策略,该方案考虑了信道分配在时间域的拓展。方案根据连通节点间的传输路径构造对应每个时隙子图,并针对该子图运用图着色算法优化每个时隙的信道分配,从而提高了时隙的链路信道分配效率。进一步在满足无线mesh网络中信道分配节点接口数约束、信道数约束的条件下增加了网络吞吐量。该方法相比各种静态信道分配方案具有明显的优势,仿真结果也验证了其有效性。更多还原

【Abstract】 In the wireless network, the available spectrum is a bottleneck of network capacity. While, effective spectrum resources assignment strategy can reduce network interference, improve the utilization of spectrum resources. Wireless mesh network (WMN) is a new kind of broadband wireless access networks, spectrum resources assignment and multi-channel technology is essential for wireless mesh network.First of all, this paper introduces the concepts and overviews of spectrum resources assignment problem, including the classification of channel assignment and the algorithm models. Then, investigate the applications of channel assignment in wireless cellular network, including static channel assignment, dynamic channel assignment and hybrid channel assignment, and analyses channel assignment algorithm with several coloring models for cellular networks.Secondly, this paper focuses on the channel assignment researching in wireless mesh network, and discusses the constraints conditions of the algorithm, analyses the typical channel assignment schemes also. Under virtual hierarchical wireless mesh network structure, this paper proposed it’s channel resources assignment by introduced RF-based defense degree as the indicator of channel assignment, and proposed a generalized set T-coloring model which could maintain network connectivity and control wireless channel interference for resources assignment.Finally, this paper proposed a slot channel assignment scheme based on graph decomposition in multi-radio multi-channel wireless mesh networks by extended channel assignment in the time domain. A new algorithm based on of the transmission paths between communication nodes in each time slot corresponds to a sub-graph, and every sub-graph using a certain coloring algorithm optimizes channel assignment in each time slot. Consequently, each time slot more link can be assigned channels and network throughput can be improved. The scheme takes the precedence to other channel assignment schemes. The simulation results show the effectiveness of the algorithm.更多还原