认知无线通信系统移动性管理研究

发布时间：2018-01-05 17:31

本文关键词：认知无线通信系统移动性管理研究　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：频谱资源是不可再生的自然资源。随着无线通信技术的飞速发展和信息技术在各领域快速普及与应用,传统的频谱资源固定分配策略已经不能满足人们对频谱资源与日俱增的迫切需求。认知无线电概念的提出为解决无线频谱资源极度匮乏而大量授权频谱利用率极低的问题找到了有效的途径。认知无线电是一项基于软件无线电的热门技术,它能主动感知周围的无线电环境,找到频谱空洞,通过机会式接入空闲频谱,与主用户共享频谱资源。为避免主用户受到有害干扰,要求认知用户在检测到主用户出现时,应立即撤出当前频率,即进行频谱切换,这就产生了频谱移动性管理问题。未来通信系统的发展目标是满足人们在任何时间、于任何地点、以任何方式都能获得通信服务的需求。移动性管理是其中一项重要的支撑技术。本文首先介绍了认知无线电相关知识,指出了认知无线电关键技术及功能;然后结合蜂窝移动通信网络移动性管理方案,介绍了传统无线通信系统移动性管理的两项主要工作,即位置管理和切换管理,详细介绍了移动终端在不同场景下移动时的切换方案及流程;最后针对认知无线通信系统移动性管理中移动性触发事件多样性的特点,本文构建了一种新的频谱移动性管理框架,在该框架下研究了认知无线通信系统移动性管理中区别于传统无线通信系统的频谱移动性管理及频谱切换等问题,着重研究了认知无线通信系统应对各类移动性触发事件的处理方式,主要包括主用户出现和用户移动性带来的频谱移动性和小区选择等问题。在研究认知无线通信系统的移动性管理时,本文将一个以以太网为骨干连接的、认知用户与主用户并存的多小区认知无线通信场景归纳为具有认知功能的蜂窝移动通信网络进行研究,并且定义了认知无线通信系统移动性管理相关的各功能实体。为提高认知用户的移动性性能,本文在认知蜂窝移动通信网络架构中引入了基本区(使用本地频谱的区域)、扩展区(使用扩展频谱的区域)和分级频谱池的概念;通过对扩展频谱的资源重配置提高了系统总体容量和移动性性能;由于引入了扩展区的概念,提高了用户移动性性能;通过频谱池,减小了频谱可用性的差异;本文提出的频谱移动性管理方案能使网络根据当前小区频谱的使用状况和随机连接模型为移动用户提供合适的频带和目标小区;用户移动性管理通过基于切换时延开销的机制选择合适的切换类型减小通信质量降低,形成了一个有效的频谱移动性管理方案。仿真结果表明,使用本文构建的频谱移动性管理框架和方法,与传统的方法相比,能得到更大的小区容量和更好的移动性支持性能。
[Abstract]:The spectrum resources are non renewable natural resources. With the rapid development of wireless communication technology and information technology in the field of rapid popularization and application, the traditional fixed spectrum resource allocation strategy has been unable to meet the urgent needs of people grow with each passing day of spectrum resources. Put forward the concept of cognitive radio for wireless spectrum resource scarcity and a large number of authorized spectrum found the effective rate is very low. The problem of cognitive radio is a hot technology based on software radio, it can perceive the surrounding radio environment actively, find the spectrum holes, through opportunistic access idle spectrum, spectrum sharing resources and primary users. In order to avoid the main users from harmful interference in the detection to the main cognitive user requirements users appear, should immediately withdraw from the current frequency, the spectrum handoff, which produced a spectrum of mobility management in future. The development goal of communication system is to meet the people at any time, at any place, in any way can obtain the communication service demand. Mobility management is one of the important supporting technologies. This paper firstly introduces the related knowledge of cognitive radio, cognitive radio technology and points out the key function; and then combined with the mobility management scheme for cellular mobile communications network, introduces the two main tasks of traditional wireless communication system mobility management, location management and handoff management, introduces the mobile terminal mobile switching in different scenarios when the case and process; finally, the mobility of cognitive wireless communication system in the mobility management of trigger event diversity, this paper constructs a new the spectrum mobility management framework, under the framework of cognitive wireless communication system, mobility management is different from the traditional wireless communication area The problem of spectrum mobility management and spectrum switching system, focuses on the research of the cognitive wireless communication system to deal with all kinds of mobility events trigger processing methods, including the main users and user mobility spectrum mobility and cell selection and other issues. In the mobility management research of cognitive radio communication system, the one based on Ethernet the backbone connection, multi cell cognitive radio scene cognitive users and primary users coexist into cellular mobile communication network with cognitive function were studied, and the definition of cognitive wireless communication system related to mobility management entities. In order to improve the mobility performance of cognitive users, this paper introduces the basic framework of cognitive area in cellular mobile in a communication network (using the local region of the spectrum), extension (extended spectrum region) and spectrum pool classification Concept; through the reconfiguration of resources to expand the spectrum of the overall system capacity and improve the performance of mobility; by using the concept of extension, improve the user mobility performance; through the spectrum pool, reduce the differences of spectrum availability; spectrum mobility management scheme is proposed in this paper can make the network according to the current conditions and the use of random cell spectrum the connection model provides the frequency band and the target cell suitable for mobile users through the user mobility management mechanism; handoff delay overhead to choose appropriate types of reduced lower quality communication based on the formation of an effective spectrum mobility management scheme. The simulation results show that the use of spectrum mobility management framework and method in this paper, compared with the traditional method support, performance can get larger capacity and better mobility.

【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN925

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