【作者】 王岭；

【导师】 冯文江；

【作者基本信息】 重庆大学 ， 电路与系统， 2011， 硕士

【摘要】 认知无线电依靠人工智能技术感知无线通信环境,根据学习和决策算法自适应调整自身工作参数,从而动态检测和有效利用空闲频谱,是缓解频谱需求与资源有限之间矛盾的一种有效途径。IEEE802.22是一种无线区域网(WRAN)的技术规范,允许未授权用户在不影响授权用户(电视广播)业务的前提下,动态接入电视广播频段中的空闲信道。无线电环境地图(REM)是一种综合各种无线电环境信息的数据库,将REM引入无线区域网可以增强认知无线电的环境感知能力,通过从过去经验和当前结果的学习和推理,辅助认知无线电识别无线电场景的可靠性和准确性。论文重点研究无线电环境地图的生成技术,主要内容有:1)深入分析认知无线电涉及到的环境参数的构成、各参数的影响特性,将无线电环境地图引入无线区域网的作用和意义。2)针对认知无线电中位置感知和环境感知方法开展研究。在位置感知方法研究中,针对传统的基于无线电波传播的定位方法,设计了WRAN中CPE的定位模型和方法,并设计了一种定位精度自适应算法;在环境感知方法研究中,阐述了地理环境信息包括的内容和获得这些信息的方法。3)针对认知无线电中频谱感知方法开展研究,阐述了研究无线电环境地图中频谱感知技术的背景;对感知技术与无线环境地图的相互关系进行分析并对现有频谱感知技术进行分析和总结;并提出一种WRAN-REM信息辅助的协作频谱感知算法。4)设计了一种生成无线电环境地图的数据格式及数据库结构,阐述了无线电环境地图的生成步骤,建立了全局无线电环境地图的E-R模型和无线电环境信息数字化表,为认知无线电调用无线电环境地图信息提供支撑。更多还原

【Abstract】 Cognitive radio relies on the support of artificial intelligence to sense the wireless communication environment. Based on certain learning and decision-making algorithms, the working parameters of system are changed adaptively in real-time, and then the idle spectrum is tested dynamically and can be used effectively. Cognitive radio technology is considered as an effective way to alleviate the contradiction between the current increasing spectrum demand and the limited spectrum resources.IEEE802.22 is a Wireless Regional Area Network (WRAN) specification to support the unlicensed operation in TV bands (54-862 MHz), which is to coexist with incumbent users and provide wideband internet access to rural and suburban areas. Radio Environment Map (REM) is a comprehensive database which contains radio environment information. Knowledge derived from querying a local or global REM can contribute to the radio’s environment awareness. Reasoning and learning help the CR to identify the specific radio scenario. The paper focus on the generation technique of REM and the main contents are:(1)It analyses the composition of environmental parameters and the influence of various parameters of cognitive radio and the role and significance of REM in WRAN.(2) Location and environment awareness which are two prominent features of cognitive radios are researched. Based on the traditional position method of radio wave propagation, WRAN CPE location model and method are designed. And a positioning accuracy adaptive algorithm is mentioned; Entities of geographical environmental information are mentioned and we have introduced some methods of how to acquire this information, too.(3) Spectrum sensing methods for cognitive radio are researched. The technical background of researching spectrum sensing methods in REM is introduced. Then, we have analyzed the relationship between REM and spectrum sensing methods and compared strengths and weaknesses of the existing various spectrum sensing methods. At last, we present a WRAN-REM information assisted Collaborative spectrum sensing algorithm.(4) Data format and database structure of REM are designed. The generation steps of REM are described. The E-R model of a global REM and the retrieving REM information are found for supporting calling REM information in cognitive radios.更多还原