基于USRP的认知无线电频谱感知及动态接入技术研究

发布时间：2018-01-08 11:37

本文关键词：基于USRP的认知无线电频谱感知及动态接入技术研究　出处：《广西师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着无线通信技术快速发展,人们对于无线业务需求不断增加,无线电频谱作为一种不可再生资源在无线通信技术及业务中的地位变得至关重要。然而目前的频谱分配均采用静态分配原则,这种固定的分配方式使得无线通信中可用未授权频段越来越少,且容易因为授权频段利用率低造成频谱浪费。认知无线电理论被认为是解决上述问题的有效方法,其允许认知用户在不对授权用户产生不可忍受干扰的前提下使用授权用户信道进行通信和数据传输,这就要求认知无线电系统具有快速的频谱感知和灵活的动态接入能力。目前,国内外关于认知无线电的研究大多基十理论和仿真,缺少实际无线环境中的测试,因此,本文使用USRP(Universal Software Radio Peripheral,通用软件无线电外设)作为硬件平台,GNU Radio(开源软件无线电)作为软件平台,搭建了认知无线电通信系统。能够在实际工作环境中实现频谱感知和动态频谱接入技术。本文的核心内容主要包括以下几个方面:第一,在USRP和GNU Radio平台上实现了大范围的频谱感知。通过研究能量检测算法的基本原理,在USRP和GNU Radio平台上实现了大范围能量检测方法,测试了虚警概率对检测效果的影响。第二,在传统能量检测算法的基础上,针对广播电视系统和蜂窝网式的移动通信系统这两种不同授权用户环境下的认知无线电系统,提出并实现了两种基于先验信息的能量检测优化算法,通过分析这两类认知无线电系统的特点,分别从检测序列和子信道划分两个方面对传统能量检测方法进行改进,使用USRP和GNU Radio平台测试并验证了上述两种改进方法的可行性。第三,在频谱感知的基础上,建立了集中式认知无线网络。使用两台USRP硬件分别作为认知基站和认知用户,设计了网络的基本构架。实现了认知基站和认知用户之间从频谱感知到空闲频段下发再到空闲频段动态接入等过程。完成了上.述关键过程的测试,并在此基础上测试了网络的整体性能。
[Abstract]:In recent years, with the rapid development of wireless communication technology, the demand for wireless services is increasing. The status of radio spectrum as a non-renewable resource in wireless communication technology and services has become very important. However, the static allocation principle is adopted in the current spectrum allocation. This fixed allocation method makes less and less unauthorized frequency bands are available in wireless communication. Cognitive radio theory is considered to be an effective method to solve the above problems. It allows cognitive users to communicate and transmit data using authorized user channels without causing intolerable interference to authorized users. This requires the cognitive radio system to have fast spectrum sensing and flexible dynamic access ability. At present, most of the researches on cognitive radio are based on the theory and simulation, and lack of testing in the actual wireless environment. Therefore, this paper uses USRP(Universal Software Radio Peripheral (Universal Software Radio Peripheral) as the hardware platform. GNU Radio (open source software radio) serves as a software platform. The cognitive radio communication system is built. It can realize spectrum sensing and dynamic spectrum access technology in the actual working environment. The core content of this paper mainly includes the following aspects: first. The spectrum sensing is realized on the platform of USRP and GNU Radio, and the basic principle of energy detection algorithm is studied. A large-scale energy detection method is implemented on the platform of USRP and GNU Radio, and the influence of false alarm probability on the detection effect is tested. Secondly, based on the traditional energy detection algorithm. Aiming at two kinds of cognitive radio systems under different authorized user environments, radio and television systems and cellular mobile communication systems, two energy detection optimization algorithms based on prior information are proposed and implemented. By analyzing the characteristics of these two kinds of cognitive radio systems, the traditional energy detection methods are improved from two aspects: detection sequence and sub-channel division. Using USRP and GNU Radio platform to test and verify the feasibility of these two improved methods. Third, on the basis of spectrum sensing. A centralized cognitive wireless network is established using two USRP hardware as cognitive base stations and cognitive users. The basic architecture of the network is designed. The process from spectrum sensing to dynamic access of idle frequency band and then to idle frequency band between cognitive base station and cognitive user is realized. The testing of the key process mentioned above is completed. On this basis, the overall performance of the network is tested.
【学位授予单位】：广西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925

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