基于USRP的认知无线电通信终端设计-通信与信息系统专业论文.docx

摘 要 在无线通信技术迅速发展的今天，频谱资源也愈加紧张。为了解决频谱资源 匮乏的问题，人们提出了认知无线电这一概念。认知无线电利用具有认知功能的 无线通信设备感知周围的环境，若发现某段授权频谱当前空闲，就将该频段分配 给认知用户使用；一旦发现授权用户重新使用该频段，则认知用户应采用某种方 式立即退避，从而避免对授权用户造成有害干扰。总之，认知无线电通过灵活智 能的运作，发现“频谱空洞”，并合理地对其充分利用，从而极大的提高了频谱利 用率。为了能够准确灵敏地发现“频谱空洞”，其中的频谱感知技术便成为认知无 线电中的研究热点。 本文针对认知无线电通信演示系统的单小区通信场景，设计基于 USRP 的认 知无线电通信终端。文中首先对认知无线电做了简要介绍，然后说明小区的整体 场景，最后重点对终端节点的感知功能及通信功能进行详细设计和实现。基于 GNU Radio 开源软件和 USRP （通用软件无线电外设）搭建了认知无线电平台，使用 Python 脚本语言进行开发，并且通过 wxPython 描绘出图形界面对实现的结果予以 直观显示。 关键词：认知无线电 频谱空洞 频谱感知技术 GNU Radio USRP Abstract With the rapid development of the wireless communication technology, the spectrum resource is becoming more and more important. The cognitive radio is put forward to solve the shortage of the spectrum. The wireless communication equipment which has the cognitive function is used to sense the surrounding environment. Once the spectrum hole is found it can be used by the cognitive user freely. But when the licensed user is returned, the cognitive user has to use other spectrum so that the licensed user should not be disturbed. In brief, the cognitive radio works intelligently to find the spectrum hole to improve the utilization of the spectrum. In order to find the free spectrum sensitively and accurately, the spectrum sensing technology is one of the most important technologies in cognitive radio. This paper is based on the cognitive radio communication and designs a single cell communication scene. The design is about the cognitive radio communication terminal which is based on the USRP. The paper first gives a brief introduction of the cognitive radio. Then a design of the overall scene is described. Finally it focuses on the design and the realization of the perception function and the communication function of the terminal node. This design of the cognitive radio platform is based on the GNU Radio which is an open source software and the USRP which stands for the general software radio peripherals. The language what is used in this development is Python