基于OFDM的认知无线电技术研究

发布时间：2018-01-16 01:12

本文关键词：基于OFDM的认知无线电技术研究　出处：《吉林大学》2014年硕士论文　论文类型：学位论文

【摘要】：目前，无线通信技术发展十分迅速，迫切需要大量的无线频谱资源，而频谱资源的匮乏极大地阻碍了无线通信技术的发展。目前固定频率的静态频谱资源分配技术使频谱资源利用率极低。认知无线电为动态的频谱资源管理策略，它被认为是一种提高频谱资源使用效率和扩大系统容量，缓解频谱资源使用压力的新方法。本文将认知无线电技术和OFDM技术两者结合，提高了频谱利用率。本文首先介绍了认知无线电系统中的一些常见概念和关键技术，基于常见概念和关键技术对认知无线电频谱感知技术进行研究，介绍单用户感知和协作检测这两类频谱检测方法，并对它们进行性能仿真比较。每种频谱检测方式都有各自的优缺点，只有根据认知用户的性质及需求来选取合适的检测方法才能得到最优检测结果。然后，阐述了OFDM技术的基本工作原理及资源分配方式，，建立基于OFDM的认知无线电系统模型，分析系统中认知用户对主用户的干扰及主用户对认知用户的干扰。最后，通过研究学习认知无线电频谱资源分配的分类及分配原则，基于建立的基于OFDM的认知无线电系统模型，介绍频谱资源分配方案中的四种子载波分配算法和基于线性注水机制的功率分配算法，提出了PI算法的简化算法PIA和PIB，简化算法的复杂度低但性能接近原算法。结尾对全文进行总结和展望，对文中所做研究工作进行了初步归纳，并对研究工作中存在的不足进行了分析，对以后需要进一步开展的研究工作进行了简要描述。
[Abstract]:At present, wireless communication technology is developing very rapidly, and a large number of wireless spectrum resources are urgently needed. The lack of spectrum resources greatly hinders the development of wireless communication technology. At present, the static spectrum resource allocation technology with fixed frequency makes the spectrum resource efficiency extremely low. Cognitive radio is a dynamic spectrum resource management strategy. It is considered to be a new method to improve the efficiency of spectrum resources, expand the system capacity and relieve the pressure of spectrum resources. This paper combines cognitive radio technology and OFDM technology. The spectrum efficiency is improved. This paper first introduces some common concepts and key technologies in cognitive radio system. Based on common concepts and key technologies, the spectrum sensing technology of cognitive radio is studied. Two kinds of spectrum detection methods, single user sensing and cooperative detection, are introduced, and their performance is simulated and compared. Each spectrum detection method has its own advantages and disadvantages. Only according to the nature and needs of cognitive users to select the appropriate detection method can get the optimal detection results. Then, the basic working principle and resource allocation of OFDM technology are expounded. A cognitive radio system model based on OFDM is established to analyze the interference of cognitive users to primary users and the interference of primary users to cognitive users. Finally. By studying the classification and allocation principle of learning cognitive radio spectrum resource allocation, a cognitive radio system model based on OFDM is established. The four subcarrier allocation algorithms and the power allocation algorithm based on linear water injection mechanism are introduced in the spectrum resource allocation scheme. A simplified Pi algorithm, PIA and PIB, is proposed. The simplified algorithm has a low complexity but its performance is similar to the original algorithm. At the end of the paper the paper summarizes and prospects the research work and analyzes the shortcomings of the research work. The further research work needed to be carried out in the future is briefly described.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN925

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