认知无线电系统中频谱资源空域重用方法研究

发布时间：2018-03-09 12:23

本文选题：认知无线电　切入点：空域重用　出处：《东北大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着无线电通信技术的飞速发展和无线业务数量的不断增长,频谱资源日益匮乏。相关研究表明频谱资源静态分配机制是造成频谱资源匮乏的主要原因之一。为了提高频谱资源利用率,从根本上解决频谱资源短缺问题,Joseph Mitola于1999年提出了认知无线电技术(Cognitive Radio, CR),其核心思想是允许认知用户在不对授权用户通信造成干扰的前提下,动态接入空闲频谱资源,从而有效地提高频谱资源利用率。在认知无线电系统中进行频谱重用是提高频谱资源利用率的核心手段,因此研究频谱资源重用方法具有重要的理论意义和实用价值。本文主要研究了认知无线电系统中频谱资源空域重用方法,主要工作如下：(1)阐述了认知无线电和频谱资源重用的研究背景及意义,总结了频谱重用的国内外研究现状,介绍了认知无线电的关键技术。(2)针对频谱资源空域重用中网络传输总功率优化问题,提出了一种基于博弈论的频谱资源空域重用算法。利用博弈论建立了频谱资源空域重用问题的博弈模型,然后基于认知用户的信道质量引入价格因子来保证认知用户在各信道上分配功率的公平性。通过理论分析证明了纳什均衡点的存在性,然后利用逐次松弛迭代算法求解纳什均衡点,获得了功率分配的最优解。所提算法不仅能够实现最小化网络传输总功率,而且能够保证认知用户的服务质量。(3)针对频谱资源空域重用中系统容量最大化问题,提出了一种基于对偶理论的频谱资源空域重用算法。首先构建了基于价格函数的系统容量最大化数学模型,为便于求解将原问题转化为对偶问题,然后采用基于Armijo步长的梯度迭代算法求解纳什均衡点,有效地实现了频谱资源空域重用。与相关算法相比,该算法具有较低的计算复杂度。仿真实验结果表明所提算法不仅能够最大化系统容量,而且能够有效地抑制网络中用户之间的干扰。
[Abstract]:With the rapid development of radio communication technology and the increasing number of wireless services, Spectrum resources are becoming increasingly scarce. Related studies show that the static allocation mechanism of spectrum resources is one of the main causes of spectrum resource scarcity. In order to improve the efficiency of spectrum resources, In 1999, Mitola put forward Cognitive Radio (CR), a cognitive radio technology, whose core idea is to allow cognitive users to access idle spectrum resources dynamically without interfering with the communication of authorized users. Spectrum reuse in cognitive radio system is the key means to improve the efficiency of spectrum resources. Therefore, it is of great theoretical significance and practical value to study the method of spectrum resource reuse. In this paper, the spatial reuse method of spectrum resource in cognitive radio system is mainly studied. The main work is as follows: (1) the research background and significance of cognitive radio and spectrum resource reuse are expounded, and the research status of spectrum reuse at home and abroad is summarized. This paper introduces the key technology of cognitive radio. A spatial reuse algorithm of spectrum resources based on game theory is proposed, and a game model for spatial reuse of spectrum resources is established by using game theory. Then the price factor is introduced based on the channel quality of the cognitive user to ensure the fairness of the power allocation between the cognitive users on each channel. The existence of Nash equalization point is proved by theoretical analysis. Then the Nash equilibrium point is solved by successive relaxation iterative algorithm, and the optimal solution of power allocation is obtained. The proposed algorithm can not only minimize the total transmission power of the network. Moreover, it can guarantee the quality of service (QoS) of cognitive users. (3) aiming at the problem of maximizing system capacity in spatial reuse of spectrum resources, A spatial reuse algorithm of spectrum resources based on duality theory is proposed. Firstly, a mathematical model of system capacity maximization based on price function is constructed. Then the gradient iterative algorithm based on Armijo step size is used to solve the Nash equilibrium point, which effectively realizes the spatial reuse of spectrum resources. The simulation results show that the proposed algorithm can not only maximize the system capacity, but also effectively suppress the interference between users in the network.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN925

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