认知无线电中协作频谱感知研究

认知无线电中协作频谱感知研究(论文16000字)
摘要
随着频谱资源日趋紧张，人们越来越意识到频谱分配与使用之间的矛盾。认知无线电(Cognitive Radio, CR)的出现将为频谱资源僵乏的问题提供有效的解决手段。认知无线电技术作为一种革命性的智能频谱共享技术，己成为无线通信领域新的研究热点。
本文从不同的方面对协作频谱感知性能进行了研究。首先，文章阐述了协作频谱检测的基本原理，分类及主要衡量指标。然后，着重介绍协作频谱技术中设计的判决及决策规则。最后，在协作频谱感知系统中，针对认知用户数与认知用户的感知时长的参数优化问题，基于优化系统资源利用效率和归一化吞吐量的目标，建立了系统效用函数。在确定的检测概率和虚警概率的条件限制下，通过对用户数和感知时长的变化分析来求解系统效应函数的最优化问题。通过研究系统效用函数的变化曲线，初步提出一种快速寻找最优值的方法，并且通过仿真找出用户数和感知时长的最优值，从而实现系统效用函数的优化。
关键词：认知无线电；协作频谱感知；虚警概率；检测概率
Research on Cooperative Spectrum Sensing of
Cognitive Radio
ABSTRACT
As radio resource is becoming increasingly scarce, more and more people realize the contradiction between the allocation and the usage of the spectrum. The appearance of Cognitive Radio (CR) will provide effective solution to the problem of spectrum shortage. CR as a revolutionary intelligence technology is becoming a hot research topic in wireless communication field.
The paper studies cooperative spectrum sensing from different aspects. Firstly, the basic principles of cooperative spectrum detection, classification, and the main measure are described. Secondly, cooperative spectrum technology is focused on the design of judgment and decision-making rules. Finally, according to the parameter optimization problem of the number and sensing time of cooperative users in cooperative spectrum sensing system, the system utility function is established based on the system resource utilization efficiency and normalized throughput. In different conditions of detection probability and false alarm probability, the optimal problem of system utility function is solved by analyzing the change of the number and sensing time of cooperative users. A fast way to find the optimal value is proposed that makes the cooperative spectrum sensing system get the best performance.
Key words: cognitive radio; cooperative spectrum sensing; false alarm probability; detection probability
 
目  录
摘要    I
ABSTRACT    II
第一章 绪论    5
1.1研究背景及意义    5
1.2认知无线电概述    6
1.3频谱感知技术    8
1.4 主要研究内容和章节安排    11
第二章 协作频谱感知技术    13
2.1协作频谱感知技术    13
2.2协作频谱感知性能衡量指标    15
2.3判决融合与决策规则    16
2.4协作频谱感知技术存在的问题    18
2.5本章小结      19
第三章 协作频谱感知技术的优化    20
3.1系统模型    20
3.2用户数量和感知时长参数的优化    23
3.3仿真及结果    25
3.4本章小结    26
第四章 结语    28
参考文献    29
致  谢    31
附录    32