时频聚集性分析的频谱感知方法  

Spectrum sensing method for the time-frequency gathering density analysis

作　　者：郑文秀[1] 

机构地区：[1]西安邮电大学通信与信息工程学院,陕西西安710121

出　　处：《西安电子科技大学学报》2012年第6期176-180,194,共6页Journal of Xidian University

基　　金：国家自然科学基金资助项目(61271276;61172071);新世纪人才计划资助项目(NCET-08-0891);陕西省自然科学基础研究计划资助项目(2010JQ80241;2011JQ8027)

摘　　要：针对单载波和最小频移键控(MSK)调制的主用户信号,提出了一种基于时频聚集度分析的频谱感知算法.计算接收数据互相关函数的时频脊线,统计时频脊线点集的概率向量;利用信号能量在时频谱上的聚集性和信道噪声时频点的均匀分散性的特点,定义时频聚集度来评价时频点的聚集程度,并设定聚集度门限,用以判断主用户信号的存在性.仿真实验表明,该算法对一般信道和衰落信道都是有效的,并在较低信噪比下保持了良好的检测性能;在相同的噪声功率不确定度下,其虚警概率低于能量检测法.Aiming at the primary users＇ signals with single carrier or MSK modulation,a novel spectrum sensing algorithm is proposed based on the time-frequency gathering density analysis.The time-frequency ridge line of the received data＇s mutual correlation is calculated,with whose statistics the probability vector is formed.The time-frequency gathering density is defined to evaluate the gathering level of the time-frequency dots according to the fact that the signal energy gathers around the carrier frequency and that the noise energy disperses evenly among all frequencies.The gathering threshold is set to judge the existence of the primary user＇s signal.Simulation indicates that the proposed algorithm is effective for both the normal and fading channel and maintains good detecting performance at lower SNRs and that with the same noise power uncertainty,the false alarm of the proposed algorithm is lower than that of the energy detection method.

关 键 词：认知无线电 频谱感知 动态频谱获取 信号检测 

分 类 号：TN911.23[电子电信—通信与信息系统]