结合循环平稳特征和自适应双门限检测的频谱感知算法  

The Spectrum Sensing Algorithm Based on Cyclostationary Feature and Adaptive Dual-threshold Detection

作　　者：袁海英[1] 胡瑜[2] 

机构地区：[1]北京工业大学电子信息与控制工程学院,北京100124 [2]中国科学院计算技术研究所计算机体系结构国家重点实验室,北京100190

出　　处：《计算机辅助设计与图形学学报》2013年第4期573-577,共5页Journal of Computer-Aided Design & Computer Graphics

基　　金：国家自然科学基金(61001049);计算机体系结构国家重点实验室开放课题(CARCH201103)

摘　　要：针对单门限能量检测算法存在虚警率高、循环平稳特征检测算法计算复杂等问题,为了降低无线信道平均捕获时间和信号检测算法复杂度,提出一种联合循环平稳特征的自适应双门限能量检测算法.该算法根据无线信道占用状态自适应调整双门限值搜索频谱信息,将无线麦克风信号接收后直接送入第1个积分电路,在双门限区域之外采用无线信号能量检测;当第1个比较器中能量累积输出低于检测下门限时,表明未检测到无线信号;当积分电路输出超过检测下门限时则启动第2个积分电路,当第2个比较器中能量累积超过检测上门限时启动第3个比较器,超过同步门限判断虚警状态;在双门限区域之间采用循环平稳特征检测快速、准确地捕获无线麦克风信号,并合理设置保护频带,让非授权用户充分利用保护频带之外的频谱资源.仿真结果表明,文中算法有效地提高了无线认知网络的无线信号检测概率和频谱感知精度.A method with adaptive dual-threshold energy and cyclostationary feature detection is presented, which aims at reducing high false alarm rate and computation complexity occurred in the single threshold energy detection algorithm and obtaining the less radio channel average capture time and lower signal detection computational complexity. The two thresholds are adaptively adjusted to search the spectrum based on the channel status of occupancy, the wireless signal received in radio microphone is send to the first integrator, and the signal outside dual-threshold region isdetected using the energy detection method. The output of the energy accumulated in the first comparator less than the low-threshold shows no wireless signal be detected, the second integrator works if the output of energy accumulated exceed the low-threshold, when the energy accumulated in second comparator exceed upper-threshold, the third comparator starts to judge, the false alarm state is detected if the energy exceed the synchronous threshold, the wireless microphone signal is detected using the cyclostationary feature detection outside the dual-threshold, and the guardband is properly set up, it permits the unauthorized users to make full use of spectrum oeellrod cmt^irl~ ＊h ,4 I.~,~ Tk^simulation results show that, it is effectively using the detection algorithm proposed to improve signal detection efficiency and spectrum sensing accuracy in wireless cognitive networks.

关 键 词：频谱感知 无线麦克风信号 双门限能量检测 循环平稳特征 虚警率 

分 类 号：TN911[电子电信—通信与信息系统]