采用离散小波变换的认知无线电频谱能量检测  

Spectrum Energy Detection Using Discrete Wavelet Transform for Cognitive Radios

作　　者：魏东兴[1] 殷福亮[1] 

机构地区：[1]大连理工大学信息与通信工程学院,辽宁大连116024

出　　处：《信号处理》2014年第3期306-313,共8页Journal of Signal Processing

摘　　要：在认知无线电系统中,频谱检测是搜索空闲信道,避免对授权用户产生干扰的关键环节。本文提出了一种离散小波变换与时域能量检测相结合的频谱检测方法,对认知用户共享的宽带信道中的窄带授权用户信号进行预检测。首先对接收信号进行离散小波变换,获得能够反映信道频谱变化的细节小波系数,然后以该系数作为统计量,对其进行时域能量统计计算,以进行频谱检测。该方法计算量较小,易于实现,可进行多分辨率分析,能够提高检测的灵敏度和低信噪比下的检测性能且不需要被检测信号的先验知识,适用于检测各种未知信号。仿真实验对无线麦克信号和地面无线数字电视信号进行了检测,验证了该方法的正确性。In a cognitive radio （CR） context,spectrum.detection is a key task for searching white space and avoiding harmful interference to primary users.A spectrum sensing scheme of time domain energy detector based on discrete wavelet transform （DWT） is proposed for sensing a narrow band PU signal in the channel accessed by SU.DWT is first to used to decompose the received signals,and one of the wavelet detail spaces may show the irregularities in channel signals,then calculate the energy of the detail space in time domain.The proposed scheme which has lower computational complexity,can perform multi-resolution spectrum sensing and exhibits a good detection performance at low SNR.Because of easy to implement and no requirement of any priori information about signals,it can be used to detect unknown signals.Simulations for wireless microphone signals and terrestrial digital TV channels are carried to verify the proposed scheme.

关 键 词：认知无线电 频谱检测 离散小波变换 能量检测 

分 类 号：TN92[电子电信—通信与信息系统]