一种基于小波变换的混合频谱检测方法  

Mixed Method for Spectrum Sensing Based on Wavelet Transform

作　　者：仇帅[1] 陈西宏[1] 赵宇[1] 

机构地区：[1]空军工程大学防空反导学院,西安710051

出　　处：《数据采集与处理》2013年第6期834-838,共5页Journal of Data Acquisition and Processing

摘　　要：能量检测法和循环平稳特征检测法是频谱检测的两种常用方法。能量检测法的频域分辨率固定;而循环平稳特征检测峰值判决缺乏量化,噪声较大时会造成误检。针对这两种方法的不足,提出了基于小波变换的改进两步检测方案。改进的两步检测法先由多分辨率频谱检测对较宽的频带进行粗检测,对于粗检测未能检测出的频段,再由基于小波降噪的循环平稳特征检测进行细检测,判断是否存在授权用户。理论分析及仿真结果表明,在低信噪比情况下,改进算法不仅可以实现灵活可变的动态频谱检测,而且可以有效地抑制噪声影响,降低误检率,提高频谱检测性能。Energy detection and cyclostationary detection are two commonly used methods of spectrum sensing. However the frequency-domain resolution of energy detection is fixed, and cyclostationary detection lacks quantitative peak-value judgement, which will cause false detec- tion when the noise is big. A modified two steps detection scheme based on wavelet transform is proposed to over come the shortage of these two methods. The improved spectrum sensing method firstly uses muhi-resolution spectrum detection to realize coarse sensing, and then cy- clostationary detection based on wavelet denoise is used to decide whether the interference sig- nal is present or not. Theorital analysis and simulation results show that, in the case of low signal-to-noise ratio （SNR）, the proposed method can implement the flexible and alterable dy- namic spectrum sensing, restrain the noise influence, reduce the probability of false detection, and improve the detection performance.

关 键 词：频谱检测 多分辨率 循环平稳特征检测 小波变换 

分 类 号：TN92[电子电信—通信与信息系统]