一种改进的跳频信号时频分析方法  

An improved time-frequency analysis method for frequency hopping signal

作　　者：冯维婷 梁青 谷静 FENG Weiting;LIANG Qing;GU Jing(School of Electronic Engineering,Xi＇an University of Posts and Telecommunications,Xi＇an 710121,China)

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121

出　　处：《西安邮电大学学报》2018年第3期26-30,共5页Journal of Xi’an University of Posts and Telecommunications

基　　金：国家自然科学基金资助项目(61202490);陕西省自然科学基金资助项目(2014JM2-6117);陕西省教育厅科学研究计划资助项目(15JK1654);西安邮电大学校青年教师科研基金资助项目(101-0486)

摘　　要：利用正交匹配追踪的稀疏表示算法进行跳频信号时频分析时,性能受到傅里叶基矩阵长度和稀疏度未知的限制。针对此问题,结合跳频信号特点对稀疏表示算法加以改进:将跳频信号分段,对每段信号进行傅里叶变换并进行门限检测,得到频率预估计值和信号稀疏度;利用频率预估计值构造频率细化子傅里叶基矩阵;基于正交匹配追踪算法得时频谱图。在运算量相同的情况下,改进方法比直接采用正交匹配追踪算法可获得更高精度的时频谱。The performance of time-frequency analysis of frequency-hopping signals using sparse representation algorithm based on orthogonal matching pursuit is limited by the length of Fourier basis matrix and blind sparsity.To solve this problem,the sparse representation algorithm is improved by combining the characteristics of frequency-hopping signals.The frequency-hopping signal is segmented,each segment signal is transformed by Fourier transform and the threshold is detected to get the frequency pre-estimated value and signal sparsity.According to the pre-estimated value of frequency,the frequency thinning sub-Fourier basis matrix is constructed,and then,the time-frequency spectrum with high accuracy is achieved based on the orthogonal matching pursuit algorithm.In the case of the same computation,the improved method can obtain a higher precision time-frequency spectrum than the original orthogonal matching pursuit algorithm.

关 键 词：时频分析 跳频信号 稀疏表示 正交匹配追踪 

分 类 号：TN911.7[电子电信—通信与信息系统]