基于时频图局部方差的跳频信号检测  

The Detection of Frequency Hopping Signal Based on Local Variance of Time-frequency Spectrum Diagram

作　　者：李春 赵知劲[1,2] 岳克强[1] 叶学义[1] LI Chun;ZHAO Zhijin;YUE Keqiang;YEXueyi(College of Communication Engineering,Hangzhou University of Electronic Science and Technology,Hangzhou 310018,China;National Key Lab of Communication System Information Control Technology of No.36th Institute of China Electronis Technology Group,Jiaxing 314001,China)

机构地区：[1]杭州电子科技大学通信工程学院,杭州310018 [2]中国电子科技集团第三十六研究所通信系统信息控制技术国家级重点实验室,浙江嘉兴314001

出　　处：《火力与指挥控制》2022年第10期67-70,76,共5页Fire Control & Command Control

摘　　要：为提高低信噪比下跳频信号的检测性能,充分利用跳频信号、定频信号、高斯白噪声具有的不同时频分布特点,提出一种基于时频谱图局部方差的跳频信号检测算法。利用短时傅里叶变换得到时频图,由于跳频信号在不同时间段具有不同频率,跳频信号的时频谱分布离散性大于高斯白噪声和定频信号,因此,引入时频谱图局部方差作为检测统计量,反映信号时频谱分布离散性,理论推导了检测门限。仿真结果表明,该算法具有抗噪声功率不确定性能力;当跳频信号检测概率高于0.8时,相比于时频对消比算法,该算法改善信噪比大约1 dB左右。In order to improve the detection performance of frequency hopping signals under low signal-to-noise ratio,the different characteristics of time-frequency distribution of frequency hopping signals,fixed frequency signals,and Gaussian white noise are made full use of respectively,and a detection algorithm of frequency hopping signal based on the local variance of the time-frequency spectrum diagram is proposed.The time-frequency spectrum diagram is obtained by using short-time Fourier transform the dispersion of distribution of time-frequency spectrum.As the frequency hopping signal has different frequencies in different time periods,of the frequency hopping signal is greater than Gaussian white noise and fixed-frequency signals.The local variance of the time-frequency spectrum diagram is introduced as a detection statistic quantity,which reflects the dispersion of the time-frequency spectrum diagram of the signal.And then the detection threshold is theoretically derived.The simulation results show that the proposed algorithm has the uncertainty to resist noise power;when the detection probability of the frequency hopping signal is higher than 0.8,the proposed algorithm improves the signal-to-noise ratio by about 1 dB compared with the time frequency cancellation ratio algorithm.

关 键 词：跳频信号检测 时频对消 短时傅里叶变换 局部方差 

分 类 号：TN9[电子电信—信息与通信工程]