一种改进多分量LFM信号时频分布估计方法  

An Improved Time-Frequency Distribution Estimation Method for Multicomponent LFM Signals

作　　者：孔慧芳[1] 张子煜 KONG Hui-fang;ZHANG Zi-yu(School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽合肥230009

出　　处：《测控技术》2018年第11期112-115,共4页Measurement & Control Technology

基　　金：国家重大科学仪器设备开发专项资助项目(2012YQ20022406)

摘　　要：传统时频分布方法在估计多分量线性调频信号时,交叉项影响导致时频估计精度低。因此,提出建立信号调频斜率因子库,对时频分布核函数进行改进,使核函数能有效抑制由多分量信号引起的交叉项干扰。通过分析核函数与信号模糊函数交叉项及自身项的关系,将时频估计问题转化为求解最优调频斜率因子库来对核函数进行改进,使信号的广义模糊函数能量最大。以多分量线性调频信号为例进行仿真,结果证明与传统时频分布方法相比,改进的时频估计方法可以在有效抑制交叉项干扰的同时保留大部分自身项,提高了多分量信号时频估计的精度和抗噪声能力。There is a notable drawback for traditional time-frequency distribution method that it fails to sup- press cross-terms caused by muhicomponent linear frequency modulation （LFM） signals. To effectively sup- press the cross-temls, an improved method based on frequency rate database is proposed. By analyzing the rela- tionship between kernel function and signal fuzzy functions cross and self terms, the time-frequency question is transferred to establish a frequency rate database which can adjust the kernel function optimally and get the maximum fuzzy function energy. By applying muhicomponent LFM signal as an example, the simulation results show that compared with the traditional time-frequency distribution method, the proposed method can effective- ly suppress the cross-terms and retain most of the self-terms, which improves the accuracy and anti-noise ca- pacity of time-frequency distribution estimation.

关 键 词：多分量线性调频信号 时频分布 核函数 调频斜率因子库 交叉项 

分 类 号：TN911.72[电子电信—通信与信息系统] TP277[电子电信—信息与通信工程]