一种改进多分量LFM信号时频分布估计方法

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。

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

There is a notable drawback for traditional time-frequency distribution method that it fails to suppress cross-terms caused by multicomponent linear frequency modulation (LFM) signals.To effectively suppress the cross-terms,an improved method based on frequency rate database is proposed.By analyzing the relationship 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 multicomponent LFM signal as an example,the simulation results show that compared with the traditional time-frequency distribution method,the proposed method can effectively suppress the cross-terms and retain most of the self-terms,which improves the accuracy and anti-noise capacity of time-frequency distribution estimation.