多LFM信号自适应时频表示方法  

Novel method for multi-LFM signals adaptive time-frequency representation

作　　者：杜雨洺[1] 杨建宇[2] 张富贵[1] 王江[1] 

机构地区：[1]成都信息工程学院电子工程系,四川成都610225 [2]电子科技大学电子工程学院,四川成都610054

出　　处：《系统工程与电子技术》2008年第7期1245-1248,共4页Systems Engineering and Electronics

摘　　要：提出了一种多线性调频信号自适应时频表示方法及其快速算法:首先采用分数阶傅里叶变换的快速算法计算出模糊函数,再通过Radon-Ambiguity变换设计出信号的最优核函数,以滤除噪声和多线性调频信号在模糊域中的互项,最后通过二维傅里叶变换得到信号的时频表示。在多分量线性调频信号情况下借助"clean"的思想来抑制强分量对弱分量的干扰。仿真表明该方法在低信噪比环境下也十分有效,且运算复杂度小。A method for multi-LFM signals adaptive time-frequency representation is proposed. Firstly, the ambiguity function is realized by fast algorithm of fractional Fourier transform. Secondly, the optimal kernel function is designed by Radon-Ambiguity transform, which can remove the cross term and partly noise. Finally, the time-frequency representation is realized by two-dimensional Fourier transform. To eliminate the mutual in- terference of multiple LFM components, especially the strong LFM signals to weak LFM signals, a scheme based on the idea of clean is proposed. The simulation results show that the method is effective even in low SNR environment with less computational complexity.

关 键 词：时频表示 线性调频信号 分数阶傅里叶变换 RADON-AMBIGUITY变换 模糊函数 

分 类 号：TN95[电子电信—信号与信息处理]