基于MDCFT的线性调频信号参数估计方法及仿真  

Chirp Signal Parameters Estimation and Simulation Based on Modified Discrete Chirp-Fourier Transform

作　　者：黄瑶[1,2] 夏玉立[1,2] 雷宏[1] 

机构地区：[1]中国科学院电子学研究所,北京100080 [2]中国科学院研究生院,北京100039

出　　处：《系统仿真学报》2009年第5期1462-1466,共5页Journal of System Simulation

摘　　要：修正的离散线性调频傅氏变换(MDCFT:Modified Discrete Chirp-Fourier Transform)消除了离散线性调频傅氏变换(DCFT:Discrete Chirp-Fourier Transform)对参数的限制,实用性大大增加。但是由于其过高的旁瓣,在检测相同频率分辨单元的不同目标时存在缺陷。提出了一种从比较MDCFT幅度值矩阵行(列)的峰值旁瓣比来分别定位线性调频信号的多普勒中心频率和调频率的方法。分析了多普勒调频率和中心频率对邻近目标分辨的影响,并通过本方法解决了相邻目标分辨的问题。通过一系列的仿真,证明了所提方法的有效性和正确性。Modified Discrete Chirp-Fourier transform （MDCFT） eliminates the signal parameters restrictions of Discrete Chirp-Fourier transform （DCFT）, so it is of more practical sense. But the MDCFT has high sidelobes, it has serious disadvantages when there are more than one signals in the same frequency cell. A chirp parameters estimation method was proposed which could evaluate the Doppler frequency and chirp rate separately of the linear frequency modulation signals by comparing the mainlobe and sidelobe magnitude ratio of the rows or columns in the MDCFT amplitude matrix. The influence of the Doppler frequency and chirp rate on the resolving capability of the adjacent targets was analyzed and solved by the method. The simulation results proved that the method is effective and correct.

关 键 词：离散CHIRP-FOURIER变换 修正的离散Chirp—Fourier变换 线性调频信号 多普勒频率 峰值旁瓣比 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]