未知包络多分量线性调频脉冲信号参数估计  

Parameter Estimation of Unknown Envelope Multicomponent LFM Signal

作　　者：徐舟[1] 张浩[1] 程水英[1] 

机构地区：[1]电子工程学院雷达对抗系,安徽合肥230000

出　　处：《兵工学报》2016年第3期462-470,共9页Acta Armamentarii

基　　金：国家自然科学基金项目(61201379)

摘　　要：针对雷达侦察中的未知包络线性调频(LFM)信号参数估计问题,基于时频分析与相干积累,提出了脉冲数、调频率、中心频率、时延和脉宽参数的估计方法。利用时频分析对脉冲数与调频率进行粗估计,结合分数阶傅里叶变换(FRFT)完成脉冲数与调频率精估计;进行局部相干积累,提取中心频率、时延和脉宽。仿真分析表明:多分量LFM信号中的强脉冲可能对弱脉冲信号的参数估计产生干扰。针对该问题,在FRFT域对强脉冲进行了遮蔽处理。推导了估计参数的克拉美劳下界,并对估计误差进行了分析,结果表明:对于多分量LFM脉冲信号,遮蔽强脉冲信号后,弱脉冲信号的脉宽估计精度可显著提高。For the estimation of unknown envelope multicomponent linear frequency modulation（ LFM）signal in radar reconnaissance,the methods for the estimation of pulse number,frequency modulation rate,center frequency,delay and pulse width are proposed based on time-frequency analysis and coherent accumulation. A rough estimation is done for the parameters of pulse number as well as frequency modulation rate by time-frequency analysis,after which a fine estimation is conducted based on fractional Fourier transform（ FRFT）. Then some parameters,such as center pulse,delay and pulse width,can be extracted by coherent accumulation. Simulation results show that the weak pulse parameters estimation may be affected by strong pulse,which can be solved by filtering in FRFT domain. At last,Cramer-Rao low bounds of parameters are derived,and the estimation errors of parameters are analyzed. Results show that the estimation accuracy of width of weak pulse can be improved significantly after strong pulse filtering.

关 键 词：雷达工程 多分量线性调频信号参数估计 时频分析 分数阶傅里叶变换 克拉美劳下界 

分 类 号：TN911[电子电信—通信与信息系统]