摘要
针对传统基于分数阶傅里叶变换(fractional Fourier transform,FRFT)的线性调频(linear frequency modulated,LFM)信号参数估计方法中估计精度和计算量难以同时满足实际要求的问题,提出一种分数域二分法的LFM信号参数估计方法。该方法分析量化了变换阶次误差对参数估计误差的影响,利用单分量LFM信号变换阶次和分数域展宽的关系,通过迭代不断缩小变换阶次的取值范围,获得满足初设阈值的最优阶次,并利用最优阶次和峰值位置对LFM信号进行参数估计。采用逐次重构消除的方法,可以对强弱混合的多分量LFM信号进行参数估计。仿真结果表明,在满足信噪比要求的条件下,该方法能够有效地对LFM信号进行参数估计,可以通过参数估计精度的要求选择不同阈值,与传统方法相比,在参数估计精度相当的情况下大大地减小了计算量。
Traditional parameter estimation methods of linear frequency modulation( LFM ) signal based on fractional fourier transform did not deal with the contradiction between the satisfactoiy precision and the lesser computation cost . Therefore,a fractional domain dichotomy is proposed in this paper. Firstly, the effect of the transform order error on the parameter estimation error is analyzed and quantified. Then, the fractional domain dichotomy is adopted to obtain the optimal order of single component LFM signal corresponding to fractional domain minimum bandspread. Finally, the parameters are estimated according to the optimal order and the peak position. The parameters of strong and weak mixing multi-component LFM signal are estimated by using successive reconstruction and elimination method. Simulation results show that, compared with the traditional method, the method can meet the requirement of estimation precision with the computation cost reduced significantly.
作者
孙乐
魏军
张衡阳
刘立
王建翔
SUN Le;WEI Jim;ZHANG Hengyang;LIU Li;WANG Jianxiang(Information and Navigation College, Air Force Engineering University, Xi’a n , 710077, P. R. China;Air Force 95801 Army, Beijing 100076,P. R. China)
出处
《重庆邮电大学学报（自然科学版）》
CSCD
北大核心
2016年第4期473-480,共8页
Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)
基金
国家自然科学基金(61202490)
航空科学基金(2013ZC15008)~~
关键词
分数阶傅里叶变换
线性调频(LFM)信号
分数域
二分法
最优阶次
fractional Fourier transform
linear frequency modulated ( LFM ) signal
fractional domain
dichotomy
the optimal order
