基于FrFT的欠采样LFM信号分离与参数估计

An Algorithm for Separation and Parameter Estimation for Sub-sampled LFM Signals Based on FrFT

基于分数阶傅里叶变换,本文提出了一种欠采样条件下的宽带与窄带线性调频信号分离与参数估计方法。该方法先由延迟相乘和牛顿迭代算法估计信号的调频斜率,然后在分数阶傅立叶变换域进行滤波,实现信号分离。最后对欠采样信号解频率模糊,估计信号的初始频率。仿真表明了该方法分离宽带与窄带线性调频信号的可行性与分离后信号参数估计的有效性。

Based on the Fractional Fourier Transform（ FrFF）, an algorithm, which separates and estimates parameters on the sub-sampled LFM signals, is given. After modulation rate estimated roughly using the signal with its delay version production and Newton＇s iterative method, signals are filtered and separated in the Fractional Fourier Transform domain. Moreover, the initial frequencies of the sub-sampled LFM signal are estimated by the signal with its delay version production unambiguously. Simulations testify not only the feasibility of separation for both wide and narrow band LFM signals, but also the validity of signal parameter estimation after separation.