多分量LFM信号在分数阶Fourier域的参数估计与分离

Parameters estimation and separation of multi-component LFM signal in fractional Fourier domain

分数阶Fourier变换由于其特有的性质,非常适合处理LFM(linear frequency modulation)信号,尤其是作为一种线性变换,可以克服多分量LFM信号交叉项的干扰。在分数阶Fourier变换用于单分量LFM参数估计的基础上,采用预判与分数阶自相关相结合的方法,在分数阶Fourier域对多分量LFM信号模型进行检测和参数估计,极大地减小了计算量,并采用Clean法实现了不同强度LFM信号的分离,抑制了强分量信号对弱分量信号的遮蔽干扰。仿真实验表明,该方法具有较好的效果。

Fractional Fourier transform （FRFT） is very suitable to process linear frequency modulation （LFM） signal, and espe- cially, as a kind of linear transformation, can overcome cross-term interference of multi-component LFM signal because of its spe- cial nature. This study uses anticipation and fractional autocorrelation methods to estimate the parameters of multi-component LFM signal in fractional Fourier domain based on FRFT that is for estimating single component LFM signal parameters, and a- dopts the Clean method to realize the separation of different strength LFM signals and inhibit the sheltering and interference of strong component signal to weak component signal. The simulation shows that this method is fairly effective.