基于FrFT和子空间正交的LFM信号参数估计

基于分数阶Fourier变换和子空间正交性,提出了一种低信噪比下线性调频信号检测与参数估计方法。讨论过程中将线性调频信号通过适当的分数阶Fourier变换得到一个单频复正弦信号,在此基础上,利用信号子空间与噪声子空间的正交性处理其正弦信号,再对线性调频信号的检测和参数估计转化为函数极值求解;最后,利用计算机模拟证实了方法的有效性。

An Approach for Estimating Parameters of LFM Signal Based on Fractional Fourier Transform and Subspace Orthogonality

Based on the fraction Fouier transform and subspace orthogonality,an approach,which detects and estimates the parameters of the low SNR LFM signal,is proposed in this paper.The LFM signal is first transformed into a complex sinusoidal signal in term of the fraction Fourier transform,and then using the orthogonality between the subspace of noise and the subspace of the transformed signal,the detection and parameters estimation of LFM signal is achieved by finding the minimum/maximum. Computer simulation confirms its availability.