LFM的一种自适应滤波方法

An Adaptive Filter Method of LFM Signal

研究了白噪声环境下线性调频信号的自适应滤波问题。提出了一种LFM自适应滤波算法,该算法利用分数阶傅里叶变换将LFM信号转化为正弦信号,在u域进行自适应滤波,利用分数阶傅里叶反变换得到滤波后的时域信号。该算法为白噪声下LFM信号增强、滤波提供了一种算法框架。性能分析表明,该算法的滤波效果取决于自适应滤波器的效果。最后仿真表明该算法效果明显,计算方便。

An adaptive filter method of LFM signal in white noise is discussed. The conception and character of FRFT（FRactional Fourier Transform） is analyzed, and the result is that LFM signal can be transformed to sinusoid signal approximately using FRFT. The adaptive filter is implemented in u-domain, and the filtered signal in time domain is gained using fractional Fourier reverse transform. This method provides a uniform frame of LFM signal enhancement and filter in white noise. The results show that the performance of the method depends on the performance of adaptive filter. When LMS algorithm is used, the performance of ALE is decided by step parameter, and the step parameter is selected in practice. At last, simulation results show that this filtering algorithm is simple in computation and easy in implementation.