基于FRFT的复合chirp信号分析

Composite Chirp Signal Analysis based on FRFT

作为Fourier变换的一种广义形式,分数阶傅里叶变换(FRFT)同时融合了信号在时域和频域的信息,是一种新的时频分析方法。而复合线性调频(chirp)信号相对单斜率线性调频信号具有更好的速度分辨力和距离速度联合分辨力。为了分析该信号的特征,提出了一种基于分数阶Fourier变换的分析方法。由于复合chirp信号在FRFT域呈现的冲激特性,以此实现复合chirp信号的检测。实验结果表明,该方法对复合chirp信号的检测是有效的。

As a generalization of Fourier transform, the Fractional Fourier Transform （FRFT） contains the time-frequency information of the signal, and is considered as a new tool for time-frequency analysis. The composite chirp signal has a better performance on velocity resolution and joint distance-velocity-resolu- tion than the single slope chirp signal. In order to analyze the characteristics of the signal, a new approach based on fractional Fourier Transform is presented. With the help of the property that the composite chirp signal can produce a strong impulse in the FRFF domain, the signal could be detected conveniently. Ex- perimental result indicates that the proposed method is effective in detecting composite chirp signals.