基于分数阶功率谱的LFM信号检测

LFM signal detection based on fractional power spectrum

从分数阶傅里叶变换与Winger-Ville分布的关系出发,推导出分数阶功率谱与模糊函数过原点切片之间的傅里叶变换关系,提出了一种基于分数阶功率谱的LFM信号检测新因子,并证明了该因子与RAT检测因子等价。基于新因子的检测只需计算信号一定角度区域内的分数阶功率谱就能实现检测,因此相比于RAT方法在计算量上具有比较明显的优势。

The interesting fact that the radial slice of the ambiguity function is the Fourier transform of the fractional power spectrum is deduced from the relationships between fractional Fourier transform （FRFT） and time-frequency distributions. Then a new detector for linear frequency modulated signals is proposed, and the equivalence between the new detector and the RAT detector is demonstrated. Therefore a new LFM signal detection method using the new detector is proposed. Only some FRFT calculation in certain angle is essential for the new method, so its computational complexity is lower than that of the RAT method.