基于加权型三次相位函数和FRFT的LPI信号识别研究

针对低截获概率雷达信号难以识别和分类的问题,提出了基于加权型三次相位函数和分数阶傅里叶变换的低截获概率雷达信号识别算法。用短时傅里叶变换剖析了应用较广的八种低截获概率雷达信号的时频特性,然后依据调频率将其分为两类。先用加权型三次相位函数估计信号的调频率,然后再用分数阶傅里叶变换获得信号的各分量峰值,根据峰值能量比进行细分类。通过大量的实验仿真验证,本算法在信噪比为0 d B的条件下,正确识别率能够达到95%以上。

Research of LPI signals recognition based on WCPF and FRFT

For the problem that LPI radar signals is difficult to identify and classify, an algorithm of LPI radar signal recognition based on the weighted-type cubic phase function and Fractional Fourier Transform is proposed. Eight common LPI radar signals are divided into two categories by frequency modulation rate after time-frequency characteristics analysis with short-time Fourier transform. First with an estimated modulation frequency of the signals by weighted-type cubic phase function, the peaks of each component are obtained by the fractional Fourier transform and then the LPI signals are sub-classified according to the ratio of the peak energy rate. Through a large number of simulation experiments, the correct recognition rate can reach 95% with this algorithm under the condition of SNR=0dB.