常见低截获概率雷达信号调制参数估计研究

研究了线性调频信号、相位编码信号的调制参数识别问题。解线调方法估计线调频参数精度不高,提出了频谱细化与解线调结合的改进方法,该方法计算量较小,精度很高。给出了加性高斯白噪声中相位编码信号的编码规律识别方法。利用估计出的载频对原信号进行解调得到基带信号,根据基带编码信号逐段光滑特点,提出通过正交小波分解估计码元宽度和阈值降噪,并对一个码元内的一阶非相邻相位差分进行滑动平均,消除了阈值滤波引入的“类吉布斯”现象,提高了低信噪比下编码规律识别的正确概率。

Research on Modulation Parameter Estimation of LPI Radar Signals

The modulation parameter estimation of LFM signal and MPSK signal was studied. De-chirp method is frequently used in parameter estimation of LFM signal, but its accuracy is poor. A method combining spectrum zoom and de-chirp was presented, which was more accuracy and computationally efficient. In the second part, modulation scheme recognition method of MPSK signal was given. As the base-band MPSK is piece-smoothing and singular points exist when phase changes abruptly, wavelet analysis method was proposed to de-noise the base-band signal and estimate the code rate, then a simple sliding window was used to remove the pseudo-Gibbs phenomena of the thresholding based wavelet De-Noising. This method performs well even in low SNR.