基于谱相关的正弦调频和脉间伪码调相复合体制侦察信号识别

Signal Recognition of Sine FM and Interpulse Pseudo Code PM Based on Spectral Correlation Method

推导了正弦调频和脉间伪码调相复合体制信号的谱相关函数(SCF),基于谱相关特征给出了对该复合体制侦察信号的自动识别算法。分析了宽带调频和窄带调频两种情况下谱相关函数的特征,对载频、调制频率、调制系数以及伪码的子脉冲宽度、子脉冲重复周期、编码个数进行了盲估计,分析了信噪比对参数估计精度的影响。仿真分析表明,在SNR为-5 dB时,对载频和调制频率估计的归一化均方根误差(NRMSE)小于2.5%,在SNR>0 dB时,对伪码参数估计的NRMSE小于7.5%.

The spectral correlation funetion（SCF） of the reconnaissance signal combined sine FM and interpulse pseudo-random code PM was deduced. A recognition algorithm was given, which included the estimation of carrier frequency, modulation frequency, modulation coefficient, and the width and period of subpulse and coding number based on the characteristic of SCF of narrowband and broadband FM. The influence of SNR on parameter estimation precision was analyzed. The simulation results show that the NRMSE of estimation of carrier frequency and modulation frequency is less than 2.5 % when SNR is equal to - 5 dB, and the NRMSE of pseudo-random code less than 7.5% when SNR is more than 0 dB.