非合作跳频信号特征参数盲估计方法

Estimation Method for Characteristic Parameters of Non-Cooperative Frequency Hopping Signals

针对使用谱图法的跳频信号特征参数盲估计实时性较好,但抗噪性和估计精度难以兼顾的问题,提出了一种基于时频分析的跳频信号特征参数盲估计方法。在短时傅里叶变换进行时频分析得到的跳频信号谱图基础上,利用能量检测的方法得到自适应阈值对时频图进行修正。根据修正后的时频图,使用二次估计和信号DFT变换系数构造频率修正项方法来估计信号跳变时刻和载频频率,从而得到更为精确的特征参数估计值。仿真结果表明:该方法的参数估计精度、抗噪性和实时性都较好,能够满足实际应用要求。

When the spectral method is used,the real-time function of the blind estimation of the characteristic parameters of the frequency hopping signal is better,but the noise resistance and estimation accuracy are unsatisfactory.Therefore,a blind estimation method for characteristic parameters of frequency hopping signals based on time-frequency analysis was proposed.The frequency hopping signal spectrum was obtained by time-frequency analysis using short-time Fourier transform,and then the hopping time was roughly estimated.Then,the energy detection method was used to modify the time-frequency diagram,and the blind estimation of the characteristic parameters of the frequency-hopping signal was carried out according to the revised time-frequency diagram,so that more accurate estimation of the characteristic parameters can be obtained.The simulation results show that the parameter estimation accuracy,anti-noise and real-time performance of the method are good,and it can meet the practical application requirements.