基于局部自适应阈值的跳频信号提取和检测

Frequency Hopping Signal Extraction and Detection Based on Local Adaptive Threshold

针对通信对抗中跳频(FH)信号的提取和检测问题,考虑存在定频干扰的情况下,提出了一种基于局部自适应阈值的跳频信号提取和检测方法。在短时傅里叶变换(STFT)的基础上,通过求解合适的局部自适应阈值,消除定频干扰的影响,实现对跳频信号的提取。然后,根据跳频信号在驻留时间上的连续性对提取结果进行检测。仿真结果表明,当干信比(ISR)为10 dB时,无论是否发生频率碰撞(跳频信号的频率与干扰频率相同),算法均可以实现对跳频信号的有效检测,且算法复杂度低、可靠性高。

In order to extract and detect the Frequency Hopping(FH)signals in communication confrontation under fixed-frequency interference a method based on local adaptive threshold is proposed.On the basis of Short Time Fourier Transform(STFT)a suitable local adaptive threshold value is obtained to eliminate the effects of fixed-frequency interference and to extract the frequency hopping signals.Furthermore the signals can be detected by using the difference between the signals and Gaussian noise on continuity.Simulation results show that this algorithm can detect the frequency hopping signals effectively with low computational complexity and high reliability when the Interference to Signal Ratio(ISR)is 10 dB whether there is frequency collision(The hopping signal has the same frequency as the interference frequency)or not.