短波信道下跳频信号检测

DETECTION OF FREQUENCY HOPPING SIGNAL IN SHORT WAVE CIRCUMSTANCE

跳频信号检测是当前通信对抗领域紧迫而困难的任务之一,提出了一种在复杂短波环境下有效检测跳频信号的新方法。首先,对已有动态门限算法进行改进,提出一种新的估计噪声基底的方法;用该方法对信号时频图每个时间单元的功率谱图进行滤波,将信号的时频图降噪处理;然后根据短波信道特点设计了参数统计规则,得到信号描述表,最后采用直方图方法对各信号持续时间统计分类判断出是否存在跳频信号。仿真实验证明,该方法运算简单,能够较好地解决噪声和干扰较大的复杂短波信道环境下跳频信号的检测问题。

Detection of frequency hopping（FH） signal is one of the difficult and urgent tasks in communication countermeasures field.We propose a new approach for effective detection of FH signals in complex short wave circumstance.First,after making improvement on current dynamic threshold algorithm,we propose a new algorithm to estimate noise floor,and use it to filter power spectrum of signal time frequency spectrogram along time axis,and denoise the time frequency spectrogram of single.Then,based on characteristics of short wave channel,we design the parameters statistical criterion,and the signal description table is derived.Finally,we apply histogram in counting and classifying the lasting time of each signal to determine whether or not the frequency hopping signals exist.Simulation experiments show that the proposed method is simple in calculation,and can preferably detect frequency hopping signals in complex short wave circumstance with heavy noise and interference.