强干扰下非平稳跳频信号高分辨测试技术研究

为了提高对强电磁辐射干扰下的非平稳跳频信号检测性能,提出一种基于时频分析的非平稳跳频信号高分辨测试技术.采用短时傅立叶变换构建非平稳信号的时频分析模型,把信号划分成许多小的时间间隔,在时间轴连续滑动窗口上对信号进行固有模态分解,提取非平稳跳频信号的Hilbert谱特征,谱特征有效反映了信号的幅值在整个频率段上随频率的变化情况,从而找出信号中跳变的频率分量,实现信号高分辨测试.仿真结果表明,采用该方法在强干扰条件下进行信号测试,信号输出的分辨能力较强,准确检测概率较高,性能优于传统方法.

Research on high resolution measurement of non-stationary frequency hopping signals under strong interference

In order to improve the detection performance of non-stationary frequency hopping signals under strong electromagnetic interference, a new method based on time frequency analysis for high resolution measurement of non-stationary frequency hopping signals is proposed.When constructing the time-frequency analysis model of non-stationary signal with short-time Fourier transform, the signal is divided into many small intervals.On the time axis continuous sliding window, generate intrinsic mode decomposition of the signal, then extract Hilbert spectrum feature of non-stationary frequency hopping signal, which could effectively reflect signal amplitude in the whole frequency range with the change of the frequency;on the basis of the above, find out the frequency hop signals, and realize high resolution signal test.The simulation results show that the proposed method can be used to test the signal under the condition of strong interference, and the resolution of the signal output is strong, the probability of detection is high, meanwhile the performance is better than the traditional method.