一种基于多重同步压缩的高动态信号捕获技术

A High Dynamic Signal Acquisition Technology Based on Multisynchro Squeezing Transform(MSST)

为了解决高速飞行器通信时的高动态信号捕获问题,根据多普勒变化特点,将信号建模为非线性调频信号,采用时频分析的方式提取瞬时频率,设计了一种基于多重同步压缩(Multisynchro Squeezing Transform,MSST)的时频分析方法,有效提高了时频能量聚集能力和鲁棒性。为了避免时频图起始点选择错误引起的频率估计误差过大的问题,提出了一种分段能量泛函最小化法,将时频面分成多个部分,向前向后分别提取脊线,提高了低信噪比下频率估计的准确性。仿真结果表明,对6 Ma、40g、100 g/s的高动态信号,相比传统时频分析方法频率估计精度提高50%以上,所提方法捕获概率可达到95%以上,对低信噪比高动态信号有较强的适应能力。

In order to solve the problem of high dynamic signal acquisition of aerial vehicles with high speed,the signal is modeled as a nonlinear frequency modulation(FM)signal according to the characteristics of Doppler change,and the instantaneous frequency is extracted by time-frequency analysis.A time-frequency analysis method based on Multisynchro Squeezing Transform(MSST)is designed,which effectively improves the time-frequency energy focusing ability and robustness.In order to avoid the problem of excessive frequency estimation error caused by the wrong selection of the starting point of the time-frequency map,a subsection energy functional minimization method is proposed,which divides the time-frequency surface into multiple parts and extracts ridge lines forward and backward respectively,thus improving the accuracy of frequency estimation under low signal-to-noise ratio(SNR).The simulation results show that the frequency estimation accuracy of the proposed method is more than 50% higher than that of the traditional time-frequency analysis method for 8 Ma,40g and 100 g/s high dynamic signals,and the acquisition probability can reach more than 95%.The method has strong adaptability to low SNR and high dynamic signals.