宽带体制下混响和目标空时分布特征研究

传统的空时自适应处理(Space-Time Adaptive Processing,STAP)利用窄带混响和目标在空时平面的可分辨特征抑制窄带混响。对宽带混响和目标在空时平面分布特征进行研究,并通过理论推导,得出带宽对混响和目标空时分辨特征的影响公式。结果表明:宽带混响和目标在空时平面分布特征部分重叠,导致传统STAP效果不佳。在此基础上,借鉴STAP思想,并利用线性调频(Linear Frequency Modulation,LFM)信号在分数阶Fourier变换域上的聚焦性,分析了在空-分数阶Fourier域三维空间上抑制宽带LFM混响的可行性。

Study of space-time distribution characteristics of wideband reverberation and target echo

The traditional space-time adaptive processing （STAP） suppresses narrowband reverberation by utilizing the distinguishable characteristics of narrowband reverberation and target echo in space-time plane. In the paper the distribution characteristics of wideband reverberation and target echo in space-time plane are studied. Based on this, the theoretical formula is derived to analyze the influence of bandwidth on reverberation and target echo’s distinguishable characteristics. It shows that the performance of traditional STAP is degraded seriously due to the overlap of wideband reverberation and target echo in space-time plane. And then, the possibility of cancelling wideband linear frequency modulation （LFM） reverberation in space-fractional Fourier domain is analyzed by integrating the space domain and the concentration characteristic of LFM signal in fractional Fourier domain.