基于信道分段平滑的外辐射源雷达非平稳杂波抑制方法

Nonstationary Clutter Suppression Method for Passive Radar Based on Channel Segmentation and Smoothing

复杂电磁环境下,外辐射源雷达中多径杂波可能具备非平稳的跳变特性。该文针对这种跳变型非平稳杂波,结合辐射源信号的正交频分复用(OFDM)调制特性,提出一种基于信道分段平滑的杂波抑制方法。首先建立了跳变杂波的时域信号模型,然后结合OFDM信号结构将其变换到子载波域,接着在子载波域对各OFDM符号进行信道估计与分段平滑,最后利用该信道平滑值和对应段的参考信号抑制非平稳杂波。仿真和实测数据表明,该文方法能够有效抑制跳变型的非平稳杂波。

In the complex electromagnetic environment,multipath clutter in passive radar may be nonstationary and has jump characteristics.In order to suppress this kind of non-stationary clutter,a clutter suppression method is proposed based on channel segmentation and smoothing,which combines the Orthogonal Frequency Division Multiplexing(OFDM)modulation of the transmitting signal.First,the temporal domain signal model of the jumping clutter is established.Then it is transformed into subcarrier-domain by using the OFDM structure.After channel estimation of each OFDM symbol and smoothing the segmented channel estimation,the non-stationary clutter can be suppressed by the smoothed channel estimation and reference signal in each segment.Simulation and experiment data show that the proposed method can effectively suppress the nonstationary clutter with jumping characteristic.