稀疏矢量阵信号栅瓣及对称伪峰干扰抑制

稀疏矢量阵进行宽带信号处理时,强目标的栅瓣及对称伪峰会干扰弱目标的检测,提出了一种基于理论干扰预测的加权抑制方法。方法利用矢量阵波束形成先获得强目标的波达方向(Direction Of Arrival,DOA)信息以及目标所在方位各频率的幅度谱信息,再利用理论计算公式获得强目标的栅瓣和对称伪峰角度上对应的各频率点的幅度谱强度信息,通过在方位、频率维度加权的方式对强目标的栅瓣和伪峰干扰进行抑制,来改善在强干扰下的弱目标检测能力。方法也适用于多目标情况,对各个目标依次使用,减少多目标时栅瓣和对称伪峰对方位历程的影响,净化了时间方位历程图。对所提方法给出了理论推导过程并进行了仿真和实验验证,实验结果验证可行。结果表明,新方法可以有效地抑制强目标的栅瓣和对称伪峰干扰,提高弱目标的检测能力,此外,净化后的时间方位历程图更利于弱目标检测和目标数量的估计。 

An interference suppression algorithm of Grating lobe and symmetrical pseudo-peak for sparse vector array

The presence of both the grating lobe and symmetrical pseudo-peak of strong targets constitutes a major impediment to the detection of weak targets via sparse vector sensor array.We proposed a weighted interference suppression algorithm based on theoretical interference prediction.Firstly,the beamforming for vector senor array is conducted to extract the Direction Of Arrival(DOA) and magnitude spectrum of the strong target.As for the grating lobe and symmetrical pseudo-peak caused by the strong target,their directions and magnitude spectrums at each frequency bin will be obtained according to the theoretical formula.Then,both types of interference are largely removed through joint azimuth-frequency weighting,in turn,a significant improvement in the detection of the weaker target is finally achieved.Moreover,the proposed algorithm can also be used for multi-target case,where the interference suppression is performed sequentially for each target.Numerical simulation and experimental verification are carried out.Simulation results demonstrate that the proposed algorithm can effectively suppress interference of strong targets,and offer good performance in the detection of weak targets.Moreover,a purified time-orientation history map is more conducive for the estimation of target number.