An interference suppression algorithm of grating lobe and symmetrical pseudo-peak for sparse vector sensor 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.