A novel DOA estimation method of antenna array under strong interference

Abstract This paper investigates the weak signal direction of arrival (DOA) estimation for an antenna array under strong interference signals, and a novel DOA estimation method is proposed for strong interference source suppression and weighted l1-norm sparse representation. The parallel adaptive beamforming algorithm based on power inversion is used to suppress strong interference and form a new array data, and the weighted matrix is determined according to the optimized subspace algorithm of the subspace projection. Then, the DOA estimation, which is calculated by weighted l1-norm sparse representation, is formed by the weighted matrix and new array data. In this paper, the superiority of proposed algorithm is illustrated by an example of unmanned aerial vehicle (UAV) video signal DOA estimation under strong interference signals. The simulated results of orthogonal frequency division multiplexing (OFDM) signal indicate that the proposed algorithm shows merits of less snapshots, sharper main lobe, lower average noise spectrum value, higher DOA estimation accuracy and success rate. For validation, an outdoor experiment was conducted, demonstrating that the proposed algorithm is superior to other algorithms and can be used for DOA estimation of UAV video signal under strong WiFi interferences. Both the simulations and experiments have verified the proposed algorithm can effectively suppress the strong interference and achieve better DOA estimation performance of weak signal.