Strong coherent interference suppression based on second- order cone null steering beamforming

¹ Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001, China
² Key Laboratory of Marine Information Acquisition and Security (Harbin Engineering University), Ministry of Industry and Information Technology, Harbin, 150001, China
³ College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin, 150001, China
⁴ China Ship Development and Design Center, No.268, ZhangZhiDong Road, Wuchang District, Wuhan, 430064 Wuhan, China

^* Corresponding author: tengtingting@hrbeu.edu.cn

Abstract

For active sonar systems, coherent interference, such as direct-path wave and strong multi-path, will shield the weak target echo signal, which is one of the main factors affecting the target detection performance. Null steering beamforming is an important signal processing method that suppresses strong interference. In this paper, the second-order cone programming (SOCP) method is used to perform null steering beamforming on the uniform linear array. Beam null is caused in the direction of interference to suppress strong coherent interference in the active sonar system during detection. However, there are two limitations that can causes decline of the algorithm performance. A norm-control method is proposed to limit the response near the end-fire direction of linear array, and an array manifold compensation method is introduced to solve the array manifold mismatch. Simulated and experimental data was used to evaluate the performance and verify the feasibility of the methods.