一种双基地声呐直达波干扰抑制的高分辨算法

A High Resolution Algorithm of Direct Path Interference Suppression for Bistatic Sonar

针对双基地声呐系统中存在强直达波干扰掩蔽目标回波的问题,该文在双基地配置已知的前提下,提出一种直达波抑制的高分辨算法。该方法在约束条件下将N维空间划分为两个正交子空间,将平滑最小方差无畸变响应(MVDR)算法的扫描权矩阵分解到各子空间,在约束子空间使用输出功率最小化法则得到最优权。仿真结果表明,在仅能提供直达波大致方位的情况下,该方法在约束方向提供比常规波束零点更深的零陷,并能对多个未知的相干信号进行无畸变输出。该算法在抑制强直达波干扰的同时具有对多个相干目标信号高分辨的能力。

In view of the problem of target echoes interfered by strong direct path-wave in bistatic sonar, a high resolution algorithm of direct path interference suppression is proposed when the deployment is known. The method divides the space of N dimension into two orthogonal subspaces under the condition of constraint, the weight matrix of smoothing MVDR（Minimum Variance Distortional Response） algorithm is decomposed into these subspaces, and the optimal weight is obtained by output power minimization in the constraint subspace.The simulation results show that a deeper null appear at the constraint direction compared to conventional beam when the probable direction just is knew, and it yields distortionless response of multi-coherent unknown signals.The algorithm not only suppresses the direct path interference effectively, but also possesses the capability of high resolution for multi-coherent unknown signals.