基于动态阈值匹配追踪的主动声呐直达波抑制方法

双基地声呐中的直达波干扰可以通过重构抵消的方式进行抑制。这种方法需要对直达波信道进行估计，传统的正交匹配追踪算法的收敛速度慢，分步正交匹配追踪等算法在提高收敛速度时牺牲了信道估计精度，导致回波检测能力下降。本文提出一种动态阈值匹配追踪算法估计直达波的信道响应，在提高收敛速度的同时兼顾了信道估计精度。在仿真环境中，达到同样的直达波抑制效果，所提算法与传统正交匹配追踪算法相比，收敛速度显著提升，检测输出的回波强度比分步正交匹配追踪算法高4dB；海试数据处理结果中，所提方法迭代收敛速度较正交匹配追踪算法提升4倍；输出的回波强度比分步正交匹配追踪算法高2dB。

Active sonar direct blast suppression based on dynamic threshold matching pursuit algorithm

Direct blast interference in bistatic sonar can be suppressed by reconstructing interference waveform. This method requires appropriate channel estimation algorithm. The convergence speed of the existing orthogonal matching pursuit algorithm is slow, and its improved algorithms sacrifice the accuracy of channel estimation to improve the convergence speed. In this paper, a dynamic threshold matching pursuit algorithm is proposed to speed up convergence and ensure accuracy while estimating the interference channel response. Numerical simulation results show that the proposed algorithm can suppress direct blast more efficiently compared with orthogonal matching pursuit algorithm. The echo energy of proposed algorithm outperforms stagewise orthogonal matching pursuit algorithm about 4dB. The results of sea trial data processing show that the proposed algorithm can suppress direct blast within less iterations which is a four-fold reduction compared with orthogonal matching pursuit algorithm. The output of proposed algorithm exceeds stagewise orthogonal matching pursuit algorithm by 2dB.