混响是影响双基地或多基地声呐对水中目标探测识别的最主要干扰，提高抗混响能力对识别水中目标有极其重要意义。本文针对混响对目标回波的强时频干扰特性，基于分数阶傅里叶变换所具有的时频耦合分离特性，研究一种基于分数阶傅里叶变换的强混响抑制方法，并进行模拟仿真和水池测试研究，研究结果验证算法的有效性。本算法适用于信号形式为线性调频的宽带信号抗混响干扰，将脉冲信号在分数阶变换域进行尺度压缩，进而将目标信号和干扰信号在变换域中进行分离，有效达到抗混响的目的。
In bistaic or multistaic sonar, the main interference of the underwater target detection is reverberation. It is of great signiticance to imporove the ability of anti reverberation for the identification of underwater targets. This paper is according to the high-frequency disturbance characteristics of the reverberation and based on the time-frequency coupling separation characteristics of fractional Fourier transform domain, to identify a method of strong reverberation suooression. And to proved the effectiveness of the algorithm by simulation and tank test. The algorithm is applied to the anti reverberation interference of wideband signals in the form of LFM signals, that achieved the purpose of reverberation resistance-scaling the pulse signal in fractional transform domain and then separating the target signal and the interference signal in the transform domain.
2017,39(6): 83-87 收稿日期：2017-04-06
DOI：10.3404/j.issn.1672-7619.2017.06.017
分类号：TN911
作者简介：李希友(1975-),男,高级工程师,主要从事数据分析技术研究。
参考文献：
[1] HENRY C. Fundamentals of bistatic active sonar[C]//Underwater acoustic data processing. Klvwer academic publishers, 1989, p3-24.
[2] ALAN A. WINDER. Sonar system technology[C]//Ieee Transaixions on Sonics and Ultrasonics. VOL. su-22, NO. 5, SEPTEMBER 1975, p291-332.
[3] CHEN Y F, WANG Z S, JIA B. Rejection of direct blast interference based on signal phase-matching array processing[J], Journal of Electronic Science and Technology, 2013, 11(1):106-109.
[4] 李秀坤, 孟祥夏, 夏峙. 水下目标几何声散射回波在分数阶傅里叶变换域中的特性[J], 物理学报, 2015, 64(6).LI Xiu-kun, MENG Xiang-xia, XIA Shi. The characteristics of underwater acoustic scattering echo target geometry in the fractional Fourier transform domain[J]. Physics Journal, 2015, 64(6).
[5] OZAKTAS H M, KUTAY M A, ZALEVSKY Z. The fractional fourier transform with applications in optics and signal processing (new york:wiley)[C]//2001:118-122.
[6] 梁红, 李志舜, 王惠刚. 一种变步长自适应格型ⅡR陷波器及其在混响抵消中的应用研究[J], 电声技术, 2004(2).LIANG Hong, LI Zhi-shun, WANG Hui-gang. A variable step-size adaptive ⅡR Notch Filter and its application in reverberation cancellation research[J], Electro-acoustic Technology, 2004(2).
[7] YAO Shuai, FANG Shi-liang, WANG Xiao-yan. Principal component inverse-recursive leastsquare algorithm for direct wave suppression in bistatic sonar[J]. Jouurnal of Nanjing University, 2012.
[8] 高勇. 收发分置主动声呐混响特性和抑制方法的研究[D]. 南京:东南大学, 2009GAO Yong. Study on reverberation characteristics and suppression methods of active sonar[D]. Nanjing:Southeast University. 2009.
