基于FRFT的强时频干扰抑制方法

Reverberation suppression based on fractional fourier transform

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.