基于分数阶傅立叶变换的水下动目标检测  

Application of FRFT to Moving Underwater Target Detection

作　　者：范广伟[1] 马艳[1] 年华[1] 陈永森[1] 

机构地区：[1]西北工业大学航海学院,陕西西安710072

出　　处：《计算机仿真》2009年第9期313-316,共4页Computer Simulation

摘　　要：当发射信号为线性调频信号(LFM)时,水下动目标径向运动速度使得回波和副本不匹配,从而导致传统的最佳检测器——匹配滤波器对线性调频信号的检测性能下降。动目标的回波信号依然为LFM信号和分数阶傅立叶变换对线性调频信号的聚焦特性,提出了以信号的分数阶能量谱的峰值作为统计量来进行检测,并且给出了细化搜索峰值的自适应方法,提高了搜索速度。仿真结果表明,算法在高斯噪声背景下对径向速度未知的运动目标线性调频回波具有良好的检测性能,并分析了信号参数对检测器性能的影响。When the transmitted signal is Linear Frequency Modulation （LFM） , the underwater moving target radial velocity makes the echo unmatch the replica. So the performance of traditional detector, named match filter, declines in the case of detecting the LFM signal. Because the echo of the moving target is still a LFM signal and the fractional Fourier transform（FRFT） of LFM signal is centered, the peak of signal＇s fractional energy spectrum is treated as the statistics. The adaptive searching of peak is proposed for improving the search speed. The numerical simulation results show that this algorithm has a good detection performance in the Gaussian noise and with the unknown radial velocity, and the effect of signal parameter on the detection performance are discussed.

关 键 词：分数阶傅立叶变换 线性调频信号 径向速度 检测 

分 类 号：TN911[电子电信—通信与信息系统]