高斯白噪声背景下的LFM信号的分数阶Fourier域信噪比分析  

SNR Analysis of LFM Signal with Gaussian White Noise in Fractional Fourier Transform Domain

作　　者：刘建成[1] 刘忠[1] 王雪松[1] 肖顺平[1] 王国玉[1] 

机构地区：[1]国防科技大学电子科学与工程学院,长沙410073

出　　处：《电子与信息学报》2007年第10期2337-2340,共4页Journal of Electronics & Information Technology

基　　金：全国优秀博士学位论文专项资金(08100101)资助课题

摘　　要：目标大机动运动使雷达回波表现为频率和调频率参数均未知的LFM信号。未知参数LFM信号的检测和估计采用分数阶Fourier变换来实现受到越来越多的关注,为此本文着重分析其分数阶Fourier变换的信噪比。首先推导出时限线性调频信号的分数阶Fourier变换模平方,给出了在分数阶Fourier域的峰值点与未知参数的关系,然后研究了附加白噪声LFM信号在分数阶Fourier域的统计特性,确定了其信噪比,并与理想情况(即参数频率和调频率参数已知)下线性相位匹配滤波器的输出信噪比进行了比较。Due to the motion of a target, radar return signals are usually LFM signals with unknown frequency and unknown frequency modulated rate. Fractional Fourier transform has recently attracted much attention in detection and parameter estimation of multi-component LFM signals. Fractional Fourier transform of LFM signal of finite duration is derived and a relation between coordinate of the peak and unknown parameters is given. Statistical characteristic of LFM signal with white noise in fractional Fourier domain is studied, a closed form expression is found for Signal-to-Noise Ratio（SNR）, and it is compared with matched filter of ideal situation （i.e. parameters of LFM signal are known）.

关 键 词：LFM信号 参数估计 分数阶FOURIER变换 信噪比 

分 类 号：TN957.51[电子电信—信号与信息处理]