基于分数阶傅立叶变换的线性调频回波参数估计  

Parameter estimations of linear frequency modem echo based on fractional Fourier transform

作　　者：任仕伟[1] 马晓川[1] 鄢社锋[1] 

机构地区：[1]中国科学院声学研究所声场声信息国家重点实验室,北京100190

出　　处：《应用声学》2012年第2期118-122,共5页Journal of Applied Acoustics

摘　　要：本文提出了一种适用于宽带线性调频回波的分数阶傅立叶变换参数估计方法。它通过寻找合适的信号代替发射信号做模版,使得模版信号与接收信号的模糊函数匹配度高,峰值尖锐,失真率低。再利用分数阶傅立叶变换与模糊函数的关系,使用两次分数阶域的峰值搜索代替原有的一次二维搜索降低计算量。仿真实验结果表明,本文提出的方法在精确估计宽带回波的时延和频移的同时降低了计算复杂度。A method for parameter estimations of wideband Linear Frequency Modem echo in sonar by fractional Fourier transform is proposed. It is implemented by choosing the most suitable signal as a reference first. As a result, the ambiguity function will be matched well and have a sharpened peak. Then based on the relationship between fractional Fourier transform and ambiguity function, one-dimensional search twice in two different fractional Fourier domains instead of a two-dimensional search over the ambiguity plane is used. It is demonstrated that the approach can estimate time delay and frequency shift precisely. Besides, it yields less computation than previously known schemes.

关 键 词：宽带线性调频回波 模版信号 分数阶傅立叶变换 计算复杂度 

分 类 号：TN95[电子电信—信号与信息处理] O427[电子电信—信息与通信工程]