一种基于时间反转镜和Wigner-Hough变换的线性调频信号检测方法

A detection method for LFM signals based on TRM and Wigner-Hough transform

在分析时间反转自适应聚焦原理的基础上,提出一种基于时间反转镜(Timereversalmirror,TRM)和Wigner-Hough变换(WHT)的线性调频信号检测方法。在实验水槽内进行时频分析的仿真研究,将TRM被动接收的信号进行时间反转再发射到同一媒质中,在信号源处将接收到的信号进行WHT时频分析,同时比较WVD时频分布和WHT变换的LFM信号检测性能。研究结果表明,对于多分量LFM信号,WVD在每个散射信号的低频和高频段产生交叉干扰项,对LFM信号的检测产生影响;利用TRM可以对非平稳信号进行WHT时频分析,同时采用TRM和WHT进行分析能够抑制多途效应,减少交叉项,提高双分量LFM信号的检测性能。

Using time-reversal focusing theory, a detection method for linear frequency modulation （LFM） signals based on time reversal mirror （TRM） and Wigner-Hough Transform （WHT） was proposed. The simulation on time frequency analysis was made in a lab water tank. A signal was received passively by TRM, time-reversed and re-transmitted into the same medium. The re-transmitted signal was received near the source and WHT time frequency analysis was performed. Comparison between detection performance of WVD and WHT on LFM signal was made. The simulation results show that Wigner-Ville （WVD） of multiple component LFM signal causes cross-term interference signals at low frequency and corresponding high frequency segments of every scattering point. This new method can suppress multi-scattering, reduce cross-term and enhance the detection performance of double component LFM signal.