基于FRFT的对流层散射Chirp信号重构方法

摘要

针对对流层散射的辐射源信号侦察中提取低信噪比信号特征难的问题，采用分数阶傅里叶变换(FRFT)提取了对流层散射线性调频信号的调频斜率与载频；在低信噪比条件下，给出了信号初步检测及采用FRFT、滤波和反FRFT进行信号特征估计与重构的方法。实测数据的处理结果证明了该方法的有效性，为脉宽测量和脉内调制特征分析提供了高信噪比基础。%Aimed at the problem that it is hard to extract the features of low SNR signals for the electronic reconnaissance of emitter signals in troposphere scattering, the fractional Fourier transform (FRFT) is used for extracting the FM slope and carrier of linear FM signals with troposphere scattering in this paper. On the condition of low SNR, the initial detection of signals, the methods for estimation of signal features and its reconstruction are given by using FRFT, fitering and counter FRFT. The results by processing the real data shows that this proposed scheme is of feasibility, thus providing a basis with high SNR for the analysis of pulse-width measurement and in-pulse modulation characteristics.