基于分数阶傅里叶变换的高动态目标检测方法

摘要

针对高动态环境下接收机的接收信号含有较大多普勒频率及其变化率，传统捕获方法无法对多普勒频率变化率进行有效补偿的问题，提出了基于分段自相关分数阶傅里叶变换的高动态目标检测方法。该方法首先对接收信号进行载频预测，将接收信号调制到基带信号，然后利用分数阶傅里叶变换对线性调频信号在最优阶次具有能量聚集的特点，采用分段自相关与离散分数阶傅里叶变换相结合的处理方法，快速而准确的估计出多普勒频率及其变化率。仿真验证表明，该方法解决了传统方法在高动态环境下难以对信号多普勒变化率进行有效补偿的问题，并提高了检测信噪比和接收机捕获概率。%The received signal contained large Doppler frequency and its changing rate was high when the receiv-er in high dynamic environment,and traditional methods could not capture the changing rate of Doppler frequen-cy for effective compensation.Aiming at this problem,a high dynamic target detection method based on frac-tional Fourier transform was proposed.This method first projected the receiving signals’carrier frequency, Then using fractional Fourier transform of linear frequency modulation signal of the characteristics of energy in the optimal order times.The method of segmented autocorrelation combined discrete fractional Fourier trans-form to process the signal quickly and accurately.The theoretical analysis and simulation showed that this meth-od could solve the problem that the traditional methods could not capture the changing rate of Doppler frequency for effective compensation,and improved the detection SNR and receiver’s capture probability.