中文摘要：

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进行了研究,提出了一种基于分数阶傅里叶变换的捕获新方法。所提算法尝试采用匹配滤波器与分数阶傅里叶变换相结合的方法,利用在高动态环境下载波多普勒呈现近似线性调频信号的特点,寻找变换后峰值所在位置即可对多普勒频率和频率变化率进行有效估计,无须进行频域搜索,大大节省了捕获时间。理论分析和仿真验证表明,所提算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,尤其在低信噪比情况下,更好地提高了接收机捕获概率、缩短了捕获时间。

英文摘要：

Aiming at question that the received signal in high dynamic environment contained large Doppler frequency and its rate of change, the traditional methods could not acquisition the rate of change of Doppler frequency for effective compensation, this paper proposed a new scheme that high dynamic target detection method based on fractional Fourier transform. This method used fractional Fourier transform of linear frequency modulation signal with the characteristics of energy in the optimal order times, combined the matched filter and the discrete fractional Fourier transform to process the signal, quickly and accurately estimated the Doppler frequency and its rate of change. The theoretical analysis and simulation shows that this method can solve the problem that the traditional methods can not acquisition the rate of change of Doppler frequency for effective compensation, and improves the detection SNR and receiver＇ s capture probability.