基于FrFT的LFM相参脉冲信号多普勒频率变化率估计算法

线性调频信号(LFM)在雷达中广泛应用,精确获取观测LFM信号中的多普勒频率变化率信息是单站无源定位与跟踪系统的一项关键技术。该文提出了基于分数阶Fourier变换(FrFT)的多普勒频率变化率估计算法,在分数阶变换域上使信号能量聚集,消除调频率对参数估计的影响的同时充分提高了信噪比,进而利用保留的脉冲间相对相位关系获得了多普勒频率变化率的高精度估计。理论分析表明,该算法估计精度接近理论下界,数值仿真验证了算法的有效性。

A FrFT Based Algorithm for Doppler Frequency Rate Estimation from LFM Coherent Pulse Train

LFM signal is widely used in radar application. It is a key technology to obtain the high accuracy estimation of the Doppler frequency rate from the observed LFM signals. In this paper, a Fractional Fourier Transform (FrFT) based Doppler frequency rate estimation algorithm is proposed. The signal energy is congregated in the fractional Fourier transform domain. The signal to noise rate is strengthen and the infection of the frequency rate of LFM signal is eliminated. The coherent phase information is utilized to obtain the Doppler frequency rate estimates. The theoretical analysis indicates that the estimation variance approaches the theoretical low band. The simulation results validate the presented algorithm.