LFMCW雷达高速运动目标检测与估计

High-speed target detection and estimation in LFMCW radar

针对LFMCW雷达高速运动目标的检测问题,本文提出了一种二次混频与MTD处理相结合的方法。根据上、下调频差拍信号对称特点,采用二次混频处理解决多周期信号中心频率偏移问题,同时实现了距离-多普勒解耦合。MTD处理则等效地实现了多周期信号的积累,并得到目标速度估计。然后根据速度估计值对差拍信号进行运动补偿,获取目标距离信息。性能分析结果表明,与传统MTD方法相比,在输入信噪比一定的情况下,该方法的处理增益不受目标多普勒的影响,因此更适用于高速运动目标的检测。仿真结果验证了该方法的有效性。

A combination method based on secondary mixing and MTD （Moving Target Detection） processing is proposed for high-speed targets detection in linear frequency-modulated continuous wave （LFMCW） radar. According to the symmetry characteristics of up-sweep and down-sweep beat signals, secondary mixing is adopted to remove the central frequency offset from multi-cycles, and range-Doppler coupling is resolved at the same time. MTD processing is used to realize multi-cycle integration and get the target velocity. Motion compensation based on the velocity estimated then follows to bring out the target range information. Performance analysis is given in detail. Compared to traditional MTD processing, the proposed method isn＇ t sensitive to target Doppler with a given input SNR （ Signalto-Noise Ratio）. So it is preferred in high-speed targets detection. Simulation results prove the efficiency of the method.