基于正负斜率调频多带Chirp信号的移动目标参数估计

由于移动目标产生多普勒频移受到Chirp信号的调制，已有的单带线性调频连续波(linear frequency modulated continuous wave，LFMCW)信号对移动目标的速度和加速度估计方法存在较大误差。在多带Chirp系统中，通过对正负斜率调频多带Chirp信号进行差拍处理与傅里叶变换有效地抑制了这种因素引起的误差。除此之外，正负斜率调频多带Chirp信号测速方法有效地提高了移动目标分辨距离。同时，通过对接收信号的差拍结果进行基于重排的平滑伪魏格纳威利时频分布（reassign smooth pseudo wigner ville distribution，RSPWVD）与Radon变换，恒虚警（constant false alarm rate，CFAR）检测和阈值处理，实现对移动目标的加速度和速度估计。给出了移动目标速度与加速度估计算法，具体实现步骤和仿真结果。仿真实验验证表明，改进后的移动目标参数估计方法对低速移动目标测速精度有明显提高。

Parameters estimation of a moving target with multi-band chirp signal

Since the Doppler shift of moving target is modulated by Chirp signal, the existing methods which use single-band LFMCW signal to estimate the moving target velocity and acceleration would produce large error. Through introducing the positive and negative multi-band Chirp signal correlation signal processing and Fourier transform obtains effective error suppression. In addition, the positive and negative multi-band Chirp signals improve the resolution of the moving targets effectively. The acceleration and velocity of moving target are estimated by further RSPWVD-Radon transform, CFAR detection and threshold processing. The implementation and simulation of this method are presented in depth. Simulation results show that, the accuracy of velocity estimation has improved significantly for low-speed moving target with this method.