提高LFMCW雷达测距精度的改进型ZFFT算法

The Improved ZFFT Algorithm for Improving the LFMCW Radar Ranging Accuracy

线性调频连续波雷达信号频谱分析系统中,传统的快速傅里叶(FFT)算法只能粗略的计算频谱,且受到采样点数的限制,频谱的分辨率不高。而曲线拟合方法,在计算量不多的情况下,可以大大提高测距精度。传统ZFFT算法在复调制的过程中是对整个信号进行操作,导致计算量增大,并且无法满足测距精度很高的场合。为了获得更为精确的距离信息,本文提出了改进型ZFFT,先用拟合法拟合出比较接近理论的频率,然后根据拟合后的频率获得需要的频率段并对其频谱细化。同其他频谱细化算法相比,改进的ZFFT算法在分析精度,计算效率,分辨率方面有很大优势,通过仿真实验进行验证,表明该算法能有效提高测距精度。

In LFMCW radar signal spectrum analysis system,the traditional fast Fourier(FFT) algorithm only rough analyses the frequency spectrum.Because of the sampling points,the resolution of the frequency spectrum is not high.And in the case of a small amount of calculation,the curve fitting method can greatly improve the ranging accuracy.Traditional ZFFT algorithm in the process of modulation is for the whole signal,leading to increase the amount of calculation,and can’t meet the occasions of the high accuracy.In order to obtain more accurate distance information,this paper presents a modified ZFFT,with first fitting out close to the theory of frequency,and then according to the needed frequency after fitting of the frequency and refining the frequency spectrum.Compared with other frequency spectrum refinement algorithm,the improved ZFFT algorithm based on the analysis of accuracy and computational efficiency,has great advantage,and by simulation experiment,it shows that the algorithm can effectively improve the ranging accuracy.