基于子载频相干与二次拟合的FMCW雷达高精度测距算法OA

When the modulation bandwidth of frequency modulation continuous wave(FMCW)radar is de-creased,the coherent spectrum of the coherent chirp-Z transform(CCZT)ranging algorithm is prone to exhibit dense periodic peaks,making it difficult to accurately locate the true spectral peaks,thereby leading to a reduction in ranging precision.Aiming at this problem,this paper proposes a high precision ranging algorithm that combines sub-carrier fre-quency coherence and quadratic fitting(SFC-QF).The algorithm first performs coherent processing on the beat signals of different sub-carriers,by introducing carrier frequency difference weighting into the coherent spectrum to suppress periodic peaks under low-bandwidth conditions.Then,the estimation results of the coherent spectrum and its neighbor-hood are quadratically fitted to reduce the dependence of the algorithm performance on the number of spectrum refine-ments and achieve higher estimation accuracy.Simulation results demonstrate that,compared with the CCZT and other comparison algorithms,the proposed SFC-QF method can significantly improve the ranging estimation precision in low-bandwidth radars at the hundred-megahertz level,which provides an effective solution for high precision distance measurement of low-bandwidth FMCW radar.