宽带 LFMCW 雷达运动目标测速误差分析与抑制方法

Stretch processing is typically used by broadband linear frequency modulation continuous wave (LFMCW) radars to achieve high range resolution in the precise measurement of moving targets. However, the sampling echoes of the motion target could cause interference components on the Doppler velocity spectrum. To address such an issue, this paper proposes a novel method to reduce its influence on the estimation of target radial velocity in wideband LFMCW radar. The phenomenon is first studied in theory by using the mathematical model of wideband LFMCW radar echoes. On this basis, a suppression method of radial velocity estimation error for moving targets is proposed. The Chirp-z transform in the fast-time domain is introduced in the refined processing over the beat frequency signal spectrum. It could help improve the estimation accuracy of target radial velocity with much less computational cost. Finally, comparative simulations are carried out to evaluate the performance of the proposed method. The results show that the proposed method can effectively suppress the residual phase caused by pulse compression in the discrete fast-time domain and the estimation error of target radial velocity in the wideband LFMCW radar. Additionally, it performs better in terms of computing cost than the traditional fast Fourier transform (FFT) based approach and is robust to noise.