基于LFMCW雷达测距的改进频域CFAR算法

复杂环境中,多径和杂波共存,杂波的存在严重影响了目标的检测;多径尤其在首径(FAP)不是最强路径时,首径的正确检测是提高测距和定位性能的关键。本文针对多径和杂波对目标检测的影响以及传统的首径检测算法的局限性,将频域恒虚警率(CFAR)算法运用到线性调频连续波(LFMCW)雷达中,并从抑制虚假目标,提高测距定位精确度的角度出发,提出了2种虚假目标抑制策略——距离分辨单元约束法和二元积累法。最后通过仿真比较考察了不同信杂比下不同首径检测算法对测距性能的影响。仿真结果表明修正的频域CFAR算法相比于传统的首径检测算法和修正前的频域CFAR算法具有更好的检测性能,论证了所提修正策略的有效性。

An improved CFAR algorithm in frequency domain based on LFMCW radar for ranging

Under complicated environments existing multipath and clutters, clutters affect the detection severely. When multipath especially First Arrival Path(FAP) is not the strongest path, the key to improve the performance of ranging and locating is to detect the FAP of the target correctly. In this paper, the effects of multipath and clutter, as well as the limitation of the traditional algorithm of detection, are considered. And an improved Constant False Alarm Rate(CFAR) algorithm in frequency domain is applied to Linear Frequency Modulation Continuous Wave(LFMCW) radar. In order to suppress the false target and improve the ranging ability, two suppression strategies, range cell constraint method and binary integration, are proposed. The Simulation results indicate that the improved CFAR algorithm in frequency domain bears better detection performance than conventional FAP detection method and unimproved CFAR method.