采用Hop-LFMCW波形的雷达信号处理研究

    Radar Signal Processing Research UsingHop-LFMCW Waveform

    • 摘要: 线性调频连续波(LFMCW)是一种被广泛使用的雷达调制波形,对比脉冲体制雷达波形,LFMCW雷达具有高时宽积、结构简单、易于工程实现的显著优势,在汽车、室内监控等领域得到了广泛的应用。线性调频连续波雷达的回波信号,在经过混频、AD采样、以及一系列数字信号处理后,可获得目标的距离-速度2D频谱,得到目标的距离、速度信息1-2。但是距离分辨力与速度范围之间存在显著相互制约关系3,往往难以兼顾,在保证速度范围的前提下,难以获得很高的距离分辨力。针对上述的问题,本文首先以LFMCW为基础,按照设计的跳频序列,在不同的chirp间附加一定频移,设计了一种跳频线性调频连续波(Hop-LFMCW)的波形。随后,理论说明了Hop-LFMCW信号处理的数学计算过程,并以理论说明为基础归纳了完整的信号处理流程。最后,在仿真环境下,对Hop-LFMCW进行了验证,并与常规LFMCW进行了性能对比,结果表明在基本参数一致的前提下,Hop-LFMCW方案在保证相同速度分辨力的同时,可以获得更高的距离分辨力。

       

      Abstract: Linear frequency modulated continuous wave (LFMCW) is a widely used radar modulation waveform. Compared with pulse radar waveforms, LFMCW radar has significant advantages such as high bandwidth product, simple structure, and easy engineering implementation. It has been widely used in fields such as automotive and indoor monitoring. The echo signal of linear frequency modulation continuous wave radar can obtain the range velocity 2D spectrum of the target after mixing, AD sampling, and a series of digital signal processing, and obtain the distance and velocity information of the target. However, there is a significant mutual constraint between distance resolution and velocity range, which is often difficult to balance. It is difficult to achieve high distance resolution while ensuring the velocity range. In response to the above issues, this article first uses LFMCW as the basis and, according to the designed hopping sequence, adds a certain frequency shift between different chirps to design a Hop-LFFMCW waveform. Subsequently, the mathematical calculation process of Hop-LFMCW signal processing was theoretically explained, and the complete signal processing flow was summarized based on the theoretical explanation. Finally, the Hop-LFFMCW scheme was validated in a simulation environment and compared with conventional LFMCW in terms of performance. The results showed that under the premise of consistent basic parameters, the Hop-LFFMCW scheme can achieve higher distance resolution while ensuring the same velocity resolution.

       

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