LFMCW雷达目标检测与参数估计方法研究

【作者】 李政；

【导师】 杨建宇；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2006， 硕士

【摘要】 线性调频连续波(LFMCW)雷达是一种通过对连续波进行频率调制来获得距离与速度信息的雷达体制。由于其具有无距离盲区、高距离分辨率、低发射功率、结构简单等优点,近年来受到广泛关注,理论、关键技术和应用得到迅速发展。LFMCW雷达也存在着作用距离短、运动目标距离-速度耦合等缺点,其应用远不及脉冲雷达广泛,有关理论和技术的发展水平也大大落后于脉冲雷达。当前,LFMCW雷达信号处理的研究热点集中在目标检测与参数估计方法、运动目标距离-速度去耦合方法等方向上,并已取得一系列成果。但是,相对于脉冲雷达来说,LFMCW雷达依然处于不成熟的阶段,相关理论问题还缺乏全面而深入的研究。本文通过理论和仿真研究,解决了一系列有关LFMCW雷达的关键性理论和技术问题。在对LFMCW雷达回波信号和LFMCW雷达模糊函数进行分析的基础上,提出了LFMCW雷达目标检测与参数估计方法,并利用MTD-频域配对法消除LFMCW雷达距离-速度耦合。本文的主要工作包括:对LFMCW雷达回波信号(单目标差拍信号和多目标差拍信号)进行了分析;对LFMCW雷达模糊函数进行了分析。包括对称三角LFMCW雷达信号模糊函数分析和多周期对称三角LFMCW雷达信号模糊函数分析。提出了LFMCW雷达目标检测与参数估计方法。包括基于多项相位变换的LFMCW雷达速度和加速度估计方法;基于修正多项相位变换的多目标LFMCW雷达速度和加速度估计方法;基于一般高斯噪声环境下的LFMCW雷达速度和加速度联合估计方法;另外提出了基于频域增采样内插方法以提高LFMCW雷达测距精度。对LFMCW雷达距离-速度去耦合方法进行了分析和研究。本文完整分析了LFMCW雷达的回波信号和模糊函数,为LFMCW雷达特殊的波形设计与处理奠定基础;采用的基于多项相位变换的LFMCW雷达速度和加速度估计方法,可以解决由于存在运动目标加速度造成的LFMCW雷达多普勒谱畸变的问题,能对目标加速度进行有效的补偿;采用的基于修正多项相位变换的更多还原

【Abstract】 LFMCW (Linear Frequency Modulation Continuous Wave) Radar is a radar system which can get the information of range and velocity through modulating the frequency of continuous wave. Because of the advantages of no range blind area, high range resolution, low signal power and simple structure, recently LFMCW radar has attracted more and more attention. The theories, key technologies and applications develop rapidly.LFMCW radar also has disadvantages of restricted detecting distance and range-velocity coupling, etc. Its applications are not as wide as Pulse radar. The development level of correlative theories drops behind Pulse radar too.Recently years, the hot research directions of signal processing concentrate on the new theories of LFMCW radar signal detection and estimation, the new methods of eliminating range-velocity coupling, etc. A series of accomplishments have been achieved. Relative to Pulse radar, LFMCW radar is also immature.This dissertation solves a series of key academic and technical problems through theories analysis and simulations. Based on the analysis of echo signal and ambiguity function of LFMCW radar, this dissertation advances new theories of LFMCW radar signal detection and estimation and eliminates range-velocity coupling using MTD-Frequency Domain Pairing.The main research work and results can be summarized as follows:1. Analysis of echo signal of LFMCW radar, including beat signal of single- target and multi-target.2. Analysis of ambiguity-function of LFMCW radar, including symmetrical triangular LFMCW signal and multiple periods’symmetrical triangular LFMCW signal.3. This dissertation advances new theories of LFMCW radar signal detection and estimation, including method for acceleration and velocity estimation based on Polynomial Phase Transform; method for multi-target acceleration and velocity estimation based on Modification Polynomial Phase Transform;更多还原