【作者】 张容权；

【导师】 杨建宇；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2005， 博士

【摘要】 本文研究双基地线性调频连续波(LFMCW)雷达的信号处理理论及系统关键技术，包括： 1) 从双基地雷达几何结构和LFMCW信号特点出发，分析了双基地环境下的对称三角LFMCW信号特性，包括：具有速度和加速度的运动目标的回波信号、差拍信号、多普勒信号分析，以及在高斯白噪声环境下信号的最佳检测模型。 2) 分析单基地对称三角LFMCW信号和双基地LFMCW信号模糊函数及特性，然后结合二者，导出双基地对称三角LFMCW雷达信号的模糊函数及特性；并分析了距离分辨率、速度分辨率，以及距离速度耦合特性。 3) 针对单目标环境，提出了基于多项相位变换的双基地LFMCW雷达运动目标的速度和加速度估计方法；针对同一距离单元的多个目标环境，提出了一种修正的多项相位变换方法的双基地LFMCW运动目标的速度和加速度估计方法。通过仿真验证了这两种算法的有效性。 4) 针对双基地LFMCW高斯色噪声环境下的速度和加速度估计问题，提出了一种通用离散Chirp—Fourier变换方法。此变换方法有效利用了色噪声的功率谱密度信息，使其在实际目标检测与参数估计中，其性能明显优于现有的离散Chirp—Fourier变换方法。另外推导了色高斯环境下的Chirp信号参数估计的CRB，为实际情况的参数估计方差提供较精确的下限。 5) 提出了将LFMCW雷达差拍信号离散频谱增采样内插以提高雷达测距精度的方法。仿真结果表明，这种方法可以有效降低FFT固有频域采样间隔带来的测距误差，能够在整个频域轴上更准确地反映多个不同距离目标的差拍信号频谱特性，且运算量低。 6) 对双基地LFMCW雷达的距离速度去耦合进行研究，提出了“MTD—频域配对法”的距离速度去耦合方案。仿真分析表明，该方法能简化目标环境，可实现各种复杂多目标环境下的目标检测与距离速度去耦合，实现目标速度、距离精确估计。 7) 研究了双基地LFMCW雷达的一些关键技术，包括： 多径效应分析、杂波与直达波抑制技术及方案；LFMCW的数字AGC设计方案。更多还原

【Abstract】 This dissertation has completed the following research of signal processing theory and system key techniques for Bistatic Linear Frequency Modulation Continuous Wave (LFMCW) radar.1) From the geometry structure of Bistatic and the characteristic of LFMCW signal, the symmetrical triangle LFMCW signal applied in Bistatic radar is analyzed, which include the target echo signal, the beating signal of moving target with velocity and acceleration, as well as the signal optimal detection model in white Gaussian noise.2) The ambiguity function and its characteristic of monostatic symmetrical triangle and Bistatic single sweep frequency LFMCW signal are analyzed. By combining the above two signals, then the ambiguity function and its characteristic of Bistatic symmetrical triangle LFMCW signal is analyzed. The range resolution, velocity resolution and rang-velocity coupling characteristic are also derived and analyzed.3 ) Aiming at single target environment, a method of moving target’s velocity and acceleration estimation using polynomial phase transform for Bistatic LFMCW radar is presented. Aiming at the velocity and acceleration estimation problem of multi-targets in the same range cell, a modified polynomial phase transform method is also presented. The simulation has tested the validity of the algorism.4) Aiming at the parameter estimation problem of velocity and acceleration of Bistatic LFMCW radar in color Gaussian noise, a general discrete Chirp-Fourier transform is presented. The algorithm efficiently makes use of the power spectrum information of color noise, which makes its capability obviously better than the existing discrete Chirp-Fourier transform in actual target detection and parameter estimation, In addition, the CRB of the chirp signal’s parameter estimation under the condition of normal Gaussian noise is also derived, which can provide a precise lower bound for the variance of actual parameter estimation.5) A method of improving range precision of LFMCW radar based on frequency domain up-sampling-interpolating is presented. The simulation indicates that the更多还原