中文摘要：

针对伪码-线性调频复合信号参数估计的理论性能评价问题,该文分析了分步估计方法对参数估计的影响,给出了较高信噪比时分步估计方法的理论近似性能;推导了高斯白噪声环境中伪码-线性调频信号参数无偏估计的修正克拉美-罗下限（MCRLB）的解析表达式。利用伪码序列的统计特征推导出起始频率、调制斜率、初始相位及码元宽度参数联合估计的修正Fisher信息矩阵,从而得到各参数估计的MCRLB。对结果进行了对比分析,并通过数值仿真实验,证明了该理论下限的有效性。

英文摘要：

According to the theoretical performance for parameter estimators of a signal combined Pseudo-Random Binary-phase Code（PRBC） and Linear Frequency Modulation（LFM）, this paper analyzes the impact of step-bystep method on the signal estimation problem and gives the analytical expressions of Modified Cramer-Rao Lower Bound（MCRLB） for parameter estimation of PRBC-LFM signal in white Gaussian noise. Using the statistical characteristics of PRBCs, the Fisher＇s information matrix is derived for parameters including initial frequency, chirp rate, initial phase and code width. The MCRLBs are therefore calculated. The MCRLBs are analyzed by comparison and the validity is demonstrated by numerical simulation experiments.