伪码调相连续波雷达微弱机动目标高精度参数估计方法  

High-Precision Parameter Estimation Method for Weak Maneuvering Target in the Pseudorandom Code Phase Modulated Radar

作　　者：崔嵬[1] 邢天乐 金小萍 吴爽[1] CUI Wei;XING Tianle;JIN Xiaoping;WU Shuang(School of Information and Electronics,Beijing Institute of Technology,Beijing 100081,China;Shanghai Institute of Aerospace System Engineering,Shanghai 201109,China)

机构地区：[1]北京理工大学信息与电子学院,北京100081 [2]上海宇航系统工程研究所,上海201109

出　　处：《信号处理》2025年第1期31-42,共12页Journal of Signal Processing

基　　金：国家杰出青年科学基金(62025103);国家青年科学基金(62201053);天基智能信息处理全国重点实验室基金(TJ-03-23-02)。

摘　　要：伪码调相连续波雷达具有探测距离远、测量精度高、抗干扰能力强等优势,是天基雷达空间目标探测的重要手段。本文针对高速伪码调相连续波雷达对远距、机动目标的高精度参数估计问题,提出了一种基于跟踪环路的机动目标参数高精度估计算法。该算法首先利用分数阶傅里叶变换获得载波多普勒频率初始值和多普勒频率变化率的估计,并构造对数据跳变不敏感的相干载波提取环路,实现对伪码调相信号中载波参数的鲁棒提取与精确跟踪,从而得到高精度的相对速度估计结果;之后,利用载波多普勒频率估计结果“修正”本地发射伪码,消除伪码相位偏移。在通过相关处理得到伪码相位初始估计后,构造载波辅助相干伪码跟踪环路,实现对伪码相位的精确跟踪,从而获得高精度的相对距离估计结果。所提算法利用参数跟踪环路实时动态匹配的优点,解决了机动目标回波信号伪码相位偏移和多普勒扩展引入的积累效能降低和检测性能恶化问题,有效提高了机动目标参数估计精度。与部分相关-分数阶傅里叶变换、广义拉登傅里叶变换方法、迭代相邻相关运算方法相比,所提算法将机动目标多维参数搜索与匹配问题转化为两次一维参数精确提取问题,在获得机动目标相对距离、相对速度高精度估计的同时,有效降低了算法的运算量,为航天器空间平台资源强约束下实现自主探测感知提供了一种可行思路。The pseudorandom code phase modulated radar has the advantages of covering a larger region,higher measuring accuracy,and stronger anti-interference ability,making it increasingly important in the field of space target detection.This paper proposes a precise parameter estimation method for a far-field,maneuvering target based on the parameter tracking loop.First,the proposed method acquires the initial estimate of the Doppler frequency via fractional Fourier transform,and a coherent carrier extraction loop,which is insensitive to the pseudorandom code modulation,is developed to robustly and accurately track the carrier of the pseudorandom code phase modulated signal.Thus,the velocity of a target can be estimated with high precision.Subsequently,using the relationship between the carrier Doppler frequency and the pseudorandom code Doppler frequency,the local transmit signal is“modified”and the code phase drift is eliminated.Upon obtaining the initial estimation of the pseudorandom code phase based on the autocorrelation characteristics of the pseudorandom code,a carrier-aided coherent code tracking loop is constructed to accurately track the pseudorandom code phases of the maneuvering target and accurately estimate the target range.The proposed method effectively resolves the loss of integration efficiency and deterioration of detection performance induced by autocorrelation-loss,code phase drift,and Doppler spread of the maneuvering target,thus greatly improving parameter estimation accuracy.Compared with partial correlation-fractional Fourier transform,generalized radon-Fourier transform,and the iterative adjacent cross correlation function,the proposed method transforms the traditional multi-dimensional parameter searching problem for the maneuvering target into two successive one-dimensional parameter extraction problems.Consequently,the proposed method significantly reduces the computational cost and decreases the computation time on the premise of obtaining high-precision estimations of the target paramet

关 键 词：伪码调相连续波雷达 机动目标 相干载波提取 伪码跟踪 参数估计 

分 类 号：TN95[电子电信—信号与信息处理]