基于相参积累的宽带跳频信号时差和速度差联合估计方法  

A Joint Estimation Method of Time Difference and Velocity Difference for Wideband Frequency Hopping Signal Based on Coherent Accumulation

作　　者：朱毅 吴癸周 张源 刘钊 张敏[1] 郭福成[1] ZHU Yi;WU Guizhou;ZHANG Yuan;LIU Zhao;ZHANG Min;GUO Fucheng(College of Electronic Engineering,National University of Defense Technology,Changsha,Hunan 410073,China)

机构地区：[1]国防科技大学电子科学学院,湖南长沙410073

出　　处：《信号处理》2023年第5期849-857,共9页Journal of Signal Processing

基　　金：国家自然科学基金(62101563,61901494);国防科技大学科研计划项目(ZK20-26)。

摘　　要：运动多站无源定位场景下,宽带跳频通信信号载频跳变会产生变化的多普勒频移,从而导致无法直接估计多脉冲跳频观测信号的多普勒频差,而单跳信号的时频差估计精度又不能满足定位要求。针对该问题,本文提出了一种跳频信号多脉冲相参积累的时差和多普勒速度差联合估计算法。首先对宽带跳频观测信号建立时差-多普勒速度差模型,然后对脉冲对的频域共轭积补偿相位后累加求和,最后通过代价函数的二维峰值搜索求得跳频信号时差和多普勒速度差估计值。仿真结果表明,本文所提方法相比于单跳方法和多脉冲非相参积累方法,估计精度提升显著且在中高信噪比条件下能够贴近CRLB,验证了所提方法的正确性与精度优势。It was impossible to directly estimate the Doppler frequency difference of the frequency-hopping observation signal containing multiple pulses in the passive positioning scenario of moving multi-station because the wideband frequencyhopping communication signal’s carrier frequency hopping results in a changing Doppler frequency shift.If only the singlehop signal’s time-frequency difference is evaluated,the estimation precision won’t be sufficient for locating.This study suggested a joint time difference and Doppler velocity difference estimation approach for coherent accumulation of multipulse coherent accumulation of frequency hopping signals in order to address this issue.Firstly,a time difference-Doppler velocity difference model was established for the wideband frequency hopping observation signal.Then,each pulse pair’s frequency domain conjugate product was phase-compensated and accumulated.Finally,by looking for the two-dimensional peak value of the cost function,the predicted time difference and Doppler velocity difference of the multi-pulse frequency hopping signal were discovered.The simulation results demonstrated that the method proposed in this paper had a significant improvement in estimation accuracy compared to the single-hop method and the multi-pulse non-coherent accumulation method,and can be close to CRLB under the condition of medium and high signal-to-noise ratio.This demonstrates the correctness and precision advantages of the proposed method.

关 键 词：宽带跳频信号 相参积累 时差 多普勒速度差 估计 无源定位 

分 类 号：TN97[电子电信—信号与信息处理]