| 摘要: |
| 在运动多站定位场景下，宽带跳频通信信号的载频跳变会产生变化的多普勒频移，因此无法直接利用跳频信号的多个不同脉冲估计多普勒频率差，若仅估计单个跳频脉冲的时频差，则精度低而无法满足定位要求。针对此问题，提出了一种基于互模糊函数相参积累的宽带跳频信号时差和多普勒速度差估计方法。首先将宽带跳频信号的多普勒效应差建模为多普勒速度差，从而无需对多普勒频差进行估计，避免载频跳变对多普勒效应差估计造成影响，并建立了时变时差的时差和速度差信号模型。然后对各单跳信号的互模糊函数进行相位补偿以实现相位对齐，通过对相参积累后的互模糊函数进行时差和速度差的二维峰值搜索，可以得到多跳频脉冲信号初始时刻时差和速度差的相参估计结果。最后以Link16数据链信号为例对算法进行了仿真实验，验证了算法的正确性与精度优势。 |
| 关键词: 宽带跳频信号 时差估计 速度差估计 相参积累 互模糊函数 |
| DOI：10.20079/j.issn.1001-893x.220714003 |
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| 基金项目:国家自然科学基金资助项目（62101563）；国防科技大学科研计划项目（ZK20-26） |
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| An Estimation Method of Time Difference and Velocity Difference for FH Signal Based on Coherent Accumulation of Cross Ambiguity Function |
| ZHU Yi,WU Guizhou,XU Yingjie,GUO Fucheng |
| ((1.College of Electronic Engineering,National University of Defense Technology,Changsha 410073,China;2.Unit 93196 of PLA,Malan 841700,China)) |
| Abstract: |
| The wideband frequency hopping(FH) communication signal搒 carrier FH will result in a fluctuating Doppler frequency shift in the case of shifting multi-station location.As a result,the Doppler frequency difference cannot be estimated directly by using multiple different pulses of the FH signal.So the precision is poor and the positioning requirements cannot be met if the time-frequency difference of a single FH pulse is estimated alone.A method based on the coherent accumulation of cross ambiguity function for calculating the time difference and Doppler velocity difference of wideband FH signals is suggested to address this problem.In the first place,the Doppler effect difference of the wideband FH signal is represented as the Doppler velocity difference,eliminating the necessity to estimate the Doppler frequency difference and the impact of carrier FH on the estimation of the Doppler effect difference.Additionally,the time-varying velocity-difference and time-varying time-difference signal models are developed.The cross ambiguity function of each single-hop signal is then phase-compensated to achieve phase alignment.The coherence estimation results of the initial time difference and velocity difference of the multi-FH pulse signal can be obtained by conducting the two-dimensional peak search of the time difference and velocity difference on the cross ambiguity function after coherent accumulation.Finally,with Link16 data link signal as an example,the correctness and accuracy of the algorithm is proved by simulation experiment. |
| Key words: wideband FH signal time difference estimation velocity difference estimation coherent accumulation cross ambiguity function |
