面向地电极电流场透地通信的两阶段长相关信号捕获方法  

Two-stage Long-correlation Signal Acquisition Method for Through-the-earth Communication of the Ground Electrode Current Field

作　　者：徐湛[1,2] 张旭 杨小龙 XU Zhan;ZHANG Xu;YANG Xiaolong(Key Laboratory of Modern Measurement and Control Technology of the Ministry of Education,Beijing Information Science and Technology University,Beijing 102206,China;Institute of Information and Communication Engineering,Beijing Information Science and Technology University,Beijing 102206,China)

机构地区：[1]北京信息科技大学现代测控技术教育部重点实验室,北京102206 [2]北京信息科技大学信息与通信工程学院,北京102206

出　　处：《电子与信息学报》2024年第12期4504-4512,共9页Journal of Electronics & Information Technology

基　　金：国家重点研发项目(2020YFC1511701);北京市教育委员会科学研究计划(KM202211232006);北京信息科技大学促进高校分类发展-重点研究培育基金(2121YJPY222)。

摘　　要：地电极电流场透地通信可以为地下强遮蔽空间信息传输提供解决方案。针对接收的电流场信号信噪比(SNR)低、易畸变且受载波频偏影响大导致捕获困难的问题,该文设计一种长同步信号帧结构,在此基础上提出一种联合频偏粗估计和精估计的两阶段长相关信号捕获算法。该算法第1阶段利用接收时域信号中的训练符号,依据最大似然算法进行采样间隔偏差粗估计,并计算采样点补偿间隔粗估计值。第2阶段结合粗估计值和接收信噪比,确定采样点补偿间隔精估计值的遍历范围,进而设计本地补偿后的长相关模板信号,实现电流场信号的精确捕获。本研究在距离地面30.26 m的地下强遮蔽空间中进行了算法性能验证。实验结果表明,与传统的滑动相关算法相比,该文所提算法具有更高的捕获成功概率。Wireless through-the-earth communication provides a solution for information transmission in heavily shielded space.The received current field signal has low Signal-to-Noise Ratio(SNR),is easily distorted,and is greatly affected by carrier frequency offset,making signal acquisition difficult.In this paper,a long synchronization signal frame structure is designed and a two-stage long correlation signal acquisition algorithm is proposed that combines coarse and fine frequency offset estimation.In the first stage,the training symbols in the received time-domain signal are used for coarse estimation of sampling interval deviation based on the maximum likelihood algorithm,and the coarse estimation value of the sampling point compensation interval is calculated.In the second stage,the coarse estimation value and the received SNR are combined to determine the traversal range of the fine estimation value of the sampling point compensation interval.A long correlation template signal with local compensation is designed to achieve accurate acquisition of the current field signal.The algorithm’s performance is verified in a heavily shielded space located 30.26 m below the ground.Experimental results show that compared to traditional sliding correlation algorithms,the proposed algorithm has a higher acquisition success probability.

关 键 词：强遮蔽空间 透地通信 地电极电流场 长相关模板信号 捕获算法 

分 类 号：TN929.4[电子电信—通信与信息系统]