基于中继传输的海-空跨界磁感应通信覆盖范围与可用带宽分析

Coverage and transmission bandwidth analyses of underseato-air magnetic induction communication with relay transmission

跨空海界面(跨界)的信息传输具有非常重要的实际意义,磁感应通信具有可以双向跨界传输、不易受复杂水文环境影响的独特优势,具备成为跨界通信技术的潜力.但磁场分量随距离和频率增加的快速衰减限制了磁感应通信的覆盖范围和传输速率.本文提出基于中继传输的海-空跨界磁感应通信方案,利用中继传输获取分布式空间分集增益,用来增强水下的磁场分量,扩大跨界磁感应通信的水下覆盖范围和传输带宽.利用分层导电媒质中的磁偶极子模型,建立了基于中继传输的海-空跨界磁感应通信的传播模型;提出了确定中继位置的方法与步骤;通过水下磁感应强度分布的计算,对比分析了不同中继条件下,基于中继传输的海-空跨界磁感应通信的通信范围和可用带宽.数值分析的结果表明,选取合适的中继数量和位置,中继传输可同时使跨界磁感应通信的水下覆盖范围和有效数据率成倍地增加,从而使得基于中继传输的磁感应通信有望为跨界通信提供有效的解决方案.

The transboundary information transmission across the air-and-sea interface is of great practical significance.No matter from the perspective of scientific research or from the view of applications,transboundary communication is a hot and challenging field.Magnetic induction communication has the unique advantages of two-way transboundary transmission,insusceptible to complex hydro-logical environment,and especially suitable for shallow water channel and other environments with harsh propagation characteristics,providing a promising solution for transboundary information transmission.However,the rapid attenuation of magnetic field component with the increase of distance and frequency limits the coverage and transmission rate of the transboundary magnetic induction communication.Therefore,enhancing magnetic field component at a distance has become a focus of magnetic induction communication research.An undersea-to-air transboundary magnetic induction communication scheme based on relay transmission is proposed in this paper,in which a virtual distributed antenna array is formed by processing and relaying the received signals performed at the relay terminals,and the distributed spatial diversity gain can be obtained which is used to enhance the underwater magnetic field component,expand the magnetic induction propagation range,and increase the transmission bandwidth and improve the receiving signal-to-noise ratio as well.Moreover,even in a dynamic marine environment,the relay transmission can be effectively realized and the communication performance can be guaranteed.In this paper,the propagation model of relay transmission based undersea-to-air transboundary magnetic induction communication is established by using the magnetic dipole model in layered conductive media.The effective communication range of direct and relay communication are defined by using their receiving thresholds,and the basic methods and steps to determine the relay location are presented.The communication coverage and available transmission bandwidth of undersea-to-air transboundary magnetic induction communication under different relay scenarios are analyzed and compared by calculating the underwater magnetic induction strength distribution.The numerical results indicate that the underwater coverage and available bandwidth of transboundary magnetic induction communication can be simultaneously doubled under the appropriate number and location of relays.The research in this paper suggests that the relay transmission scheme for magnetic induction communication is suitable for the application in dynamic environment with high propagation loss,which greatly increases the feasibility and effectiveness of the magnetic induction communication as a transboundary communication technology.