Channel Characterization of Magnetic Human Body Communication
Channel Characterization of Magnetic Human Body Communication
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DOI：
10.1109/tbme.2021.3101766
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发表时间：
2022-02-01
影响因子：
4.6
通讯作者：
Mercier, Patrick P.
中科院分区：
文献类型：
--
作者：
Wen, Erda;Sievenpiper, Daniel F.;Mercier, Patrick P.
目的：本文的目的是建模和实验验证磁性人体通信（mHBC）的路径损耗的好处，使用小形状因子，准确的线圈在现实条件下工作。研究方法：辐射近场耦合模型和数值模拟表明，谐振线圈之间的磁主导的近场耦合提供低路径损耗的身体，并表现出额外的鲁棒性天线失调相比，远场RF计划。为了克服传统的矢量网络分析仪为基础的测量配置的陷阱，我们提出了一个标准化的设置适用于宽带信道损耗测量与便携式仪器。分别为智能手机等大型设备和耳塞等小型设备设计的两种类型的mHBC通信PCB线圈被构建和测量。结果如下：用于耳到耳非视线（NLOS）路径的mHBC链路在大线圈和小线圈的情况下分别测量到高达-23.1dB和-31.2dB，这比利用类似尺寸的天线的传统蓝牙信道高50 dB。耳朵到口袋和口袋到口袋的信道也显示出比蓝牙信道至少高16 dB的传输。结论：在路径损耗方面，mHBC方法为身体区域的短程应用提供了令人信服的性能。对于尺寸为几厘米的线圈，在100 MHz和200 MHz之间工作可以最大限度地减少通道损耗，同时保持带宽高于1 MHz。重要性：所提出的mHBC通道的极高效率为小型化可穿戴设备的能源问题提供了解决方案，可能导致新的可穿戴设备设计。
Objective: The objective of this paper is to model and experimentally validate the path loss benefits of magnetic human body communication (mHBC) using small form-factor-accurate coils operating under realistic conditions. Methods: A radiating near-field coupling model and numerical simulations are presented to show that the magnetic-dominant near-field coupling between resonant coils offers low path loss across the body and exhibits extra robustness to antenna misalignment compared to far-field RF schemes. To overcome the pitfalls in conventional vector-network-analyzer-based measurement configurations, we propose a standardized setup applied to broadband channel loss measurement with portable instruments. Two types of PCB coils for mHBC communication, designed for large devices such as smartphones and small devices such as earbuds, respectively, are built and measured. Results: The mHBC link for the ear-to-ear non-line-of-sight (NLOS) path measures up to -23.1 dB and -31.2 dB with large and small coils, respectively, which is 50 dB more efficient than the conventional Bluetooth channels utilizing antennas of similar sizes. Ear-to-pocket and pocket-to-pocket channels also show at least 16 dB higher transmission than the Bluetooth channel. Conclusion: In terms of path loss, the mHBC approach offers compelling performance for short-range applications over the body region. For coils with dimensions of several centimeters, working between 100 MHz and 200 MHz minimizes the channel loss while keeping the bandwidth above 1 MHz. Significance: The extremely high efficiency of the proposed mHBC channel provides a solution to the energy problem for miniaturized wearables, potentially leading to new wearable device designs.