人体通信频段体内至体表信道特性分析与建模

为探究人体通信(HBC)频段体内无线通信系统的传输特性，该文对解剖学数值人体模型和多层异质几何人体模型的体内至体表信道特性进行电磁仿真分析，首次建立了人体通信频段内10～50 MHz体内至体表路径损耗模型，并通过生物液态仿体内测量验证了电磁仿真和路径损耗模型的有效性。首先，结合时域有限积分法和数值人体模型计算10～50 MHz人体心脏节点至体表各节点的平均路径损耗，分析对比解剖学数值人体模型和多层异质人体模型的路径损耗、阴影衰落和电磁场分布特性。其次，基于表面波传播机理，提出一个带有线性修正项的对数路径损耗模型，最后建立完整的10～50 MHz体内至体表植入式人体信道模型。仿真分析和实验结果表明，该文提出的带有线性修正项的路径损耗模型可以更准确地描述此频段体内至体表路径损耗特性，采用解剖学数值人体模型进行此频段信道建模与特性研究可以有效提高植入式信道模型的可靠性。

In-body to On-body Channel Characteristics Analysis and Modeling in Human Body Communication Frequency Band

To investigate the in-body transmission mechanism and propose a comprehensive channel model at Human Body Communication (HBC) band, two types of human body model, that is, an anatomical numerical human model and a multi-layer heterogeneous geometric human model, are adopted to derive the path loss characteristics using electromagnetic simulations. The average path losses from the human heart transmitter to each receiver node on the body surface are first calculated by the Time-Domain Finite Integration method incorporated with the human model. A comprehensive logarithmic path loss model with a linear regulation term is proposed based on the surface wave propagation mechanism to describe the channel characteristics accurately. The shadow fading in decibel is found to follow Normal distribution. The simulation and experimental measurement results demonstrate that the proposed path loss model can well characterize the implant channel characteristics for 10～50 MHz HBC band signals. Using the anatomical numerical human model to perform the channel modeling and channel characteristics study in this frequency band can improve the accuracy and reliability of the constructed implant channel model. This work is the first time to construct the in-body to on-body path loss model for ultra-wideband 10～50 MHz signals at the HBC band.