人体通信信道特性研究

发布时间：2019-04-10 10:07

【摘要】：近年来,人体通信逐渐成为医疗领域的一项更加新颖的技术,这项新的技术包含了无线通信与生物电磁方面的诸多领域。人体通信以人体作为主要的传输信道,相比传统的无线信道以空气等作为媒质,具有更加复杂的研究方向和内容。人体信道是人体通信研究的重中之重,希望通过本文的研究能对人体通信的发展起到一定的促进作用,进而提高人类的健康水平。本篇文章的主要工作如下:首先,详细分析了时域有限差分方法的使用步骤与原理,从稳定性条件、单元格大小的确定、吸收边界条件等方面展开分析。接着,分不同的频率段提出了不同路径损耗模型,在频率较高的UWB、MICS、ISM等频段提出了对数型路径损耗模型和指数型路径损耗模型。在HBC频段提出了分段的路径损耗模型。然后,基于XFDTD软件和时域有限差分算法对人体信道进行三维建模,不同于以往研究所使用的简单几何形状组成的人体模型,本文采用了更加接近人体组织参数和形状的人体模型,在人体模型表面上放置发射点和186个接收点仿真人体体表信道,对所提出的信道模型进行验证。最后,在已验证的信道模型基础上分析人体信道的特性,主要分析了不同频率、不同传播距离以及改变收发点到人体表面间距、不同人体组织下人体信道的特性改变。并采用简单圆柱体建立人体的手臂模型对体表信道的传播特性进行分析。仿真结果表明:人体信道在高频段通常符合对数路径损耗模型,而在HBC频段则为分段直线的路径损耗模型。证明了,人体躯干部位频率越大路径损耗越小,传播距离增大路径损耗变大,收发点到人体表面距离越大路径损耗越小,由此验证了人体组织对信道特性的重要影响,通过对人体不同部位的仿真证明了不同人体组织对路径损耗的影响不同,以及通过手臂模型的仿真表明了人体体表信道的表面波特性。
[Abstract]:In recent years, human body communication has gradually become a more novel technology in medical field. This new technology includes many fields in wireless communication and bio-electromagnetism. Human body communication takes human body as the main transmission channel. Compared with the traditional wireless channel using air as the medium, it has more complex research direction and content. The channel of human body is the most important in the research of human body communication. It is hoped that the research in this paper can promote the development of human communication and improve the level of human health. The main work of this paper is as follows: firstly, the steps and principles of finite-difference time-domain (FDTD) method are analyzed in detail, including stability conditions, cell size determination, absorbing boundary conditions and so on. Then, different path loss models are proposed in different frequency segments, and logarithmic path loss models and exponential path loss models are proposed in UWB,MICS,ISM and other frequency bands. A piecewise path loss model is proposed in the HBC band. Then, based on XFDTD software and finite-difference time-domain (FDTD) algorithm, three-dimensional modeling of human channel is carried out, which is different from the human body model composed of simple geometric shapes used in previous studies. In this paper, a human model, which is closer to the parameters and shape of human body tissue, is used to simulate the body surface channel by placing the emissive points and 186 receiving points on the surface of the human body model, and the proposed channel model is verified. Finally, based on the verified channel model, the characteristics of human body channel are analyzed, including different frequency, different propagation distance, changing the distance between receiving point and human surface, and the characteristic change of human body channel under different human tissues. A simple cylinder is used to build the arm model to analyze the propagation characteristics of the body surface channel. The simulation results show that the human channel usually conforms to the logarithmic path loss model in the high frequency segment, while the path loss model in the HBC band is a piecewise straight line path loss model. It is proved that the greater the frequency of the human body is, the smaller the path loss is, the greater the propagation distance is, and the smaller the path loss is. The larger the distance from the receiving point to the surface of the human body, the smaller the path loss, thus validating the important influence of the human tissue on the channel characteristics. Through the simulation of different parts of the human body, it is proved that different human tissues have different effects on the path loss, and the simulation of the arm model shows the surface wave characteristics of the body surface channel of the human body.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN911

【参考文献】