超宽带信号在运动人体下阴影衰落对 通信性能的影响

超宽带信号在人体通信技术中具有低功耗、抗衰减等优势。针对人体信道建模工作中阴影衰落与运动状态关联性的问题，文章基于人体不同运动姿态与组织电磁特性建立人体模型，分析超宽带信号下的动态人体信道阴影衰落特性。首先，通过建立80条数据传播链路分析人体不同状态下的体表传播特性，给出了一种体表传播距离与路径损耗的二阶指数衰减关系。其次，分析了动态模型组织电特性变化对路径损耗的影响情况。最后，使用平均误码率研究了UWB系统在动态阴影衰落下的性能差异。结果表明，在动态人体模型下UWB频段的抗损耗性能优于HBC频段，其阴影衰落强度受运动状态影响程度强于HBC频段。研究对超宽带信号在人体通信的建模、应用工作中提供了动态人体阴影衰落强度分布的理论基础。

Influence of shadow fading of UWB signal under moving human body on communication performance

Ultra-wideband signals have the advantages of low power consumption and anti-attenuation in human body communication technology. Aiming at the problem of the correlation between shadow fading and motion state in the human body channel modeling work, this article establishes a human body model based on the human body''s different motion postures and the electromagnetic characteristics of tissues, and analyzes the dynamic human body channel shadow fading characteristics under ultra-wideband signals. First, by establishing 80 data transmission links to analyze the body surface propagation characteristics of the human body in different states, a second-order exponential attenuation relationship between body surface propagation distance and path loss is given. Secondly, the influence of changes in the electrical characteristics of the dynamic model organization on the path loss is analyzed. Finally, the average bit error rate is used to study the performance difference of UWB system under dynamic shadow fading. The results show that the antiloss performance of the UWB frequency band under the dynamic human body model is better than that of the HBC frequency band, and the intensity of shadow fading is affected by the motion state more than the HBC frequency band. The research provides a theoretical basis for dynamic human shadow fading intensity distribution in the modeling and application of ultra-wideband signals in human body communication.