摘要
利用无线信号进行呼吸检测已被证明具备可行性,但仍存在一些不足之处,如实验设置需要较大的空间;呼吸检测时容易受到非目标活动干扰等。本文通过数学分析方式指出最短菲涅尔区半径所在位置,并结合自由空间传播路径损耗公式和天线电磁场特征,优化了天线设置方式,提出了一种WI-BD呼吸检测模型。实验结果表明,本文所述的WI-BD模型切实可行,信道状态信息变化幅度可达4~8 dB,且具有显著优势:有效减小检测空间;获得最佳菲涅尔区半径;天线间距的可调控性有助于模型的实际应用。
Detecting breathing with wireless signal has been proved to be feasible, but there are still some problems that should be improved. For example, the experiment usually requires a large space. Also, the experiment is vulnerable to environmental factors like surrounding people’s activities. This paper analyzes and compares the radius of the Fresnel Zone in different directions mathematically. We have built an optimization model for the antenna setting exploring of the classic path loss model in free space propagation and the characteristics of electromagnetic field of antennas. The results of our experiments show that the WI-BD model based on Fresnel Zone is feasible. The change range of channel state information can reach 4 - 8 dB, and the model has several significant advantages: Firstly, it effectively reduces the size of the space required by the experiments;Secondly, we can directly get the best radius of Fresnel Zone;Lastly, we can adjust the distance between the antennas to get the best performance.
作者
谷雨
刘博文
占金海
Yu Gu;Bowen Liu;Jinhai Zhan(University of Technology, Hefei Anhui)
出处
《无线通信》
2018年第3期87-96,共10页
Hans Journal of Wireless Communications
基金
国家自然科学基金面上项目(61772169)。
关键词
菲涅尔区
信道状态信息
呼吸频率
视距范围
反射信号
外接天线
Fresnel Zone
Channel State Information
Respiratory Rate
Line Of Sight
Reflected Signal
External Antenna
