WiEps：用普通WiFi器件测量介电性能--在乙醇/水混合物中的应用
WiEps: Measurement of Dielectric Property with Commodity WiFi Device -- An application to Ethanol/Water Mixture
摘要：
WiFi信号变得无处不在，提供高速数据传输体验。除了通信服务之外，WiFi信号的信道状态信息（CSI）被广泛用于许多物联网（IoT）应用。最近，这些应用中的大多数都是基于对物体物理运动引起的微波反射的分析。在本文中，一种新的非接触式无线传感技术命名为WiEps的开发来测量材料的介电性能，利用WiFi信号的传输特性。在WiEps中，被测材料被放置在发射器天线和接收器天线之间。提出了一个理论模型来定量描述CSI数据和材料的介电性能之间的关系。在实验过程中，从测量的CSI数据中提取所发送的WiFi信号的相位和幅度。使用已知材料的测量数据计算理论模型的参数。然后，WiEps被用来估计未知材料的介电性能。所提出的技术首次应用于乙醇/水混合物。然后，测量额外的液体以进行进一步验证。估算的电导率和电导率与实际值吻合较好，平均误差分别为4.0%和8.9%，表明WiEps的有效性。通过测量介电特性，该技术有望应用于使用无处不在的WiFi信号的新物联网应用，如食品工程，材料制造过程监控和安全检查。
英文摘要：
WiFi signal has become accessible everywhere, providing high-speed data transmission experience. Besides the communication service, channel state information (CSI) of the WiFi signals is widely employed for numerous Internet of Things (IoT) applications. Recently, most of these applications are based on analysis of the microwave reflections caused by physical movement of the objective. In this paper, a novel contactless wireless sensing technique named WiEps is developed to measure the dielectric properties of the material, exploiting the transmission characteristics of the WiFi signals. In WiEps, the material under test is placed between the transmitter antenna and receiver antenna. A theoretical model is proposed to quantitatively describe the relationship between CSI data and dielectric properties of the material. During the experiment, the phase and amplitude of the transmitted WiFi signals are extracted from the measured CSI data. The parameters of the theoretical model are calculated using measured data from the known materials. Then, WiEps is utilized to estimate the dielectric properties of unknown materials. The proposed technique is first applied to the ethanol/water mixtures. Then, additional liquids are measured for further verification. The estimated permittivities and conductivities show good agreement with the actual values, with the average error of 4.0% and 8.9%, respectively, indicating the efficacy of WiEps. By measuring the dielectric property, this technique is promising to be applied to new IoT applications using ubiquitous WiFi signals, such as food engineering, material manufacturing process monitoring, and security check.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
