A Non-Line-of-Sight Mitigation Method For Indoor Ultra-Wideband Localization With Multiple Walls

Ultra-wideband (UWB) ranging techniques can provide accurate distance measurement under line-of-sight (LOS) conditions. However, various walls and obstacles in indoor non-LOS (NLOS) environments, which obstruct the direct propagation of UWB signals, can generate significant ranging errors. Due to the complex through-wall UWB signal propagation, most conventional studies simplify the ranging error model by assuming that the incidence angle is zero or the relative permittivity\u27s for different walls are the same to improve the through-wall UWB localization performance. Considering walls are different in realistic settings, this article presents a through-multiple-wall NLOS mitigation method for UWB indoor positioning. First, spatial geometric equilibrium equations of UWB through-wall propagation and a numerical method are developed for the precise modeling of UWB through-wall ranging errors. Then, calculated error maps are determined numerically without field measurements. Finally, the determined error maps are combined with a gray wolf optimization algorithm for localization. The proposed method is evaluated via field experiments with four rooms, three walls, and six penetration cases. The results demonstrate that the method can strongly mitigate the multi-wall. NLOS effects on the performance of UWB positioning systems. This solution can reduce project costs and number of power supplies for UWB indoor positioning applications

A throughput Fast Measurement Method for Two-Antenna Equipped Wireless MIMO Terminals

According to the Third Generation Partnership Project Specification, a Period of 8-12.8 H is Required to Evaluate the Multiple-Input-Multiple-Output (MIMO) Performance of a Wireless Terminal for a Single Frequency Point and Channel Model Combination. the Following Article Proposes a Semi-Simulation, Semi-Measurement-Based MIMO throughput Modeling Scheme Which Can Reduce the 8-12.8-H Measurement Time to 40-60 Min, Corresponding to More Than a Ten Times Improvement of the Test Efficiency, Without Loss of the Test Accuracy

A Compact And High-Efficiency Antenna Design For Tire Pressure Monitoring System Applications

This article proposes a novel design for a compact antenna that exhibits high efficiency and low interference and is suitable for tire pressure monitoring systems (TPMSs) based on Bluetooth communication interface at 2.4 GHz. Tires constitute a dissipative environment, where the efficiency of the TPMS is affected by both antenna losses and losses from the tire parts, both conductive and dielectric. This article conducts an analysis and simulation of the electromagnetic (EM) environment of the tire and identifies the optimal polarization and placement position for the TPMS antenna to minimize resonance losses of EM waves within the tire, enhance lateral radiation, and thereby improve the overall efficiency of the TPMS. The requirements for the TPMS antenna, including pure linear polarization, low common mode currents, compact size, wide bandwidth, high efficiency, and static mechanical protection, are derived from the requirements of the TPMS application and the EM environment within the tire. The proposed antenna satisfies all of these requirements and is based on a wideband, high-efficiency EM structure. The final antenna design achieves a bandwidth of 35% (2.24-3.22 GHz), a gain of 2.1-2.4 dBi, and a cross-polarization level ranging from -29 to -16 dB. These results demonstrate that the antenna is a strong candidate for being employed in TPMS applications

キャノピーモデルを用いた都市域内および複雑地形上の乱流場の数値予測

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 石原 孟, 東京大学准教授 知花 武佳, 東京大学准教授 長山 智則, 東京大学特任講師 山口 敦, 東京大学教授 大岡 龍三University of Tokyo(東京大学

Huber Kalman Filter for Wi-Fi based Vehicle Driver\u27s Respiration Detection

The use of breath detection in vehicles can reduce the number of vehicular accidents caused by drivers in poor physical condition. Prior studies of contactless respiration detection mainly targeted a static person. However, there are emerging applications to sense a driver, with emphasis on contactless methods. For example, being able to detect a driver\u27s respiration while driving by using a vehicular Wi-Fi system can significantly enhance driving safety. The sensing system can be mounted on the back of the driver\u27s seat, and it can sense the tiny chest displacement of the driver via Wi-Fi signals. The body displacement and car vibrations could introduce significant noise in the sensed signal. The noise then needs to be filtered to obtain the driver\u27s respiration. In this work, the noise in the sensed signal is proposed to be reduced using a Huber Kalman filter to restore the original respiration curve. Through several experiments in terms of different drivers, different car models, multiple passengers, and abnormal breathing, we demonstrate the accuracy and robustness of the Huber Kalman filter in driver\u27s respiration