IEEE 802.15.4a UWB 기반 실내 위치측정 시스템의 설계 및 구현

Abstract

Nowadays, many people spend most of their life indoor. Thus, positioning and tracking of target at indoor environment have become very important applications. The conventional positioning systems such as global positioning system (GPS) have limited performance at the indoor environment because GPS signal is weakened. For indoor positioning, there are many possible approaches such as WiFi, BLE, Infrared Ray, UWB, and so on. This thesis discusses a design and implementation of ultra wideband (UWB) positioning system based on IEEE 802.15.4a standard. This IEEE 802.15.4 UWB positioning system uses time based positioning scheme called time of arrival (TOA) to measure the distance from a target tag. In order to measure TOA, a mobile tag performs the two way ranging (TWR) with adjacent 3 fixed anchors. After that, the position of tag is calculated by trilateration using distance between tag and each anchor. This thesis introduces a practical TWR algorithm and trilateration method for indoor positioning system. Also, the thesis shows the result of performance evaluation of the proposed UWB based positioning system. The experimental results validate that the proposed IEEE 802.15.4a UWB based positioning system measures the moving tag’s position with tolerable error of 1m.