Owing to the rapid increase of smartphone users recently, there is a wide spread of WiFi AP for wireless Internet. Also, many researches have been made for localization methods of user's position. While user position can be acquired by using GPS for the outdoor environment, there is a difficulty in indoor acquisition of GPS weak signals. For indoor positioning using WiFi APs, The fingerprint method based on received signal strength (RSS) is widely researched. To increase the positioning accuracy, many WiFi APs are needed, which leads interference between WiFi APs. The proximity method using beacon AP and directional antenna minimizes interference between APs. However, this method provides positioning with accuracy of few meters only in the small coverage. Moreover, positioning error could be induced due to low latency of RSS of beacon APs in the smartphone. In this paper, angle of arrival (AOA) based positioning estimation method using multi-antenna is introduced. By using this, positioning accuracy of under meter within ten meters could be fulfilled. Finally, field experiment is performed for performance estimation of AOA based positioning.

Keywords: WiFi, indoor positioning, angle of arrival