Directional of Arrival Tag Response for Reverse RFID Localization

Abstract

A positioning system implemented with RFID technology is explored for a GPS-denied environment such as an underground mine or tunnel. A new method of two-dimensional localization is developed based on the angles of arrival of three tag’s responses that are located at known positions. This method reduces the error when the localization process is based on the received signal strength from an RFID tag signal. Passive tags are placed in predefined locations with known information about their coordinates. An RFID reader attached to a robot with a directive antenna is used to get the AOA of the signals received from the tags. The AOA information is then used for triangulating the position of a reader’s location (reverse localization).