Current status of the repealite based approach: A sub-meter indoor positioning system

The paper presents experimental validations of a new approach of GNSS indoor positioning. Combining the best of pseudolites [1] and repeaters [2], the new "repealite" technique allows carrier phase measurements (in order to improve positioning accuracy and multipath mitigation) and self synchronised transmissions. Thus, this method greatly simplifies the still required infrastructure and provides better accuracy. Following theoretical aspects described in previous journals and conferences [3]-[4], we propose to give and comment experimental results. In addition, when dealing with a local infrastructure, deployment considerations are of uppermost importance. In order to remove the coaxial cable links from the central controller to the various indoor transmitting antennas, we decided to use Radio Over Fibre (RoF) techniques. The continuity of the positioning service appears as a real challenge for the next years. GNSS approaches, sensor networks or WLAN are thus proposed in order to provide this continuity. The GNSS based solutions present the advantage of making better use of the satellite receiver. Unfortunately, techniques like HS-GPS or A-GPS do not seem to give a definitive answer. Local infrastructure based solutions help in a final system with good accuracy and large coverage: the one described in the paper uses GPS so-called repealites that make GPS-like signals available indoors.