Analysis of Time of Arrival Estimation Using Wideband Measurements of Indoor Radio Propagations

Using time of arrival (TOA) to determine the distance between the transmitter and the receiver is the most popular technique for accurate indoor positioning. The accuracy of measuring the distance using this method is sensitive to the bandwidth of the system and the multipath condition between the wireless terminal and the access point. In general, as the bandwidth increases beyond a certain value, it is expected that the measured TOA error approaches zero. However, for the so-called undetected direct path (UDP) conditions, the system exhibits substantially high distance measurement errors that cannot be eliminated with the increase in the bandwidth of the system. In this paper, we provide an analysis of the behavior of superresolution and traditional TOA estimation algorithms in line-of-sight (LOS), non-LOS, and UDP conditions in indoor areas. The analysis is based on wideband frequency- domain measurements of the indoor radio channel propagations in several indoor areas, with special attention to the UDP conditions.