Performance of TOA estimation algorithms in different indoor multipath conditions

Using TOA to determine the distance between the transmitter and the receiver is the most popular technique for accurate indoor positioning. Accuracy of measuring the distance using TOA is sensitive to the bandwidth of the system and the multipath condition between the wireless terminal and the access point. The behavior of the distance measurement error using TOA techniques in LOS and OLOS indoor environments are substantially different. In general, as the bandwidth increases the distance measurement error decreases. However, for the so called undetected direct path (UDP) conditions the system exhibits substantially high distance measurement errors that can not be eliminated with the increase in the bandwidth of the system. In this paper we provide an analysis of the behavior of super-resolution and traditional TOA estimation algorithms in LOS, OLOS and UDP conditions in indoor areas. The analysis is based on the frequency domain measurements of the indoor radio channel propagations in several indoor areas with special attention to the UDP conditions.