Application of the Improved FOCUSS for Arrival Time Estimation (IFATE) algorithm to WLAN high accuracy positioning services

Many Location Based Services (LBS) have emerged in the past few years. However, the provision of underlying positioning technologies to support these services in indoor environments is still challenging. The indoor environment with its propagation complexity presents a burden to achieve affordable, high accuracy and real-time positioning. A recent development, the Improved FOCUSS for Arrival Time Estimation (IFATE) algorithm, addresses some of the indoor propagation environment limitations and enables real-time sub-metre ranging accuracy. This paper introduces a number of measures for the practical implementation of IFATE to support affordable real-time and high accuracy WLAN positioning. These measures include the introduction of the architecture for an IFATE-enabled WLAN reference node. Furthermore, the paper evaluates the performance of IFATE in comparison to superresolution sub-space decomposition and basic cross-correlation based techniques. IFATE performance is also validated using real data collected from different WLAN indoor environment settings.