Anchorless Cooperative Tracking Using Multipath Channel Information

Highly accurate location information is a key facilitator to stimulate future services for the commercial and public sectors. Positioning and tracking of absolute positions of wireless nodes usually requires information provided from technical infrastructure, e.g., satellites or fixed anchor nodes, whose maintenance is costly and whose limited operating coverage narrows the positioning service. In this paper, we present an algorithm aimed at the tracking of absolute positions without using information from fixed anchors, odometers, or inertial measurement units. We perform radio channel measurements, in order to exploit position-related information contained in multipath components (MPCs). Tracking of the absolute node positions is enabled by the estimation of MPC parameters followed by the association of these parameters to a floorplan. To account for uncertainties in the floorplan and for propagation effects like diffraction and penetration, we recursively update the provided floorplan using the measured MPC parameters. We demonstrate the ability to localize two agent nodes without the employment of further infrastructure, using data from ultra-wideband channel measurements. Furthermore, we show the potential performance gain if also one fixed anchor is available, and we validate the algorithm for a range of different signal bandwidths and a number of nodes.