Indoor positioning based on a radiating cable system: a theoretical and experimental evaluation

A positioning system in confined environments is not only used for entertainment, but also for other applications, such as security and safety, where it has become a priority. On the other hand, radiating cables have been successfully used to provide coverage in these harsh environments. This paper presents the evaluation of an alternative use of radiating cables for indoor positioning. Specifically, the mean delay and received power are used as measurable variables for position determination, using the location error for evaluating the goodness of such methods in two different scenarios. The first scenario is inside a tunnel where a theoretical evaluation is carried out by considering the cable as an array of magnetic dipoles. For the second scenario, the radiating cable is considered to be inside a building where a theoretical and an experimental evaluation is performed. The experimental demonstration is based on wideband measurements of channel frequency responses inside the building. Channel impulse responses are generated considering the environment, and various channel characteristics are used for positioning, i.e., decreased signal strength and multipath propagation. Fingerprinting is used to determine position, and its implementation promises to be a feasible option for indoor positioning, specifically in venues where traditional positioning systems do not work properly and the radiating cable characteristics can be exploited, i.e., corridors, mines, production lines in factories, airports, tunnels, etc.