Recent advances in RF-based passive device-free localisation for indoor applications

In this article, we survey the recent progress of IDFL prioritising on indoor positioning. We decompose the localisation dimensions into occupants, space and time, provide a detailed taxonomy and a comprehensive review of these techniques. We divide the state of the art mainly into Wireless Network-based and Radar-based, evaluate the respective technologies and the techniques qualitatively, discuss trends, limitations and also indicate future research directions relevant to this field.