Track estimation using link line crossing information in wireless networks

Device-free or non-cooperative localization uses the changes in signal strength measured on links in a wireless network to estimate a person´s position in the network area. Existing methods provide an instantaneous coordinate estimate via radio tomographic imaging or location fingerprinting. In this paper, we explore the problem of, after a person has exited the area of the network, how can we estimate their path through the area? We present two methods which use recent line crossings detected by the network´s links to estimate the person´s path through the area. We assume that the person took a linear path and estimate the path´s parameters. One method formulates path estimation as a line stabbing problem, and another method is a linear regression formulation. Through simulation we show that the line stabbing approach is more robust to false detections, but in the absence of false detections, the linear regression method provides superior performance.