A Model for Spatial Behavior of Multipath Components Pertinent to Indoor Geolocation Using Ray Optics

Challenges for precise indoor geolocation cannot be overcome by using the existing RF models for multipath components (MPC). These models were designed for communication applications without specific attention to relation among the physical distance between the transmitter and the receiver and characteristics of MPCs pertinent to indoor geolocation applications. In this paper, we propose a novel model for the spatial behavior of MPCs which addresses these issues. This model uses principles of ray optics to explain the spatial evolution of path gains, time-of-arrival, and angle-of-arrival of MPCs observed by a mobile terminal operating in an indoor environment. The relation between the transmitter-receiver separation and the number of paths as well as statistical modeling of lifetime and birth rate of the paths are also incorporated in our model based on empirical data obtained by using a measurement calibrated ray-tracing tool.