Movement of Equivalent Scatterers in Geometry-Based Stochastic Channel Models

Channel models are widely used to test receiver algorithms and, therefore, should model the propagation behavior as completely as possible. A promising type of channel model is the geometry-based stochastic channel model (GSCM), which represents the propagation channel by placing equivalent scatterers (ES) within a simulated geometry. Each of these ES is associated to a propagation path between the transmitter and the receiver. The propagation length of a modeled path can be calculated in a straightforward manner knowing the ES, the transmitter, and receiver locations by simple distance calculations. If the receiver is moving, an ES may change its location in order to model a propagation path accurately. However, this movement has not been sufficiently taken into account so far. Within this contribution, we show that the movement of an ES lies on a trajectory described by an ellipse or hyperbola when the receiver is in motion. Based on this derivation, a modeling approach for a propagation path resulting from multiple reflections is given, where at least one reflector is geometrically static in its position. Our description supports the simulation of an arbitrary receiver movement. Finally, we provide an example from an outdoor-to-indoor measurement campaign that confirms the movement of the ES.