Time-varying UWB channel model for mobile robot-to-robot communication systems

This paper presents a geometric-based time-varying ultrawideband (UWA) channel model for the mobile robot-to-robot (R2R) communication scenario. The proposed model takes the nonstationarity of the channel into account. The influence of the ground reflected signal on the R2R channel is also considered in the model. To provide insight into the time-varying behaviour of the R2R channel, the concept of channel stationarity is explored. This concept is used to evaluate the deviation of the channel characteristics in the scenario where both robots are moving, from the scenario where only one robot is moving. Simulation results show that in the case of line-of-sight (LOS) and at 99% correlation, the stationarity bandwidth of the channel when only one robot is moving is larger than when both robots are moving. However, in the case of non-LOS (NLOS), the stationarity bandwidths for both scenarios are observed to dependent essentially on the proximity and distribution of the scatterers, but less on the distance between the robots.