Modeling of Time-varying Ultra Wideband Multiple-input Multiple-output Channel

Ultra wideband (UWB) communication is a promising technology for achieving high data rate wireless communications. UWB transmission can be operated in the range of 3.1 to 10.6 GHz with low transmission power to prevent interference with other wireless systems. However, the low transmission power of the UWB signal limits the coverage distance of the UWB system. By using diversity techniques such as the multiple-input multiple-output (MIMO) scheme, enhancement in the communication range can be obtained without compromising data rate. For the purposes of system and network design, it is always important to understand the behavior of the MIMO - UWB channel through modeling. In this paper, we propose a method to derive the synthesis equation for the time-varying MIMO-UWB channel in the time scale-domain. The channel modeling is based on the MIMO correlative modeling approach. The channel operator is represented as a fourth order tensor and the synthesis equation is derived and illustrated. The UWB correlation matrix was plotted for the stationary situation. The results show the importance of the off-diagonal channel correlation elements on the MIMO-UWB channel.