A model of MIMO system over a three-dimensional rough surface

Multiple input-multiple output (MIMO) system is a promising technique for B3G/4G development. In this paper, the MIMO system above a 3-D randomly rough surface is modelled and numerically analyzed. The Monte Carlo method is employed to generate randomly rough surface, and the Kirchhoff approximation (KA) is applied to calculation of system scattering and the channel transfer matrix. It shows the dependence of the system capacity upon the array geometry and underlying surface parameters. It is found that the channel capacity significantly related with the inter-element separation of the antenna array. When the separation is small, the MIMO capacity due to presence of rough surface can be enhanced. However, when the separation is increased, the MIMO capacity becomes significantly reduced.