Effects of Wall Reflection on Indoor MIMO Channel Capacity

The channel capacity of the indoor multiple input multiple output (MIMO) system is investigated with consideration of the effects of the wall by using a hybrid method of the finite difference time domain (FDTD) method and the method of moments (MoM). Firstly, the effects of wall material on indoor MIMO channel capacity are investigated according to the physical parameters of the wall, i.e. the relative permittivity, the conductivity and the thickness. Secondly, the channel capacity, the average received power on each receiving branch and the effective degrees of freedom (EDOF) of multiple paths of the indoor MIMO system are statistically analyzed with the wall reflectivity instead of the physical parameters of the wall. Finally, the effects of wall reflection on the eigenvalues of the MIMO channel transfer matrix and the spatial correlation between the antenna elements are statistically investigated. It is found that the wall reflectivity is a suitable parameter to investigate the wall effects on the indoor MIMO system.