MIMO Channel Capacity in 2D and 3D Isotropic Environments

We analyze theoretical distributions of MIMO channel capacity for different antennas in 2D and 3D statistically isotropic environments, which may be generated by multiprobe anechoic and reverberation chambers, respectively. We observe that the two environments yield comparable capacity distributions provided that (1) the 2D statistically isotropic environment’s capacity data are taken at many different antenna orientations and (2) the radiation elements have a low directivity. When these conditions are met, we find that the relative error between the 2D statistically isotropic environment’s orientation-combined capacity distribution and the 3D statistically isotropic environment’s capacity distribution is typically less than 10% for signal-to-noise ratios greater than 5 dB