Analysis of MIMO Channel Capacity Dependence on Antenna Geometry and Environmental Parameters

We evaluate the multiple-input multiple-output (MIMO) channel capacity dependence on angular spread, antenna element separation, and angle of arrival. The empirically derived spatial channel model (SCM) is selected for the simulations and an uncoupled ideal dipole uniform linear array is considered. We show that for a small angular spread (8deg), the angle of arrival (AoA) will increase the required signal-to-noise ratio (SNR) for a high ergodic capacity by more than 4 dB as it moves away from the array broadside. For the case of a large angular spread (68deg), the AoA has a minimal impact on the ergodic capacity. Insight into the capacity behavior is explained in terms of the minimum channel eigenvalue and the path correlation. We also found that as the channel outage capacity threshold decreases, the impact of the system parameters is reduced.