Effect of Antenna Patterns on Narrowband MIMO Capacity

In this paper, a model for MIMO capacity calculation with array element radiation patterns is proposed. The proposed model considers effect of radiation pattern, channel impulse responses and elements correlation separately. The effects of both directional and omni-directional antennas to the MIMO capacity are investigated. For the directional antenna case, horizontal polarized Dipole and Yagi-uda antennas are employed in the array. The omni-directional antennas case is considered to be an ideal MIMO capacity. We have shown that directional antennas reduce the narrowband MIMO capacity when the angle of arrival (AOA) is uniformly distributed. When the directional antennas with proper alignment to the mean AOA are used in a scenario where the AOA is Laplacian distribution, the capacity is increased. However, if the antenna alignment is off from the mean AOA, then the capacity is decreased.