Relations Between 3-Dimensions Antenna Pattern and Narrowband MIMO Capacity

In this paper, the antenna radiation pattern is introduce for a multiple input multiple output system (MIMO) capacity model calculation. MIMO model considers effect of radiation pattern in 3-dimention, channel impulse responses and elements correlation in separately. This paper investigates effects of both directional and omni-directional antennas to the MIMO capacity. For the directional antenna case, horizontal polarized dipole and Yagi-Uda antennas are employed in the array. The capacity is compared to the capacity calculated by employing omni-directional antennas that considered to be an ideal MIMO capacity. The results 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.