MIMO capacity estimation in urban cellular environment with a ray model

MIMO technology promises a linear increase of capacity in function of the minimum antenna number at the transmitter and at the receiver. In order to test if these performances can be actually met in mobile communications, we proposed here a study of MIMO capacity in urban cellular environment at 2 GHz thanks to an efficient ray propagation model. We have tested different types of base station antennas (vertically or plusmn45deg polarized) and two different types of mobile. Capacity increases between SISO and MIMO systems, but this increase is lower than the expected one. We show that return and coupling losses even around 10% can decrease significantly the capacity. Moreover, we propose a study of the MIMO capacity in function of the received signal power level.