Large-Scale Electromagnetic Characterization of Urban MIMO Communication Systems

Multiple-input multiple-output (MIMO) wireless communication systems are of increased interest due to their high spectral efficiency and substantial diversity. Full characterization of the MIMO channel is very important, yet remains a challenge due to the complex electromagnetic interactions between the antenna elements and the environment. We use computational electromagnetics (CEM) to study the performance of MIMO links, and present large-scale simulation results in an outdoor urban environment. We examine the impact of the location of the antenna array in the environment, the average received power, and the angle spread on the average mutual information (AMI) of the MIMO channel. We find that locations closer to the base transceiver station (BTS) correspond to higher AMI, especially when these locations receive line-of-sight (LOS) rays. However, if perfect transmit power control is used, MIMO systems have higher capacity in nonline-of-sight (NLOS) regions due to increased spatial modes in the channel.