Effect of element polarization on the capacity of a MIMO system

We have analyzed the behavior of a multiple element antenna system in an indoor environment based on the measurements taken in the Lucent Crawford Hill building with a system of 12 transmitters and 15 receivers. The parameters that we investigated were the distance between the transmitting and the receiving arrays, and the polarization of the transmitter/receiver elements. Our measurements show that the capacity of single polarization systems (only vertical or only horizontal) decays with distance in the presence of a strong line-of-sight component. The same is observed in the absence of a strong line-of-sight component if instead there is a dominant propagation path. Systems with elements of both polarizations perform better in terms of capacity in both environments.