Recent Advances in MIMO Systems Exploiting Polarization Diversity

Abstract

International audienceSince few years MIMO systems are used to enhance channel capacity. The allowable spectrum bandwidth becomes more and more rare and expensive, which encourages the researchers in the field to exploit more advanced signal processing techniques. In recent years ‘Polarization Diversity' proves that the capacity can be boosted under certain conditions. In this Keynote, propagation geometric scattering models are presented in detail for 2D and 3D fields. It will be the basic model to simulate and calculate the different wave polarization and configuration. Some parameters are also explained such as Cross Polarization Ratio (XPR) and Space-Time Correlation. These parameters are necessary to understand the gain in channel capacity in function of the spatial configuration. The impact of the CSI on the capacity is also studied and simulated in case of using the Water Filling principle in the transmitter side. Each scattering process is represented by a matrix corresponding to the depolarization and the distortion of the electromagnetic wave. The validation of dual-polarized MIMO channels is examined and compared with the single-polarized MIMO channels. The simulation results demonstrate that the transmit and receive antenna correlations can be reduced, so that the channel capacity can be improved for dual-polarized or Multi-polarized MIMO channels. Finally, some conclusions and perspectives are shown with recent applications