Research On Correlated MIMO Channel Capacity

Multiple-input multiple-output (MIMO) antenna systems have recently attracted considerable research attention as they offer substantial capacity improvements over single-antenna systems without requiring additional power or bandwith. This high capacity is obtained by the assumption that there are sufficient scatters between the transmitter and receiver so that the fading is independent and identically Rayleigh distributed, however, in a real world scenario the fades are usually not independent, but will exhibit certain fading correlations, such as spatial fading correlation caused by small antenna separation and the angular spread, multi-tap correlation due to the transmit and receive pulse shaping filters as well as propagation channel itself, and the presence of dominant nonfading paths (possibly line-of-sight). These realistic characteristics will have significant effects on MIMO capacity. To this end, in this paper, based on the analysis of the statistic characteristics of wireless channel and the comprehension of the features of MIMO capacity from an information theory point of view, the effects of the propagation and system parameters such as Rician factor, multipath tap gain correlation and spatial fading correlations at both ends on the capacity are evaluated both by theoretical derivation and by numerical simulations.