Effect of Multiple Clusters on the Correlated MIMO Capacity in Geometrical Channel Model

It has been proved that in an uncorrelated condition, the capacity of MIMO system will linearly increase with the minimum number of transmitter and receiver antennas. However, the practical capacity of Multiple-Antenna system may vary because of the existence of spatial-temporal correlation. Factors such as Antennas Spacing, Angular Spread, Power Angular Spectrum, Mean Angle-Of-Arrival, Multiple Clusters, Doppler Spread and Delay Spread, will comprehensively affect the space-time correlation coefficients. The multiple clusters´ incident waves may cause oscillation of correlation coefficient and capacity as Antenna spacing increase. In this paper, based on the two-ring model, equations of multiple clustered correlation coefficient and channel capacity will be derived. Both ergodic and outage capacity in multiple clustered environments will be simulated.