Tight lower bounds on the ergodic capacity of Ricean fading MIMO channels

The ergodic capacity of multiple antenna system in Ricean fading is considered under the assumption that channel state information (CSI) is available only at the receiver and the transmitter has no knowledge of the CSI. Using complex noncentral Wishart distribution and Bartlett´s decomposition, we derive tight closed-form lower bounds on the ergodic capacity of such channels. We have also derived analytical approximations to the lower bound. Moreover, we show that our lower bounds tighter than previously reported analytical lower bounds. Numerical results also show that our results closely match the actual capacity of Ricean fading MIMO channels.