Optimum Power Allocation for Maximizing the Capacity both with Nonzero Mean and Covariance at the Transmitters

The performance of MIMO systems may be improved significantly by using some set of channel knowledge at the transmitter. However, accurate instantaneous channel knowledge at the transmitter is costly and may be difficult to acquire. When the receiver side has the perfect channel state information, the capacity can be found with the transmit covariance which involves to find the optimum transmit directions and the optimum power allocation polices. Most recent work has been done on the MIMO capcity with channel side information, channel mean or channel covariance. But sometimes the trasmitter can get the channel mean and channel voariance simultaneously. this paper will study the optimum power allocation for maximizing the MIMO capcity both with the channel mean and channel covariance. It was shown that this policy can improve system performance compared with the only channel mean or channel covariance.