A Statistical Transmit Power Allocation Scheme for Spatially Correlated MIMO Systems and Its Robustness to Estimation Errors
The authors consider a simple statistical transmit power allocation scheme for spatially correlated Multiple-Input Multiple-Output (MIMO) systems, which is based on the Karhunen-Loueve transform. The considered scheme is solely based on second-order channel statistics, i.e., no instantaneous channel knowledge is required at the transmitter. They consider different transmit power allocation strategies and propose a simple transmitter-sided maximum-ratio-combining scheme, which provides near-optimum performance over a wide signal-to-noise ratio range. Specifically, substantial gains over equal power allocation are obtained. Finally, the impact of estimation errors concerning the transmitter correlation matrix is studied, and it is shown that the considered transmit power allocation scheme provides a robust performance.