Transmit rank selection in double-correlated Rayleigh fading MIMO systems

In this paper, the transmit signaling problem for multiple-input multiple-output (MIMO) systems with statistical channel state information (CSI) at the transmitter under double-correlated Rayleigh fading channels is considered. We propose a low complexity transmit signaling algorithm, which we refer to as the rank selection algorithm, based on the upper bound of the ergodic mutual information. This algorithm can achieve higher ergodic mutual information with less power allocation information feedback bits, and does not require computationally complex numerical optimizations over random processes. Simulation results confirm the performance.