Optimum power allocation and complete characterization of the impact of correlation on the capacity of MISO systems with different CSI at the transmitter

We study the optimal transmission strategy of a multiple-input single-output (MISO) wireless communication link. We analyze the impact of correlation on the ergodic capacity of the MISO system with different CSI schemes. We show that the ergodic capacity with perfect CSI and without CSI at the transmitter is Schur-concave. In addition, we show that the ergodic capacity with covariance knowledge at the transmitter is Schur-convex with respect to the correlation properties. Furthermore, we develop a new characterization of the optimum power allocation for the covariance feedback scenario.