Date Added: Mar 2012
Optimizing Energy Efficiency (EE) for the MIMO Broadcasting Channels (BC) is considered in this paper, where a practical power model is taken into account. Although the EE of the MIMO BC is non-concave, the authors reformulate it as a quasi-concave function based on the uplink-downlink duality. After that, an energy efficient iterative water-filling scheme is proposed based on the block-coordinate ascent algorithm to obtain the optimal transmission policy efficiently, and the solution is proved to be convergent. Through simulations, they validate the efficiency of the proposed scheme and discuss the system parameters' effect on the EE.