Mobile network energy efficiency optimization in MIMO multi-cell systems

In this paper, we consider the energy efficiency maximization problem in downlink multi-input multi-output (MIMO) multi-cell systems, where all users suffer from inter-cell interference. To solve this optimization problem with a nonconcave objective function and a complex-valued matrix variable, we extend the recently developed successive pseudo-convex approximation framework and propose a novel iterative algorithm that has the following advantages: 1) fast convergence as the structure of the original optimization problem is preserved as much as possible in the approximate problem solved in each iteration, 2) easy implementation as each approximate problem is natural for parallel computation and its solution has a closed-form expression, and 3) guaranteed convergence to a stationary point. The advantages of the proposed algorithm are also illustrated numerically in terms of energy efficiency gains from mobile network infrastructure perspective.