Energy Efficiency in MIMO Interference Channels: Social Optimality and Max-Min Fairness

In this paper, we consider the energy efficiency optimization problem in MIMO multi-cell systems, where all users suffer from intercell interference. To solve this multi-objective optimization problem, we consider both socially optimal solutions and max-min fairness solutions. We propose two novel iterative algorithms that converge to socially optimal solutions and max-min fairness solutions. The proposed algorithms have 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, and 2) efficient implementation as each approximate problem is natural for parallel computation and/or its solution has a closed-form expression. The advantages of the proposed algorithms are also illustrated numerically.