Coordinated energy-efficient precoding for CR MIMO interference channels

In this paper we study energy-efficient cooperative precoding for cognitive radio multiple-input multiple-output (MIMO) interference channel. Our objective is to maximize the weighted sum per-user energy efficiencies subject to predefined rate and interference requirements, which is more general than the conventional design and can be used to characterize the achievable energy efficiency region. To address this non-convex problem, the original problem is firstly transformed into a slightly tractable form and then is recast into a parametric subtractive quadratic optimization problem. Based on that, an alternating optimization algorithm with provable convergence is developed to solve the equivalent problem, which can also be modified to solve the weighted sum rate maximization problem subject to the same constraints. Finally, numerical results are provided to verify the effectiveness of the proposed schemes.