QoS-constrained weighted sum-rate maximization in multi-cell multi-user MIMO systems: An ADMM approach

Much of research focus has been given to weighted sum rate maximization (WSRM) without Quality-of-Service (QoS) constraints. However, QoS is an important performance measure for wireless communication systems. This paper considers WSRM with both user specific QoS constraints and base station transmission power constraints in multi-cell multi-user multiple-input-multiple-output (MU-MIMO) systems. Based on the celebrated alternating direction method of multipliers (ADMM), we propose a distributed iterative algorithm for QoS-constrained weighted sum-rate maximization (QCWSRM) problem. Specifically, we first reformulate the original problem as an equivalent problem using the popular weighted minimal mean square error (WMMSE) framework. Then, by introducing auxiliary variables, the ADMM is used to devise a distributed solution. Finally, our simulation results illustrate a good performance of the proposed iterative algorithm.