Effective bandwidth maximization for uplink/downlink multi-antenna systems

We study optimization criteria for uplink and downlink wireless transmission, assuming that the base station is equipped with multiple antennas and the mobiles have single antennas. In particular, we focus on the mean effective bandwidth, which provides a measure for the overall quality of the multiuser channel. In the uplink, maximizing the mean effective bandwidth is a convex optimization problem, which can be solved by standard optimization tools. The downlink has a more complicated analytical structure, which prevents direct optimization. In this work we make use of the duality between uplink and downlink, which facilitates an indirect approach: the optimizer of the downlink mean effective bandwidth is found by first solving the convex uplink problem, then adjusting the downlink transmission powers.