Adaptive user scheduling and resource management for multiuser MIMO downlink systems with heterogeneous delay requirements

In this paper, we propose an adaptive user scheduling and resource management algorithm for multiuser MIMO downlink systems with heterogeneous delay requirements, in order to not only maximize the system throughput but also maintain delay constraints as well. We adopt the concepts of effective capacity and effective bandwidth to illustrate the behaviors of different traffic characteristics such as different source statistics and queue dynamics. It is shown that the scheduling problem can be formulated as a mixed convex and combinational optimization problem, and the proposed scheme is thus a water-filling solution. Simulation results show that the proposed algorithm maintains the delay constraints for the delay sensitive users in the presence of bursty data traffic and maximizes the system throughput by exploiting the multiplexing diversity gain and multiuser selection gain.