Massachusetts Institute of Technology
The authors address multi-user scheduling over the downlink channel in wireless data systems. Specifically, they consider a time-slotted system with a single transmitter serving multiple users, where the channel condition of each user is time varying. Based on the throughput requirements, the user set is divided into two classes throughput guaranteed Quality of Service (QoS) users, and, Best Effort (BE) users. For this system they obtain the optimal policy that serves the QoS users with the minimum time-slot utilization and maximizes the total fraction of time-slots allocated to the BE users. They show that the optimal policy has a simple geometric structure that can be easily visualized graphically.