A traffic load adaptive fair scheduler for MIMO systems

In this paper, we address the problem of cross layer scheduling for the downlinks of multiple-input multiple-output (MIMO) cellular systems. Previously proposed MIMO schedulers have problems such as ignoring traffic arrival process or complexity. We focus on designing an adaptive fair scheduling algorithm to traffic load changes. We propose a load adaptive multi-output fair queueing (LA-MO-FQ) scheduler, which is based on a fair queueing algorithm with mechanisms for rate selection, compensation of lagging users, and virtual time system. Since some of the scheduler’s system parameters are sensitive to the traffic load, it dynamically adjusts them in a way with low complexity so the system performs better. Furthermore, we also propose in this paper some formulae for the time and service fairness comparisons of MIMO schedulers. Intensive simulation studies considering the mobility of users and the traffic characteristics demonstrate the good performance of LA-MO-FQ. Finally, we compare both the performance and fairness of our scheduler with some famous existing schedulers.