Downlink packet scheduling with minimum throughput guarantee in TDD-OFDMA cellular network

This paper proposes a channel scheduler in downlink of IEEE 802.16e TDD-OFDMA cellular network which provides users the minimum throughput for best effort traffic. The proposed scheduler is further developed in the consideration of the case that network might become unfeasible, where extra weight functions are introduced into the proportional fair (PF) scheduler so that the proposed extra weight function provides more resources to users who are easier to achieve the target throughput than those who cannot. It does not guarantee target throughput for all users but eventually increases the number of users being served with the guaranteed minimum throughput. It is investigated for the proposed schedulers and other conventional ones how large the throughput is and how many users are guaranteed the target throughput. Simulation results show that the proposed algorithms have 10 to 20 % more users being served with the minimum guaranteed throughput. The trade-off between the throughput guarantee level and sector throughput is shown in the proposed schedulers.