Opportunistic feedback for proportional fair scheduling

Proportional fair (PF) scheduling can maximise the net throughput of multiuser systems with high fairness. Typically, the scheduling requires that knowledge of channel state information (CSI) from all users be made available to the transmitter. In this paper, a feedback reporting technique in which the feedback is limited to two bits per CSI command for multiuser systems with PF scheduling is proposed. Simulation results show that the proposed scheme can achieve the same net throughput as full-CSI case and significantly outperforms one-bit feedback scheme when the feedback thresholds are optimally selected to suit the system conditions while the feedback load is dramatically reduced compared with the full-CSI.