A Hybrid CQI Feedback Scheme for 4G Wireless Systems

In this paper, we propose a novel channel quality indicator (CQI) feedback reduction scheme. In the proposed scheme, the base station (BS) calculates the urgency information of each user according to the quality of service (QoS) and queue conditions and informs users of their urgency information, then the users will send the CQI feedback information with different feedback schemes which are threshold based scheme and best-m scheme. This hybrid scheme overcomes the disadvantages of both threshold based scheme and best-m scheme. It not only reduces the feedback load but also guarantees the fairness and QoS requirement of users with bad channel condition. The proposed scheme is a good tradeoff between the best-m scheme and threshold based scheme. The numerical results confirm that our CQI feedback scheme achieves a remarkable reduction in the amount of feedback information without significant throughput degradation.