Joint Proportional Fair Scheduling for Uplink and Downlink in Wireless Networks

Since many users share limited wireless resources in wireless networks, it is important for resources to be allocated among users in a fair and efficient manner. The scheduler at the base station is responsible for allocating resources to users. Many researchers have developed efficient scheduling algorithms but most these algorithms were designed separately and independently for the uplink or downlink. Because a user generally has two communication links, an uplink and a downlink, the overall satisfaction with a communication service can be formulated as the sum of the quality of the uplink and downlink services. Hence, the poor quality of either link can degrade the overall quality of service. This paper proposes a joint proportional fair (PF) scheduling algorithm for wireless networks, where the scheduling of the uplink and downlink is done jointly so that the bandwidth can be shared efficiently and fairly between the uplink and the downlink. The paper introduces three joint scheduling algorithms: joint delay-based scheduling, joint maximum rate scheduling, and joint PF scheduling. The simulation results show that in comparison with conventional scheduling algorithms the proposed joint PF scheduling algorithm achieves a better compromise between the throughput and user fairness by adjusting the weighting factor between the uplink and downlink.