Research On Users’ Fairness Scheduling Algorithms For Wireless Communication System

With the development of technology, the demand of the people for information in all directions becomes higher and higher, Wireless communication is the most effective measure to meet the need. Wireless communication has the characteristics of convenient mobility, networking flexibility, good coverage and scalability, etc. The demand of communication rate is in rapid growth along with wide application of multimedia service, Internet service and electronic commerce in the world. However, wireless resource is limited. So how to design reasonable scheduling mechanism is one of the pop topics in the research area, which can improve the performance of wireless system and spectrum efficiency. Scheduling algorithms which guarantees user fairness are studied in this paper. Corresponding scheduling algorithms in multi-user MIMO and cooperative communication system are designed respectively.The user fairness scheduling problem for MU-MIMO downlink is studied. A fairness scheduling algorithm based on weighted user correlation(WUCFS) is proposed for MU-MIMO downlink broadcast channels, to address the problem that traditional fairness scheduling algorithms cannot accurately compute the achievable rate for each user in the process of iterative user selection thus results in non-favorable tradeoff between fairness and system sum rate. With the method, users are activated by comprehensively considering the correlation between candidate users and selected users as well as those to be scheduled potentially. Then weighted correlation maximization is employed as scheduling criterion. The proposed algorithm could estimate the actual transmission rate of each user more precisely, and activate a set of users of small mutual interference with more fairness and appropriateness. Compared with existing schemes the proposed algorithm could achieve better fairness among users while ensuring high system sum rate.In addition, the fairness scheduling problem for cooperative relay system is studied. A fairness scheduling mechanism with dynamic relay stimulation(CDRSFS) is proposed for cooperative downlink communication system. The scheme implements joint fairness scheduling of target user and relay node. As a reward, certain resource is offered to mobile node that assists in other user’s data transmission. The cooperative contributionof relay node to target user is quantized. Based on this parameter as well as user’s residual energy, the scheduling weight is computed. Then dynamic compensation of scheduling opportunity for relay node is achieved.