Research On Uplink Scheduling Algorithm In WiMAX

WiMAX is a broadband wireless access technology,as a candidate of 4G standards,WiMAX provides fixed broadband wireless access and mobile broadband wireless access.WiMAX technology advantage lies not only in higher transmission rate, longer transmission distance,and greater system capacity,it also provide support for multimedia services with QoS guarantees.Efficient resource scheduling algorithm is the key to providing support multimedia services,this paper focus on uplink scheduling algorithm in WiMAX system under PMP network typology.The wireless access technology as a starting point for WiMAX technologies, IEEE 802.16 standard based, such as WiMAX link scheduling algorithm research is briefly introduced.After that, according to the IEEE 802.16 standard MAC layer specification, a detailed description of the MAC layer specification related content scheduling mechanism and QoS mechanisms, including WiMAX system architecture and other related content,summed up the existing scheduling algorithms for WiMAX systems Research.Based on the above study,we use a joint scheduling strategy,combined uplink resource scheduling tasks performed by the base station and the subscriber station to constrained optimization problem as a mathematical tool, will translate resource scheduling problem as a constraint optimization problem establish two utility model.Firstly, a base station suitable uplink scheduling algorithm, the base station side uplink scheduling algorithm using cross-layer architecture, considering the MAC layer and physical layer scheduling information user channel quality information to make slot allocation decisions, the algorithm can improve the system throughput while providing a scheduling fairness.Secondly, the subscriber station is proposed for QoS fairness scheduling algorithm in the base station uplink resource scheduling after the completion of the first user station in the second scheduling.User station side scheduling algorithm design different base station side,the user station side connection bandwidth scheduling to ensure QoS requirements as the main objective, fair QoS scheduling algorithm proposed in this paper applies to the subscriber station to ensure different QoS requirements of various types of connections, while ensuring a certain scheduling fairness, low complexity and easy to implement.At last, based on OMNeT++ to build the WiMAX MAC layer system simulation platform, set out a detailed simulation environment and simulation parameters to achieve performance simulation algorithm on the platform,the proposed algorithm is given and the existing classical algorithm comparative analysis of simulation results.