Packet Scheduling Algorithm Research Of LTE Downlink

The research of LTE system started by3GPP becomes a hot spot in current mobile communication. In order to improve system capacity and spectrum efficiency, we pay more attention to study on the Radio Resource Management of LTE system. Packet Scheduling, as an important part of RRM, allocates limited system radio resources to users. According to a certain mechanism, Packet Scheduling algorithms determine the priority and the service order of users or traffics. As a result, system resource can be flexibly allocated and dynamic scheduled. A detailed analysis of Packet Scheduling algorithms of LTE downlink is presented in this paper.Firstly, a high-level overview of LTE system is given, such as evolution objectives, network architecture and key technologies, with special emphasis on the important components related to Radio Resource Management Packet Scheduling of the next generation mobile telecommunication system.Secondly, problems that should be considered during Packet Scheduling Algorithm design in wireless communication systems are proposed. Three main performance evaluation criterions, Throughput, Fairness and Packet Lost Ratio, are introduced. Some classic Packet Scheduling algorithms, Round Robin algorithm, Maximum Carrier/Interference algorithm and Proportional Fairness algorithm are analyzed. The analysis focuses on scheduling theories, operation processes and simulation results. The characteristics of these algorithms are acquired based on the performance comparison.Finally, UE-Based Scheduling algorithm and E-UE Scheduling algorithm on the basis of improving scheduling priority index are proposed. The scheduling theories, operation process design and simulation results of UE-Based and E-UE are presented, also the comparison with classic algorithms. It is shown that the overall performance of E-UE algorithm is better and can be further improved. E-UE Packet Scheduling algorithm is valuable to practical application.