The Study On LTE Downlink Wireless Resources Scheduling Algorithm Supporting QoS Of Real-time Multimedia Services

With the rapid development of wireless networks, more and more real-time multimedia servicessuch as VoIP and Video applied to LTE systems. Future mobile communication systems need tomeet the QoS of multi-services and guarantee the efficient use of scarce radio resources. This is oneof the key issues of the LTE radio resource scheduling.Based on the author’s research experience in the NSFC project, the thesis discusses existinginternational research results on LTE radio resource scheduling and proposes LTE downlinkscheduling algorithms for both real-time and non-real-time multimedia services.First of all, the research background and contents are outlined and a brief introduction of the LTEsystem is given, including the network architecture, key technologies, radio resource managementtechniques, as well as an analysis of typical LTE downlink scheduling algorithms. Then, an LTEdownlink system-level simulation platform is developed to verify the follow-up proposedscheduling algorithms. Furthermore, based on the LTE downlink generic scheduling model, a mixedservices scheduling scheme is proposed supporting real-time services with multi-level delayconstraints. The simulation results have shown that the algorithm reduces packet loss rate ofreal-time services. Finally, the thesis proposes a two-level scheduling algorithm for multimediaservices in LTE networks. The upper level scheduler uses the improved algorithm to compute theamount of to be transmitted within one wireless frame according to the delay requirements of thereal-time services. The lower scheduler allocates radio resources for mixed services based on utilityfunction. Simulation results have shown that the algorithm reduces the packet loss rate of real-timeservices, effectively guaranteeing their QoS, and in the meantime obtains a higher throughput ofnon-real-time services.