Downlink Scheduling Algorithm Research Based On QoS In LTE

With the increasing number of mobile subscribers, the services supported bysystem diversify and people are looking forward to complete broadband deals easilyand quickly whenever and wherever. In this context, the LTE system was born, itrepresents an important milestone from3G to4G in the cellular networks. In order tomake the performance of the system closer to the limit of Shannon’s theorem, usingthe wireless resource management process is a key feature in LTE. The packetscheduling mechanism is of great significance, because they are in charge of thechoice of time and frequency resource, they are under different scenarios based onchannel condition and the QoS requirements and decide how to allocate the limitedwireless resources. At the same time, the scheduler in the spectrum obtained effectivebalance between efficiency and fairness.This paper mainly studies the LTE downlink services scheduling algorithms andresource allocation methods at the MAC layer design, including the selection ofscheduling mechanism and improvement of the scheduling algorithm.Firstly, the paper analyzes the LTE system architecture and the structure andeach layer’s function, and mainly introduces the MAC layer scheduling. Weenumerate the different traffic types and characteristics which are supported by LTEsystem.Then, we go deep into study the advantages and disadvantages of the existingscheduling mechanisms and scheduling methods, put forward the joint schedulingmechanism and new scheduling algorithm under joint scheduling mechanism whichsupports the LTE mixed traffics, and finish the LTE system level simulation workunder the Linux and Windows operating environment. Through the simulationanalysis of the different scheduling mechanisms, we research the signaling usage,complete the performance comparison of different algorithms, the emulationconsequences manifest that the new scheduling mechanism can take full advantage ofthe characteristics of the business itself, it saves signaling effectively,and the newscheduling algorithm ensures the user fairness and system throughput,effectivelyreduce the packet loss rate of the services,and it is more suitable for LTE system.