Research On The Resource Scheduling Strategy Of LTE Based On QoS

With the rapid development of wireless multimedia services, the LTE system with the advantages of high throughput, low latency and the QoS for the traffic is needed. Different channel qualities of Multi-user and different traffic requirements make the resource scheduling in LTE system complicate. At the same time, to improve the system throughput, traffic delay, packet loss rate and fairness must be considered.The OFDM and MIMO technology in the physical layer are studied in the thesis, and the frame structure of LTE FDD/TDD is analyzed. In the past research on the LTE resource scheduling algorithm, the measuring method of signal to interference plus noise ratio(SINR) is not provided when searching channel quality indication(CQI). A method for measuring SINR would be put forward in this thesis, and then the method of finding the CQI and its feedback mechanism will be introduced.In order to verify the performance of the resource scheduling algorithm based on Qo S for LTE, an improved simulation platform for LTE system level has been built, and its overall system architecture, link quality model and link performance model are introduced. Finally, the Round-Robin algorithm, maximum carrier-interference ratio algorithm and the proportional fair algorithm are simulated on the simulation platform to verify the rationality of the platform.Traditional LTE downlink scheduling algorithm such as M-LWDF algorithm and EXP-PF algorithm only consider the head of line(HOL) delay of traffic, the channel quality of wireless and the resource required for best-effort traffic are not considered. Therefore, a fuzzy logic scheduling algorithm based on QoS is put forward for discussion in this thesis, in which the packet loss rate, HOL delay, throughput and channel quality for services are considered, and the priority of best-effort traffic could be adjusted dynamically by dynamic controller. Finally, the M-LWDF algorithm,EXPPF algorithm and fuzzy logic scheduling algorithm are simulated on the simulation platform, and the results show that the fuzzy logic scheduling algorithm has a better performance in terms of throughput and packet loss.