Study On Downlink Packet Scheduling Algorithm For 3GPP Long Term Evolution System

3GPP LTE(Long Term Evolution) is the evolution of 3G standards, which can be used to improve the 3G air interface performance, due to the adoption of several advanced wireless communications technologies such as OFDM,MIMO etc. As spectrum resources are limited, how to rational and effective use of limited wireless resources and support as many users at the same time ensure quality of service is an important research topic. The packet scheduling algorithm can allocate the wireless resources rationally for packet radio services. Not only the fairness between users can be ensured, but also the utilization of radio channel and the quality of service (QoS) of packet radio services can be improved by packet scheduling algorithm.After introducing the development of the 3 GPP LTE network, the network structure and key technologies of LTE are studied in this paper, and many advantages and characteristics of LTE are put forward. Then, the wireless resources management, scheduling algorithm and the target of the packet scheduling algorithm are introduced. With four classical packet scheduling algorithms available lucubrated, their performances and shortages are analyzed. Based on the analysis, improved algorithms are proposed. Finally, the improved algorithms are analyzed and simulated. Compared with classical packet scheduling algorithms, simulation results show that, in the downlink 3GPP LTE system supporting video streaming services, exponential rule/proportional fair(EXP/PF) algorithm outperforms other packet scheduling algorithms by providing a higher system throughput, supporting a higher number of users and guaranteeing fairness at a satisfactory level.