Researches On Resource Allocation And Scheduling Algorithm For Carrier Aggregation

With the development of 5G, more and more companies and institutions are joining the research of 5G.5G is not a single wireless access technology, or a few new wireless access technologies. Instead, it’s an intergration solution of new wireless access technologies and existing wireless access technology (beyond 4G technology), the key technology of which includes the carrier aggregation technology, relay technology, cooperative multi-point transmission technology and enhanced multi antenna technology. The carrier aggregation technology raises the theoretical peak rate LTE system up to 1Gbit/s and the maximum bandwidth up to 100MHz. This thesis aims at the resource allocation scheduling scheme under the scene of carrier aggregation with relay deployment.The current research hotspots of carrier aggregation technology are how to assign the members of the carriers to UEs in Radio Resource Control (RRC) layer and schedule the wireless resources in Media Access Control (MAC) layer. Firstly, the thesis introduces technologies of carrier aggregation and packet scheduling algorithm and then focuses on the research of allocation schemes for the carriers in RRC layer and the resource scheduling algorithms in MAC layer. Finally, the schemes and algorithms are simulated and evaluated on the system level simulation platform.Aiming at the allocation schemes for the carriers in RRC layer, the thesis analyzes the traditional carrier allocation schemes based on the load balancing and the channel quality, builds the system level simulation platform and finishes the simulation and verification for the channel characteristics of the high and low frequency carriers in scenes of inter band carrier aggregation. Further, a dynamic allocation schemes for the carriers based on the load balancing and the channel quality is proposed, which is shown through simulation that can promote the user throughput while ensuring the load balancing of carriers in scene (b) of carrier aggregation when deploying different types of users. At last, we summarize and analyze the advantages and limitations of the dynamic allocation schemes for the carriers in scene (b) of carrier aggregation, and optimizes the scene.Aiming at the scheduling of wireless resources in MAC layer, the traditional packet scheduling algorithms in the scene of inter band carrier aggregation are studied to analyze the limits and the mathematical derivation, based on which, we propose an improved proportional fair(PF) scheduling algorithm to promote the priority of the users that do not support carrier aggregation without sacrificing too much of the users’throughput that support carrier aggregation. The simulation results prove that the technology of carrier aggregation can improve the throughput of the cells significantly when the rate of users that support carrier aggregation increases. The results also show that even the improved PF scheduling algorithm may decrease the throughputs of the cells to some extent compared with the traditional PF scheduling algorithms, it improves the priority of the users that do not support carrier aggregation to ensure the fairness among users. With the increase of the portion of users supporing carrier aggregation, the throughputs of cells are improved significantly.