Research On Resource Allocation Algorithm In LTE-advanced Systems With Carrier Aggregation

With the development of the mobile Internet business and the intelligentization ofuser terminal, user demand for high data transmission rate has become an important partof the mobile communication system. Carrier Aggregation, as the key technology ofLTE-Advanced, not only greatly improves rate of user data, but also effectively resolvesthe current problem of scarcity and discrete spectrum resources in mobile communica-tion system, which has become a research hotspot. But compared to the LTE system, thecarrier aggregation system belongs to the multicarrier system, whose resources alloca-tion is different and more complicated. Therefore, it’s worthy to study how to allocateresources of carrier aggregation system to maximize system performance. The mainwork is as follows:Firstly, according to the analysis of high complexity and low resource utilization ofthe existing resource allocation scheme and consideration of different wireless trans-mission characteristics of different frequency band, a component carrier selectionscheme based on carrier grouped is proposed. In the proposed scheme, a threshold valueof the component carrier grouped is calculated, and then the carrier groups and resourceallocation schedulers are configured. Finally, in accordance with the demands of userand terminal location, the network selects appropriate resources and completes datatransmission. The algorithm only configures resource schedulers for carrier groups,which can reduce the complexity of wireless resource management structure and powerconsumption of terminal. In addition, the algorithm can obtain good load balancing andhigh resource utilization in each group. Simulation results show that the proposed algo-rithm, compared to the traditional Joint Carrier scheduling schemes, sacrifices about6%system throughput, but can effectively reduce the average user delay and user over-stocking, maintains a low computational complexity and energy consumption of theterminal.Secondly, according to the analysis of the existing component carrier selection al-gorithm which does not consider the channel quality and cannot guarantee the load bal-ancing in discontinuous carrier aggregation scene, a component carrier selection re-source allocation algorithm based on channel quality is proposed. In the proposed algo-rithm, the radio propagation characteristics and channel qu ality are considered. Then a priority factor, which is used to choose component carrier, is achieved by mathematicalderivation. Because of the definition of priority factor, the proposed algorithm can pref-erentially select component carrier which coverage radius is small, but relatively goodchannel quality. In addition, the improved algorithm can also avoid edge users in awaiting state. So the system resources can be effectively allocated and utilized. Simula-tion results show that the improved algorithm, compared to the traditional Least Loadalgorithm, ensure the load balancing of component carrier at the same time, enhanceabout9%system throughput, and reduce the average waiting time of user, meet theneeds of users.