Research On Resource Scheduling For LTE-A Carrier Aggregation

Since LTE-A system has high requirement for bandwidth and the spectrumresources become increasingly scarce, carrier aggregation has turned to be the keytechnology of LTE-A system. Under carrier aggregation, resource scheduling getsmore complicated for the existence of multiple carriers. On the other hand, since aQuality-of-Service (QoS) protection mechanism has been adopted, the QoS-basedresource scheduling has become a very important research direction.Based on the analysis and simulation on the specific carrier aggregation,dual-mode scheduling algorithms with QoS guarantee performance, have beenproposed for the carrier aggregation scenarios. First of all, in the paper, thebackground, purpose and significance of the research are introduced. The currentresearch progress in literatures of the carrier aggragtion in LTE-A system and theapplication situation of the wireless resource scheduling algorithm are discussed.The article describes the wireless protocol architecture of the LTE-A system,introduces and examples the aggregation methods according to the band deploymentscheme for LTE-A, analyzes the carrier aggregation scenarios in relevant protocolsof3rdGeneration Partnership Project (3GPP), and constructs the system model ofCarrier Aggregation (CA) Scenario3. In the CA Scenario3spectrum analysis, thepaper does the analysis and simulation on the impact of resource blocks from thefrequency and the orientation aspect. The theoretical derivation on the jointprobability distribution behind average Channel Quality Indicator (CQI) in differentcomponent carrier of users is described, and the extreme of system throughout in CAScenario3is presented.Secondly, we proposed a configurable dual-mode adaptive schedulingalgorithm, which is called Configurable Dual-mode (CD) algorithm. This algorithmcan make a compromise of system throughout and user fairness, while keeping theQoS guaranteed. After the description of the algorithm, the configurability of thealgorithm is proved by simulation. Based on this, for a comprehensive analysis ofCD algorithm performance, CD and Proportional Fairness (PF) algorithm aresimulated in several scenarios.Finally, this paper proposed two carrier level scheduling algorithms for CAScenario3: Pre-selected Carrier Configurable Dual-mode (PsC-CD) algorithm andFixed-selected Carrier Configurable Dual-mode (FsC-CD) algorithm. And theirperformances are analyzed by simulations in different scenarios. In the study of theresource scheduling for inter-band carrier aggregation scenario, Maximum Deviation Carrier First (MDCF) carrier scheduling algorithm is proposed. Thesimulation on the cell edge throughput enhancement performance of CA Scenario3suggests that the cell edge throughput of CA Scenario3is significantly higher thanthe non-carrier aggragation scenario of same configuration.