Traffic load balance methods in the LTE-Advanced system with carrier aggregation

In the further advancements for the third generation (3G) long-term evolution (LTE) system, i.e. the LTE-Advanced system, carrier aggregation (CA) is applied to support wide system bandwidth and ensure backward compatibility. In this paper, two traffic load balance methods are proposed to improve the performance of the independent carrier scheduling (ICS) scheme in CA based LTE-Advanced system with time-variant user population. One is to utilize advanced user allocation rules. The other is a novel method which couples the component carriers (CCs) together in the scenario that the CCs are in the different working states. Our simulation results show that well-designed user allocation rules can achieve better traffic load balance across the CCs than the simplest random allocation rule. Moreover, the CC coupling method can make the ICS scheme achieve optimal performance as the joint carrier scheduling (JCS) scheme, irrespective of the traffic intensity and the used user allocation rule. However, using better user allocation rule can reduce the CC coupling time for the ICS scheme, which is essential to the practicality of ICS.