Handover Methods Considering Channel Conditions of Multiple Aggregated Carriers

Carrier aggregation was introduced to Long Term Evolution Advanced in order to improve the performance especially in terms of a higher peak data rate. When employed, sets of user equipment will have a set of serving cells, which includes a Primary cell (PCell) and Secondary cells (SCells). For inter evolved Node B (eNB) handover, target eNB is selected only consider the channel condition of the PCell. Thus, a suitable set of serving cells cannot be selected. In order to address this problem, this paper proposes three handover methods considering channel conditions for multiple cells. Methods 1 and 2 adjust the handover margin according to the difference in channel conditions between the PCell and SCells for the serving eNB. Method 3 decides handover based on equivalent channel conditions for the PCell and SCells in both the serving eNB and neighboring eNBs. Simulation results show that the proposed methods provide higher cell-edge throughput and a much smoother handover at the cost of a slightly increased number of handovers.