Parameter optimization for adaptive control CRE in HetNet

This paper describes a state-of-the-art cell range expansion (CRE) technique in HetNet to increase the system capacity and/or improve the user throughput. Adaptive control CRE is proposed with the use of an optimal combination of two different cell selection offsets (CSOs) for each user equipment (UE), although the conventional CRE provides a fixed CSO for all UEs. The control algorithm of the proposed method is clarified from an overall system perspective. We also discuss ways to optimize the proposed method by evaluating the average user throughput and the cell edge user throughput. Computer simulation results are provided as parameters of the combination of two different CSOs under the condition of a clustered distribution of UEs. We confirmed that the proposed method can improve cell edge user throughput, while maintaining the average user throughput by choosing the optimal combination of two different CSOs. This will provide a remarkably effective solution for HetNet in LTE-Advanced and beyond.