A dynamic cell range expansion scheme based on fuzzy logic system in LTE-advanced heterogeneous networks

In heterogeneous network, the coverage area of picocell is usually small due to transmission power difference between macro eNodeB (eNB) and pico eNB. As a result, the traffic load is distributed unequally which yields to macrocell overloading. In order to overcome this issue, cell range expansion (CRE) technique has been recently proposed. However, the fixed CRE scheme cannot follow the UE distribution and then satisfy the system requirements. Therefore, fixed CRE scheme is unable to proportionally offload the traffic between the macrocells and picocells. In order to deal with the mentioned problem, this paper proposes a dynamic CRE scheme based on fuzzy logic system. Simulation results demonstrate that the proposed scheme can improve the system performance in terms of throughput and outage probability.