On the Fairness of Range Expansion With Interference Mitigation in Heterogeneous Networks

A fair range expansion (RE) with interference mitigation scheme is exploited for heterogeneous networks (HetNet) in which picocells is overlaid with macrocells. In this strategy, not only the bias value of range expansion but also the number of users attached to the picocell is considered to improve the fairness of user association. According to the ratio of the users in the area of range expansion, certain portion of the system spectrum resources are intelligently scheduled, on which the transmit power of macro base station (MBS) is optimized via pricing-based algorithm to alleviate the macrocell´s interference to the picocell users in the range expansion zone. Fairness indexes of inter-tier and intra-tier are introduced to evaluate the association fairness of users between and within the two tiers respectively. Simulation results demonstrate that the proposed method can provide greater system fairness and capacity, especially when large bias value of RE is configured.