Spectrum sharing in heterogeneous networks based on multi-objective optimization

Heterogeneous Networks (HetNets) are being considered a promising way to significantly boost the overall spectral efficiency by using spectrum-sharing scheme to deploy femto base stations (FBSs) within a macrocell network. However, the co-channel deployment also brings a severe problem of interference containing intra-tier interference among FBSs and inter-tier interference between FBSs and the macro base station (MBS), which significantly influences the system capacity. In this paper, we investigate a spectrum sharing scheme in the downlink for HetNets, aiming to mitigate the intra-tier interference and improve the capacity of system. The spectrum-sharing scheme is described as a multi-objective optimization problem. The problem is solved by nondominated sorting genetic algorithm version II(NSGA-II). The simulations show that the proposed spectrum-sharing scheme is superior to the existing APLCA.