ENERGY-EFFICIENT RESOURCE ALLOCATION IN NOMA HETEROGENEOUS NETWORKS

Non-orthogonal multiple access has attracted much recent attention due to its capability of improving the system spectral efficiency in wireless communications. Deploying NOMA in a heterogeneous network can satisfy users' explosive data traffic requirements, arid NOMA will likely play an important role in the next generation mobile communication networks. However, NOMA brings new technical challenges on resource allocation due 10 the mutual cross-tier interference in heterogeneous networks. In this article, to study the trade-off between data rate performance and energy consumption in NOMA, we examine the problem of energy-efficient user scheduling and power optimization in NOMA heterogeneous networks. The energy-efficient user scheduling and power allocation schemes are introduced for the downlink NOMA heterogeneous network for perfect and imperfect CSI, respectively. Simulation results show that the resource allocation schemes can significantly increase the energy efficiency of NOMA heterogeneous networks for cases of both perfect CSI and imperfect CSI.