Location and Density Optimisation of a Two-Tier NOMA-Based 5G HetNet

With the ever increasing data demands, integration of small base stations (sBSs) within the existing networks has been proposed as a potential solution to absorb this upsurge in traffic demand. However, the resulting heterogeneous networks (HetNets), consisting of macro base stations (mBSs) and sBSs, present a complex network topology. In this paper, we investigate the challenge of optimally locating small cells to reduce their complexity and enhance their performance. The locations of the sBSs are therefore formulated as an optimisation problem. Locating small cells optimally reduces the required number of sBSs for a target HetNet performance and minimizes the over-loading of the mBSs. A uniform Non-Orthogonal Multiple Access (NOMA)-based HetNet is considered due to its high spectral efficiency properties that are attained by exploiting power domain multiplexing. This paper also utilizes simulated annealing, a meta-heuristic optimization algorithm, to optimize the network by proposing optimal candidate locations. A placement algorithm is then proposed to select the optimal set of locations viable for the deployment of small cells.