On the Performance of Power Allocation Schemes in Ultra Dense Networks

In this paper, user association and power allocation in the uplink transmission of ultra-dense networks are studied. Solutions are proposed for cell grouping and resource sharing based on cell locations. The performance of non-orthogonal multiple access (NOMA) is compared to other power allocation schemes used in literature, namely, power control, the waterfilling algorithm as well as uniform power allocation. It is shown that while NOMA guarantees fairness among transmitting nodes, other power allocation schemes achieve higher aggregate throughput at the expense of some nodes deprived their right for transmission. Therefore, in data-centric application, e.g. Internet of Things-based application and Machine Type Communication-based application, where higher data rate transmission is prioritized irrespective the transmitting nodes, NOMA cannot be recommended as an optimum solution.