Power Allocation Optimization of Cooperative Relaying Systems Using Non-orthogonal Multiple Access

A novel scheme termed Hybrid Power Allocation Strategy (H-PAS), which is integrated with Statistical Channel State Information (S-CSI) and Instantaneous Channel State Information (I-CSI), is proposed for Non-Orthogonal Multiple Access (NOMA) based on cooperative relaying systems to achieve a better performance-complexity tradeoff. Simulation results demonstrate that, with the proposed H-PAS, on the one hand, NOMA shows distinct advantage on the sum-rate compared with conventional orthogonal multiple access techniques in which only the knowledge of S-CSI is available; On the other hand, NOMA reduces the signaling overhead and computational complexity at the expense of marginal sum rate degradation when compared with the cases in which only the knowledge of I-CSI is available for it.