Optimal Power Allocation in NOMA-Based Diamond Relaying Networks

Unlike conventional cooperative networks, diamond relaying networks can provide higher achievable data rates. In a non-orthogonal multiple access (NOMA) based diamond relaying network (DRN), two relays work together to transmit two messages to the destination within only two-time slots. Power allocation is crucial for improving system performance in NOMA-based networks. Accordingly, the effect of optimizing the power allocation coefficients for the DRN system is investigated. A closed-form analytical solution for obtaining the optimum power allocation coefficients of the DRN model is presented. Simulation results show the superiority of the analytical solution of optimal power allocation assignment over a fixed power allocation. A comparison between the proposed analytical solution with other exhaustive search algorithms is discussed. Finally, the accuracy of the suggested solution is confirmed via simulation results.