Max-min Energy Efficiency Optimization of NOMA Enabled Backscatter Communication Systems

Backscatter network is a low power green communication technology. This paper studies the resource optimization of backscatter communication network systems based on non-orthogonal multiple access (NOMA). Considering the influence of large-scale fading and the fairness among the users, the minimum energy efficiency (EE) of the system is maximized by optimizing the transmit power from the base station to the users and the reflection coefficient. As the max-min EE optimization problem is a non-convex problem which is difficult to find the global optimal solution directly. By adopting variable substitution method, the primitive non-convex problem is converted into the equivalent convex optimization problem. Then, a joint power and backscatter's reflection coefficient allocation algorithm based on convex optimization is proposed to maximize EE. Finally, the simulation results verify the effectiveness of the proposed algorithm.