Non-Orthogonal Multiple Access in Two-Hop Wireless Powered Communication Networks

• Published in: IEEE wireless communications letters Vol. 9; no. 9; pp. 1398 - 1402
• Main Authors: de Carvalho, J. A., da Costa, D. B., Lima, F. Rafael M., Oliveira, R., Dias, U. S.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01-09-2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Approximation; Communication networks; Communications networks; Linear programming; Newton method; NOMA; Nonorthogonal multiple access; Optimization; power allocation; Quality of service; Resource allocation; Resource management; Wireless communication; Wireless communications; Wireless networks; WPCN
• ISSN: 2162-2337; 2162-2345
• DOI: 10.1109/LWC.2020.2992049

This letter studies the resource allocation problem of sum rate maximization in wireless powered communication networks (WPCNs) with non-orthogonal multiple access (NOMA) that satisfy minimum data rate requirements per user. Firstly, we derive closed-form solutions for the time-splitting ratio and power allocation coefficients that maximize the approximated sum rate NOMA expression. Then, we use the solution of the approximated problem as the starting point for solving the original problem through Newton's method. Simulation results show the effectiveness of the proposed approximation as well as the fast convergence of the optimal solution.