Joint Power Allocation and Relay Beamforming in Nonorthogonal Multiple Access Amplify-and-Forward Relay Networks

• Published in: IEEE transactions on vehicular technology Vol. 66; no. 8; pp. 7558 - 7562
• Main Authors: Xue, Chong, Zhang, Qi, Li, Quanzhong, Qin, Jiayin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplify-and-forward (AF); Array signal processing; Beamforming; Computer simulation; Frame relay; NOMA; Nonorthogonal multiple access; nonorthogonal multiple access (NOMA); Optimization; power allocation; Power management; Programming; Relay networks; Relay networks (telecommunications); Resource management; Search algorithms; Semidefinite programming
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2017.2657741

In this paper, we investigate joint power allocation and relay beamforming design problem for a nonorthogonal multiple access (NOMA) amplify-and-forward (AF) relay network, which employs successive interference cancellation to decode signals. Our objective is to maximize the achievable rate of the destination, which has the best channel condition subject to achievable rate constraints at other destinations and individual transmit power constraints. We propose an alternating optimization-based algorithm where, given power allocation, we transform the problem into a second-order cone programming and, given relay beamforming, we transform the problem into a convex linear-fractional programming. When the number of destinations is two, we propose a semidefinite programming-based one-dimensional search algorithm which achieves the globally optimal solution. Simulation results demonstrate that our proposed NOMA AF relay network outperforms the conventional orthogonal multiple access AF relay network.