Angle-Domain NOMA Over Multicell Millimeter Wave Massive MIMO Networks

• Published in: IEEE transactions on communications Vol. 68; no. 4; pp. 2277 - 2292
• Main Authors: Shao, Weidong, Zhang, Shun, Li, Hongyan, Zhao, Nan, Dobre, Octavia A.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; angle domain; Computer simulation; Constraints; Decoders; Domains; Indexes; Interference; interference alignment (IA); Massive MIMO; massive multiple-input multiple-output (MIMO); Millimeter wave (mmWave); Millimeter waves; MIMO (control systems); NOMA; non-orthogonal multiple access (NOMA); Nonorthogonal multiple access; Optimization; Quality of service; Resource management; Scheduling
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2020.2968881

The application of non-orthogonal multiple access (NOMA) in millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems can enhance spectral efficiency. In this paper, we propose an angle-domain NOMA scheme over the multi-cell mmWave massive MIMO networks. This scheme is optimized through both user scheduling and precoders/decoders design to maximize the system sum rate, where the precoders are decomposed into outer and inner ones. We construct the outer precoders with the help of the users' spatial angle information, i.e., beam signatures , and propose two design strategies for both inner precoders and decoders, i.e., joint optimization of precoders/decoders (JOPD) and cooperative NOMA (C-NOMA). Specifically, in JOPD, the precoders/decoders are obtained through maximizing a nonconvex function subject to the users' quality-of-service (QoS) constraints, where an alternate optimization algorithm based on the constrained concave-convex procedure is proposed for its solutions. In C-NOMA, we adopt interference alignment to cooperatively serve the cell-edge users and achieve simplified yet effective precoders/decoders. Furthermore, we optimize C-NOMA through power allocation. Afterwards, user scheduling algorithms are proposed for both JOPD and C-NOMA. Extensive simulations verify that the proposed schemes exhibit improved performance in terms of both sum rate and users' QoS compared to that of existing mmWave NOMA schemes.