On the Energy Efficiency Maximization of NOMA-Aided Downlink Networks With Dynamic User Pairing
- Authors
- Nguyen, Kha-Hung; Nguyen, Hieu V.; Le, Mai T. P.; Sanguinetti, Luca; Shin, Oh-Soon
- Issue Date
- Mar-2022
- Publisher
- IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
- Keywords
- NOMA; Array signal processing; Resource management; Complexity theory; Uncertainty; Optimization; Massive MIMO; Beamforming; non-orthogonal multiple access (NOMA); convex optimization; user pairing; energy efficiency; robust design
- Citation
- IEEE ACCESS, v.10, pp.35131 - 35145
- Journal Title
- IEEE ACCESS
- Volume
- 10
- Start Page
- 35131
- End Page
- 35145
- URI
- http://scholarworks.bwise.kr/ssu/handle/2018.sw.ssu/42286
- DOI
- 10.1109/ACCESS.2022.3162875
- ISSN
- 2169-3536
- Abstract
- This study investigates a combined system comprising non-orthogonal multiple access (NOMA) and beamforming in a downlink network. To fully exploit the advantages of NOMA, user (UE) pairing and beamforming design are jointly optimized via a generalized model for UE association, subject to energy efficiency maximization. Owing to the combination of binary variables and nonconvex constraints, the resulting optimization problem belongs to the class of mixed-integer nonconvex programming. An innovative algorithm, integrating the inner-approximation and Dinkelbach methods, is proposed herein to address a nonconvex fractional function. By introducing a pairing matrix and relaxing the binary variables into continuous ones, our approach is capable of reaching an optimal solution, where two arbitrary UEs are optimally paired regardless of geographical or spatial constraints. For practical scenarios, we further propose a robust design to manage the effect of channel estimation errors under settings involving channel uncertainty. Numerical results show that our proposed designs, even with the presence of the imperfect channel state information at the base station, significantly outperform the conventional beamforming and existing pairing schemes.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - College of Information Technology > ETC > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.