AUT Journal of Electrical Engineering

AUT Journal of Electrical Engineering

The Upper-Bound of the Average Achievable Rate of Non Orthogonal Multiple Access

Document Type : Research Article

Author
Mina Baghani
Faculty of Technical and Engineering, Imam Khomeini International University, Qazvin, Iran.
10.22060/eej.2025.24031.5647
Abstract
The Non Orthogonal Multiple Access (NOMA) is a popular candidate for the next generation of wireless networks. Two advantages of NOMA are that it can achieve a higher rate and support more users compared to orthogonal multiple access (OMA). By increasing the number of users occupied a subchannel in NOMA, the achievable rate and the number of supported users of the system have been increased. Thus, we can assume there are infinite users in the system wanting to share one subchannel to derive the upper bound of the achievable rate of NOMA. In this article, the optimal power allocation function of infinite users in NOMAis derived, which maximizes the average achievable rate of the system under the maximum power constraint. The performances of the proposed power allocation strategy are compared with the simple case with only two users in NOMA. The simulation results show the gap between the average achievable rate and the outage probability of infinite users and two users in the NOMA system.
Keywords
Resource Allocation
NOMA
Successive Interference Cancellation
Convex Optimization
Subjects
[1] Y. Liu, Z. Qin, M. Elkashlan, Z. Ding, A. Nallanathan, L. Hanzo, Nonorthogonal multiple access for 5G and beyond, Proceedings of the IEEE, 105(12) (2017) 2347–2381.
[2] C.Y. Wong, R.S. Cheng, K.B. Lataief, R.D. Murch, Multiuser OFDM with adaptive subcarrier, bit, and power allocation, IEEE Journal on selected areas in communications, 17(10) (1999) 1747–1758.
[3] M.S. Elbamby, M. Bennis, W. Saad, M. Debbah, M. Latva-Aho, Resource optimization and power allocation in in-band full duplex-enabled non-orthogonal multiple access networks, IEEE Journal on Selected Areas in Communications, 35(12) (2017) 2860–2873.
[4] Z. Chen, Z. Ding, X. Dai, R. Zhang, An optimization perspective of the superiority of NOMA compared to conventional OMA, IEEE Transactions on Signal Processing, 65(19) (2017) 5191–5202.
[5] S. Shamai, A. Steiner, A broadcast approach for a single-user slowly fading MIMO channel, IEEE Transactions on Information Theory, 49(10) (2003) 2617–2635.
[6] S. Akhlaghi, M. Baghani, On the average achievable rate of block fading decentralized interference channel, IEEE communications letters, 15(9) (2011) 992–994.
[7] L. Dai, B. Wang, Y. Yuan, S. Han, I. Chih-Lin, Z. Wang, Non-orthogonal multiple access for 5G: solutions, challenges, opportunities, and future research trends, IEEE Communications Magazine, 53(9) (2015) 74–81.
[8] A.J. Muhammed, Z. Ma, P.D. Diamantoulakis, L. Li, G.K. Karagiannidis, Energy-efficient resource allocation in multicarrier NOMA systems with fairness, IEEE Transactions on Communications, 67(12) (2019) 8639–8654.
[9] M.F. Hanif, Z. Ding, T. Ratnarajah, G.K. Karagiannidis, A minorization-maximization method for optimizing sum rate in the downlink of non-orthogonal multiple access systems, IEEE Transactions on Signal Processing, 64(1) (2015) 76–88.
[10] H. Xing, Y. Liu, A. Nallanathan, Z. Ding, H.V. Poor, Optimal throughput fairness tradeoffs for downlink non-orthogonal multiple access over fading channels, IEEE Transactions on Wireless Communications, 17(6) (2018) 3556–3571.
[11] M. Baghani, S. Parsaeefard, M. Derakhshani, W. Saad, Dynamic non-orthogonal multiple access and orthogonal multiple access in 5G wireless networks, IEEE Transactions on Communications, 67(9) (2019) 6360–6373.
[12] O. Maraqa, A.S. Rajasekaran, S. Al-Ahmadi, H. Yanikomeroglu, S.M. Sait, A survey of rate-optimal power domain NOMA with enabling technologies of future wireless networks, IEEE Communications Surveys & Tutorials, 22(4) (2020) 2192–2235.
[13] B. Chong, H. Lu, Y. Chen, L. Qin, F. Guo, Achievable sum rate optimization on NOMA-aided cell-free massive MIMO with finite blocklength coding, IEEE Transactions on Vehicular Technology,  (2025).
[14] A. Powari, K.Z. Shen, D.K. So, Sum Rate Maximization for NOMA With Simultaneous Cache-Enabled D2D Communications, IEEE Wireless Communications Letters,  (2024).
[15] Y. Peng, Y. Xiao, Q. Yang, Sum Rate Maximization of Active RIS-Aided FD-NOMA System, IEEE Access,  (2024).
[16] P. Wang, W. Wu, H. Wang, R. Song, Sum Rate Maximization for Cooperative STAR-RISs Aided NOMA System, IEEE Wireless Communications Letters,  (2025).
[17] T.-H. Vu, T.N. Nguyen, T.-T. Nguyen, S. Kim, Hybrid active-passive STAR-RIS-based NOMA systems: energy/rate-reliability trade-offs and rate adaptation, IEEE Wireless Communications Letters,  (2024).
[18] Q. Wu, Z. Zhang, H. Zhu, P. Fan, Q. Fan, H. Zhu, J. Wang, Deep reinforcement learning-based power allocation for minimizing age of information and energy consumption in multi-input multi-output and non-orthogonal multiple access internet of things systems, Sensors, 23(24) (2023) 9687.
[19] Z. Ding, P. Fan, H.V. Poor, Impact of user pairing on 5G nonorthogonal multiple-access downlink transmissions, IEEE Transactions on Vehicular Technology, 65(8) (2015) 6010–6023.
[20] I.M. Gelfand, R.A. Silverman, Calculus of variations, Courier Corporation, 2000.