Open Access

ARTICLE

Modeling and Analysis of OFDMA-NOMA-RA Protocol Considering Imperfect SIC in Multi-User Uplink WLANs

Hailing Yang¹, Suoping Li^1,2,*, Duo Peng²

1 School of Science, Lanzhou University of Technology, Lanzhou, 730050, China
2 School of Computer & Communication, Lanzhou University of Technology, Lanzhou, 730050, China

* Corresponding Author: Suoping Li. Email:

(This article belongs to the Special Issue: Innovative Security for the Next Generation Mobile Communication and Internet Systems)

Computers, Materials & Continua 2024, 79(3), 5273-5294. https://doi.org/10.32604/cmc.2024.050869

Received 20 February 2024; Accepted 09 May 2024; Issue published 20 June 2024

Abstract

To address the problems of network congestion and spectrum resources shortage in multi-user large-scale scenarios, this paper proposes a twice random access OFDMA-NOMA-RA protocol combining the advantages of orthogonal frequency division multiple access (OFDMA) and non-orthogonal multiple access (NOMA). The idea of this protocol is that OFMDA is used to divide the entire frequency field into multiple orthogonal resource units (RUs), and NOMA is used on each RU to enable more users to access the channel and improve spectrum efficiency. Based on the protocol designed in this paper, in the case of imperfect successive interference cancellation (SIC), the probability of successful competition subchannels and the outage probability are derived for two scenarios: Users occupy the subchannel individually and users share the subchannel. Moreover, when two users share the channel, the decoding order of the users and the corresponding probabilities are considered. Then, the system throughput is obtained. To achieve better outage performance in the system, the optimal power allocation algorithm is proposed in this paper, which enables the optimal power allocation strategy to be obtained. Numerical results show that the larger the imperfect SIC coefficient, the worse the outage performance of weak users. Compared with pure OFDMA and NOMA, OFDMA-NOMA-RA always maintains an advantage when the imperfect SIC coefficient is less than a specific value.

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Keywords

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