Sum-rate Maximization and Outage Analysis of RIS assisted RSMA System under Electromagnetic Interference

Authors

Keywords:

Electromagnetic interference, reconfigurable intelligent surfaces, rate splitting multiple access, multiple access techniques, alternating optimization, outage probability

Abstract

Rate-splitting multiple access (RSMA) and reconfigurable intelligent surfaces (RIS) are key enablers for 6G communications. This study examines a downlink multiple-input single-output system using RIS-assisted RSMA (RIS-RSMA) in the presence of electromagnetic interference (EMI). Although RIS improves wireless propagation through passive beamforming, it can also reflect EMI from ambient sources, which may disrupt the decoding order and limit system performance. To overcome this, we jointly optimize the transmit beamformer and phase shifts of the RIS using an alternating optimization approach. We derive and validate the analytical expressions for the outage probability (OP) and sum rate of the system via Monte Carlo simulations. The obtained results validate that RIS-RSMA reduces the OP by $60\%$ and achieves a higher sum rate of $3.22 \times 10^{5}$ bit/s compared with RIS-assisted NOMA, and mitigates the impact of EMI.

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Author Biographies

Nishandhi Soudarsanane, NITPY-Central University

Nishandhi Soudarsanane received the B.Tech. degree in Electronics and Communication Engineering and the M.Tech. degree in Wireless Communication from Pondicherry University, Puducherry, India. She is currently pursuing the Ph.D. degree in Wireless Communications with the Department of Electronics and Communication Engineering, National Institute of Technology, Puducherry, India. She is a recipient of the MHRD scholarship for her Ph.D. program. Her research interests include non-orthogonal multiple access (NOMA), rate-splitting multiple access (RSMA), physical (PHY)-layer design and green communication paradigms for 6G networks.

Surendar Maruthu, NITPY-Central University

Surendar Maruthu (Member, IEEE) received the B.E. and M.Tech. degrees in Electronics and Communication Engineering (ECE) from Thiagarajar College of Engineering, Madurai, India, and the Ph.D. degree in ECE from the National Institute of Technology, Tiruchirappalli, India. Since 2018, he has been an Assistant Professor with the Department of Electronics and Communication Engineering, National Institute of Technology, Puducherry, Karaikal, India. He has published several research articles in reputed journals and international conferences. He has also delivered invited lectures and keynote speeches at various premier institutes. He is currently serving as a Co-Principal Investigator for a project in collaboration with the Sri Lanka Technological Campus, Padukka, Sri Lanka. His research interests include the physical (PHY) layer aspects of 5G and beyond wireless communications, and signal processing for next-generation communication systems.

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Published

2026-10-20

How to Cite

Soudarsanane, N., & Maruthu, S. (2026). Sum-rate Maximization and Outage Analysis of RIS assisted RSMA System under Electromagnetic Interference. IEEE Latin America Transactions, 24(11), 1400–1409. Retrieved from https://latamt.ieeer9.org/index.php/transactions/article/view/10605

Issue

Vol. 24 No. 11 (2026): Ordinary Issue

Section

Electronics