Sum Rate Maximization for Practical RIS-Enhanced Rate-Splitting Multiple Access Systems
Abstract
Reconfigurable intelligent surfaces (RIS) combined with rate-splitting multiple access (RSMA) provide a promising solution for improving the spectral efficiency (SE) of sixth-generation (6G) communication systems. However, most existing studies neglect the practical coupling between the RIS phase shift and amplitude, which may cause phase-shift mismatch and significant performance loss. In this paper, we investigate the multiuser sum-rate maximization problem for practical RIS-enhanced RSMA systems considering amplitude-phase coupling. To address the resulting non-convex problem, an effective variable separation algorithm is proposed. The proposed algorithm is compatible with RIS reflecting optimization under the continuous phase shift or any amplitude-phase coupling relationship and can also be directly extended to practical RIS-enhanced NOMA and OMA systems. Simulation results demonstrate performance gain of over 190\% compared with the ideal-RIS-based benchmark, while the proposed RSMA scheme significantly outperforms the corresponding NOMA and OMA schemes.
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BibTeX
@misc{zhang2026rate,
title = {{Sum Rate Maximization for Practical RIS-Enhanced Rate-Splitting Multiple Access Systems}},
author = {Qian Zhang and Xuejun Cheng and Jiaming Shi and Yufei Zhao and Rugui Yao and Ye Fan},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.14765},
eprint = {2610.14765},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.14765},
}
RIS
TY - UNPB
TI - Sum Rate Maximization for Practical RIS-Enhanced Rate-Splitting Multiple Access Systems
AU - Qian Zhang
AU - Xuejun Cheng
AU - Jiaming Shi
AU - Yufei Zhao
AU - Rugui Yao
AU - Ye Fan
PY - 2026
DA - 2026/10/10
PB - arXiv
DO - 10.48550/arxiv.2610.14765
UR - https://arxiv.org/abs/2610.14765
AB - Reconfigurable intelligent surfaces (RIS) combined with rate-splitting multiple access (RSMA) provide a promising solution for improving the spectral efficiency (SE) of sixth-generation (6G) communication systems. However, most existing studies neglect the practical coupling between the RIS phase shift and amplitude, which may cause phase-shift mismatch and significant performance loss. In this paper, we investigate the multiuser sum-rate maximization problem for practical RIS-enhanced RSMA systems considering amplitude-phase coupling. To address the resulting non-convex problem, an effective variable separation algorithm is proposed. The proposed algorithm is compatible with RIS reflecting optimization under the continuous phase shift or any amplitude-phase coupling relationship and can also be directly extended to practical RIS-enhanced NOMA and OMA systems. Simulation results demonstrate performance gain of over 190\% compared with the ideal-RIS-based benchmark, while the proposed RSMA scheme significantly outperforms the corresponding NOMA and OMA schemes.
ER -