| Title | Joint Design for Simultaneously Transmitting and Reflecting (STAR) RIS Assisted NOMA Systems |
| Authors | Zuo, Jiakuo Liu, Yuanwei Ding, Zhiguo Song, Lingyang Poor, H. Vincent |
| Affiliation | Nanjing Univ Posts & Telecommun, Sch Internet Things, Nanjing 210003, Peoples R China Queen Mary Univ London, Sch Elect Engn & Comp Sci, London E1 4NS, England Univ Manchester, Sch Elect & Elect Engn, Manchester M13 9PL, Lancs, England Peking Univ, Dept Elect, Beijing 100871, Peoples R China Princeton Univ, Dept Elect & Comp Engn, Princeton, NJ 08544 USA |
| Keywords | RECONFIGURABLE INTELLIGENT SURFACES MULTIPLE-ACCESS RESOURCE-ALLOCATION |
| Issue Date | Jan-2023 |
| Publisher | IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS |
| Abstract | Different from traditional reflection-only reconfigurable intelligent surfaces (RISs), simultaneously transmitting and reflecting RISs (STAR-RISs) represent a novel technology, which extends the half-space coverage to full-space coverage by simultaneously transmitting and reflecting incident signals. STAR-RISs provide new degrees-of-freedom (DoF) for manipulating signal propagation. Motivated by the above, a novel STAR-RIS assisted non-orthogonal multiple access (NOMA) (STAR-RIS-NOMA) system is proposed in this paper. Our objective is to maximize the achievable sum rate by jointly optimizing the decoding order, power allocation coefficients, active beamforming, and transmission and reflection beamforming. However, the formulated problem is non-convex with intricately coupled variables. To tackle this challenge, a suboptimal two-layer iterative algorithm is proposed. Specifically, in the inner-layer iteration, for a given decoding order, the power allocation coefficients, active beamforming, transmission and reflection beamforming are optimized alternatingly. For the outer-layer iteration, the decoding order of NOMA users in each cluster is updated with the solutions obtained from the inner-layer iteration. Moreover, an efficient decoding order determination scheme is proposed based on the equivalent-combined channel gains. Simulation results are provided to demonstrate that the proposed STAR-RIS-NOMA system, aided by our proposed algorithm, outperforms conventional RIS-NOMA and RIS assisted orthogonal multiple access (RIS-OMA) systems. |
| URI | http://hdl.handle.net/20.500.11897/671054 |
| ISSN | 1536-1276 |
| DOI | 10.1109/TWC.2022.3197079 |
| Indexed | SCI(E) |
| Appears in Collections: | 电子学院 |
