Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems
Simultaneous transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) can reflect signals and transmissive signals simultaneously and can extend the coverage of signals. A conventional RIS mainly focuses on the case where the signal source and the target are on the same side. In t...
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| Format: | Article |
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MDPI AG
2023-06-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/23/12/5504 |
| _version_ | 1827735650477015040 |
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| author | Xiaoping Zhou Hanqi Wang Jiajia Chen |
| author_facet | Xiaoping Zhou Hanqi Wang Jiajia Chen |
| author_sort | Xiaoping Zhou |
| collection | DOAJ |
| description | Simultaneous transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) can reflect signals and transmissive signals simultaneously and can extend the coverage of signals. A conventional RIS mainly focuses on the case where the signal source and the target are on the same side. In this paper, a STAR-RIS-assisted non-orthogonal multiple access (NOMA) downlink communication system is considered to maximize the achievable rate for users by jointly optimizing the power-allocation coefficients, active beamforming, and STAR-RIS beamforming under the mode-switching (MS) protocol. The critical information of the channel is first extracted using the Uniform Manifold Approximation and Projection (UMAP) method. Based on the key extracted channel features, STAR-RIS elements and users are clustered individually using the fuzzy C-mean clustering (FCM) method. The alternating optimization method decomposes the original optimization problem into three sub-optimization problems. Finally, the sub-problems are converted to unconstrained optimization methods using penalty functions for the solution. Simulation results show that when the number of elements of RIS is 60, the achievable rate of the STAR-RIS–NOMA system is about 18% higher than that of the RIS–NOMA system. |
| first_indexed | 2024-03-11T01:56:47Z |
| format | Article |
| id | doaj.art-31495875c6284a459c8e87faf2f301f3 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-11T01:56:47Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-31495875c6284a459c8e87faf2f301f32023-11-18T12:31:59ZengMDPI AGSensors1424-82202023-06-012312550410.3390/s23125504Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA SystemsXiaoping Zhou0Hanqi Wang1Jiajia Chen2The College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234, ChinaThe College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234, ChinaThe College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234, ChinaSimultaneous transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) can reflect signals and transmissive signals simultaneously and can extend the coverage of signals. A conventional RIS mainly focuses on the case where the signal source and the target are on the same side. In this paper, a STAR-RIS-assisted non-orthogonal multiple access (NOMA) downlink communication system is considered to maximize the achievable rate for users by jointly optimizing the power-allocation coefficients, active beamforming, and STAR-RIS beamforming under the mode-switching (MS) protocol. The critical information of the channel is first extracted using the Uniform Manifold Approximation and Projection (UMAP) method. Based on the key extracted channel features, STAR-RIS elements and users are clustered individually using the fuzzy C-mean clustering (FCM) method. The alternating optimization method decomposes the original optimization problem into three sub-optimization problems. Finally, the sub-problems are converted to unconstrained optimization methods using penalty functions for the solution. Simulation results show that when the number of elements of RIS is 60, the achievable rate of the STAR-RIS–NOMA system is about 18% higher than that of the RIS–NOMA system.https://www.mdpi.com/1424-8220/23/12/5504reconfigurable intelligent surfacesnon-orthogonal multiple accessbeamformingsimultaneous transmission and reflection |
| spellingShingle | Xiaoping Zhou Hanqi Wang Jiajia Chen Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems Sensors reconfigurable intelligent surfaces non-orthogonal multiple access beamforming simultaneous transmission and reflection |
| title | Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems |
| title_full | Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems |
| title_fullStr | Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems |
| title_full_unstemmed | Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems |
| title_short | Joint Design of a Simultaneous Reflection and Transmission RIS in Mode-Switching Mode to Assist NOMA Systems |
| title_sort | joint design of a simultaneous reflection and transmission ris in mode switching mode to assist noma systems |
| topic | reconfigurable intelligent surfaces non-orthogonal multiple access beamforming simultaneous transmission and reflection |
| url | https://www.mdpi.com/1424-8220/23/12/5504 |
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