Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G
A revolutionary technology relying on Stacked Intelligent Metasurfaces (SIM) is capable of carrying out advanced signal processing directly in the native electromagnetic (EM) wave regime. An SIM is fabricated by a sophisticated amalgam of multiple stacked metasurface layers, which may outperform its...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2023
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| Online Access: | https://hdl.handle.net/10356/171423 |
| _version_ | 1826130058826219520 |
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| author | An, Jiancheng Xu, Chao Ng, Derrick Wing Kwan Alexandropoulos, George C. Huang, Chongwen Yuen, Chau Hanzo, Lajos |
| author2 | School of Electrical and Electronic Engineering |
| author_facet | School of Electrical and Electronic Engineering An, Jiancheng Xu, Chao Ng, Derrick Wing Kwan Alexandropoulos, George C. Huang, Chongwen Yuen, Chau Hanzo, Lajos |
| author_sort | An, Jiancheng |
| collection | NTU |
| description | A revolutionary technology relying on Stacked Intelligent Metasurfaces (SIM) is capable of carrying out advanced signal processing directly in the native electromagnetic (EM) wave regime. An SIM is fabricated by a sophisticated amalgam of multiple stacked metasurface layers, which may outperform its single-layer metasurface counterparts, such as reconfigurable intelligent surfaces (RIS) and metasurface lenses. We harness this new SIM for implementing holographic multiple-input multiple-output (HMIMO) communications without requiring excessive radio-frequency (RF) chains, which is a substantial benefit compared to existing implementations. First of all, we propose an HMIMO communication system based on a pair of SIM at the transmitter (TX) and receiver (RX), respectively. In sharp contrast to the conventional MIMO designs, SIM is capable of automatically accomplishing transmit precoding and receiver combining, as the EM waves propagate through them. As such, each spatial stream can be directly radiated and recovered from the corresponding transmit and receive port. Secondly, we formulate the problem of minimizing the error between the actual end-to-end channel matrix and the target diagonal one, representing a flawless interference-free system of parallel subchannels. This is achieved by jointly optimizing the phase shifts associated with all the metasurface layers of both the TX-SIM and RX-SIM. We then design a gradient descent algorithm to solve the resultant non-convex problem. Furthermore, we theoretically analyze the HMIMO channel capacity bound and provide some fundamental insights. Finally, extensive simulation results are provided for characterizing our SIM-aided HMIMO system, which quantifies its substantial performance benefits, e.g., 150% capacity improvement over both conventional MIMO and its RIS-aided counterparts. |
| first_indexed | 2024-10-01T07:50:39Z |
| format | Journal Article |
| id | ntu-10356/171423 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:50:39Z |
| publishDate | 2023 |
| record_format | dspace |
| spelling | ntu-10356/1714232023-10-24T06:31:10Z Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G An, Jiancheng Xu, Chao Ng, Derrick Wing Kwan Alexandropoulos, George C. Huang, Chongwen Yuen, Chau Hanzo, Lajos School of Electrical and Electronic Engineering Engineering::Electrical and electronic engineering Reconfigurable Intelligent Surface Stacked Intelligent Metasurfaces A revolutionary technology relying on Stacked Intelligent Metasurfaces (SIM) is capable of carrying out advanced signal processing directly in the native electromagnetic (EM) wave regime. An SIM is fabricated by a sophisticated amalgam of multiple stacked metasurface layers, which may outperform its single-layer metasurface counterparts, such as reconfigurable intelligent surfaces (RIS) and metasurface lenses. We harness this new SIM for implementing holographic multiple-input multiple-output (HMIMO) communications without requiring excessive radio-frequency (RF) chains, which is a substantial benefit compared to existing implementations. First of all, we propose an HMIMO communication system based on a pair of SIM at the transmitter (TX) and receiver (RX), respectively. In sharp contrast to the conventional MIMO designs, SIM is capable of automatically accomplishing transmit precoding and receiver combining, as the EM waves propagate through them. As such, each spatial stream can be directly radiated and recovered from the corresponding transmit and receive port. Secondly, we formulate the problem of minimizing the error between the actual end-to-end channel matrix and the target diagonal one, representing a flawless interference-free system of parallel subchannels. This is achieved by jointly optimizing the phase shifts associated with all the metasurface layers of both the TX-SIM and RX-SIM. We then design a gradient descent algorithm to solve the resultant non-convex problem. Furthermore, we theoretically analyze the HMIMO channel capacity bound and provide some fundamental insights. Finally, extensive simulation results are provided for characterizing our SIM-aided HMIMO system, which quantifies its substantial performance benefits, e.g., 150% capacity improvement over both conventional MIMO and its RIS-aided counterparts. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) This work was supported in part by the Ministry of Education, Singapore, under its Ministry of Education (MOE) Tier 2 under Award MOET2EP50220-0019; and in part by the Science and Engineering Research Council of Agency for Science, Technology and Research (A*STAR) Singapore, under Grant M22L1b0110. The work of Derrick Wing Kwan Ng was supported by the Australian Research Council’s Discovery Project under Grant DP210102169 and Grant DP230100603. The work of George C. Alexandropoulos was supported by the Smart Networks and Services Joint Undertaking (SNS JU) TERahertz ReconfigurAble METAsurfaces for ultra-high rate wireless communications (TERRAMETA) Project under European Union’s Horizon Europe Research and Innovation Program under Grant 101097101. The work of Chongwen Huang was supported by the China National Key Research and Development Program under Grant 2021YFA1000500, in part by the National Natural Science Foundation of China under Grant 62101492, in part by the Zhejiang Provincial Natural Science Foundation of China under Grant LR22F010002, in part by the Zhejiang University Global Partnership Fund, in part by the Zhejiang University Education Foundation Qizhen Scholar Foundation, and in part by the Fundamental Research Funds for the Central Universities under Grant 2021FZZX001-21. The work of Lajos Hanzo was supported in part by the Engineering and Physical Sciences Research Council under Project EP/W016605/1 and Project EP/X01228X/1 and in part by the European Research Council’s Advanced Fellow Grant QuantCom under Grant 789028. 2023-10-24T06:31:10Z 2023-10-24T06:31:10Z 2023 Journal Article An, J., Xu, C., Ng, D. W. K., Alexandropoulos, G. C., Huang, C., Yuen, C. & Hanzo, L. (2023). Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G. IEEE Journal On Selected Areas in Communications, 41(8), 2380-2396. https://dx.doi.org/10.1109/JSAC.2023.3288261 0733-8716 https://hdl.handle.net/10356/171423 10.1109/JSAC.2023.3288261 2-s2.0-85162925763 8 41 2380 2396 en MOE-T2EP50220-0019 M22L1b0110 IEEE Journal on Selected Areas in Communications © 2023 IEEE. All rights reserved. |
| spellingShingle | Engineering::Electrical and electronic engineering Reconfigurable Intelligent Surface Stacked Intelligent Metasurfaces An, Jiancheng Xu, Chao Ng, Derrick Wing Kwan Alexandropoulos, George C. Huang, Chongwen Yuen, Chau Hanzo, Lajos Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G |
| title | Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G |
| title_full | Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G |
| title_fullStr | Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G |
| title_full_unstemmed | Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G |
| title_short | Stacked Intelligent Metasurfaces for efficient holographic MIMO communications in 6G |
| title_sort | stacked intelligent metasurfaces for efficient holographic mimo communications in 6g |
| topic | Engineering::Electrical and electronic engineering Reconfigurable Intelligent Surface Stacked Intelligent Metasurfaces |
| url | https://hdl.handle.net/10356/171423 |
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