Stacked intelligent metasurfaces for efficient holographic MIMO communications in 6G
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 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 TXSIM 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.
3D integrated metasurfaces, Stacked intelligent metasurfaces (SIM), holographic MIMO (HMIMO), reconfigurable intelligent surface (RIS), wave-based computing
2380-2396
An, Jiancheng
38f5bae7-e6d1-4767-8e81-b402ac61943f
Xu, Chao
5710a067-6320-4f5a-8689-7881f6c46252
Ng, Derrick Wing Kwan
8e2a32d3-cb0d-4c38-b05c-03ef16a5c707
Alexandropoulos, George C.
652f87e4-3c86-4e0d-9166-994c55611b0f
Huang, Chongwen
cb95630b-82c2-45c1-959e-b636774b8c61
Yuen, Chau
1b26b32e-5822-4bf8-b39b-2ea02385037d
Hanzo, Lajos
66e7266f-3066-4fc0-8391-e000acce71a1
1 August 2023
An, Jiancheng
38f5bae7-e6d1-4767-8e81-b402ac61943f
Xu, Chao
5710a067-6320-4f5a-8689-7881f6c46252
Ng, Derrick Wing Kwan
8e2a32d3-cb0d-4c38-b05c-03ef16a5c707
Alexandropoulos, George C.
652f87e4-3c86-4e0d-9166-994c55611b0f
Huang, Chongwen
cb95630b-82c2-45c1-959e-b636774b8c61
Yuen, Chau
1b26b32e-5822-4bf8-b39b-2ea02385037d
Hanzo, Lajos
66e7266f-3066-4fc0-8391-e000acce71a1
An, Jiancheng, Xu, Chao, Ng, Derrick Wing Kwan, Alexandropoulos, George C., Huang, Chongwen, Yuen, Chau and Hanzo, Lajos
(2023)
Stacked intelligent metasurfaces for efficient holographic MIMO communications in 6G.
IEEE Selected Areas on Communications, 41 (8), .
(doi:10.1109/JSAC.2023.3288261).
Abstract
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 TXSIM 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.
Text
Stacked_Intelligent_Metasurfaces_for_Efficient_Holographic_MIMO_Communications_in_6G
- Accepted Manuscript
More information
Accepted/In Press date: 3 May 2023
e-pub ahead of print date: 21 June 2023
Published date: 1 August 2023
Additional Information:
Funding Information:
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.
Publisher Copyright:
© 1983-2012 IEEE.
Keywords:
3D integrated metasurfaces, Stacked intelligent metasurfaces (SIM), holographic MIMO (HMIMO), reconfigurable intelligent surface (RIS), wave-based computing
Identifiers
Local EPrints ID: 476888
URI: http://eprints.soton.ac.uk/id/eprint/476888
PURE UUID: d94def39-3ac0-44c3-9d8b-252a896f4c37
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Date deposited: 18 May 2023 16:59
Last modified: 18 Mar 2024 03:17
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Contributors
Author:
Jiancheng An
Author:
Chao Xu
Author:
Derrick Wing Kwan Ng
Author:
George C. Alexandropoulos
Author:
Chongwen Huang
Author:
Chau Yuen
Author:
Lajos Hanzo
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