Uplink Performance and Beamforming Design of SIM-enhanced Cell-Free Massive MIMO Systems
Abstract
In this paper, we explore the integration of low-power, low-cost stacked intelligent metasurfaces (SIM) into cell-free (CF) massive multiple-input multiple-output (mMIMO) systems to enhance access point (AP) capabilities and address high power consumption and cost challenges. Specifically, we investigate the uplink performance of a SIM-enhanced CF mMIMO system. First, the closed-form expressions of the spectral efficiency (SE) are obtained using the unique two-stage signal processing framework of CF mMIMO systems. Second, a wave-based beamforming algorithm for SIM is proposed, based only on statistical channel state information, which effectively reduces the fronthaul costs. The results indicate that increasing the number of SIM layers and meta-atoms leads to significant performance improvements and allows for a reduction in the number of APs and AP antennas. Moreover, the proposed wave-based beamforming algorithm can enhance the SE performance of SIM-enhanced CF-mMIMO systems by 72%, significantly outperforming traditional CF mMIMO systems.
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Shi et al. [101], [111] derived a closed-form expression for the spectrum efficiency of a SIM-enhanced CF massive MIMO uplink system.
“Additionally, Shi et al. [101], [111] derived a closed-form expression for the spectrum efficiency of a SIMenhanced CF massive MIMO uplink system, based on which a wave-domain beamforming scheme and a max-min power control algorithm were designed based on the statistical CSI.”
From Emerging Technologies in Intelligent Metasurfaces: Shaping the Future of Wireless Communications (2026) · cites this paper as [111]
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Emerging Technologies in Intelligent Metasurfaces: Shaping the Future of Wireless Communications
An, J., Debbah, M., Cui, T. J., Chen, Z. N., & Yuen, C. (2026) · IEEE Transactions on Antennas and Propagation · doi:10.1109/tap.2025.3571069 · Cited by 72 · see citing works
“In addition, Shi et al. [102], [111] derived a closed-form expression for the spectrum e ffi ciency of an SIM-enhanced CF massive MIMO uplink system, based on which a wave-domain beamforming scheme and a max–min power control algorithm were designed based on the statistical CSI.”
Self-citationRenzo, M. D. (2025) · European Conference on Antennas and Propagation · doi:10.23919/eucap63536.2025.10999805 · Cited by 10 · see citing works
An, J., Yuen, C., Renzo, M. D., Bennis, M., Debbah, M. A., & Hanzo, L. (2026) · IEEE Communications Surveys & Tutorials · doi:10.1109/comst.2026.3720502 · Cited by 4 · see citing works
Self-citationFrimpong, E. O., Wang, Y., & Tian, Z. (2025) · IEEE Transactions on Cognitive Communications and Networking · doi:10.1109/tccn.2025.3645496 · Cited by 1 · see citing works
Emerging Technologies in Intelligent Metasurfaces: Shaping the Future of Wireless Communications
An, J., Debbah, M., Cui, T. J., Chen, Z. N., & Yuen, C. (2024) · arXiv · Cited by 72 · see citing works
“In addition, Shi et al. [102], [111] derived a closed-form expression for the spectrum e ffi ciency of an SIM-enhanced CF massive MIMO uplink system, based on which a wave-domain beamforming scheme and a max–min power control algorithm were designed based on the statistical CSI.”
Self-citation
- Authors
- Shi, E., Zhang, J., Zhu, Y., Liu, Z., An, J., Yuen, C., & Ai, B.
- Affiliations
- Beijing Jiaotong University (CN)
- Nanyang Technological University (SG)
- Venue
- 2024 IEEE VTS Asia Pacific Wireless Communications Symposium (APWCS)
- Publisher
- IEEE
- Published
- 2024-08-21
- Pages
- 01-05
- OpenAlex
- W4402628031
- Cited by
- 4
- References
- 20
- Citations by year
- 2026: 1 · 2025: 3
- FWCI
- 3.06
- Type
- conference paper
- Language
- en
- Open access
- closed
- Locations
- IEEE VTS Asia Pacific Wireless Communications Symposium (APWCS) (publishedVersion)
- Topics
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Advanced Wireless Communication Technologies
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Advanced MIMO Systems Optimization
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Millimeter-Wave Propagation and Modeling
- Keywords
- cell-free massive MIMO, stacked intelligent metasurfaces, uplink performance, beamforming design, spectral efficiency, statistical channel state information, meta-atoms
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