Low-Complexity CSI-Free Reconfigurable Intelligent Surface Phase Shift Design

Wu Y, Arslan ME, Neumann N, Gerstacker W, Schober R (2025)

Publication Type: Conference contribution

Publication year: 2025

Publisher: Institute of Electrical and Electronics Engineers Inc.

Pages Range: 116-122

Conference Proceedings Title: WSA 2025 - Proceedings of the 28th International Workshop on Smart Antennas

Event location: Erlangen, DEU DE

ISBN: 9798350392685

DOI: 10.1109/WSA65299.2025.11202818

Abstract

Reconfigurable intelligent surfaces (RISs) offer a cost-effective method to enhance spectral and energy efficiency in upcoming communication networks by dynamically reconfiguring wireless propagation environments. However, existing RIS-assisted system designs heavily rely on the knowledge of the channel state information (CSI) of RIS-related channels, introducing a massive overhead for channel estimation, particularly for systems with large-scale RISs. To alleviate the dependence on CSI knowledge, this paper presents a RIS phase shift design with low complexity based on received power feedback. After initializing the RIS phase shifts, in each iteration, a set of candidate RIS configurations is generated, and the corresponding received power is measured and reported to the control unit. Utilizing the feedback from these measurements, the RIS phase shifts are adjusted in a greedy manner. The proposed method is implemented on a hardware platform with 100 RIS unit cells, and the experiments confirm the efficiency and high performance of the proposed method. Moreover, simulation results indicate that the proposed design approaches the performance of an exhaustive search but with a significantly reduced power feedback, highlighting its advantages in scenarios involving large-scale RISs.

Authors with CRIS profile

Yifei Wu Lehrstuhl für Digitale Übertragung (IDC) Wolfgang Gerstacker Lehrstuhl für Digitale Übertragung (IDC) Robert Schober Lehrstuhl für Digitale Übertragung (IDC)

Involved external institutions

Technische Universität Clausthal / Clausthal University of Technology DE Germany (DE)

How to cite

APA:

Wu, Y., Arslan, M.E., Neumann, N., Gerstacker, W., & Schober, R. (2025). Low-Complexity CSI-Free Reconfigurable Intelligent Surface Phase Shift Design. In Angelika S. Thalmayer, Maximilian Lubke (Eds.), WSA 2025 - Proceedings of the 28th International Workshop on Smart Antennas (pp. 116-122). Erlangen, DEU, DE: Institute of Electrical and Electronics Engineers Inc..

MLA:

Wu, Yifei, et al. "Low-Complexity CSI-Free Reconfigurable Intelligent Surface Phase Shift Design." Proceedings of the 28th International Workshop on Smart Antennas, WSA 2025, Erlangen, DEU Ed. Angelika S. Thalmayer, Maximilian Lubke, Institute of Electrical and Electronics Engineers Inc., 2025. 116-122.

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