Reconfigurable Intelligent Surfaces Assisted Communications With Limited Phase Shifts: How Many Phase Shifts Are Enough?

By Hongliang Zhang, Boya Di, Lingyang Song, Zhu Han. IEEE Transactions on Vehicular Technology, 2019

302 citations recorded by the source corpus.

Reconfigurable intelligent surface (RIS) has drawn a great attention worldwide as it can create favorable propagation conditions by controlling the phase shifts of the reflected signals at the surface to enhance the communication quality. However, the practical RIS only has limited phase shifts, which will lead to the performance degradation. In this paper, we evaluate the performance of an uplink RIS assisted communication system by giving an approximation of the achievable data rate, and investigate the effect of limited phase shifts on the data rate. In particular, we derive the required number of phase shifts under a data rate degradation constraint. Numerical results verify our analysis.

Subfields: Aerospace Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/0d076bbd0715ddb72772d8d442d9735efe92ca19

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Citations in the corpus

Toward Smart Wireless Communications via Intelligent Reflecting Surfaces: A Contemporary Survey (2019, background): “The authors in [98] derive an approximation of the achievable data rate and characterize the performance degradation when a practical IRS is implemented with limited phase shifts.”
Reconfigurable Intelligent Surface (RIS) Assisted Wireless Coverage Extension: RIS Orientation and Location Optimization (2020, background): “2 The channel gain for the (m,n)-th RIS-based channel can be expressed as [9],”
A Survey on Channel Estimation and Practical Passive Beamforming Design for Intelligent Reflecting Surface Aided Wireless Communications (2021, methodology): “• Relax-and-quantize technique [107], [182] • Element-wise BCD method [184], [185] • Penalty-based optimization method [186] • The effects of low-resolution phase shifters on the passive beamforming performance [187], [188]”
Hybrid Beamforming for Reconfigurable Intelligent Surface based Multi-User Communications: Achievable Rates With Limited Discrete Phase Shifts (2019, methodology): “Geometric Model of the Propagation: We now derive the above distances D l1,l2 and d (k) l1,l2 by using the geometry information [21], [22].”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How it Works, State of Research, and Road Ahead (2020, background): “In [110], the authors study the impact of the finite resolution of the RIS phase shifts on the achievable performance.”
5G-Advanced Toward 6G: Past, Present, and Future (2023, background): “The power allocation, phase shift design, beamforming strategies, channel estimation schemes, and a variety of other aspects regarding reflective RISs have been widely studied in the literature [112], [113], [114], [115], [116].”
Reconfigurable Intelligent Surfaces: Principles and Opportunities (2020, methodology): “Scenarios Direction Users Main Objectives Techniques [5] MIMO DL Multiple users OP and Throughput Fairness SEB [12] SISO DL Single user sum-rate gain Compare with Relay [26] SISO UL Single user OP and Throughput Effective Channel gain [55] SISO DL Single user Effective channel gain Compare with rand”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead (2020, background): “In [110], the authors study the impact of the finite reso-”