Weighted Sum-Rate Maximization for Reconfigurable Intelligent Surface Aided Wireless Networks
TLDR
A low-complexity algorithm is proposed to obtain the stationary solution for the joint design problem by utilizing the fractional programming technique and extended to the scenario wherein the CSI is imperfect.Abstract:
Reconfigurable intelligent surfaces (RIS) is a promising solution to build a programmable wireless environment via steering the incident signal in fully customizable ways with reconfigurable passive elements. In this paper, we consider a RIS-aided multiuser multiple-input single-output (MISO) downlink communication system. Our objective is to maximize the weighted sum-rate (WSR) of all users by joint designing the beamforming at the access point (AP) and the phase vector of the RIS elements, while both the perfect channel state information (CSI) setup and the imperfect CSI setup are investigated. For perfect CSI setup, a low-complexity algorithm is proposed to obtain the stationary solution for the joint design problem by utilizing the fractional programming technique. Then, we resort to the stochastic successive convex approximation technique and extend the proposed algorithm to the scenario wherein the CSI is imperfect. The validity of the proposed methods is confirmed by numerical results. In particular, the proposed algorithm performs quite well when the channel uncertainty is smaller than 10%.read more
Citations
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Journal ArticleDOI
Toward Smart Wireless Communications via Intelligent Reflecting Surfaces: A Contemporary Survey
TL;DR: A literature review on recent applications and design aspects of the intelligent reflecting surface (IRS) in the future wireless networks, and the joint optimization of the IRS’s phase control and the transceivers’ transmission control in different network design problems, e.g., rate maximization and power minimization problems.
Journal ArticleDOI
Two-Timescale Channel Estimation for Reconfigurable Intelligent Surface Aided Wireless Communications
TL;DR: A two-timescale channel estimation framework to exploit the property that the BS-RIS channel is high-dimensional but quasi-static, while the RIS-UE channel is mobile but low-dimensional is proposed.
Journal ArticleDOI
Active Reconfigurable Intelligent Surface-Aided Wireless Communications
TL;DR: A new type of RIS is proposed, called active RIS, where each RE is assisted by active loads (negative resistance), that reflect and amplify the incident signal instead of only reflecting it with the adjustable phase shift as in the case of a passive RIS.
Journal ArticleDOI
A Joint Precoding Framework for Wideband Reconfigurable Intelligent Surface-Aided Cell-Free Network
Zijian Zhang,Linglong Dai +1 more
TL;DR: The proposed joint precoding framework can serve as a general solution to maximize the capacity in most existing RIS-aided scenarios and simulation results demonstrate that, compared with the conventional cell-free network, the network capacity can be improved significantly.
Journal ArticleDOI
Reconfigurable Intelligent Surface Assisted Two–Way Communications: Performance Analysis and Optimization
Saman Atapattu,Rongfei Fan,Prathapasinghe Dharmawansa,Gongpu Wang,Jamie Evans,Theodoros A. Tsiftsis +5 more
TL;DR: A gamma approximation is introduced to model the product of Rayleigh random variables which is useful for the evaluation of the performance metrics in multiple-element RIS.
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Intelligent Reflecting Surface Enhanced Wireless Network via Joint Active and Passive Beamforming
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Reconfigurable Intelligent Surfaces for Energy Efficiency in Wireless Communication
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