Joint Power Control and Passive Beamforming in Reconfigurable Intelligent Surface Assisted User-Centric Networks

Lu, Hancheng; Zhao, Dan; Wang, Yazheng; Kong, Chani; Chen, Weidong

doi:10.1109/tcomm.2022.3174071

Cited by 5 publications

(3 citation statements)

References 38 publications

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“…It is obviously known that the right-hand side of ( 19) is convex about λ k due to its quadratic form. Substituting ( 18) into (19), we can acquire the convexity of ( 19) in relation to w k .…”

Section: Beamforming Designmentioning

confidence: 99%

See 1 more Smart Citation

Joint Beamforming and Phase Shifts Design for RIS-Aided Multi-User Full-Duplex Systems in Smart Cities

Pan,

Zhou,

Zhang

et al. 2023

Sensors

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Full-duplex (FD) and reconfigurable intelligent surface (RIS) are potential technologies for achieving wireless communication effectively. Therefore, in theory, the RIS-aided FD system is supposed to enhance spectral efficiency significantly for the ubiquitous Internet of Things devices in smart cities. However, this technology additionally induces the loop-interference (LI) of RIS on the residual self-interference (SI) of the FD base station, especially in complicated urban outdoor environments, which will somewhat counterbalance the performance benefit. Inspired by this, we first establish an objective and constraints considering the residual SI and LI in two typical urban outdoor scenarios. Then, we decompose the original problem into two subproblems according to the variable types and jointly design the beamforming matrices and phase shifts vector methods. Specifically, we propose a successive convex approximation algorithm and a soft actor–critic deep reinforcement learning-related scheme to solve the subproblems alternately. To prove the effectiveness of our proposal, we introduce benchmarks of RIS phase shifts design for comparison. The simulation results show that the performance of the low-complexity proposed algorithm is only slightly lower than the exhaustive search method and outperforms the fixed-point iteration scheme. Moreover, the proposal in scenario two is more outstanding, demonstrating the application predominance in urban outdoor environments.

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Section: Beamforming Designmentioning

confidence: 99%

“…Meanwhile, RIS is a disruptive technology that is greatly concerned by many scholars. Therefore, the scholars of [ 19 ] introduced RIS to formulate a target optimization problem with respect to channel cascade. They obtained the global EE optimum by alternating optimization of fixed variables.…”

Section: Introductionmentioning

confidence: 99%

Joint Beamforming and Phase Shifts Design for RIS-Aided Multi-User Full-Duplex Systems in Smart Cities

Pan,

Zhou,

Zhang

et al. 2023

Sensors

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show abstract

“…Due to the energy-saving characteristic of RIS, it has been embedded in fully coordinated CF network to replace some inefficient APs in Ref. [18]. In Ref.…”

Section: Resource Allocationmentioning

confidence: 99%

Joint association and beamforming optimization in reconfigurable intelligent surface-enhanced user-centric networks

Yao

Tian

Chen

et al. 2022

Intell. and Converged Netw.

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Fully coordinated Cell-Free (CF) networks can alleviate the Inter-Cell Interference (ICI) for the cell-edge users in cellular networks. Due to the complex topology of the association between the Access Points (APs) and the users in CF networks, it is challenging to deploy CF networks in practical scenarios. In order to make CF networks feasible, we introduce User-Centric (UC) networks enabling each user served by a limited number of APs. As a low-cost and energyefficient technology, Reconfigurable Intelligent Surface (RIS) can be embedded in UC networks to further improve the system performance. First, we provide a brief survey on the prior works in UC networks for clear comprehension. Then, we formulate a Spectral Efficiency (SE) maximization problem for RIS-enhanced UC networks. For solving the nonconvex problem, we divide it into three subproblems and propose a joint optimization framework for optimizing APuser association, active beamforming of multiple antennas at the APs, and the passive beamforming of the RIS. Besides, a channel gain based association method coupled with the design of RIS is proposed to construct a dynamic and efficient association. The subproblems about optimizing active and passive beamforming are solved with the fractional programming. Simulation results show that the proposed joint optimization framework for RIS-enhanced UC networks can obtain good SE compared with other benchmark schemes.

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An optimization framework for RIS-based energy-efficient multi-cell NOMA systems

Salem

Ibrahim

Ismail

2023

Vehicular Communications

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Joint Power Control and Passive Beamforming in Reconfigurable Intelligent Surface Assisted User-Centric Networks

Cited by 5 publications

References 38 publications

Joint Beamforming and Phase Shifts Design for RIS-Aided Multi-User Full-Duplex Systems in Smart Cities

Joint Beamforming and Phase Shifts Design for RIS-Aided Multi-User Full-Duplex Systems in Smart Cities

Joint association and beamforming optimization in reconfigurable intelligent surface-enhanced user-centric networks

An optimization framework for RIS-based energy-efficient multi-cell NOMA systems

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