Practical Design Considerations for Reconfigurable Intelligent Surfaces

Rains, James; Kazim, Jalil ur Rehman; Tukmanov, Anvar; Zhang, Lei; Abbasi, Qammer H.; Imran, Muhammad Ali

doi:10.1002/9781119875284.ch6

Cited by 4 publications

(2 citation statements)

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“…The RIS is a planar surface that consists of a large number of equalspaced tunable elements with no RF chain. On one side, by smartly turning the phase shifts of the passive elements, the reflected beam can be adjusted to achieve the desired pattern [4]; on the other side, the implementation of RIS poses no significant cost burden when added to the existing cellular network architecture [5].…”

Section: Introductionmentioning

confidence: 99%

Joint Wide Illumination and Null Insertion Design in RIS-Assisted System

Lin,

Zhou,

Zhang

et al. 2024

2024 18th European Conference on Antennas and Propagation (EuCAP)

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In this paper, we focus on reconfigurable intelligent surface (RIS)-aided joint wide illumination and null insertion design. This design can be applied in cellular networks, broadcasting, and radar systems, enabling multiple wide null and illumination at arbitrary directions. Our objective is to minimize the deviation between the target pattern and the practical power pattern by designing the passive beamforming at RIS, while the RIS unit modulus weights constraint is illustrated. To tackle the non-convex optimization problem, the low-complexity alternating direction method of multipliers (ADMM) algorithm is proposed. In particular, the augmented objective function is firstly formulated with introduced auxiliary variables, which is then rephrased as a Lagrangian function. By alternatively updating the variables, the objective function converges with the optimized RIS phase shifts. The convergence of simulation results proves the validity of our proposed algorithm, and the proposed algorithm performs quite well in matching the desired and actual power patterns with practical channel model under different number and size of illumination and null areas.

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Section: Introductionmentioning

confidence: 99%

Joint Wide Illumination and Null Insertion Design in RIS-Assisted System

Lin,

Zhou,

Zhang

et al. 2024

2024 18th European Conference on Antennas and Propagation (EuCAP)

Self Cite

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“…Furthermore, RIS can work with other B5G techniques such as massive MIMO [18,19], fullduplex technique [20]. Regarding to practical aspect, the RIS-assisted network architecture and RIS design were investigated in [21,22].…”

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confidence: 99%

Improving Performance of the Typical User in the Indoor Cooperative NOMA Millimeter Wave Networks with Presence of Walls

Lam,

Tran

2024

EAI Endorsed Trans Ind Net Intel Syst

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INTRODUCTION: The beyond 5G millimeter wave cellular network system is expecting to provide the high quality of service in indoor areas. OBJECTIVES: Due to the high density of obstacles, the cooperative communication technique is employed to improve the user's desired signal power by finding more than one appropriate station to serve that user. METHODS: While the conventional system utilizes additional equipment such as Reconfigurable Intelligent Surfaces (RIS) and relays to enable the cooperative features, the paper introduces a new network paradigm that utilizes the second nearest Base Station (BS) of the typical user as the Decode and Forward (DF) relay. Thus, depends on the success of decoding the message from the user' serving BS of the second nearest BS, the typical user can work with and without assistance from the relay whose operation follows the discipline of the power-domain NOMA technique. In the case of with relay assistance, the Maximum Ratio Combining technique is utilized by the typical user to combine the desired signals. RESULTS: To examine the performance of the proposed system, the Nakagami-m and the newly developed path loss model, which considers the density of walls and their properties, are adopted to derive the coverage probability of the user with and without relay assistance. The closed-form expressions of this performance metric are derived by Gauss quadrature and Welch-Satterthwaite approximation.

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