Throughput Maximization for IRS-Assisted Wireless Powered Hybrid NOMA and TDMA

Article Telecommunications

Sum Rate Maximization for IRS-Assisted Uplink NOMA

Ming Zeng et al.

Summary: An intelligent reflecting surface (IRS) is composed of low-cost reflecting elements that collaboratively steer incident signals to enhance system performance. Using semidefinite relaxation to handle the non-convex problem, the NOMA-based scheme achieves a larger sum rate than the OMA-based one. The impact of the number of reflecting elements on the sum rate is also revealed.

IEEE COMMUNICATIONS LETTERS (2021)

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Article Engineering, Electrical & Electronic

Optimized Energy and Information Relaying in Self-Sustainable IRS-Empowered WPCN

Bin Lyu et al.

Summary: This paper proposes a hybrid-relaying scheme with an IRS to optimize both downlink energy transfer and uplink information transmission in a WPCN. By using TS and PS schemes, the IRS's phase shifts and network resource allocation are jointly optimized to maximize the sum-rate. Through numerical results, significant system sum-rate gain is demonstrated compared to the baseline scheme without IRS.

IEEE TRANSACTIONS ON COMMUNICATIONS (2021)

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Article Engineering, Electrical & Electronic

Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial

Qingqing Wu et al.

Summary: Intelligent reflecting surface (IRS) is a technology that can alter wireless signal propagation in wireless networks by dynamically changing wireless channels to enhance communication performance. The future hybrid wireless network aided by IRS, comprising both active and passive components, is expected to achieve sustainable capacity growth cost-effectively.

IEEE TRANSACTIONS ON COMMUNICATIONS (2021)

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Article Engineering, Electrical & Electronic

Power Efficient IRS-Assisted NOMA

Jianyue Zhu et al.

Summary: The study proposes a MISO NOMA system assisted by an intelligent reflecting surface, where beamforming vectors and IRS phase shift matrix are optimized to minimize transmission power. An improved quasi-degradation condition using IRS is introduced to ensure NOMA achieves capacity region with high probability. Comparison between NOMA and ZFBF shows NOMA outperforms ZFBF with the same IRS phase shift matrix and improved quasi-degradation condition, motivating the proposed hybrid NOMA transmission. Simulation results demonstrate the proposed IRS-assisted MISO system outperforms the MISO case without IRS, and the hybrid NOMA transmission scheme always achieves better performance than orthogonal multiple access.

IEEE TRANSACTIONS ON COMMUNICATIONS (2021)

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Article Engineering, Electrical & Electronic