Intelligent Reflecting Surface Aided Multiple Access Over Fading Channels

Abstract

This paper considers a two-user downlink transmission in intelligent reflecting surface (IRS) aided network over fading channels. Particularly, non-orthogonal multiple access (NOMA) and two orthogonal multiple access (OMA) schemes, namely, time division multiple access (TDMA) and frequency division multiple access (FDMA), are studied. The objective is to maximize the system average sum rate for the delay-tolerant transmission. We propose two adjustment schemes, namely, dynamic phase adjustment and one-time phase adjustment. The power budget, minimum average data rate, and discrete unit modulus reflection coefficient are considered as constrains. To solve the problem, two phase shifters adjustment algorithms with low complexity are proposed to obtain near optimal solutions. With given phase shifters and satisfaction of time-sharing condition, the optimal resource allocations are obtained using the Lagrangian dual decomposition. The numerical results reveal that: i) the average sum rate of proposed NOMA network aided by IRS outperforms the conventional NOMA network over fading channels; ii) with continuous IRS adjustment in the fading block, the proposed TDMA scheme performs better than the FDMA scheme; iii) increasing the minimum average user rate requirement has less impact on the proposed IRS-NOMA system than on the IRS-OMA system.

References in corpus (11)

• Wireless Communications with Reconfigurable Intelligent Surface: Path Loss Modeling and Experimental Measurement
• Intelligent Reflecting Surface-Assisted Multiple Access with User Pairing: NOMA or OMA?
• Massive Non-Orthogonal Multiple Access for Cellular IoT: Potentials and Limitations
• Capacity and Optimal Resource Allocation for IRS-assisted Multi-user Communication Systems
• Capacity Characterization for Intelligent Reflecting Surface Aided MIMO Communication
• Multi-Antenna Relaying and Reconfigurable Intelligent Surfaces: End-to-End SNR and Achievable Rate
• Intelligent Reflecting Surface Assisted Secrecy Communication: Is Artificial Noise Helpful or Not?
• Large Intelligent Surface/Antennas (LISA): Making Reflective Radios Smart
• Performance Analysis of Intelligent Reflecting Surface Assisted NOMA Networks
• Reconfigurable Intelligent Surface Aided NOMA Networks
• Reconfigurable Intelligent Surface Empowered Downlink Non-Orthogonal Multiple Access