Energy-Efficient Design of IRS-NOMA Networks

Abstract

Combining intelligent reflecting surface (IRS) and non-orthogonal multiple access (NOMA) is an effective solution to enhance communication coverage and energy efficiency. In this paper, we focus on an IRS-assisted NOMA network and propose an energy-efficient algorithm to yield a good tradeoff between the sum-rate maximization and total power consumption minimization. We aim to maximize the system energy efficiency by jointly optimizing the transmit beamforming at the BS and the reflecting beamforming at the IRS. Specifically, the transmit beamforming and the phases of the low-cost passive elements on the IRS are alternatively optimized until the convergence. Simulation results demonstrate that the proposed algorithm in IRS-NOMA can yield superior performance compared with the conventional OMA-IRS and NOMA with a random phase IRS.

Large Intelligent Surfaces With Discrete Set of Phase-Shifts Communicating Through Double-Rayleigh Fading Channels

“…Figure 3 presents some comparisons of the normalized histogram of the random variable given by the instantaneous SNR (see (5)) against the theoretical PDF given by (11). As can be noticed, even for a small number of reflecting elements and quantization bits, the approximation is quite tight.…”

“…It comes with the promise to satisfy the requirements of reliability, low latency, and high data rates for heterogeneous devices, which the fifth generation (5G) was not able to fully meet [3]. Its structure consists of many electromagnetic elements acting individually as scatterers, capable of jointly reflecting the incident signal to the desired direction [4,5]. Among its advantages, we can mention the ideally passive nature This work is licensed under a Creative Commons Attribution 4.0 License.…”

Survey on 6G Frontiers: Trends, Applications, Requirements, Technologies and Future Research

“…Moreover, traditional Orthogonal Multiple Access (OMA) based schemes cannot provide access to a massive number of IoE devices due to limitations in the radio spectrum. This requires new technologies such as NOMA to be applied to cellular IoT to provide access to a massive number of IoT devices [13], [39]. In addition, providing seamless connectivity to IoE devices that lie beyond the coverage of terrestrial cellular networks requires UAV and satellites to work in coordination to form a cognitive satellite-UAV network [45].…”

“…Internet-enabled resource-constrained objects are increasing rapidly and these objects required highly efficient hardware that can be self-powered. However, research revealed that the traditional devices are integrated with large-scale antenna arrays (e.g., MIMO) that will inevitably bring high power consumption [13]. In 5G network, several technologies are available to facilitate low power communication with 5G communication networks.…”

“…Recent developments in communications have introduced many new concepts such as Edge Intelligence (EI), beyond sub 6GHz to THz communication, Non-Orthogonal Multiple Access (NOMA), Large Intelligent Surfaces (LIS), swarm networks, and Self-Sustaining Networks (SSN) [12], [13]. These concepts are evolving to become fully-fledged technologies that can power future generations of communication networks.…”