Intelligent Reflecting Surface-Assisted Multiple Access With User Pairing: NOMA or OMA?

By Beixiong Zheng, Qingqing Wu, Rui Zhang. IEEE Communications Letters, 2020

333 citations recorded by the source corpus.

The integration of intelligent reflecting surface (IRS) to multiple access networks is a cost-effective solution for boosting spectrum/energy efficiency and enlarging network coverage/connections. However, due to the new capability of IRS in reconfiguring the wireless propagation channels, it is fundamentally unknown which multiple access scheme is superior in the IRS-assisted wireless network. In this letter, we pursue a theoretical performance comparison between non-orthogonal multiple access (NOMA) and orthogonal multiple access (OMA) in the IRS-assisted downlink communication, for which the transmit power minimization problems are formulated under the discrete unit-modulus reflection constraint on each IRS element. We analyze the minimum transmit powers required by different multiple access schemes and compare them numerically, which turn out to not fully comply with the stereotyped superiority of NOMA over OMA in conventional systems without IRS. Moreover, to avoid the exponential complexity of the brute-force search for the optimal discrete IRS phase shifts, we propose a low-complexity solution to achieve near-optimal performance.

Subfields: Electrical and Electronic Engineering, Genetics

View Paper: https://www.semanticscholar.org/paper/75e0889d83da8bea61a72d1679d59a2a961137e0

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Electrical and Electronic Engineering

In Genetics

Citations in the corpus

Simultaneously Transmitting And Reflecting (STAR) RIS Aided Wireless Communications (2021, background): “Furthermore, the authors of [12] minimized the transmit power of RIS-aided multi-user systems employing orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA), respectively.”
Toward Smart Wireless Communications via Intelligent Reflecting Surfaces: A Contemporary Survey (2019, background): “The special case with single-antenna BS is studied in [131], [142], [153].”
Modeling and Architecture Design of Reconfigurable Intelligent Surfaces Using Scattering Parameter Network Analysis (2020, background): “…to provide performance enhancement in orthogonal frequency division multiplexing (OFDM) [12], [13], non-orthogonal multiple access (NOMA) [14], and emerging areas such as secure wireless communication [15], backscatter communication [16], simultaneous wireless information and power…”
Intelligent Reflecting Surface-Assisted Multi-User MISO Communication: Channel Estimation and Beamforming Design (2020, background): “IRSs have also found applications in wide-band orthogonal frequency division multiplexing (OFDM) systems in [21] and non-orthogonal multiple-access systems in [22].”
Double-IRS Assisted Multi-User MIMO: Cooperative Passive Beamforming Design (2020, background): “, orthogonal frequency division multiplexing (OFDM) [6]– [10], multi-antenna communication [11]–[13], non-orthogonal multiple access (NOMA) [14]–[16], etc.”
An Overview of Signal Processing Techniques for RIS/IRS-Aided Wireless Systems (2021, neutral): “cell systems [107], [152], [153], physical layer security systems [89], [93], [94], [103], [104], [154], [155], simultaneous wireless information and power transfer (SWIPT) [105], [114], [119], [156]–[160], mobile edge computing networks [80], [117], [161]–[166], multicast networks [102], [167], cog”
Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial (2020, methodology): “Similar to [62], the number of IRS reflecting elements is set as N = 100, which are divided into 5 sub-surfaces; the reflection coefficient at each element is assumed to have unit amplitude and discrete phase shift with 8 levels; all the channels are modeled by i.”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead (2020, background): “In [215], the authors compare the performance between NOMA and OMA.”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How it Works, State of Research, and Road Ahead (2020, background): “In [214], the authors compare the performance between”
Reconfigurable Intelligent Surfaces: Principles and Opportunities (2020, background): “Scenarios Phase shifts CSI Main Objectives Techniques/Characteristics [73] SU/MU-DL-MISO Continuous Perfect Transmit power AO-SDR-based algorithm and two stage algorithm [74] SU/MU-DL-MISO Discrete Perfect Transmit power Near-optimal ZF-based successive refinement method [75] MU-DL-MISO Continuous P”