Intelligent Reflecting Surface Versus Decode-and-Forward: How Large Surfaces are Needed to Beat Relaying?

By Emil Björnson, Özgecan Özdogan, Erik G. Larsson. IEEE Wireless Communications Letters, 2019

925 citations recorded by the source corpus.

The rate and energy efficiency of wireless channels can be improved by deploying software-controlled metasurfaces to reflect signals from the source to the destination, especially when the direct path is weak. While previous works mainly optimized the reflections, this letter compares the new technology with classic decode-and-forward (DF) relaying. The main observation is that very high rates and/or large metasurfaces are needed to outperform DF relaying, both in terms of minimizing the total transmit power and maximizing the energy efficiency, which also includes the dissipation in the transceiver hardware.

Subfields: Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/32cfe017bafe9a86546c026dd7e220b4aa0d5293

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Citations in the corpus

Prospective Multiple Antenna Technologies for Beyond 5G (2019, background): “Third, in order to achieve a reasonable system performance, a large aperture with a large number of meta-atom elements is required [169].”
Multicell MIMO Communications Relying on Intelligent Reflecting Surfaces (2019, methodology): “Performance comparisons between AF relay and IRS were performed in [9], [10].”
Power Scaling Laws and Near-Field Behaviors of Massive MIMO and Intelligent Reflecting Surfaces (2020, background): “This observation is in line with previous results in [19], [44].”
Reconfigurable Intelligent Surfaces vs. Relaying: Differences, Similarities, and Performance Comparison (2019, background): “On the other hand, the average end-to-end signal-to-noise ratio of an RIS made of N individually tunable antennas (or N reconfigurable meta-surfaces, each of them made of an appropriate number of meta-atoms to realize the desired wave transformations) increases quadratically with N , while still bei”
Toward Smart Wireless Communications via Intelligent Reflecting Surfaces: A Contemporary Survey (2019, result): “The authors in [155] compare the performance between the IRS-assisted system and the conventional decode-and-forward (DF) relay communications.”
Reconfigurable Intelligent Surfaces for Wireless Communications: Principles, Challenges, and Opportunities (2020, background): “Experimental Validation of Path Loss Scaling: Path loss through the RIS will be an important factor in determining the practicality of RIS-assisted communications [64].”
A Survey on Scalable LoRaWAN for Massive IoT: Recent Advances, Potentials, and Challenges (2022, background): “This study concluded by suggesting the intelligent reflecting surface and an alternative to the legacy relay strategy for LoRa networks [169].”
Intelligent Reflecting Surface Aided Multigroup Multicast MISO Communication Systems (2019, methodology): “In the IRS-aided system, we adopt Power = η(pT + prelay) +NPt +MPIRS , where the circuit power consumption of the passive reflection elements is set as PIRS = 5 mW [38].”
An Overview of Signal Processing Techniques for Terahertz Communications (2020, background): “Performance analysis studies for IRS-assisted communications include [394], [407]–[413].”
Reconfigurable Intelligent Surfaces: Principles and Opportunities (2020, methodology): “[12] compared the achievable data rate of both the RIS-aided and DF-relay-aided SISO network, where the direct links between the BS and users are blocked.”
Reconfigurable Intelligent Surface Aided NOMA Networks (2019, methodology): “The performance of RIS-aided and relay-assisted networks was compared in [16], indicating that RIS-aided networks may have better network performances, provided that the number of RISs is high enough.”
Radio Localization and Mapping With Reconfigurable Intelligent Surfaces: Challenges, Opportunities, and Research Directions (2019, background): “Based on these fundamental operating modes, an RIS can act as a transmitter [2], a receiver [3], and an anomalous reflector, where the direction of the reflected wave is no longer specular according to natural reflection laws, but it is steerable [4], [5].”
Modeling and Architecture Design of Reconfigurable Intelligent Surfaces Using Scattering Parameter Network Analysis (2020, background): “In addition, comparisons with massive MIMO [35] and decode-and-forward relays [36] indicate that RIS needs a large number of elements to be competitive.”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How it Works, State of Research, and Road Ahead (2020, background): “In [49] and [256], the authors report a comparative study of RISs against decode and forward relaying.”
Intelligent Reflecting Surfaces: Physics, Propagation, and Pathloss Modeling (2019, methodology): “However, the system models used in [6], [9], [10] are essentially correct, if the pathloss of each element are selected according to (20).”
Active RIS Versus Passive RIS: Which is Superior With the Same Power Budget? (2021, background): “This “double path-loss” attenuation limits the potential of RIS to a large extent [6].”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead (2020, background): “In [49] and [257], the authors report a comparative study of RISs against decode and forward relaying.”