A New RIS Architecture with a Single Power Amplifier: Energy Efficiency and Error Performance Analysis

TL;DR

This paper introduces a novel RIS architecture with a single amplifier to enhance energy efficiency and error performance, addressing the limitations of passive RIS by reducing path loss and double fading effects.

Contribution

The paper proposes a simple amplifying RIS design with a single variable gain amplifier, providing a new hardware architecture that improves energy efficiency and signal quality.

Findings

Significantly reduces multiplicative path loss compared to passive RIS.

Eliminates double fading problem in RIS-assisted systems.

Enhances energy efficiency and error performance in wireless communication.

Abstract

Reconfigurable intelligent surface (RIS)-assisted communication have recently attracted the attention of the wireless communication community as a potential candidate for the next $6$-th generation (6G) of wireless networks. Various studies have been carried out on the RIS technology, which is capable of enabling the control of the signal propagation environment by network operators. However, when an RIS is used in its inherently passive structure, it appears to be only a supportive technology for communications, while suffering from a multiplicative path loss. Therefore, researchers have lately begun to focus on RIS hardware designs with minimal active elements to further boost the benefits of this technology. In this paper, we present a simple RIS hardware architecture including a single and variable gain amplifier for reflection amplification to confront the multiplicative path loss. The end-to-end signal model for communication systems assisted with the proposed amplifying RIS design is presented, together with an analysis focusing on the capacity maximization and theoretical bit error probability performance, which is corroborated by computer simulations. In addition, the major advantages of the proposed amplifying RIS design compared to its passive counterpart are discussed. It is shown that the proposed RIS-based wireless system significantly eliminates the double fading problem appearing in conventional passive RIS-assisted systems and improves the communication energy efficiency.