RIS-based Over-the-air Diffractional Channel Coding

TL;DR

This paper introduces RIS-based diffractional channel coding (DCC), a novel electromagnetic wave manipulation technique that uses diffraction between RIS layers for efficient, power-free signal encoding in advanced wireless systems.

Contribution

It presents a new RIS-based coding scheme leveraging diffraction for signal encoding, expanding the capabilities of RIS in wireless communication.

Findings

DCC can construct block and trellis codes.

DCC eliminates extra power for encoding.

DCC enables computation at the speed of light.

Abstract

Reconfigurable Intelligent Surfaces (RIS) are programmable metasurfaces utilizing sub-wavelength meta-atoms and a controller for precise electromagnetic wave manipulation. This work introduces an innovative channel coding scheme, termed RIS-based diffractional channel coding (DCC), which capitalizes on diffraction between two RIS layers for signal-level encoding. Contrary to traditional methods, DCC expands signal dimensions through diffraction, presenting a novel countermeasure to channel effects. This paper focuses on the operational principles of DCC, including encoder and decoder designs, and explores its possibilities to construct block and trellis codes, demonstrating its potential as both an alternative and a supplementary conventional coding scheme. Key advantages of DCC include eliminating extra power requirements for encoding, achieving computation at the speed of light, and enabling adjustable code distance, making it a progressive solution for efficient wireless communication, particularly in systems with large-scale data or massive MIMO.