NOMA-enabled Backscatter Communications for Green Transportation in Automotive-Industry 5.0

TL;DR

This paper explores the integration of NOMA and backscatter communications in 6G vehicular networks for green transportation, proposing an optimization framework to enhance energy efficiency and discussing future research directions.

Contribution

It introduces a multi-cell optimization framework for NOMA-enabled backscatter vehicular networks, jointly optimizing transmit power and reflection coefficients for energy efficiency.

Findings

Proposed a joint power and reflection coefficient optimization method.

Utilized Dinkelbach, dual theory, and KKT conditions for problem solving.

Identified open issues and future research directions.

Abstract

Automotive-Industry 5.0 will use emerging 6G communications to provide robust, computationally intelligent, and energy-efficient data sharing among various onboard sensors, vehicles, and other Intelligent Transportation System (ITS) entities. Non-Orthogonal Multiple Access (NOMA) and backscatter communications are two key techniques of 6G communications for enhanced spectrum and energy efficiency. In this paper, we provide an introduction to green transportation and also discuss the advantages of using backscatter communications and NOMA in Automotive Industry 5.0. We also briefly review the recent work in the area of NOMA empowered backscatter communications. We discuss different use cases of backscatter communications in NOMA-enabled 6G vehicular networks. We also propose a multi-cell optimization framework to maximize the energy efficiency of the backscatter-enabled NOMA vehicular network. In particular, we jointly optimize the transmit power of the roadside unit and the reflection coefficient of the backscatter device in each cell, where several practical constraints are also taken into account. The problem of energy efficiency is formulated as nonconvex which is hard to solve directly. Thus, first, we adopt the Dinkelbach method to transform the objective function into a subtractive one, then we decouple the problem into two subproblems. Second, we employ dual theory and KKT conditions to obtain efficient solutions. Finally, we highlight some open issues and future research opportunities related to NOMA-enabled backscatter communications in 6G vehicular networks.