Joint Optimization for Secure Ambient Backscatter Communication in NOMA-enabled IoT Networks

TL;DR

This paper proposes a new optimization framework to enhance physical layer security in NOMA-enabled ambient backscatter communication systems for IoT networks, considering multiple eavesdroppers and optimizing key transmission parameters.

Contribution

It introduces a novel optimization approach for improving security in NOMA ambient backscatter IoT systems, accounting for eavesdroppers and optimizing reflection and power parameters.

Findings

NOMA BC outperforms pure NOMA in secrecy rate

Optimized reflection coefficient and transmit power enhance security

Simulation confirms superiority over traditional schemes

Abstract

Non-orthogonal multiple access (NOMA) has emerged as a novel air interface technology for massive connectivity in sixth-generation (6G) era. The recent integration of NOMA in backscatter communication (BC) has triggered significant research interest due to its applications in low-powered Internet of Things (IoT) networks. However, the link security aspect of these networks has not been well investigated. This article provides a new optimization framework for improving the physical layer security of the NOMA ambient BC system. Our system model takes into account the simultaneous operation of NOMA IoT users and the backscatter node (BN) in the presence of multiple eavesdroppers (EDs). The EDs in the surrounding area can overhear the communication of base station (BS) and BN due to the wireless broadcast transmission. Thus, the main objective is to enhance the link security by optimizing the BN reflection coefficient and BS transmit power. To gauge the performance of the proposed scheme, we also present the suboptimal NOMA and conventional orthogonal multiple access as benchmark schemes. Monte Carlo simulation results demonstrate the superiority of the NOMA BC scheme over the pure NOMA scheme without BC and conventional orthogonal multiple access scheme in terms of system secrecy rate.