On Secrecy Performance of the Strong User in MISO-NOMA Visible Light Communication System

Xiang Zhao,Jinyong Sun

doi:10.3390/electronics8040462

Abstract

Since successive interference cancellation in non-orthogonal multiple access (NOMA) is enabled at the strong user to remove the signal of the weak user, if the information safety of the strong user cannot be ensured, neither can the weak user. The physical-layer security of the strong user in a two-user multiple-input single-output (MISO)-NOMA visible light communication (VLC) system in the presence of a passive eavesdropper was studied, with multiple light-emitting diodes (LEDs) transmitting and a photodiode (PD) receiver receiving. To demonstrate the superiority of the MISO-NOMA VLC system over the SISO-NOMA VLC system, numerical simulations were made, and results show that the secrecy outage probability (SOP) performance of the strong user in the MISO-NOMA VLC system is superior to that in the SISO-NOMA VLC system. Furthermore, the SOP of the strong user depends highly on the room arrangement, the difference between the legitimate channel and eavesdropper channel, and the properties of the LEDs and PD.

Highlights

As a promising alternative complementary to current radio frequency (RF) wireless communications, visible light communication (VLC) can simultaneously provide illumination and data communication by exploiting the existing lighting infrastructure, and it has been regarded as a potential technology for indoor 5G communications, Internet of Things (IoTs), and device-to-device communications [1].Due to the broadcasting nature, VLC is especially applicable for massive connectivity, supporting multiple users to access the same wireless resource
Non-orthogonal multiple access (NOMA) as a novel multiple access protocol where multiple users are multiplexed in the power domain via superposition coding at the transmitter and de-multiplexed by successive interference cancellation (SIC) at the receiver is suitable for VLC systems
We investigate the physical-layer security of a two-user multiple-input single-output (MISO)-NOMA VLC system, where multiple light-emitting diodes (LEDs) serve two legitimate users via downlink NOMA in the presence of a passive eavesdropper

Summary

Introduction

As a promising alternative complementary to current radio frequency (RF) wireless communications, visible light communication (VLC) can simultaneously provide illumination and data communication by exploiting the existing lighting infrastructure, and it has been regarded as a potential technology for indoor 5G communications, Internet of Things (IoTs), and device-to-device communications [1]. It is necessary to investigate the physical layer security of MISO-NOMA VLC systems This is due to the fact that: (1) to effectively support massive connectivity, which is important for ensuring the forthcoming 5G network to support the IoTs functionalities, it is necessary to study on NOMA VLC systems; (2) in practical application, multiple LEDs are often deployed to meet the lighting requirements. We investigate the physical-layer security of a two-user MISO-NOMA VLC system, where multiple LEDs serve two legitimate users via downlink NOMA in the presence of a passive eavesdropper. The physical-layer security of the strong user in a two-user MISO-NOMA VLC system is analyzed and measured by the secrecy outage probability (SOP) performance criteria.

System Model

Statistical Characteristic of the SNR

Secrecy Performance Analysis

Numerical Results

Conclusions