Physical Layer Security for Visible Light Communication Systems:A Survey

Due to the dramatic increase in high data rate services and in order to meet the demands of the fifth-generation (5G) networks, researchers from both academia and industry are exploring advanced transmission techniques, new network architectures and new frequency spectrum such as the visible light spectra. Visible light communication (VLC) particularly is an emerging technology that has been introduced as a promising solution for 5G and beyond. Although VLC systems are more immune against interference and less susceptible to security vulnerabilities since light does not penetrate through walls, security issues arise naturally in VLC channels due to their open and broadcasting nature, compared to fiber-optic systems. In addition, since VLC is considered to be an enabling technology for 5G, and security is one of the 5G fundamental requirements, security issues should be carefully addressed and resolved in the VLC context. On the other hand, due to the success of physical layer security (PLS) in improving the security of radio-frequency (RF) wireless networks, extending such PLS techniques to VLC systems has been of great interest. Only two survey papers on security in VLC have been published in the literature. However, a comparative and unified survey on PLS for VLC from information theoretic and signal processing point of views is still missing. This paper covers almost all aspects of PLS for VLC, including different channel models, input distributions, network configurations, precoding/signaling strategies, and secrecy capacity and information rates. Furthermore, we propose a number of timely and open research directions for PLS-VLC systems, including the application of measurement-based indoor and outdoor channel models, incorporating user mobility and device orientation into the channel model, and combining VLC and RF systems to realize the potential of such technologies

Physical layer security against eavesdropping in the internet of drones (IoD) based communication systems

rones or unmanned aerial vehicles (UAVs) communication technology, which has recently been thoroughly studied and adopted by 3GPP standard (Release 15) due to its dynamic, flexible, and flying nature, is expected to be an integral part of future wireless communications and Internet of drones (IoD) applications. However, due to the unique transmission characteristics and nature of UAV systems including broadcasting, dominant line of site and poor scattering, providing confidentiality for legitimate receivers against unintended ones (eavesdroppers) appears to be a challenging goal to achieve in such scenarios. Besides, the special features of UAVs represented by having limited power (battery-operated) and precessing (light RAM and CPU capabilities), makes applying complex cryptography approaches very challenging and inefficient for such systems. This motives the utilization of alternative approaches enabled by physical layer security (PLS) concept for securing UAV-based systems. Techniques based on PLS are deemed to be promising due to their ability to provide inherent secrecy that is complexity independent, where no matter what computational processing power the eavesdropper may have, there is no way to decrypt the PLS algorithms. This work is dedicated to highlight and overview the latest advances and state of art researches on the field of applying PLS to UAV systems in a unified and structured manner. Particularity, it discusses and explains the different, possible PLS scenarios and use cases of UAVs, which are categorized based on how the drone is utilized and employed in the communication system setup. The main classified categories include the deployment of the flying, mobile UAV as a 1) base station (BS), 2) user equipment (UE), 2) relay, or 4) jammer. Then, recommendations and future open research issues are stated and discussed.No sponso

Secrecy Design of Indoor Visible Light Communication Network under Downlink NOMA Transmission

In this work, we investigate the transmission sum rate as well as the secrecy sum rate of indoor visible light communication (VLC) networks for mobile devices with the power domain non-orthogonal multiple access (NOMA) transmission, where multiple legitimate users are equipped with photodiodes (PDs). We introduce a body blockage model of the legitimate users as well as the eavesdropper to focus on the case where the communications from transmitting light-emitting diodes (LEDs) to receiving devices are blocked by the bodies of receiving users. Furthermore, in order to improve the secrecy without any knowledge of the channel state information (CSI) of the eavesdropper, a novel LED arrangement is introduced to reduce the overlapping area covered by LED units supporting different users. We also propose two LED operation strategies, called simple and smart LED linking, and evaluate their performance against the conventional broadcasting in terms of transmission sum rate and secrecy sum rate. Through computer simulations, the superiority of our proposed strategies is demonstrated.Comment: 30 pages, 13 figures. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Relay-aided Slotted Aloha for Optical Wireless Communications

We consider a relay-aided Slotted ALOHA solution for uplink random access for an Optical Wireless Communications (OWC)-based Internet of Things (IoT). The first phase of uplink, the one between IoT devices and the relays, is realized using indoor OWC, while the second phase, between the relays and a base station, represents the long-range RF transmission based on low-power wide area network such as LoRaWAN and occurs outdoors. The throughput performance dependence on the OWC and RF channel conditions is observed. The behavior of the performance gain due to adding relays is highlighted and investigated under different channel and traffic conditions.Comment: Published in: 2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP