Abstract In this paper, the physical layer security of an indoor visible light communication system, that consists of two transmission light‐emitting diodes to broadcast the information towards the legitimate user, is investigated. Further, a secure LED selection scheme is proposed to select an LED that can perform secure information broadcasting, in the presence of an active and/or passive eavesdropper. The probability of secure information broadcasting is obtained in terms of the positive secrecy rate which is defined under the constraints of known or unknown imperfect channel state information of both legitimate and eavesdropping links. The channel state information (CSI) knowledge of each transmitting link is estimated with the use of a minimum mean square error technique. The performance metrics of the system are defined in terms of the average secrecy capacity and secrecy outage probability parameters. Further, the performance of the system is compared with the conventional stand‐alone VLC system by varying various physical parameters. Further, analytical results are corroborated with the computer simulation results.
Abstract In this paper, the physical layer security of an indoor visible light communication system, that consists of two transmission light‐emitting diodes to broadcast the information towards the legitimate user, is investigated. Further, a secure LED selection scheme is proposed to select an LED that can perform secure information broadcasting, in the presence of an active and/or passive eavesdropper. The probability of secure information broadcasting is obtained in terms of the positive secrecy rate which is defined under the constraints of known or unknown imperfect channel state information of both legitimate and eavesdropping links. The channel state information (CSI) knowledge of each transmitting link is estimated with the use of a minimum mean square error technique. The performance metrics of the system are defined in terms of the average secrecy capacity and secrecy outage probability parameters. Further, the performance of the system is compared with the conventional stand‐alone VLC system by varying various physical parameters. Further, analytical results are corroborated with the computer simulation results.
This article investigates the physical-layer security for a random indoor visible light communication (VLC) network with imperfect channel state information (CSI) and a protected zone. The VLC network consists of three nodes, i.e., a transmitter (Alice), a legitimate receiver (Bob), and an eavesdropper (Eve). Alice is fixed in the center of the ceiling, and the emitted signal at Alice satisfies the nonnegativity and the dimmable average optical intensity constraint. Bob and Eve are randomly deployed on the receiver plane. By employing the protected zone and considering the imperfect CSI, the stochastic characteristics of the channel gains for both the main and the eavesdropping channels is first analyzed. After that, the closed-form expressions of the average secrecy capacity and the lower bound of secrecy outage probability are derived, respectively. Finally, Monte Carlo simulations are provided to verify the accuracy of the derived theoretical expressions. Moreover, the impacts of the nominal optical intensity, the dimming target, the protected zone, and the imperfect CSI on secrecy performance are discussed, respectively.
This paper considers secure transmission over the visible light communication (VLC) channel by the means of physical-layer security techniques. In particular, we consider achievable secrecy rates of the multiple-input, single-output (MISO) wiretap VLC channel. The VLC channel is modeled as a deterministic and real-valued Gaussian channel subject to amplitude constraints. We utilize null-steering and artificial noise strategies to achieve positive secrecy rates when the eavesdropper's channel state information (CSI) is perfectly known and entirely unknown to the transmitter, respectively. In both scenarios, the legitimate receiver's CSI is available to the transmitter. We numerically evaluate achievable secrecy rates under typical VLC scenarios and show that simple precoding techniques can significantly improve the confidentiality of VLC links.
This paper considers improving the confidentiality of visible light communication (VLC) links within the framework of physical-layer security. We study a VLC scenario with one transmitter, one legitimate receiver, and one eavesdropper. The transmitter has multiple light sources, while the legitimate and unauthorized receivers have a single photodetector, each. We characterize secrecy rates achievable via transmit beamforming over the multiple-input, single-output (MISO) VLC wiretap channel. For VLC systems, intensity modulation (IM) via light-emitting diodes (LEDs) is the most practical transmission scheme. Because of the limited dynamic range of typical LEDs, the modulating signal must satisfy certain amplitude constraints. Hence, we begin with deriving lower and upper bounds on the secrecy capacity of the scalar Gaussian wiretap channel subject to amplitude constraints. Then, we utilize beamforming to obtain a closed-form secrecy rate expression for the MISO wiretap channel. Finally, we propose a robust beamforming scheme to consider the scenario wherein information about the eavesdropper's channel is imperfect due to location uncertainty. A typical application of the proposed scheme is to secure the communication link when the eavesdropper is expected to exist within a specified area. The performance is measured in terms of the worst-case secrecy rate guaranteed under all admissible realizations of the eavesdropper's channel.
The physical layer security analysis is required in visible light technology based optical wireless communication networks, in order to deal with the eavesdropping attacks. In this study, we consider an indoor VLC network consisting of two light emitting diode elements. Further, based on ability to negate the eavesdropping attacks, the source transmitter selects either of the element to transmit the information to the legitimate user in the presence of an eavesdropper. In particular, for the selection of the element with desired ability, we propose a two-stage secure link adaptation scheme. We develop a mathematical framework to analyse the average secrecy capacity and secrecy outage probability of both single-element and dual-element VLC links. Further, we compare the numerical results of the proposed dual-element VLC network with the conventional single-element VLC network by varying physical parameters.
In this article, we investigate the physical layer security in an indoor environment, wherein both visible light communication (VLC) as well as radio frequency (RF) technologies are codeployed. We explore the benefits of employing both technologies by imposing a limit of positive secrecy rate to prevent the eavesdropping attacks, which is an important metric in designing a secure wireless network. The VLC technology is used as a primary technology and the RF technology is used when the primary technology cannot satisfy the imposed limit. In particular, a novel secure-link selection mechanism is proposed to select the secure technology (i.e., either VLC or RF technology) based on the availability or nonavailability of instantaneous channel state information of both legitimate and eavesdropping links. The performance of the system is evaluated in terms of average secrecy capacity, connection outage probability, and secrecy outage probability. We observe the effect of various physical parameters on the security performance of the network. Further, analytical results are corroborated with the computer simulation results.
Visible light communication (VLC) is a burgeoning field in wireless communications as it considers illumination and communication simultaneously. The broadcast nature of VLC makes it necessary to consider the security of underlying transmissions. A physical-layer security (PLS) scheme by introducing jamming LEDs is considered in this paper. The secrecy rate of an indoor VLC system with multiple LEDs, one legitimate receiver, and multiple eavesdroppers is investigated. Three distributions of input signal are assumed, i.e., truncated generalized normal distribution (TGN), uniform distribution, and exponential distribution. The results show that jamming can improve the secrecy performance efficiently. This paper also demonstrates that when the numbers of LEDs transmitting information-bearing signal and jamming signal are equal, the average secrecy rate can be maximized.