In this article, the secrecy performance of a hybrid radio frequency (RF)/visible light communication (VLC) system is studied. In this hybrid system, the source node (i.e., Alice) transmits information to the relay node via the outdoor RF link. Nakagami-m fading and path loss are considered for the RF link. The relay node includes an outdoor component and an indoor component, which are connected by using a wired medium. The outdoor component receives and recovers information by using the decode-and-forward (DF) relaying scheme and then transmits it to the indoor component. The indoor component then converts the received electrical signal into an optical signal by using a light-emitting diode. A legitimate receiver (i.e., Bob) deployed on the floor receives the optical signal. An eavesdropper (i.e., Eve) deployed in the RF or VLC link wiretaps the confidential information. In this study, we use the secrecy outage probability (SOP) and the probability of strictly positive secrecy capacity (SPSC) to evaluate the system performance. We then obtain the closed-form expression for a lower bound on the SOP and an exact closed-form expression for the probability of SPSC when the RF and VLC links are wiretapped, respectively. Numerical results are presented to validate the accuracy of our derivations. We further discuss the effects of the noise standard deviation, the equivalent threshold of the signal-to-noise ratio, and the floor radius on the system secrecy performance when the VLC link is eavesdropped upon. For the case when the RF link is eavesdropped upon, the impacts of the distance between Alice and the relay, the path loss exponent, the fading factor, and the distance between Alice and Eve on secrecy performance are also provided.
In this paper, a cooperative hybrid visible light communication (VLC)-radio frequency (RF) system with spatially random terminals is considered. Especially, a source node (
S) with a group of light-emitting diode (LED) lamps transmits information bits to a destination (
D), which is located out of
S’s coverage area, via a relay node (
R).
Ris equipped with a photodetector and an antenna to set up a VLC link between
Sand
R, and a radio frequency (RF) link between
Rand
D, respectively. Meanwhile, an eavesdropper (
E) equipped with a photodetector and an antenna tries to overhear the information delivery over VLC and RF links. Also, diversity receiving scheme is considered at
E, while the same modulation scheme is considered over both VLC and RF links. Furthermore, decode-and-forward scheme is adopted at
Rto process and forward the received VLC signals. By employing stochastic geometry, we first characterize the probability density function and cumulative distribution function of the received signal-to-noise-ratio over both VLC and RF links, while considering the randomness of the locations of both
R,
E, and
D. Then, the secrecy performance of the target system is studied by deriving the approximated expressions for the secrecy outage probability under various cases. Finally, the proposed analytical models are verified via Monte-Carlo simulations.
This paper evaluates the secrecy outage probability of a hybrid radio frequency (RF) and visible light communication (VLC) network in the presence of an eavesdropper.We assume that data is transmitted over the RF and VLC links following a proposed multiplexing scheme in which the data sent by the source is split with a certain allocation ratio.Furthermore, the legitimate and eavesdropper users are assumed to have multihoming capabilities, so that they are able to receive data from both RF and VLC access points, simultaneously.We derive integral-form exact expression, as well as a closedform asymptotic expression for the secrecy outage probability and validate them via Monte Carlo simulations.Our results show that multiplexing the information signal by both links leads to an enhancement of the secrecy performance since it opportunistically takes advantages of the best characteristics of both domains.
Abstract In this paper, we investigate the secrecy performance of a dual-hop hybrid radio frequency–visible light communication (RF–VLC) system in which we consider a single source antenna ( S ) transmitting data signals via RF channel through decode and forward (DF) relay ( R ) toward an authorized receiving antenna ( D ) at the destination via VLC channel. In this system, we assume that the eavesdropper ( E ) attempts to eavesdrop the RF channel ( S , R ) during transmission of the signal. The relay decodes the incoming RF signal into corresponding optical signal and retransmits toward destination via VLC channel ( R , D ). The RF and VLC channels of the hybrid system are modelled using generalized-K fading distribution and generalized Lambertian radiant intensity distribution respectively. Also the receiver is assumed to be mobile and its mobility is defined by random waypoint (RWP) model. The channels statistics are used to derive the exact analytical expressions for average secrecy capacity and intercept probability in terms of Meijer’s G-function. The derived closed form analytical expressions are the efficient tool to illustrate the impact of variation in different channel parameters on the secrecy performance, namely, shadowing parameters of RF channel, field of view (FOV), semiangle, and the order of Lambertian emission of the VLC channel. Further, numerical analysis is carried out to support the mathematical analysis of the RF–VLC hybrid system.
In this paper, we consider an indoor environment where both visible light communication (VLC) and radio frequency (RF) networks are co-deployed. A source transmitter can use either a VLC-link or a RF-link to transmit the information to the legitimate user and we assume that an eavesdropper is also present to intercept the legitimate information transmission. Here, VLC network is considered as a primary network and RF network is used as a backup. Therefore, a source transmitter utilizes the RF-link only when VLC-link offers negative secrecy-rate for legitimate information transmission. In particular, we propose a secrecy-rate based secure link adaptation mechanism to select the RF-link. We derive the exact closed-form expressions for secrecy outage probability and system secrecy outage probability, and further, observe the effect of various physical parameters on security performance analysis.
The risk of information leakage increases when the relay technology is introduced to extend the communication range and improve the quality of communication services of cell-edge users in visible light communication (VLC) systems. To evaluate these security risks, physical layer security (PLS) performance for decode-and-forward (DF) relay-aided VLC system is investigated in this paper. Specifically, the theoretical expressions of the upper and lower bounds of the security outage probability (SOP) for the DF relay-aided VLC system under the amplitude constraint are obtained based on a stochastic geometry analysis method. Monte Carlo simulation validates the correctness of the derived theoretical expressions of the upper and lower bounds of the SOP. Moreover, simulation results show that the security outage performance of the DF relay-aided VLC system is deteriorated compared with the non-relay VLC system. Furthermore, the influences of the eavesdroppers' distribution density, the radiation radius of LED source, the radiation radius and deployment height of the relay on the SOP have been investigated. Last but not least, the optimal deployment height of the relay can be determined for achieving the optimum security outage performance. These parameters can effectively guide the design of the secure relay-aided VLC system.