In this letter the secure performance for the visible light communication (VLC) system with multiple eavesdroppers is studied. By considering the practical amplitude constraint instead of an average power constraint in the VLC system, the closed-form expressions for the upper and the lower bounds of the secrecy outage probability and the average secrecy capacity are derived. Since the locations for both legitimate receiver and eavesdroppers are unknown as well as random, the stochastic geometry method is introduced for problem formulation. Moreover, accurate expressions with a low computational complexity are obtained with the rigorous derivation. Simulation results verify the correctness of our theoretical analysis.
Over recent years, visible light communications (VLC) has gained prominence as a promising alternative to traditional RF communication, offering advantages in terms of bandwidth and security. This paper investigates the physical-layer security for a practical indoor VLC system where the positions of a legitimate receiver (Bob) and an eavesdropper (Eve) are considered to be random within their circular receiving planes. For this system model, the statistics of the VLC channel gains are obtained using which, closed-form expressions for the secrecy outage probability are derived. The analytical results, validated through Monte Carlo simulations, demonstrate the impact of key system parameters, namely signal-to-noise ratio, Bob and Eve relative positions, and the target secrecy rate on the SOP performance.
This letter investigates the secrecy performance in visible light communication (VLC) in the presence of randomly located colluding eavesdroppers (EDs). Colluding EDs can combine their observations and degrade the secrecy performance of the VLC systems. Utilizing the numerical inversion of a characteristic function, the probability distribution of the combined signal-to-noise ratio of colluding EDs is analyzed. The closed-form expression of the secrecy outage probability is derived and verified by Monte Carlo simulations.
Abstract This paper investigates the physical layer security of indoor visible light communication (VLC) systems in the presence of randomly located eavesdroppers using a stochastic geometry framework. Unlike traditional LOS-only or perfect-CSI assumptions, this work incorporates a more realistic setting where the eavesdropper’s channel state information (CSI) is unknown, and both line-of-sight (LOS) and first-order non-line-of-sight (NLOS) reflections are accounted for in the channel modelling. The analysis further integrates device orientation randomness and evaluates security under eavesdroppers employing selection combining (SC) and maximum ratio combining (MRC). Closed-form expressions for the channel gain, SNR distribution, and secrecy outage probability (SOP) are derived by exploiting the spatial statistics of a bounded Poisson point process (PPP). Results show that incorporating NLOS components significantly enhances legitimate SNR and improves secrecy performance, while eavesdropper collaboration using maximum ratio combining presents the worst-case security threat. Monte Carlo simulations validate the analytical derivations, demonstrating close agreement across various system parameters. The study offers an accurate and practical secrecy analysis framework for next-generation VLC deployments in realistic indoor environments.
We study in this paper the secrecy performance of the multiple-input single-output (MISO) visible light communication (VLC) channel in the presence of randomly located eavesdroppers. We consider a system model comprising a transmitter, equipped with multiple fixtures of LEDs, one legitimate receiver equipped with a single photo-diode (PD) and a group of randomly located (and colluding) eavesdroppers, each equipped with a single PD. We derive a closed-form expression for the average achievable secrecy rate as a function of the beamforming vector, the input distribution, and the location density of the eavesdroppers using stochastic geometry. We then investigate the optimal beamformer that maximizes the average achievable secrecy rate. We corroborate the analytical results through Monte Carlo simulations and we demonstrate substantial improvements provided by the proposed scheme over existing ones.
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.