Simulation-based modeling of quantum key distribution in a Li-Fi system using free-space optics and polarization modulation
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Rajeev Ranjan
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Pratham Vinayak Sharma
Abstract
With increasing demands for secure high-speed wireless communications, integration of quantum key distribution (QKD) into light fidelity (LiFi) systems is a promising method for boosting data confidentiality in optical wireless networks. The BB84 protocol and Mach–Zehnder modulator (MZM) are utilized with a pump-assisted continuous wave laser at 1,550 nm and polarization control components to encode quantum states onto photons. They are transmitted on free space optical (FSO) links with a length ranging from 2 km to 8 km and received using Avalanche photodiodes (APDs) and optical filters. Performance analysis conducted using bit error rate (BER) and Q-factor analysis. BER maintained at zero across all tested configuration and transmission distance up to 8 km indicating excellent signal integrity and security. A highest Q-factor achieved a maximum of 3,055.9, which ensures signal integrity and low interference noise. The system operates at a simulated data rate of 10 Gbps, suitable for high speed optical wireless communication. Consistently high eye height (∼172,210 units) and stable decision thresholds confirm minimal inter-symbol interference and accurate symbol recognition. And the Poincaré sphere showed even polarization stability for different optical power levels. This work presents a simulation-based implementation of a polarization encoded QKD system over a LiFi-enabled FSO communication channel, aiming to enhance secure optical wireless communication. Calculated based on quantum bit error rate (QBER) and included in the theoretical analysis to demonstrate practical secure throughput.
Funding source: The authors received no external funding for this work.
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Research ethics: Not applicable. This study did not involve human participants or animals.
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Informed consent: Not applicable.
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Author contributions: R. Ranjan carried out simulations and analysis, manuscript preparation and supervised the overall work. P. V. Sharma designed the study and simulations. All authors read and approved the final manuscript.
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Use of Large Language Models, AI and Machine Learning Tools: The authors used grammarly for grammar correction during manuscript preparation. All intellectual content, analysis, and conclusions are original and generated by the authors.
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Conflict of interest: The authors declare that they have no competing interests.
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Research funding: This research received no external funding.
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Data availability: Not applicable.
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