Development of Software Tools to Predict Environmental Impacts on BER and QKD in Free-Space Optical Communication

Free-Space Optical Communication (FSO) is a promising technology for high-speed data transmission, yet its performance is heavily influenced by environmental factors such as wind velocity, temperature, humidity, and environment roughness. To address these challenges, this study developed a statistical-analytic model explicitly incorporating these parameters, along with software tools designed to predict two key metrics: Bit Error Rate (BER) during Classical FSO (CFSO) and Quantum Key Distribution (QKD) rate during Quantum FSO (QFSO). The predictive applications demonstrate how receiver radius and specific humidity fluctuations affect signal quality metrics, such as BER and QKD rate. For instance, increasing the receiver radius by ∆ R = 0 . 5 m and ∆ R = 1 m led to respective increases in BER by ∆ BER = 0 . 5 × 10 - 3 and ∆ BER = 1 . 3 × 10 - 3 }, while fluctuations in specific humidity ∆ q ' = 10 g / m 3 and ∆ q ' = - 5 g / m 3 resulted in variations in QKD rate of ∆ QKD = - 2 bits / s and ∆ QKD = + 1 bits / s .These findings highlight the adaptability of FSO systems under dynamic environmental conditions, paving the way for their broader application in real-world scenarios.