Simulative Analysis of DSP-PDM-256-QAM-Enabled Free Space Optics Transmission: Impact of Rain and Fog Weather conditions

This research work presents a complete simulation-based analysis of a free-space optics (FSO) communication system that combines digital signal processing (DSP) with polarization-division multiplexing (PDM) and 256-QAM modulation. The performance of the system is assessed under different weather conditions, such as rain and fog. The design and evaluation are done using a simulation framework, with bit error rate (BER) and error vector magnitude (EVM) acting as the main performance parameters. Significant findings indicate that the system is able to transmit the data over a maximum distance of 1200 m in light fog, 700 m in moderate fog, and 550 m in heavy fog. Similarly, in rainfall conditions, the system provides data transmission over distances of 1600 m during light rain, 1250 m in moderate rain, and 750 m during heavy rain, all considering the EVM value below 3% and the BER value at or below 10–<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup>. These results explain the reliability and adaptability of the DSP-PDM-256-QAM-enabled FSO system throughout the challenging weather conditions, highlighting its suitability for implementation in difficult environments. The study gives a key understanding of optimizing FSO systems to combat harsh weather, laying the foundation for robust, high-performance communication networks.