Performance analysis and modeling: atmospheric turbulence and crosstalk of WDM-FSO network

This paper presents a comprehensive performance analysis of a Wavelength Division Multiplexing (WDM) access network utilizing high-speed Free-Space Optical (FSO) communication for its distribution links. We investigate the performance degradation of WDM-FSO systems in the presence of atmospheric turbulence, which causes scintillation, beam spreading, interchannel crosstalk, and amplified spontaneous emission noise. The analysis focuses on On–Off Keying (OOK) and Digital Pulse Position Modulation (DPPM) as modulation schemes, employing both mathematical modeling and simulations to evaluate the effects of turbulence on signal integrity and Bit Error Rate (BER) across upstream and downstream transmissions. The findings indicate that interchannel crosstalk, atmospheric scintillation, and noise processes significantly impair system performance, particularly in upstream transmissions where DPPM demonstrates greater power efficiency than OOK. This study not only identifies the critical factors influencing the reliability of WDM-FSO networks but also proposes optimization strategies suitable for dynamic atmospheric conditions, thereby contributing to more effective design frameworks for future deployments. The significance of this study lies in its potential to inform the design and optimization of WDM-FSO networks in real-world applications, especially under varying atmospheric conditions that affect signal quality. By examining the interplay between turbulence and modulation schemes, this research provides valuable insights for maintaining high communication reliability and enhancing bandwidth efficiency. Furthermore, the outcomes of this work are essential for developing adaptive optical communication systems capable of addressing the growing data traffic demands in metropolitan and regional networks, thus supporting the evolution of next-generation optical access networks.