Mitigating atmospheric turbulence in FSO communications using Reed-Solomon coding: A performance analysis

Abstract

Free-space optical (FSO) communication offers a high-bandwidth solution for modern networks, yet its reliability is critically undermined by atmospheric turbulence. This work thoroughly examines Reed-Solomon (RS) coding as an essential mitigation strategy. We evaluate the performance of the industry-standard RS(255, 223) code under moderate Gamma-Gamma turbulence. Through detailed simulations, we first quantify the coding gain, showing that the RS code breaks through the uncoded system error floor and provides a gain of over 3 dB at a bit error rate (BER) of 10⁻³. Secondly, we isolate the performance penalty imposed by turbulence, which amounts to approximately 2.5 dB compared to a clear-sky channel. Finally, we investigate the critical impact of link distance by simulating the system over 300 m, 1000 m, and 2000 m. This reveals a significant performance penalty for longer links due to the cumulative effect of turbulence. This study definitively establishes that forward error correction (FEC) is a crucial element for dependable free-space optics (FSO), while also quantifying the practical performance constraints imposed by turbulence and distance.