Applicability of 5G-NR LDPC code for Error-reduced Free-Space Optical Communication

Free-space optical (FSO) communication systems are growing in popularity due to the features they offer for Civilian and Defence applications. Features like high data rates, non-licensed spectrum, and secure link makes FSO an optimum choice for many applications. This paper will analyze the applicability of the Fifth-generation new radio (5G-NR) LDPC code for optimum FSO link quality that is severely affected by atmospheric turbulence-induced fading, weather attenuation/disturbances, geometric losses, and misalignment errors. A simulation model for a typical FSO system has been created in MATLAB to model atmospheric turbulence using a Log-normal model for weak turbulence and a Gamma-gamma model for strong turbulence. The 5G-NR standard uses Quasi-cyclic (QC) LDPC code for reduced computational complexity and excellent error performance over noisy channels. In this paper, the offset-based Min-Sum decoding Algorithm has been considered to analyze the BER performance for Uncoded, Analytical, and Coded cases for FSO system implementation. The results indicate a strong case for the applicability of the 5G-NR LDPC code in building FSO systems for reliable communication.