Research on LDPC Coding for Free Space Optical Communication with Modified Bessel-Gaussian Beams Based on K-distribution

Abstract

We investigate the performance of low-density parity-check (LDPC) coding for free space optical communication (FSO) with modified Bessel-Gaussian (MBG) beams based on K-distribution. Based on an extended Huygens–Fresnel principle, the receiver plane intensity isformulated and then we analyze the propagation characteristics of MBG beams traveling in aturbulent atmosphere. Numerical calculations show that the interaction of the transmissiondistance, refractive index structure constant, and wavelength will affect the imaginary term inthe beam, allowing the beam to exhibit the properties of the MBG beams. To further improvethe communication quality of the FSO system, we introduce a fast Quasi-Cyclic (QC)Low-Density Parity-Check (LDPC) code. Simulation results show that under weak and strong turbulence conditions, the performance of the QC-LDPC code becomes better and better as the code rate increases, and the bit error rate (BER) keeps decreasing as the code rate increases.