A study of optical satellite communication systems employing rate-adaptive forward error correction

Widely varying path loss is one of the issues involved in realizing high capacity transmission in optical low earth orbit satellite to optical ground station communication systems, as the atmospheric attenuation varies dramatically with zenith angle. We propose an optical satellite-to-ground communication system with variable forward error correction (FEC) redundancy to suit the satellite-to-ground path loss. We assume the satellite has two or more values of FEC redundancy, and FEC redundancy is changed as the zenith angle changes. By using 4 steps in the value of FEC redundancy, the transmissible data volume increases by 30% over the case of fixed FEC redundancy.