Physical layer solutions for optical communications in space

This paper is about simulation of physical layer optical link for space-to-ground laser communications. Using forward error correction (FEC) schemes outlined by the Consultative Committee for Space Data Systems (CCSDS) with non-return-to-zero (NRZ), return to zero (RZ) on-off keying (OOK) and pulse position modulation (PPM); the high photon efficiency optical communications link is analysed using Matlab. Results show the degree to which modulation schemes are susceptible to atmospheric turbulence and AWG noise with and without FEC. We show that at a bit error rate of 10e-3 4-PPM offers better resiliency to atmospheric fading than OOK RZ and NRZ respectively.