Experimental and numerical analysis of data transmission with advanced FEC code and interleaving for GEO satellite-to-ground laser links.

This paper presents an experimental and numerical evaluation of advanced FEC with interleaving on a GEO satellite-to-ground laser downlink between JAXA's LUCAS and NICT Okinawa OGS. This evaluation compares DVB-S2 and 5G NR LDPC over multiple interleaving depths, utilizing received packets and turbulence data acquired in November 2023. The experiments show that DVB-S2 consistently decodes error-free for pre-FEC BERs degraded by turbulence, outperforming 5G NR LDPC and Reed-Solomon with multiple interleaving depths. The simulations, reproducing the measured atmospheric channels, corroborate the trend and indicate that deeper interleaving is required to compensate and avoid error floors. These results provide practical design guidance for selecting FEC and interleaving depth for satellite-to-ground laser links under turbulence conditions.