FPGA-Based Real-Time Mode-Diversity Coherent Reception Experiment over a 15.6 km Horizontal Turbulence Link

In a 15.6 km near-ground FSO link, we observed turbulence-induced phase misalignment between modes. Using SC in a 1 Gbaud BPSK real-time experiment over the same link, we demonstrated 87.7% error-free frames without precise phase alignment.