Johst, AbrahamAbrahamJohstMolle, LutzLutzMollePerlot, NicolasNicolasPerlotRothe, MarcelMarcelRotheRohde, MichaelMichaelRohdeNölle, MarkusMarkusNölle2025-03-262025-03-262024https://publica.fraunhofer.de/handle/publica/48582810.1109/WiSEE61249.2024.108501172-s2.0-85218202618The increasing demand for fast and license-free satellite feeder links has put optical free-space communications on the research agenda. To compensate for atmospheric turbulence utilizing spatial diversity and post-DSP combining, a DSP is needed that works reliably even at very low SNRs. For this purpose, a custom multi-format data-aided equalizer is developed and its performance is analyzed under various conditions in a dual-polarization coherent transmission system. Numerical simulations and a field test over a 3.2-km free-space optical link are used to validate the DSP design, and show stable DSP performance for a 32 GBd coherent transmission at SNR-values down to 0 dB, even for DP-16QAM modulation.enfalsecoherent optical communicationdata-Aided DSPfree-space opticssatellite feeder linksconference paper