Proof-of-Concept Real-Time Implementation of Interleavers for Optical Satellite Links

Abstract

Ground-satellite optical links are a promising technology for increasing capacity and security over radio frequency links, while reducing weight and power consumption. However, atmospheric turbulence generates power fadings at the reception terminal. This effect can be mitigated by combining adaptive optics, forward error correction and data interleaving. While adaptive optics has been extensively studied, forward error correction together with long interleaving (e.g., multiple 10 ms) has not yet been demonstrated in this context. In this article, we present a proof of concept of an optical satellite uplink, precompensated by adaptive optics, which leverages a long interleaver in an external memory and operates at 10 Gbps with SFP+ transceivers. We account for the issues associated with real-time implementation and interfacing to a high-speed memory. To validate our proof of concept, we generate time-series for a typical ground to geostationary satellite communication link, using a field-validated simulator. Using these time series, we calculate the required interleaver time as a function of the launch power. Finally, we show the impact of different transmitter pupil diameters and of different wind speed profiles, on the interleaver duration.