Prototyping Optimized Code and Protocol for Maritime and Expeditionary FSO Links

Free-space Laser communications (Lasercomm) – or free-space optical (FSO) communications – is rapidly gaining traction as a next-generation line-of-sight (LOS) wireless technology for both commercial and military applications. Over short time scales (e.g., milliseconds), these high-bandwidth links are plagued by scintillation fading due to atmospheric turbulence and (possibly) boundary layer effects (e.g., at the surface of fast moving aircraft in ship-air links). Although somewhat analogous to the mutlipath-induced fading that is familiar in mobile RF communications, optical scintillation-induced fades typically span thousands to millions of symbols – rather than tens to hundreds – due to the higher symbol rates and longer fade durations. Consequently, solutions for combating fading in RF links do not readily extend to Lasercomm. During Phase I, TrellisWare showed that a modern coded-protocol can offer dramatic throughput improvements over existing state-of-the-art baseband approaches in scintillation-induced fading FSO links. In Phase II, TrellisWare proposes to design and implement a hardware prototype that will demonstrate that our approach can be effectively and efficiently implemented for use on real maritime and expeditionary links. TrellisWare has already received interest from its FSO industry partners in the proposed hardware thus demonstrating a clear path to commercialization during Phase III and beyond.