Optimized Coding and Protocols for FSO Communications Links

摘要

The present report summarizes the Phase 1 Option work of TrellisWare Technologies, Inc. (TrellisWare) in the development of an optimized coded protocol to combat the deep fades caused by scintillation in free-space optical (FSO) communication links. For Phase-I, TrellisWare proposed the joint use of coding and protocol ('coded-protocol') to mitigate the scintillation induced fading on FSO communication links. The proposed coded-protocol would adapt the code-rate to match prevalent channel conditions seamlessly using feedback from the receive side. The Phase-I study involved the careful development of a system simulation that included models for an FSO transmitter with code-rate adaptation and an FSO receiver with code-rate estimation capability. In order to test the utility of the proposed approach, TrellisWare also developed FSO channel models that could be configured with scintillation parameters. At the end of the Phase-I study we reported the successful completion of a coded- protocol framework combining a Hybrid Automatic Repeat reQuest (H-ARQ) protocol driven by TrellisWare's modern Flexible Low-Density Parity-Check (F-LDPC) code family. The expected throughput/latency performance of the proposed system was also reported for a wide range of scenarios.