Inventors:
Gary W. Johnson - Livermore CA, US
Farid U. Dowla - Castro Valley CA, US
Anthony J. Ruggiero - Livermore CA, US
Assignee:
The Regents of the University of California - Oakland CA
International Classification:
H04B 10/00
US Classification:
398158, 398140, 398118, 398119
Abstract:
Free-space optical (FSO) laser communication systems offer exceptionally wide-bandwidth, secure connections between platforms that cannot other wise be connected via physical means such as optical fiber or cable. However, FSO links are subject to strong channel fading due to atmospheric turbulence and beam pointing errors, limiting practical performance and reliability. We have developed a fade-tolerant architecture based on forward error correcting codes (FECs) combined with delayed, redundant, sub-channels. This redundancy is made feasible though dense wavelength division multiplexing (WDM) and/or high-order M-ary modulation. Experiments and simulations show that error-free communications is feasible even when faced with fades that are tens of milliseconds long. We describe plans for practical implementation of a complete system operating at 2. 5 Gbps.