Digital SATCOM Legacy Modem Data Converter

ABSTRACT: Welkin Sciences proposes to develop, build, test, and demonstrate Legacy Modem Data Converters (LMDC) to enable the Department of Defenses (DoD) traditional L-band analog SATCOM modems to operate with future SATCOM terminals utilizing Digital IF architectures. The LMDC will be designed to be compliant with the Army Future Advanced SATCOM Terminal (FAST) Open Standard Digital Interface (OSDI) specification. BENEFIT: Implementation of the LMDC will allow the DoD continued use of their large inventory of legacy analog modems as Digital IF technology evolves and deploys in new SATCOM terminals throughout the world. The LMDC facilitates the DoDs transition to Digital IF technology while avoiding costly new equipment purchase and potential impacts to schedule due to new equipment deployment. Two primary reasons for integrating Digital IF technology into future SATCOM terminals are to improve fidelity for L-band signal transmission within the terminal and to allow more flexible signal switching and routing. Digital IF allows signal transport over long distances without loss of signal integrity as often happens with transmission of analog L-band signals. A recognized problem in existing terminals is the loss of signal fidelity when signals are transmitted over analog-fiber, a common means for signal transport over modest distances. The loss of fidelity over analog cabling is typically not critical for receive signals on the downlink, but can be an issue for transmit signals. When Digital IF is used for signal transport over digital optical fiber, loss of signal fidelity on inter-facility cables need no longer be a consideration for antenna placement. The Digital IF advantage even opens up the possibility of inter-terminal signal transport, over Defense Information Systems Network (DISN), which is currently not practical.