  This article reports on the use of a Field Programmable Gate Array (FPGA)
platform for local ultra-stable optical frequency distribution through a 90
m-long fiber network. This platform is used to implement a fully digital
treatment of the Doppler-cancellation scheme required by fiber links to be able
to distribute ultra-stable frequencies. We present a novel protocol that uses
aliased images of a digital synthesizer output to directly generate signals
above the Nyquist frequency. This approach significantly simplifies the setup,
making it easy to duplicate within a local fiber network. We demonstrate
performances enabling the distribution of an optical signal with an instability
below $10^{-17}$ at 1 s at the receiver end. We also use the board to implement
an original characterization method. It leads to an efficient characterization
of the disturbance rejection of the system that can be realized without
accessing the remote output of the fiber link.
