11.1 Communication unit: FB-2000
11-6
11.1.2 MODEM: 16P0274
The MODEM board executes the modulation / demodulation processing (base band) and
the data encryption processing by following the FB: Fleet broadband system
communication protocol.
The I and Q signals for the modulation signals (base band) are output to the IF board, and
are converted into L-Band. The receiving signals are converted into 2
nd
IF: 1.9 MHz by the
IF board, and then are demodulated by the MODEM board.
Fig. 11.1.4 MODEM board block diagram