Wavecom W40PC, Manual

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Transmission Modes WAVECOM Decoders v6.15 W40PC, W41PC, W51PC
The HF-ACARS decoder detects each slot with the characteristic prekey (1440 Hz single
tone), uses the preamble to synchronize the slot, eliminates various distortions in the HF
communication channel, configures several components of the decoder, demodulates the user
data section and decodes it according to the HFDL protocol interpreter.
Each message is finally output on the screen in Squitter (SPDU) format, Uplink MPDU format
(from ground station to aircraft) or Downlink MPDU format (from aircraft to ground station).
Only when a HFDL slot is successfully detected, the decoder enters the "Traffic" state,
otherwise it remains in the "Sync" state.
Usually an HFDL station sends the signal with USB setting. However the decoder has the
possibility to process signal in both USB and LSB settings. This can be done setting the
Polarity in the menu to NOR for USB and INV for LSB signal.
The center frequency of the decoder should be set to 1440 Hz when the receiver is set to the
frequency of the ground station correctly. A small frequency difference will be compensated
by the decoder automatically. However the center frequency can be tuned by +/- 400 Hz from
its nominal setting.
There are two system configuration files for the display of HFDL messages: "hfacars.txt" and
"hfacars.dat".
HNG-FEC
Parameter Value
Frequency range HF
System FEC
Baudrate(s) 100.05 Baud, variable 30-650 Baud
Modulation SSB or DIRECT-FSK
Receiver settings CW, LSB or USB
Signal source(s) AF, HF or IF