WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V9.1.0
Transmission Modes
147
Tuning the decoder:
The decoder processes the signal in both SSB settings: USB and LSB. This can be
selected with
Polarity
in the menu, where NOR means USB and INV means LSB. The correct polarity for
the CODAN-3212 decoder is NOR. The
Center
frequency of the decoder should be set to 1500 Hz when
decoding a CODAN-3212 signal. Small frequency deviations are automatically compensated in the decod-
er. By using the bar-graph, any remaining frequency difference can be compensated by fine tuning of the
receiver frequency or by adjusting the center frequency of the decoder.
Decoder Output Display:
The decoded CODAN-3212 data stream can be displayed in
HEX
,
BINARY
,
ASCII ASYNC
,
ASCII SYNC
, or in conjunction with the
STANAG-5066
protocol, selected from
Options,
Message type
. The decoder stops displaying data when the EOM message is received. In
HEX
and in
BI-
NARY
the decoded binary data is simply displayed as it is. In
ASCII ASYNC
the data is displayed with the
following structure: 1 start bit (= 0), 7 data bits and 1 stop bit (= 1). The display is stopped when more
than 3 NULL characters are received or when the asynchronous data structure is violated more than 8
times. In
ASCII SYNC
the data is displayed with 8 data bits and no start and stop bits. In the
STANAG-
5066
protocol the number of data bits should be set to 8-bits, the synchronization mode should be SYNC,
the order of synchronization should be LSB and the polarity should be NORMAL. The STANAG-5066 proto-
col interpreter processes the data until the SYNC sequence (0x09 0xD7) has been found. This sequence
can appear more than once in a row. This sequence is followed by the protocol header, which is followed
by the actual data. A 32-bit data CRC indicates if the data is corrupted or not. If the CRC is wrong and the
data has been transmitted with a compression, the resulting output of the decoder is not reliable anymore
until the next transmission. Without compression the resulting output is still readable, except for the bytes
which are corrupt.
Dedicated Phase Plane:
The decoder uses an equalizer to demodulate the PSK and QAM symbols. To
visualize the performance of the equalizer, the user can turn on the phase plane in
Options -> Show
Phase Plane
. The points in yellow is before the equalizer and points in blue is after the equalizer. With
“Show trace” the Phase Plane displays the trace between two neighbouring symbols. The user can pause
the display by clicking in the Phase Plane.
CODAN-9001
CODAN-9001 is an asynchronous adaptive ARQ system. Data is modulated onto 16 tones, spaced at
112.5Hz intervals. The modulation rate of each tone is 75 Baud; the modulation type is differential qua-
ternary phase-shift keying (differential PSK4A).
Parameter
Value
