Wavecom W74PC V8.7.0 - Manual (Page 105)

WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0 Analysis Tools
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 Try and view the phase plane of the signal using the DPSK demodulator. If the signal is a PSK sig-
nal, the phase plane should be visible.
 If the DPSK demodulator failed to produce a meaningful display, try the IQ demodulator. This re-
quires accurate adjustment of the reference signal to produce a meaningful display.
Dedicated Phase Plane for MIL/STANAG Modes
Most MIL and STANAG modes employ high-speed (e.g., 2400 Bd) PSK or QAM modulations. Phase Plane
with traditional demodulators will deliver only unsatisfying visualization result. There is a dedicated “Phase
Plane” in most MIL/STANAG modes to show the phase constellation before (in yellow) and after (in blue)
the equalizer. The phase display in yellow would correspond to the display in the traditional phase plane.
User can display this dedicated phase plane in Options -> Show Phase Plane.
PSK Code Check (HF, DIR and SUB)
PSK code check is started by selecting the PSK Code Check button or from HF-Modes | Analysis | PSK
Code Check.
The PSK code check is initialized with default values. In many cases the user needs to set up the following
values:
 center frequency
 baudrate
 number of channels
 bandwidth (use the pb tuning to enter the correct bandwidth
The center frequency can be set by using the cursors in the FFT Window as shown below, or by selecting
Center in the Demodulator menu. The baud rate can also be configured.
The number of channels is set to one for all single channel modes and to two for two channel modes like
PACTOR II/II-FEC. Modes with more than one channel need the shift settings in addition to the center fre-
quency.
Note: The accuracy of the center frequency and shift settings is very important and directly influences the
performance of the decoding.