Wavecom W61PC V7.5.0 - Manual (Page 91)

WAVECOM Decoder W61PC/LAN Manual V7.5 Analysis Tools  81
PSK Phase Plane (HF, DIR, SUB, SAT)
The phase analysis tool is used for analyzing the characteristics of phase modulated signals, and to a lim-
ited extent, m-ary PAM (Phase Amplitude Modulation) signals.
If the symbol rate is known (for details see “ PSK Symbol Rate (HF, DIR, SUB, SAT) ” on page 80), start the
PSK phase plane analysis tool.
The display can be started and stopped by clicking on it. If stopped, a Paused message is displayed.
You can use an existing demodulator (BPSK, QPSK or DPSK) or IQ to decode the signal, and produce a
phase plane display of the output of the demodulator. For BPSK and QPSK, this provides a check of the
quality of the signal. When using DPSK, this provides an indication of the level of phase modulation which
is being used, i.e. 2-PSK to 16-PSK. As the symbol rate is equal to the baud rate of the signal, the baud
rate must be known to configure the demodulator.
Center
The Center allows the center frequency for the demodulator to be adjusted. A center frequency error nor-
mally results in a phase plane that is rotating with a speed proportional to the frequency error.
Hold Time
The Hold Time adjusts the number of points displayed on the screen. Increasing the hold time increases
the amount of time a dot will remain in the image before being overwritten by a new value.