Measuring Ber Of Qpsk Digital Channels (Qpsk) - Promax PROLINK-3 Premium Manual De Instrucciones

USER'S MANUAL. PROLINK-3/3C
The PROLINK-3/3C Premium, also offers the possiblity of measuring the
modulation error ratio (MER) for COFDM signals. Once the COFDM signal parameters
have been defined, you can access to the digital mode function menu by pressing the
rotary selector [4], then turn it to select COFDM setup function and finally press it again.
The monitor will show a screen displaying two possibilities: CSI and MER, then turn the
rotary selector [4] to select the desired option and finally press it to confirm.
Figure 16.- MER measuring screen for COFDM-modulated signals.
DVB-T channels tuning may require an adjusting process. It is recommended to
follow next procedure:
1.- From the spectrum analyser mode, tune the channel at its central
frequency.
2.- Switch to TV mode, BER measuring mode.
3.- If in the lower line of the screen does not appear MPEG-2 message (and
consequently BER is unacceptable), by turning the rotary selector deviate
the tuning frequency until MPEG-2 message appears. Finally tune channel
again to minimize the frequency deviation which optimizes the BER and
therefore minimize the BER.
If it is not possible to detect any MPEG-2 channel, make sure that digital signal
parameters are correctly defined and if signal level is too low, check that the 30 dB
attenuator is not activated (Attenuator 0 dB).

4.9.1.5.3 Measuring BER of QPSK Digital Channels (QPSK)

Press the rotary selector to access the QPSK signals parameters that must be
defined by user and that are described below:
Only for models with this option available
06/2005
Premium
IMPORTANT REMARK
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