Dvb-S/S2 Signals - Promax TV EXPLORER HD User Manual

TV EXPLORER HD / HD
USER'S MANUAL.
AFC in lock
The system automatic frequency control can identify and lock a digital
transmission (TDT) but its parameters can not be obtained. It can be due to a
transitory situation previous to the TPS identification (Transmission Parameter
Signalling) or well to a TDT transmission with an insufficient C/N ratio.
TPS in lock
The TPS (Transmission Parameter Signalling) are decoded. The TPS are carriers
(17 in the 2k system and 68 in the 8k system) modulated in DBPSK, containing
information related to the transmission, modulation and codification: Modulation
type (QPSK, 16-QAM, 64-QAM), Hierarchy, Guard Interval, Viterbi Code Rate,
Transmission mode (2k or 8k) and Number of the received frame.
MPEG-2 TS DVB-T
Correct detection of a DVB-T signal, the demodulator provides a TS MPEG-2.
MPEG-2 TS DVB-H
Correct detection of a DVB-H signal, the demodulator provides a TS MPEG-2.

5.14.7.3 DVB-S/S2 signals

Once determined the parameters of
BER
. Following is shown the BER measurement before the error corrections:
before the FEC CBER
:
Figure 34.- DVB-S
In a digital reception system for satellite signals (
two different correction methods are applied (see following Figure). Obviously, each time
we apply an error corrector to a digital signal, the error rate changes, therefore if we
measure in a digital satellite television system, for example, the error rate at the output of
QPSK
the demodulator, at the output of the Viterbi decoder, and at the output of the
Reed-Solomon decoder, we obtain nothing more than different error rates. This is the
BER
reason because the
10/2012
LE
QPSK
.
QPSK
( ) signals
measurement is provided before
signal, it will be possible to measure
CBER
measurement screen.
DVB-S
), after the
FEC Viterbi
, after
BER
QPSK
decoder
VBER
( ).
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