Dvb-S/S2 Signals - Promax TV EXPLORER II Manual De Instrucciones

With the aim to have a reference about the signal quality, it is considered that a
system has a good quality when it decodes less than one non-correctable error for every
transmission hour. This border is known as QEF (Quasi-Error-Free) and it corresponds
approximately to a BER after Viterbi of 2.0E-4 BER (2.0x10
of each 10000). This value is marked on the measurement bar of the BER and therefore,
BER for acceptable signals must be at the left side of this mark.
Finally it is shown a status line with information about the detected signal. The
possible messages that can appear and its meaning are showing the following list. The
messages are exposed from less to more fulfilment of the MPEG-2 standard:
No signal received
No signal has been detected.
Timing recovered
Only it is possible to recuperate the symbol time.
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 QPSK signal, it will be possible to measure
BER. Following is shown the BER measurement before the error corrections: BER
before the FEC: CBER.
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USER'S MANUAL. TV EXPLORER II/II+
-4
, that is to say 2 wrong bits
12/2013