Promax TV EXPLORER HD Manual De Usuario página 153

USER'S MANUAL. TV EXPLORER HD
Figure 29.- DVB-S (QPSK) signals CBER measurement screen.
In a digital reception system for satellite signals (DVB-S), after the QPSK decoder
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
the QPSK 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
reason because the BER measurement is provided before FEC, after Viterbi (VBER).
Figure 30.- Digital reception system via satellite. (DVB-S)
Figure 31.- DVB-S (QPSK) signals VBER measurement screen.
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