Digital Tv: Measuring Mer - Promax TV EXPLORER HD+ Manual De Instrucciones

The LBER measurement is provided in scientific notation (i.e. 2.7 E-7 means
-7
2.7x10 , that is to say two incorrect bits of every 1,000) and through an analogue bar (as
its length is smaller the signal quality will be better). The analogue representation is done
on a logarithmic scale (not linear).
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
the measurement bar of the BER after Viterbi and therefore, BER for acceptable signals
must be at the left side of this mark.
Next it is shown the tuning frequency and the frequency deviation in MHz between
the tuned frequency and the one, which optimises the BER.
Finally it is shown a status line with information about the detected signal. The
possible messages that can appear and its meaning are shown in the following list. The
messages are exposed from less to more fulfilment of the MPEG-2 standard:
No signal received
Any signal has been detected.
Signal received
A signal is detected but it can not be decoded.
Carrier recovered
A digital carrier has been detected but it can not be decoded.
Viterbi synchronized
A digital carrier has been detected and the Viterbi algorithm is synchronized, but
too many frames arrive with non correctable errors. It is not possible to quantify the
BER.
MPEG-2 TS DVB-S
Correct detection of a MPEG-2 signal.

5.14.8 Digital TV: Measuring MER

Once determined the suitable parameters for COFDM, QAM, QPSK or 8PSK
signal reception, it will be possible to measure MER, press
the MER measurement screen.
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USER'S MANUAL. TV EXPLORER HD+
-4
). This value is marked on
[12] key until it appears
11/2013