Promax HD RANGER 2 User Manual page 155

DVB-T2 Measurements
Power
Measured power over the entire bandwidth of the channel.
C/N
(Carrier/Noise) where C is the received power of the modulated carrier
signal and N is the noise power received. To measure it correctly the
channel should be tuned at its centre frequency.
PLP id
It is the PLP identifier. In the case of PLP Single mode identifies the input
stream (0-255).In the case of PLP Multiple mode clients can choose the
PLP ID to view.
MER
Modulation Error ratio with indication of Link Margin (LM).The link margin
indicates the safety margin respect to the MER level, measured for the
degradation of the signal up to the QEF (Quasi Error Free) value. MER
represents the ratio between the average power of the DVB signal and the
average noise power of the signal constellation.
BER (CBER/LBER)
It is the bit error rate. There are two measurements related to BER:
CBER (Channel Bit Error Rate):
BER of the signal after the COFDM demodulator and before applying
the error correction or FEC (Forward Error Correction).
LBER (LDPC Bit Error Rate):
BER after been applied the LDPC (Low-density parity-check) error
correction.
In a digital signal reception (DVB-T2), after the COFDM decoder two
methods of error correction are applied. DVB-T2 uses two codes to correct
errors that are the LDPC (Low Density Parity Check) combined with the
BCH (Bose-Chaudhuri - Hocquengham) to protect against high levels of
signal noise and interferences. Next to the measurement LBER is shown
the number of iterations LDPC, that is, the number of times the LDPC
error correction decoder has to pass through the signal and the ESR
(Error Second Ratio) after 20 seconds of the BCH decoder. This measure
indicates the percentage of time with errors after the BCH. Error
correction is internal with BCH and external with LDPC. The internal gives
basic error correction with minimum load while the external gives error
correction with a correction additional charge.
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June 2014