Promax HD Ranger + Manual de usuario descargar pdf (Pagina 114)

10 March 2015

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DVB-C Measurements

Power

Measured power over the entire bandwidth of the channel.

C/N

Carrier/Noise ratio 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.

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)

It is the system error rate. In a digital signal reception via cable, after the

QAM demodulator an error correction method is applied, called Reed-

Solomon. The error rate after correction is less than the error rate at the

output of the QAM demodulator. For this reason the BER is given prior to

error correction.

CBER

BER measurement for digital signal before the error correction (BER

before FEC)

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Promax HD Ranger + Manual de usuario Pagina 114