Dvb-T2 - Alcad 918 Serie Manuel D'utilisation

•
PER: error rate after Reed Solomon (error rate packet)
•
MER: modulation error rate
•
LKM: noise margin (Link Margin)
BERx: 'bits' error rate
Ratio between the number of false bits / number of transmitted bits during the measurement time
PER: 'paquets' error rate
Ratio between the number of false packets / number of transmitted packets during the measurement
time
Recall: Under DVB-T/H, a packet is made of 204 octets; a packet is "false" if it includes more than 8
wrong octets (correction by Reed Solomon coding).
Display of the type of Modulation detected:
•
number of carriers (8 K)
•
constellation (64QAM)
•
guard interval (1/32 auto)
•
Viterbi rate (2/3)
•
spectrum inversion
In case of poor signal quality or co-frequent analogical signal, it is wise to switch to the manual guard
interval mode. To do so, you have to select the « Modulation » line and set the guard interval parameter to
the right value.
Display of the value of Cell ID from the diffuser and specific to the emitter.

11.9 DVB-T2

Display of the measures of:
•
BERi: error rate before LDPC
•
BERo: error rate after LDPC
•
error rate after BCH (lost packets)
PER:
•
MER: modulation error rate
•
LKM: noise margin (Link Margin)
Recall:
LDPC: Low Density Parity Check
BCH: Bose Chauhuri Houquenohem
54
DEMODULATOR
TUNER
BERi
DECODING
LDPC BCH
MPEG
BERo
PER