Link HD System Manual
Document # -HD System Man Iss 1.1 Issue 1.1 06/11/2007
Page 10 of 31
2.1.3.1 DVB-T Operation
The following sequence defines the changes and sequence required when changing to DVB-T operation :-
Step Menu Sub Menu Option Setting
1 Advanced Unit Unit Mode DVB-T
2 Advanced DVBT/LMST Guard Interval As Required
3 Advanced DVBT/LMST Modulation As Required
4 Advanced DVBT/LMST FEC Rate As Required
5 Advanced DVBT/LMST Polarity Normal
6 Advanced DVBT/LMST Width Fixed at 8MHz
7 Advanced DVBT/LMST Power As Required
8 Advanced DVBT/LMST Frequency As Required
9 Advanced DVBT/LMST Output On
The MPEG2 encoder will set the data rate appropriately to match the modulation scheme settings.
The Table below defines the corresponding bit rates for DVB-T operation.
Modulation GI
CR
1/4 1/8 1/16 1/32
QPSK 1/2 4.97 5.52 5.85 6.03
QPSK 2/3 6.63 7.37 7.80 8.04
QPSK 3/4 7.46 8.29 8.78 9.04
QPSK 5/6 8.29 9.21 9.75 10.05
QPSK 7/8 8.70 9.67 10.24 10.55
16QAM 1/2 9.95 11.05 11.70 12.06
16QAM 2/3 13.27 14.74 15.61 16.08
16QAM 3/4 14.92 16.58 17.56 18.09
16QAM 5/6 16.58 18.43 19.51 20.10
16QAM 7/8 17.41 19.35 20.49 21.11
64QAM 1/2 14.92 16.58 17.56 18.09
64QAM 2/3 19.90 22.11 23.41 24.12
64QAM 3/4 22.39 24.88 26.34 27.14
64QAM 5/6 24.88 27.64 29.27 30.16
64QAM 7/8 26.12 29.02 30.73 31.66
These rates can be confirmed by checking the Advanced/Multiplexer/ Bit Rate menu.
It should be noted that this corresponds to the total data rate from the multiplexer which includes the video, audio and any
user data.
2.1.3.2 LMS-T Operation
The following sequence defines the changes and sequence required when changing to LMS-T operation :-
Step Menu Sub Menu Option Setting
1 Advanced Unit Unit Mode LMS-T
2 Advanced DVBT/LMST Guard
Interval
As Required. 1/8 or 1/16
3 Advanced DVBT/LMST Modulation As Required 16Q or
QPSK
4 Advanced DVBT/LMST FEC Rate 2/3 Only
5 Advanced DVBT/LMST Polarity Normal
6 Advanced DVBT/LMST Width 10MHz or 20MHz
7 Advanced DVBT/LMST Power As Required
8 Advanced DVBT/LMST Frequency As Required
9 Advanced DVBT/LMST Output On
10 Advanced Encoder Bit Rate Auto
The encoder will set the data rate appropriately to match the modulation scheme settings.
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