D-Cam Clip-On Operators Manual
Issue 1
Page 23 of 23
UNUM-CCAM -0104
5.3 COFDM Modulator
“Coded Orthogonal Frequency Division Multiplexing – a modulation scheme which is used
by the DVB digital television system.”
The COFDM modulator has been designed to take its input from the MPEG2 encoder.
This Transport stream is then modulated directly to the 2.5GHz band. This method
reduces the occurrence of intermodulated harmonic frequencies and requires less
upconvertors to reduce microphony.
The COFDM modulator RF output is via the SMB connector. This output is then fed into
the power amplifier, via the short RF cable. The nominal RF output level is –9dBm of the
Modulator.
The modulator is automatically configured to match the data rate of the MPEG2 Encoder
as defined by the selected parameter set. 3.2.4
The modulator can support the following modulation schemes / data rates:
Mode
Code
Rate
Guard
Interval
TS Data Mux Rate
64 QAM
1/2
1/32
18.096257
64 QAM
1/2
1/32
18.096257
16 QAM
1/2
1/32
12.064171
16 QAM
1/2
1/32
12.064171
QPSK
3/4
1/32
9.048128
QPSK
3/4
1/32
9.048128
QPSK
1/2
1/32
6.032086
QPSK
1/2
1/32
6.032086
There are no field replaceable parts on the COFDM modulator. If a fault occurs with the
board please contact Gigawave for technical assistance.
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