- 21 -
CCS-2 2001
Cofdm
set tings
In this menu, you can set the bandwidth, the carrier modulation and the spectral
position of the output signal.
Bx 4
8MHz QAM64
COFDM-MODE
POS
b
andwidth
of
the
outPut
signal
Bandwidth of the output signal
To transmit the output signal in the channel range of C21 to C69 a bandwidth
of 8 MHz can be used.
In the channel range of C5 to C12 a bandwidth of
≤
7 MHz must be set.
If frequency setting is selected you can set the bandwidth dependent on the
frequency of the adjacent channel.
Bx 4
8MHz QAM64
COFDM-MODE
POS
•
Use
to set the bandwidth of the output signal ("
5 MHz
"
… "
8 MHz
").
C
arrier
modul ation
Carrier modulation
In this menu item the carrier modulation is set. At this the setting "
QPSK
" corre-
sponds to the lowest and the setting "
QAM64
" to the highest output data rate.
•
Use the
buttons to place the cursor under "
QPSK / QAM…
".
• Set the carrier modulation of the output signal using the
buttons
("
QPSK
",
"
QAM16
",
"
QAM64
").
i
nverting
the
user
signal
Inverting the user signal
For exceptional cases and "older" digital cable receivers, the spectral position
of the user signal can be inverted "
NEG
". The default setting is "
POS
".
• Use
to place the cursor under "
POS
".
• Use
to set the spectral position to "
NEG
".
• Press the
button.
—> The "Transmission parameters" – "
COFDM-MODE
" menu is activated.
