Modem
Reference Manual for EL470 IP Satellite Modem
Command
MoSpectInv
Tx spectrum inversion Tx spectrum inversio
Location
/Modem/Control/Modulation/PHY
Description
Configuration command to enable or disable spectrum inversion. The
spectrum at IFL and at RF is coupled by the installed up-converter module
and can be deduced from the frequency conversion formula. If the L-band
frequency is subtracted from the local oscillator frequency, the spectrum is
inverted in the converter module. If in this case the direct spectrum is
required, the spectrum must also be inverted at IFL.
Remark: The direct spectrum is conform with NTELSAT specification
IESS-308 (Rev.8 - pages 18 & 69) and with the DVB standard ETS 300
421 (December 1994).
RMCP
Command
TMi
array : [1 .. 2]
Access
Normal user : no access
Expert user : RW
SNMP
Table
ntcDevsMod01ModulatorEntry
Command
ntcDevsMod01MoSpectInv
OID
1.3.6.1.4.1.5835.3.1.3.1.40.1.1.[1 .. 2]
Values
Factory Default
directSpectrum
Enumeration
Value
Direct
Inverted
1
2
Command
MoLinPredMode
Linear predistortion
Linear predistortion
Location
/Modem/Control/Modulation/PHY
This predistortion feature is optional and password upgradeable.
Description
Configuration command that
enables
or
disables
the linear pre-distortion
filter. The purpose of linear pre-distortion is to compensate for transponder
amplitude and group-delay distortions. This becomes especially important
when operating at high baudrates and higher order modulation formats.
The pre-distortion filter coefficients must be calculated off-line and require
transponder amplitude and group-delay characteristics as input. The
resulting coefficient data can be uploaded via the
MoWafFirCoef
command.
RMCP
Command
LPm
Access
Normal user : no access
Expert user : RW
SNMP
Table
ntcDevsMod01ModulatorEntry
Command
ntcDevsMod01MoLinPredMode
OID
1.3.6.1.4.1.5835.3.1.3.1.98.1.1
Values
Factory Default
disable
Enumeration
Value
Disabled
Enabled
0
1
version 3.1
89
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