Adtec EN-91 User Manual page 18

Power Allows the operator to configure the
output power of the main RF output port.
The monitor output power level for the
EN-XX IF and L-Band is fixed at -45dBm.
Power is defined as the composite power
referenced to an un-modulated (Pure
Carrier) carrier.
Spectrum The Spectrum Inversion options are either
Inversion Normal or Invert. If Normal is selected,
then spectrum inversion does not occur.
Spectral inversion can occur when either
the baseband signal is up-converted to an
IF frequency or when the IF is
upconverted to the desired RF output
frequency.
FEC Frame When operating in DVB-S2, the Frame
Type options are either Normal or Short.
The Normal 64,800-bit FEC frame
provides better protection but introduces
more latency compared to the Short
16,200-bit FEC frame. Therefore, the
Short FEC frame type should be selected
in applications where latency is critical and
the longer frame type should be used to
optimize protection.
Rolloff The Rolloff selection will determine the
shape of the output filter. The occupied
bandwidth of the modulated signal is the
symbol rate multiplied by (1+α) where
alpha (α) is the rolloff factor. By using a
lower alpha, carriers can be spaced closer
together on a given transponder or an
increased symbol rate can be realized for
a given bandwidth.
Pilot When operating in DVB-S2, the Pilot
options are either ON or OFF. When pilots
are enabled, the total data throughput is
reduced by approximately 3.0%.
Rate The Rate Priority control allows the
Priority operator to designate which rate will be
kept constant. When the Symbol Rate is
entered and Rate Priority is Symbol, the
symbol rate is held constant and the
Interface rate is calculated. When the
output frequency.
7039: -50 to -7dBm LBAND
7139: -35 to +5dBm LBAND
-30 to +5dBm IF
Invert
Normal
Short
Normal
5 (requires feature key)
10 (requires feature key)
15 (requires feature key)
20
25
30
On
Off
Symbol
Interface