Harmonic ProView 2900 - Page 98

Chapter 6: Receiver Configuration Modules Satellite Receiver Configuration
© Harmonic Inc. Manual p/n 101543/Ver 1.0 6-13 ProView 2900 Series/SW Version 1.94
6.2.2.4. Roll-Off
The Roll-Off menu is used for setting the receiver’s roll-off factor value according to the roll-
off factor of the transmitted signal.
The Roll-off factor is the factor that is used for the base-band shaping of the transmitted
signal. Set the Roll-Off factor in accordance with the transmitted Roll-Off factor. The following
figure illustrates the Roll-Off screen.
Roll
Roll Roll
Roll-
--
-off
off off
off
1
11
1

 35%
35% 35%
35%
2
22
2

 25%
25% 25%
25%
3
33
3

 20%
20% 20%
20%
Available options for the Roll-off factor are: 35%. 25%, 20%
6.2.2.5. Pilots
In order to expedite carrier recovery, the standard allows two operating modes for each
modulation type: Pilot-less (i.e. no Pilot symbols are inserted) and Piloted, where Pilot
symbols are inserted to aid carrier synchronization. The Pilots menu enables to choose
between the two operating modes. The following figure illustrates the Pilots screen.
Pilots
Pilots Pilots
Pilots
1
11
1

 OFF
OFF OFF
OFF
2
22
2

 ON
ON ON
ON
The available options are:
• OFF – selects Pilot-less mode
• ON - selects Piloted mode
NOTE
The PLSCODE informs the receiver regarding the pilot configuration, which resides in the
PLHEADER. Usually, only a few modes, such as 8PSK rate 2/3, 16APSK rate 2/3 and 3/4,
and 32APSK rate 3/4, need pilot assistance for carrier recovery.