Config) Acm Config: Degradation; Config: Cnc; Config) Carrier-In-Carrier: Mode - Comtech EF Data CDM-750 Installation And Operation Manual

CDM-750 Advanced High-Speed Trunking Modem
Front Panel Operation

5.2.2.1.5.4 (CONFIG) ACM Config: Degradation

Degradation: QPSK=0.0
An additional level of signal margin can be added to the QEF switch points in ACM operation by
adding a degradation figure per modulation type. This degradation figure further increases the
Es/No required to switch to a ModCod having a degradation figure above 0.0.
First, use the ◄ ► arrow keys to select the parameter to update, and then use the ▲ ▼ arrow
keys to edit the value for that setting (factory default for all settings is 0.0). Press ENTER when
done.
Degradation figures can be used to further ensure that switching to higher order Modulation will
not cause errors, as may be the case in systems with higher levels of phase noise or non-linearities
that can impact higher-order modulation schemes (e.g., 16APSK and 32APSK operation) more
dramatically than QPSK or 8PSK operation.
5.2.2.1.6

CONFIG: CnC

For a detailed discussion of CnC operation, see Chapter 8. DOUBLETALK CARRIER-
IN-CARRIER OPTION.
IMPORTANT
Carrier-in-Carrier: Mode
Use the ◄ ► arrow keys to select Mode or Search-Delay, and then press ENTER. See Chapter 8.
DoubleTalk Carrier-in-Carrier OPTION for more information about this feature.

5.2.2.1.6.1 (CONFIG) Carrier-in-Carrier: Mode

CnC Mode:
Note: CnC operation requires installation of the DoubleTalk Carrier-in-Carrier module. In
addition to installing the CnC module, the user needs to purchase one of several available FAST
options to provide capability to a maximum of 155 Mbps. See Chapter 1. INTRODUCTION
for more information about purchasing FAST options.
Use the arrow keys to select Off or On, and then press ENTER. With no module installed,
▲ ▼
CnC Mode is forced '
16QAM=1.0 32APSK=2.0
Search-Delay
Off (Off,On)
Off ' and this submenu is inoperable.
5–22
8PSK=0.0
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