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3 (config:) rx, Rx: æ dem (demod) – Comtech EF Data CDM-700 User Manual

Page 71

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CDM-700 High Speed Satellite Modem

Revision 5

Front Panel Operation

MN/CDM700.IOM

6–17

6.3.1.3 (CONFIG:)

Rx

Rx: Dem Code Freq Data
Sym Descrm EbNo Mask (
E)

The modem symbol rate is a function of the modulation type, code rate, and data rate. If a change
to one of these parameters produces a value outside the allowable symbol rate range, the invalid
symbol rate is not programmed into the modem.


For example: If the data rate is increased at one of the interfaces and the symbol rate exceeds the
limit changing the modulation type or code rate may bring the symbol rate within range.

IMPORTANT

All possible choices are presented at all times, If an option is not installed
(either Hardware or FAST) or valid, the ◄►arrow keys will force the cursor to
skip past the unavailable choice.

Rx:

Æ Dem (Demod)

Rx Dem: Type Inv Acq α
Adap-Eq (
E)


Select Type, Inv, Acq,

α, or Adap-Eq using the ◄ ► arrow keys. Press

ENTER

.

If Rx Dem: Æ Type is selected:

Rx Type: Q 8P 16Q 64Q
(
E)

Select the Receive Demodulation Type by using the ◄ ► arrow keys. Press

ENTER

. The choices

are as follows:

Demodulation Type
(Symbol Rate) Selection

Description

Q (QPSK)

Valid for all FEC types

8P (8-PSK)

Valid for all FEC types

16Q (16-QAM)

Valid for all FEC types

64Q (64-QAM)

Valid for all FEC types