CDM-Qx Satellite Modem

Revision 5

Front Panel Operation

MN/CDMQx.IOM

If the user changes a parameter within this hierarchy, the other parameters may become invalid. In this case, the software will change those other parameters, in order that the configuration remains valid at all times.

Example: Suppose the user has selected Viterbi + Reed Solomon, QPSK, Rate 1/2. Now, the user changes the modulation type from QPSK to 16-QAM. In this case, Rate 1/2 is no longer a valid code rate, and so it will be automatically changed to the nearest valid code rate (Rate 3/4). Each of the configuration sub- branches will now be described in detail.

(Config„Tx„FEC) – TX FEC TYPE

Tx FEC: Vit Vit+RS TCM+RS

TPC

(◄ ►, ENT)

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

IMPORTANT

FEC Type

RULES

COMMENT

Vit (Viterbi)

Always valid

 

Vit+R-S (Viterbi +Concatenated

Always valid

 

Reed-Solomon)

 

 

TCM+R-S (Trellis Coded

If 8-PSK FAST is enabled

Fixed at 8-PSK and

Modulation + Concatenated Reed-

 

Rate 2/3

Solomon)

 

 

TPC (Turbo)

If the TPC codec is installed

 

(Config„Tx„Mod) – MODULATION SCHEME

Modulation: BPSK QPSK

8-PSK

16-QAM

(

►, ENT)

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

IMPORTANT cursor to skip past the unavailable choice.

CASE

RULES

BPSK

Valid for all FEC types except TCM+R-S

 

 

QPSK

Valid for all FEC types except TCM+R-S

 

 

8-PSK

Valid for TCM+R-S, TPC (Turbo) requires 8-PSK FAST option

 

 

16-QAM

Valid for Viterbi + R-S, TPC (Turbo) requires 16-QAM FAST option

 

 

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Mocomtech CDM-QX operation manual Config„Tx„FEC TX FEC Type, Config„Tx„Mod Modulation Scheme, Tx FEC Vit Vit+RS TCM+RS, Tpc