CDM-Qx Satellite Modem

Revision 5

Front Panel Operation

MN/CDMQx.IOM

The FEC type takes the highest configuration priority, and the selection here depends on what, if any, optional plug-in Codecs are installed. The choice of

FEC type then determines what demodulation types, code rates, and data rates IMPORTANT are available. The order of hierarchy is therefore:

FEC type

Demodulation type Code Rate Data Rate

(Highest)

(Lowest)

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 demodulation 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„Rx„FEC) – RX FEC TYPE

Rx 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 valid, the

IMPORTANT ◄ ► arrow keys

will force the cursor to skip past the unavailable

choice.

 

 

 

 

 

 

CASE

 

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

 

 

Rate 2/3

Reed-Solomon)

 

 

 

TPC (Turbo)

 

If the TPC codec is installed

 

If Vit, Vit+RS, TCM+RS, or TPC is selected, the following sub-menu will be displayed:

Rx Rs (n/k):

(◄ ►, ENT)

IESS-310 network

(219/201)

5–25

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Mocomtech CDM-QX operation manual Config„Rx„FEC RX FEC Type, Rx FEC Vit Vit+RS, Tcm+Rs, Case Rules Comment