Comtech EF Data CDM-Qx, Installation And Operation Manual

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CDM-Qx Satellite Modem Revision 6
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 V 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)
Selecting
Vit+RS
or
TCM+RS
displays the following submenu:
Tx Rs (n/k): ( ◄ ► , ENT)
IESS-310 network (219/201)
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 (VConcatenated
Reed-Solomon) Always valid
TCM+R-S (Trellis Coded
Modu Concatenated Reed-
Solomon) If 8-PSK FAST is enabled Fixed at 8-PSK and
Rate 2/3
TPC (Turbo) If the TPC codec is installed
(Config
%
Tx
%
Mod) – MODULATION SCHEME
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.
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 V R-S, TPC (Turbo) requires 16-QAM FAST option
Modulation: BPSK QPSK 8-PSK
16-QAM ( ◄ ► , ENT)
IMPORTANT
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