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
The overall range of data rates is from 32 to 20000 kbps. The overall range
of symbol rates is up to 10000 ksps. The minimum and maximum data rates
are dependent on modulation type and FEC encoder rate. If the user
changes the modulation or FEC, and the currently selected data rate can no
longer be supported, the data rate will be adjusted automatically, up or
down, keeping the symbol rate constant. The bottom line of the display
shows the symbol rate, based on FEC type, modulation, FEC Code Rate,
and Data Rate.
IMPORTANT
FEC Type Modulation Code Rate Data Rate Range EDMAC limited?
BPSK Rate 1/2 32 kbps to 5 Mbps
Rate 1/2 32 kbps to 10 Mbps
Rate 3/4 32 kbps to 15 Mbps
Yes – see note below Viterbi
QPSK
Rate 7/8 32 kbps to 17.5 Mbps
BPSK Rate 1/2 32 kbps to 4.5 Mbps
Rate 1/2 32 kbps to 9.1 Mbps
Rate 3/4 32 kbps to 13.7 Mbps
QPSK
Rate 7/8 32 kbps to 16 Mbps
V R-S Yes – see note below
Rate 3/4 349.1 kbps to 20 Mbps
16-QAM
Rate 7/8 407.3 kbps to 20 Mbps
TCM + R-S 8-PSK Rate 2/3 232.7 kbps to 18.3 Mbps Yes – see note below
Rate 5/16 32 kbps to 3.1 Mbps
BPSK
Rate 21/44 32 kbps to 4.7 Mbps
Rate 21/44 32 kbps to 9.5 Mbps
Rate 3/4 32 kbps to 15 Mbps
Yes – see note below
Rate 7/8 32 kbps to 17.5 Mbps
QPSK
Rate 17/18 32 kbps to 18.888 Mbps
TPC
Rate 3/4 288 kbps to 20 Mbps
Rate 7/8 336 kbps to 20 Mbps
8-PSK
Rate 17/18 362.7 kbps to 20 Mbps
No
Rate 3/4 384 kbps to 20 Mbps
16-QAM
Rate 7/8 448 kbps to 20 Mbps
Important Note : Where noted in the table above, if EDMAC framing is employed, the upper data rate will be
reduced by 5% for data rates up to 2.048 Mbps, and by 1.6% for data rates above 2.048 Mbps, where
EDMAC2 framing is used, or for Rate 21/44 BPSK/QPSK Turbo, or Rate 5/16 BPSK Turbo.
(Config
%
Rx
%
Freq) – RX FREQUENCY
Rx IF Freq: 1156.3456 MHz
( ◄ ► , ▲ ▼ , ENT)
The range of frequencies depends upon the plug-in module – the preceeding example
shows the L-Band version of the CDM-Qx. Edit the receive frequency by selecting the
digit to be edited, using the
!" arrow keys. The value of the digit is then changed using
the #$ arrow keys, then pressing
ENTER
.
If (using the
ODU, LNB
menus) the user has selected an LNB LO frequency (other than
zero) and defined whether the mix is high side or low side, the display will be modified
5–24