CDM-600 Satellite Modem Revision 7

Remote Control MN/CDM600.IOM

15–3

-55
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50
CDM-600 Modulator
typically < -50 dB, and
guaranteed to be
< -45 dB at offsets
> 0.75 Rs

Comtech EF Data

CDM-600 Transmit

Power Spectral Density,

referred to symbol rate

Symbol Rate, Rs
Spectral
density,
dB
Intelsat
IESS 308/309
Limit
Intelsat
IESS 308/309
Limit
15.2 Demodulator

Data rate range, operating modes, de-scrambling, input impedance/return loss etc, as per

Modulator

Input power range -30 to -60 dBm (desired carrier)
+35 dBC maximum composite, up to -5 dBm
FEC Viterbi: 3 bit soft decision
Sequential: 2 bit soft decision
Trellis: Per IESS-310
Reed-Solomon(Open Network): Per IESS-308/309/310
Reed-Solomon(Closed Network): Proprietary
Turbo Product Codec: 6 bit soft decision, proprietary
LDPC: 5 bit soft decision, proprietary
Acquisition range ±1 to ±32 kHz, programmable in 1kHz increments
Acquisition time Highly dependent on data rate, FEC rate, and demodulator acquisition range. Examples: 200 ms
average at 64 kbps, R1/2 QPSK, ±32 kHz acquisition sweep range, 6dB Eb/No
5 s average at 9.6 kbps, R1/2 QPSK, ±10 kHz, 6dB Eb/No
Note that Reed-Solomon increases acquisition time, due to the additional time taken for the RS
decoder to declare synchronization.
Clock tracking range ± 100 ppm min