Mocomtech CDM-570L Manuel D’Utilisation

CDM-570/570L Satellite Modem with Optional IP Module 

Revision 4 

Summary of Specifications 

 

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

 

Desired Carrier, CDM-570L: -130 + 10 log(Symbol Rate) to -90 + 10 log(Symbol Rate) 
Desired Carrier, CDM-570: -30 to -60 dBm 
 +35 dBc maximum composite, up to -5 dBm, absolute max. 

Viterbi: 3 bit soft decision 
Trellis: Pragmatic TCM/8-PSK with closed network concatenated Reed-Solomon 
Reed-Solomon (Closed Network): Proprietary 
Turbo Product Codec: 4 bit soft decision, proprietary  

±1 to ±32 kHz, programmable in 1 kHz increments, for symbol rates below 625 ksymbols/sec 
±1 to ±200 kHz, 1 kHz increments, for symbol rates above 625 ksymbols/sec, CDM-570L only 

Highly dependent on data rate, FEC rate, and demodulator acquisition range. Examples:  120 ms 
average at 64 kbps, R1/2 QPSK, ±10 kHz acquisition sweep range, 6dB Eb/No 
3.5 s average at 9.6 kbps, R1/2 QPSK, ±10 kHz, 6dB Eb/No 
Note: Reed-Solomon and TPC increases acquisition time, due to the additional time taken for the 
RS/TPC decoder to declare synchronization. 

± 100 ppm min 

-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

Intelsat

IESS 308/309 

limit

Intelsat 

IESS 308/309 

limit

CDM-570L Modulator

typically < -50 dB, and 

guaranteed to be 

< -45 dB at offsets

 > 0.75 Rs

Symbol Rate, Rs

Spectral 

density, 

dB

12–3