Comtech EF Data SLM-5650A - Manual (Page 304)

SLM5650A_CDM625 Satellite Modem Revision 8
DoubleTalk Carrier-in-Carrier Option MN-SLM5650A
15–6
Figure 15-3. Same Link Using SLM-5650A and DoubleTalk Carrier-in-Carrier
Figure 15-4. Duplex Link Optimization
The SLM-5650A CnC module operates on the near-zero signal before the demodulator, and is
waveform-agnostic. This means that no prior knowledge of the underlying modulation, FEC, or
any other waveform specific parameter is required in order to perform the signal suppression
operation. The only caveat to this is that the waveform must be sufficiently random.
Because acquiring the delay and frequency offset of the interfering carrier is fundamentally a
correlation operation, anything deterministic in the interfering carrier (within the correlation
window of the algorithm) will potentially produce false correlation peaks and result in incorrect
delays and/or frequency. Normally, this is not a problem, since energy dispersal techniques are
used in the vast majority of commercial and military modems. However, it is something that must