Comtech EF Data SDM-300A - Manual (Page 373)

SDM-300A Satellite Modem Revision 6
Specifications MN/SDM300A.IOM
19–17
19.5.12 Demodulator IF Input Shape
The modem can be set to match any of the following spectral mask specifications.
• INTELSAT/EUTELSAT
• Closed net (Comtech EF Data and Comstream)
• Closed net (Fairchild compatible)
• Closed net (SDM-51/SDM-52)
19.5.13 Channel Spacing/Adjacent Carrier Performance
The modem bit error performance will be degraded ≤ 0.5 dB with the following receive IF
signal:
• Two like-modulated carriers spaced 1.3 times the symbol rate from the receive
frequency, and/or 1.2 times the acquisition range, whichever is larger.
• Each adjacent carrier up to 10 dBc higher in power than the desired carrier.
• A single adjacent carrier spaced 1.4 times the symbol rate, up to +20 dBc.
19.6 BER Performance Specifications
Table 19-9lists referenced tables that reflect the Bit Energy-to-Noise Ratio (E
b
/N
0
) required
to achieve 10 -3 to 10 -10 BER.
Table 19-9. BER Performance Reference Tables
Table Option
Table 19-10 Viterbi Decoder with Open Network BER Data
Table 19-11 Viterbi Decoder with Closed Network BER Data
Table 19-12 Viterbi Decoder with Reed-Solomon (Optional)
Table 19-13 Sequential Decoder (56 kbps) (Optional)
Table 19-14 Sequential Decoder (1544 kbps) (Optional)
Table 19-15 Sequential Decoder with Reed-Solomon (1544 kbps) (Optional)
Table 19-16 8-PSK With/Without Reed-Solomon
Table 19-17 Viterbi Decoder and OQPSK
Table 19-18 Uncoded (1/1) BPSK, QPSK, and OQPSK