Comtech EF Data SNM-1001L - Manual (Page 324)

SNM-1001L Satellite Modem Revision 1
Burst Mode Modulator Operation MN/SNM1001L.OM
C–10
C.4.11 Channel Spacing/Adjacent Carrier Performance
The modem bit error performance will be degraded less than 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.
C.4.12 Acquisition Time
Viterbi
6 dB Eb/N0 with ± 4 kHz Frequency Uncertainty
Code Rate Data Rate Tacq P(t < Tacq)
1/2 19.2 kbps < 30 msec 93%
1/2 57.6 <11 sec 93%
C.4.13 Acquisition Probability
Viterbi
with ± 4 kHz Frequency Uncertainty
Eb/N0 Data Rate Tacq P(t < Tacq)
6 dB 19.2 kbps < 30 msec 93%
8 dB 19.2 kbps < 30 msec 99%
6 dB 57.6 kbps <11 sec 93%
8 dB 57.6 kbps < 11 sec 99%
C.4.14 Receive IF Carrier Acquisition Range
1. The modem will automatically lock to a correctly formatted carrier, which is within 4
kHz of the displayed receive frequency.
2. The operator can adjust the acquisition range from 0 to 4 kHz, in 1 Hz steps.
3. The operator can adjust the center of the acquisition range from 0 to 8 kHz, in 1 Hz
steps.