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SDM-300A Satellite Modem
C.5
Acquisition Time
Refer to Table C-16 for acquisition time.
Code Rate
Code Rate
C.5.1
Receive IF Carrier Acquisition Range
The modem automatically locks to a correcly formated carrier, which is within ± 35 kHz
of the displayed RX frequency. The operator can adjust the following:
Acquisition Range
Center of the Acquisition Range
C.5.2
Receive IF Carrier Reacquisition
The modem is programmed to delay the acquisition process upon loss of lock. This will
miniminize the acquisition time for a brief loss of the carrier. This delay can be
programmed from 0 to 999 seconds in 1 second steps.
Rev. 4
Table C-16. Acquisition Time
6 dB E b /N 0 with ± ± ± ± 35 kHz Frequency Uncertainty
Data Rate
1/2
< 9.6 kbit/s
≥ 9.6 < 64 kbit/s
1/2
≥ 64 < 196 kbit/s
1/2
≥ 196 < 512 kbit/s
1/2
≥ 512 < 1000 kbit/s
1/2
≥ 1 < 2.5 Mbit/s
1/2
6 dB E b /N 0 with ± ± ± ± 35 kHz Frequency Uncertainty
Data Rate
1/2
2.4 < 4.8 kbit/s
≥ 4.8 < 9.6 kbit/s
1/2
≥ 9.6 < 64 kbit/s
1/2
≥ 64 < 196 kbit/s
1/2
≥ 196 < 512 kbit/s
1/2
≥ 512 < 1000 kbit/s
1/2
≥ 1 < 2.5 Mbit/s
1/2
Viterbi
T acq
< 10 sec
< 5 sec
< 1 sec
< 10 sec
< 2.5 sec
< 1 sec
Sequential
T acq
< 20 sec
< 10 sec
< 5 sec
< 1 sec
< 17 sec
2.5 sec
< 1 sec
0 to 70 kHz (in 1 Hz steps)
-35 to +35 kHz (in 1 Hz steps)
Specifications
P (t < T acq)
95%
95%
95%
95%
95%
95%
P (t < T acq)
95%
95%
95%
95%
95%
95%
95%
C–37
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