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SLM-7650 Satellite Modem
Theory of Operation
4.3.7
Symbol Rate Calculations
SR = (DR + OH) * 1/FEC * MF * RSF
SR
DR
OH
FEC
MF
RSF
Overhead for IDR
Overhead for IBS/ASYNC
FEC
MF
Reed-Solomon Factor: RSF = 1.0 if Reed-Solomon is disabled, else refer to Table 4-6:
For the N/K values listed the Overhead varies from 8.96% to 12.5%
Mode
IESS-310 Compliant
(8PSK 2/3 only)
Non-IESS-310 Compliant 8PSK
2/3 and all other modulation types
and code rates.
Symbol Rate
Data Rate
Overhead Rate
Forward Error Correction
Modulation Format
Reed-Solomon Factor
96 kbps (Data rates are 1544, 2048, 6312, and 8448 Mbit/s)
DR * 1/15 (IBS Data rates are n x 64 kbit/s to 2.048 Mbit/s)
1/2
3/4
BPSK = 1, QPSK = 1/2, OQPSK = 1/2, 8PSK = 1/3, 16QAM = 1/4
Table 4-6. Reed-Solomon Factor
Overhead Type
None/ASYNC
IBS (TCM/IDR Small Carrier)
IDR (TCM/IDR at T1, E1,T2, E2)
None
VSAT-IBS
IBS-309
IBS (IDR Small Carrier)
IDR, T1
IDR, E1
IDR, T2
IDR, E2
4–12
7/8
2/3
5/6
21/44
RSF
1.0896
219
1.0896
219
1.0896
219
1.0976
225
1.0896
219
1.0896
219
1.1250
126
1.0976
225
1.0896
219
1.0899
194
1.0899
194
Revision 4
MN/SLM7650.IOM
5/16
17/18
N
K
T
I
201
9
4
201
9
4
201
9
8
205
10
8
201
9
4
201
9
4
112
7
4
205
10
4
201
9
4
178
8
4
178
8
4
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