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CiM-550 IP Enabled Satellite Modem
Forward Error Correction
FEC Mode (64 kbps data rate)
Viterbi, Rate 1/2
Sequential, Rate 1/2
Turbo Product Coding, Rate 3/4, QPSK
Turbo Product Coding, Rate 21/44,
BPSK
Turbo Product Coding, Rate 5/16,
BPSK
Note: In all cases, the delay is inversely proportional to data rate, so for 128 kbps, the delay
values would be half of those shown above.
It can be clearly seen that the concatenated Reed-Solomon cases increase the delay very
significantly (due mainly to interleaving/de-interleaving), while the TPC cases yield
delays which are less than or equal to Sequential decoding.
FOR
Exceptionally good BER performance - significant
improvement compared with every other FEC
method in use today
No pronounced threshold effect - fails gracefully
Exceptional bandwidth efficiency for Rate 3/4 QPSK
- 40% less than Viterbi and concatenated Reed-
Solomon
Coding gain independent of data rate (in this
implementation)
Low decoding delay
Easy field upgrade in CiM-550
End-to-end delay, ms
12
74
79
64
48
AGAINST
Nothing!
95
Rev. 2
CD/CIM550.IOM
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