Paradise P300 - Manual (Page 69)

P300H P300 Series Modem Installation and Operating Handbook Page 69
Tx RS outer codec: [?]
1=Off 2=INTELSAT n,k,t & depth 3=Other
Change, Tx/Rx, Mod/Demod, Reed-Solomon Menu
Scrambler: [?]
1=Off 2=Normal 3:Other
Change, Tx/Rx, Mod/Demod, Scrambler Menu
The Reed-Solomon menu appears as follows:
The Reed-Solomon outer FEC codec may be configured as follows:
OFF The Reed-Solomon out FEC is disabled. Note that for testing the effectiveness
of the RS codec, a test mode allows you to disable the RS decoder error
corrections without removing the RS overhead (which changes the satellite data
rate and therefore to a small extent the Rx Eb/No).
INTELSAT This switches the RS codec on using standard INTELSAT values which are as
follows:
FEC Framing Data Rate (n,k,t) Depth
TCM Any
> 1544 kbps 8
(219,201,9) <= 1544 kbps
4
Non-TCM
eg Turbo, Viterbi,
Sequential, or No
FEC
IDR 1544 kbps (225,205,10)
2048 kbps
Other rates
(126,112,7)
IBS or All rates
Closed Net
Note: When interworking with NEC modems in TCM mode (and IBS framing), NEC have chosen to use
Interleaving depth 4 for all data rates. For rates >1544kbps then it will be necessary to select `Other`, and
manually select the interleaving as depth 4.
OTHER This option is only available if the `Custom Features` feature is available
(standard on P300-TCM). This feature allows the operator to specify the code rate
outside of the normal INTELSAT parameters ie a fully variable code rate Reed-
Solomon codec. The limitations are as follows `n` = [60 - 255], `k` = [n - (2, 4, 6,
8, 10, 12, 14, 16, 18, or 20)] ie `t`=1 to 10.
See the applications section, para 8.4 "Choosing Optimum Custom RS N&k
Values" on page 144
6.6.13 Change, Tx/Rx, Mod/Demod, SCRAMBLER Menu
The Scrambler selection is made from OFF , NORMAL , and CUSTOM .
OFF Turns off all scrambling, and whilst this may be used for testing or carrier line up,
it is not normally used over satellite.