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Operation DMD15/DMD15L IBS/IDR Satellite Modem
3-22 TM051 – Rev. 5.8
Table 3-1. Reed-Solomon Codes for IDR
Type of
Service
Data Rate
(Kbps)
RS Code (n,
k, t)
1
Bandwidth
Expansion
[ (n/k) -1 ]
Interleaving
Depth
Maximum
2
RS Codec
Delay (ms)
Small IDR
(With 16/15
O/H)
64
128
256
384
512
768
1024
1536
(126, 112, 7)
(126, 112, 7)
(126, 112, 7)
(126, 112, 7)
(126, 112, 7)
(126, 112, 7)
(126, 112, 7)
(126, 112, 7)
0.125
0.125
0.125
0.125
0.125
0.125
0.125
0.125
4
4
4
4
4
4
4
4
115
58
29
19
15
10
8
5
IDR
(With 96
Kbps O/H)
1544
2048
6312
8448
(225, 205,10)
(219, 201, 9)
(194, 178, 8)
(194, 178, 8)
0.0976
0.0896
0.0899
0.0899
4
4
4
4
9
7
2
<2
8PSK
1544
2048
6312
8448
(219, 201, 9)
(219, 201, 9)
(219, 201, 9)
(219, 201, 9)
0.0896
0.0896
0.0896
0.0896
8
8
8
8
18
13
4
3
NOTES:
1. n = code length, k = information symbols and t = symbol error correcting capability.
2. Design objective.
3.19 DMD15 Automatic Uplink Power Control (AUPC Operation)
The DMD15 Modem has an optional built-in provision for Automatic Uplink Power Control (AUPC).
AUPC attempts to maintain a constant E
b
/N
o
at the receive end of an SCPC link. This is
especially useful when operating over a satellite at Ku-Band Frequencies in locations with high
rainfall periods.
Note: An Asynchronous or IBS Interface is required for AUPC. Also, IBS (Async Framing
Mode MUST be selected to provide a channel for AUPC operation.