Comtech EF Data OM20 - Manual (Page 55)

OM20 Universal Outdoor Modem OM20 Theory of Operation
MN-OM20– Revision 5 4–17
Figure 4-9 Reed-Solomon Decoder Functional Block Diagram
Table 4-1. Reed-Solomon Codes
Type of
Service
Data Rate
(Kbps)
R-S Code
(n, k, t)
1
Bandwidth
Expansion
[ (n/k) -1 ]
Interleaving
Depth
Maximum
2
R-S 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
DVB All (204, 188, 8) 0.0851 12 -
1. n = code length, k = information symbols and t = symbol error correcting capability.
2. Design objective.
4.10 Drop and Insert (D&I)
Refer to Appendix E