Comtech EF Data Radyne DMD1050 - Interleaving

DMD1050 Satellite Modem Board Theory of Operation
3.12.3 Interleaving
The DMD1050 allows for interleaving depths of 4 or 8 R-S Blocks so that burst errors are spread
over 4 or 8 R-S blocks to enhance the error correction of the R-S Codec. In Closed Network
Mode, manually set the interleaver depth to 4 or 8. In DVB Network Mode, the DMD1050 sets
the interleaver depth to 12 automatically.
Figure 3-10. Reed-Solomon Encoder Functional Block Diagram
Figure 3-11. Reed-Solomon Decoder Functional Block Diagram
Table 3-1. 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
Dela
y (
ms
)
Small IDR 64 (126, 112, 7) 0.125 4 115
(With 16/15 128 (126, 112, 7) 0.125 4 58
O/H) 256 (126, 112, 7) 0.125 4 29
384 (126, 112, 7) 0.125 4 19
512 (126, 112, 7) 0.125 4 15
768 (126, 112, 7) 0.125 4 10
1024 (126, 112, 7) 0.125 4 8
1536
(
126, 112, 7
)
0.125 4 5
IDR 1544 (225, 205,10) 0.0976 4 9
(With 96 Kbps 2048 (219, 201, 9) 0.0896 4 7
O/H) 6312 (194, 178, 8) 0.0899 4 2
8448 (194, 178, 8) 0.0899 4 <2
8PSK 1544 (219, 201, 9) 0.0896 8 18
2048 (219, 201, 9) 0.0896 8 13
6312 (219, 201, 9) 0.0896 8 4
8448
(
219, 201, 9
)
0.0896 8 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.
MN-DMD1050 3–21
Revision 9