SDM-9000 Satellite Modem
Options
Rev. 4
A–19
A.2.6 SYNC 1 Inversion and Scrambler/Descrambler
In compliance with the DVB specifications, and to ensure adequate binary transitions,
the payload data (187 bytes) in the transport packet is scrambled using a Pseudo Random
Binary Sequence (PRBS) generator.
The polynomial used for the PRBS is:
1 + X
14
+ X
15
The basic scrambler/descrambler is shown in Figure A-15.
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
INITIALIZATION SEQUENCE
PRBS GENERATOR
ENABLE FROM
SYNC DETECT LOGIC
CLEAR/SCRAMBLED
DATA IN
SCRAMBLED/
DESCRAMBLED
DATA OUT
1
0
0
1
0
1
0
1
0
0
0
0
0
0
0
Figure A-15. Scrambler/Descrambler
At every eighth transport packet, the sequence “100101010000000” is loaded into the
PRBS registers. The inverted sync byte is used to initialize the PRBS generator.
Содержание SDM-9000
Страница 1: ...Part Number MN SDM9000 IOM Revision 4 SDM 9000 Satellite Modem Installation and Operation Manual...
Страница 2: ......
Страница 5: ...8 Mbit s w IDR Figure 1 7 16QAM BER Performance Curves with Reed Solomon Filename T_ERRATA 3...
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Страница 27: ...SDM 9000 Satellite Modem Introduction Rev 4 1 5 Figure 1 3 SDM 9000 Block Diagram...
Страница 42: ...Introduction SDM 9000 Satellite Modem 1 20 Rev 4 This page is intentionally left blank...
Страница 64: ...Configuration SDM 9000 Satellite Modem 3 6 Rev 4 JP1 Figure 3 4 Interface PCB AS 3971...
Страница 65: ...SDM 9000 Satellite Modem Configuration Rev 4 3 7 Figure 3 5 Interface PCB AS 4477...
Страница 66: ...Configuration SDM 9000 Satellite Modem 3 8 Rev 4 JP1 JP6 JP7 Figure 3 6 Interface PCB AS 5618...
Страница 70: ...Configuration SDM 9000 Satellite Modem 3 12 Rev 4 Figure 3 7 Nyquist Filter Installation...
Страница 83: ...SDM 9000 Satellite Modem Operation Rev 4 4 9 This page is intentionally left blank...
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Страница 107: ...Operation SDM 9000 Satellite Modem 4 34 Rev 4 This page is intentionally left blank...
Страница 124: ...SDM 9000 Satellite Modem Operation Rev 4 4 51 Figure 4 17 RF Loopback Figure 4 18 IF Loopback...
Страница 133: ...SDM 9000 Satellite Modem Theory of Operation Rev 4 5 5 Figure 5 3 Modulator RF Section Block Diagram...
Страница 150: ...Theory of Operation SDM 9000 Satellite Modem 5 22 Rev 4 Figure 5 6 Interface Block Diagram...
Страница 158: ...Theory of Operation SDM 9000 Satellite Modem 5 30 Rev 4 This page is intentionally left blank...
Страница 167: ...SDM 9000 Satellite Modem Maintenance Rev 4 6 9 WITH NOISE WITHOUT NOISE Figure 6 4 Typical Eye Constellations...
Страница 186: ...Maintenance SDM 9000 Satellite Modem 6 28 Rev 4 This page is intentionally left blank...
Страница 218: ...Options SDM 9000 Satellite Modem A 32 Rev 4 This page is intentionally left blank...
Страница 242: ...Remote Control Operation SDM 9000 Satellite Modem B 24 Rev 4 ref SE_ command...
Страница 254: ...Glossary SDM 9000 Satellite Modem g 6 Rev 4 This page is intentionally left blank...
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