SDM-300A Satellite Modem
Options
Rev. 4
A–45
The branch metrics are then processed by the ASC computer. The ASC computer makes
decisions about the most probable transmitted symbol stream with the state metrics
computed for the previous 64 decoder inputs.
The results of the ASC computer are stored in the path memory (80 states in depth). The
path with the maximum metric is designated as the survivor path, and its data is used for
output. The difference between the minimum and the maximum path metrics is used as
the means of determining synchronization of the decoder.
The output data is then descrambled and differentially decoded. Both of these processes
are optional, and may be selected by the user locally or remotely. The data from the
differential decoder is sent to the interface PCB for formatting and output. The
synchronization signal is used for lock-detect and sent to the M&C.
The raw BER count is generated from the minimum and maximum metrics and sent to
the M&C for further processing. Refer to Chapter 1 for Viterbi decoder BER
specifications.
A.1.4.9 Reed-Solomon
Decoder
Refer to Section A.2, Conventional Options, for Reed-Solomon information.
Содержание SDM-300A
Страница 1: ...Part Number MN SDM300A IOM Revision 4 SDM 300A Satellite Modem Installation and Operation Manual...
Страница 33: ...Introduction SDM 300A Satellite Modem 1 14 Rev 4 This page is intentionally left blank...
Страница 36: ...SDM 300A Satellite Modem Installation Rev 4 2 3 Figure 2 1 Installation of the Mounting Bracket...
Страница 57: ...Operation SDM 300A Satellite Modem 3 4 Rev 4 This page is intentionally left blank...
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Страница 169: ...Theory of Operation SDM 300A Satellite Modem 4 18 Rev 4 This page is intentionally left blank...
Страница 176: ...SDM 300A Satellite Modem Maintenance Rev 4 5 7 WITH NOISE WITHOUT NOISE Figure 5 4 Typical Eye Constellations...
Страница 189: ...Maintenance SDM 300A Satellite Modem 5 20 Rev 4 This page is intentionally left blank...
Страница 200: ...SDM 300A Satellite Modem Options Rev 4 A 11 Figure A 2 D I with Asynchronous Overhead Data Flow...
Страница 205: ...Options SDM 300A Satellite Modem A 16 Rev 4 Figure A 3 E1 Framing Formats...
Страница 206: ...SDM 300A Satellite Modem Options Rev 4 A 17 Figure A 4 T1 Framing Formats...
Страница 237: ...Options SDM 300A Satellite Modem A 48 Rev 4 Figure A 10 IDR Interface Block Diagram...
Страница 241: ...Options SDM 300A Satellite Modem A 52 Rev 4 Figure A 11 IBS Interface Block Diagram...
Страница 257: ...Options SDM 300A Satellite Modem A 68 Rev 4 CBA Figure A 19 Reed Solomon Codec Installation...
Страница 260: ...SDM 300A Satellite Modem Options Rev 4 A 71 CBA Figure A 20 Overhead Interface PCB Installation...
Страница 265: ...Options SDM 300A Satellite Modem A 76 Rev 4 Figure A 24 8 Channel Multiplexer Installation...
Страница 273: ...Options SDM 300A Satellite Modem A 84 Rev 4 Figure A 26 Flex Mux Multiplexer Installation...
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Страница 330: ...SDM 300A Satellite Modem Remote Control Operation Rev 4 B 55...
Страница 362: ...Specifications SDM 300A Satellite Modem C 32 Rev 4 Figure C 7 8PSK BER Specification Curves 1544 kbit s...
Страница 366: ...Specifications SDM 300A Satellite Modem C 36 Rev 4 1 1 Rate Specification Figure C 9 Uncoded 1 1 BPSK QPSK and OQPSK...
Страница 388: ...Specifications SDM 300A Satellite Modem C 58 Rev 4 This page is intentionally left blank...
Страница 392: ...Glossary SDM 300A Satellite Modem g 4 Rev 4 This page is intentionally left blank...
Страница 398: ...Index SDM 300A Satellite Modem i 6 Rev 4 This page is intentionally left blank...