Descrambling types, Differential decoder, Bpsk bit ordering – Comtech EF Data SDM-300L3 User Manual

Page 324: Deinterleaver (reed-solomon codec), 3 descrambling types, 4 differential decoder, 5 bpsk bit ordering, 6 deinterleaver (reed-solomon codec)

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SDM-300L3 Satellite Modem

Revision 0

Specifications

MN/SDM300L3.IOM

14–18

14.7.3 Descrambling

Types

When descrambling is enabled, it is applied to the demodulator data according to the
programmed demodulator type as listed in Table 14-9. When descrambling is disabled, no
descrambling is applied to the demodulator data.

Table 14-9. Descrambling Types

Demodulator Type

FEC or Framing

Descrambling

EFD Closed, CSC Closed Sequential

ITU V.35

EFD Closed,
CSC Closed,
FDC Closed

Viterbi

ITU V.35 INTELSAT Modified

EFD Closed

Viterbi/RS Concatenated EFD Modified V.35

EFD Closed

Turbo

2

12-1

Synchronous

EFD CLosed

Turbo

IESS-315

EFD Closed

ASYNC

2

15-1

Synchronous

FDC Closed

Sequential or Viterbi

FDC Modified V.35

INTELSAT Open

Viterbi IDR

ITU V.35 INTELSAT Modified

INTELSAT Open

Viterbi IDR with RS

ITU V.35 INTELSAT Modified

INTELSAT Open

IBS, D&I, IESS-310

2

15-1

Synchronous

14.7.4

Differential Decoder

The differential decoder takes care of one set of ambiguities due the error correction codes
being transparent.

•

On or Off

14.7.5 BPSK

Bit

Ordering

The decoder has the ability to select whether I is the first bit or Q is the first bit in the
symbol word grouping for compatibility with any system. For standard mode Q is the first
bit.

•

Viterbi (Standard/Non-Standard)

•

Sequential (Standard/Non-Standard)

•

Turbo – fixed order only

14.7.6

Deinterleaver (Reed-Solomon Codec)

•

OQPSK, QPSK – Depth 4 (IBS, IDR, D&I)

•

8-PSK – Depth 4 (No overhead, IBS, D&I) (IESS-310)

•

Depth 8 (Closed Network, Async)

•

8-PSK – Depth 8 (IDR) (IESS-310)

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