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Descrambling types, Differential decoder, Bpsk bit ordering – Comtech EF Data SNM-1010L User Manual

Page 253: B.3.22.2 descrambling types, B.3.22.3 differential decoder, B.3.22.4 bpsk bit ordering

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SNM-1010L Data/Control Modem Revision 0
Specifications

MN/SNM1010L.OM

The following combinations of demodulation and forward error correction decoding are
available.

Encoder

Code Rate

Reed-Solomon

Modulation

Viterbi, K7

1/2

BPSK

Viterbi, K7

1/2

225/205 Closed

BPSK

Viterbi, K7

1/2, 3/4, 7/8

QPSK/OQPSK

Viterbi, K7,
TCM

2/3

8PSK

Viterbi, K7

1/2, 3/4, 7/8 225/205

Closed QPSK/OQPSK

Sequential 1/2

BPSK

Sequential

1/2

225/205 Closed

BPSK

Sequential 1/2,

3/4, 7/8

QPSK/OQPSK

Sequential

1/2, 3/4, 7/8

225/205 Closed

QPSK/OQPSK

Turbo Product

21/44, 5/16

BPSK

Turbo Product

3/4

QPSK/OQPSK

Turbo Product

3/4

8PSK

Uncoded

1/1

BPSK, QPSK, QPSK

Note: Reed Solomon is a fixed 225/205, t = 10 rate, with a fixed 8 depth interlever.

B.3.22.2 Descrambling

Types

The operator selects one of the following descrambling types.

• CCITT V.35 (

Comtech EF Data

or Comstream compatible). Sequential only

• CCITT V.35 Intelsat modified. Viterbi only
• Fairchild compatible. Sequential only
• 2^15 -1 Synchronous (for use in ASYNC overhead mode)
• Modified V.35 (Closed Network Reed-Solomon)
• None

B.3.22.3 Differential

Decoder

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

• On or off






B.3.22.4

BPSK Bit Ordering

B–11

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