Descrambling Types; Differential Decoder; Bpsk Bit Ordering; Decoding - Comtech EF Data SDM-300A Installation And Operation Manual

Specifications
C.3.3

Descrambling Types

The operator can select one of the following descrambling types:
CCITT V.35
CCITT V.35
Fairchild compatible
2^15-1 Synchronous
Modified V.35
None
C.3.4

Differential Decoder

The differential decoder takes care of one set of ambiguities due the error correction
codes being transparent.
•
C.3.5

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.
•
•
C.3.6

Decoding

C.3.6.1

BPSK Encoding

The demodulator converts transmitted baseband data into a modified BPSK carrier
2.4 kbit/s to 1.25 Mbit/s (1/2 rate) . Using vector analysis of the constellation pattern,
BPSK represents one symbol with the carrier phase either at 0° or 180°. The 1/2 rate
encoding at the convolutional encoder two symbols output for every bit input.
C–14
EFData/Comstream compatible. Sequential only
Intelsat modified. Viterbi only
IBS, Drop & Insert, ASYNC, and IESS-310
Closed Network Reed-Solomon
On or Off
Viterbi (Standard/Non-Standard)
Sequential (Standard/Non-Standard)
Code Rate
1/2
Symbols/Bit Bits/Hz
2 0.5
SDM-300A Satellite Modem
Rev. 4