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Unformatted text preview: CLTUs. Finally, when the last CLTU has been transmitted (followed or
not by an Idle sequence), the link is deactivated by the PLOP. CCSDS 201.0-B-3 Page B-3 June 2000 CCSDS RECOMMENDATION FOR TELECOMMAND: CHANNEL SERVICE INPUT DATA
from layer above TC DATA
to layer above
String of derandomized bits
(with possible fill bits). One or more contiguous frames. CODING LAYER
RANDOMIZE FILL If used for the mission (optional) DERANDOMIZE If necessary, add fill
either before or after
number of codeblocks. DECODE
delete parity and
filler bit BCH ENCODE,
add parity & filler bit
for each codeblock Sequence of Codeblocks Decoded (Randomized) Input Data
PHYSICAL LAYER ADD START
START OF DECODER Sequence of Codeblocks
CLTU Figure B-2: Sequence of Functions
If the probability of erroneous data (as measured by the channel decoder) is sufficiently high,
the spacecraft channel decoder will enter a “Search for Start Sequence” condition until reset
by the next CLTU Start sequence or (optionally) by deactivation of the link by the PLOP....
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This document was uploaded on 03/06/2014.
- Spring '14