Unformatted text preview: ere is a concern that the CLTU does
not have adequate symbol transitions to maintain symbol synchronization, then the Input TC
data may be randomized using the sequence specified by the BTG in 3.3.1. The CLTU
provides the data interface mechanism for passing the TC Codeblocks between the Coding
layer and the Physical layer.
To activate the telecommand channel in support of the Coding layer, the services of the
sending end Physical layer are invoked. An RF carrier data path is first established, upon
which various “Carrier Modulation Modes” (CMMs) may be established to support data
transfer. By selecting an appropriate sequence of CMMs, a “Physical Layer Operations
Procedure” (PLOP) is formed which activates and deactivates the link so that one or more
CLTUs may be transmitted to the spacecraft.
Upon activation of the channel by the selected PLOP, modulated radio waveforms are
radiated to the spacecraft. The receiving end of the Physical layer receives this waveform
and detects a stream of channel sy...
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- Spring '14
- Information Theory, ........., CCSDS