[SLS-CC] A couple last-minute slides about the TC tail sequence

[Andrews, Kenneth S (US 332B)]

Nicola,

Thank you very much for your work on the TC tail sequence problem.  I was just looking at your presentation, and if you’ve looked at mine, you’ll see that they complement each other pretty well, especially considering my lack of coordination in preparing them.  Based on your results, and a conversation with Victor Sank a week or two ago, I just assembled two more slides that I could show during today’s session, or not, depending on how the conversation goes.  They’re attached here, since I don’t want to catch you by surprise.

It looks like one of your proposed alternatives is to take our known distance-19 sequence, and randomize it for use as the corrected tail sequence.  Similarly, I think Victor is proposing to take the distance-18 tail sequence that’s currently in the standard, and randomize it for use as the corrected tail sequence.  These options recover the intended distance from codewords, but do not recover the “…5555” portion of the tail that’s transmitted on the RF link (for good or bad; it has a great transition density with BPSK, but is perilous with QPSK or with spectral spurs in extreme cases).  Performance notes for both of these options are shown in the attached slides, in the same format as the notes for my proposal in the slides posted to CWE.  We can discuss further in a few hours.

-Ken

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