[time-nuts] WWVB BPSK Receiver Project? (fwd)

[Poul-Henning Kamp]

In message <B8FA03DC1DD84A588A317B314A6FCB7B at vectron.com>, "Bob Camp" writes:

>Could you generate a "lead" and a "lag" estimate of the signal (in addition
>to your "center") and integrate against each of them on the fly? If so you
>would need a *lot* less memory. I seem to recall you tried something like
>this on the one of the Loran receivers. 

The reason to use the lead/center/lag model, is that you have a moving
signal you need to track, but for timenuts purposes the signal is not
going to move more than a few microseconds over an hour, so it is
probably a better strategy to just average the heck out of the signal.

It is not even clear to me that the phase-coding helps frequency
reception at all, I tried it with the very strong phase-coding of
DCF77 and there was no statistical significance relative to heavy
duty carrier averaging.

But it clearly helps a lot with phase-determination, and for that
lead/center/lag is the way to go, but you may still want to average
for a minute, then resolve the phase using the phase-modulation,
rather than run it in real-time.

-- 
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