The timing is off by a few seconds: the 2200 sequence ended at 22:20:19.
I think the old antenna is several dB down and that isn't helping things.
Oh well, at least the message arrived! It was very much a joint effort.
73
Joe
On Tue, 24 Nov 2015, Markus Vester wrote:
And any proper test will sometimes fail ;-) No success here on the 21:30
transmission, only a couple of bogus decodes with very high rank numbers. The
signal is competely invisible now, and to make thnigs worse DCF39 has gone
into another hyperactive period, splattering all over the band. Will keep
trying...
73, Markus
-----Ursprüngliche Mitteilung-----
Von: Paul Nicholson <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Di, 24 Nov 2015 11:04 pm
Betreff: Re: LF: EbNaut and The Cat / Take 3
Domenico wrote:
> a little signal, but decoded also here
Excellent result. That's the sort of test I like to
see, where Eb/N0 = 0.7 dB and the program will have
had to search for the phase and it had to use some
list decoding. That's a proper weak signal test.
I guess it should stand another dB weaker.
The 21:30 just decoded here with Eb/N0 = -0.6 dB and
the phase pattern was -30 -60 -30 -60, might be
propagation or my timing system having a hiatus.
The symbol timing of the 21:00 looked good. I tried
some time shifts both ways and it didn't improve.
Markus wrote:
> It seems that non-existing symbols with null
> amplitude are not being counted as symbol
> errors, which severely biases the error rate.
Yes it looks like you're right, the zero symbols are
not counting as errors. They contribute neither positive
or negative to the accumulated log-likelihood of the
path metric. It's effectively an erasure code. I'll
alter the BER arithmetic tomorrow, it probably should
consider only the non-zero symbols. Might need some
thought.
Have to go out now but the rx continues recording.
--
Paul Nicholson
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