Re: VLF: This weekend...

[Paul Nicholson <vlf0403@abelian.org>]

Stefan schrieb:

> f = 6470.100000 Hz
> Start time: 10.Jun.2017   04:00:00 UTC
> Symbol period: 20 s
> Characters: 100
> CRC bits: 8
> Coding 8K21A

Copied a message with md5 hash (*):  9f7707ee7424c3c07c3524616fe45b9b
Constant reference phase.

BER 31.1%

Eb/N0 = -1.1 dB, 94% of channel capacity.

Carrier S/N: 26.42 dB in 10.0 uHz,
            -23.60 dB in 1Hz,
            -57.58 dB in 2.5kHz

List rank 1159.
Decoder RAM: 10Gbyte with list length 10k.

I used ebnaut option -a 100 to normalise the amplitudes in the
decoder.  It didn't decode at all without that.

100 chars is a record message length at 6470 Hz.

Error map http://abelian.org/vlf/tmp/170612a.png

I used a night blanker setting -a 12 (in version 8 onwards),
or about -a1.2 before version 8.

(*) echo -n 'XXX...XXX' | md5sum

--
Paul Nicholson
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