Re: VLF: EbNaut transmissions on lower frequencies?, pre-tests: 6.47kHz

[Paul Nicholson <vlf0403@abelian.org>]

Stefan wrote:

> f = 6470.00000 Hz
> Start time: 23.11.2016 08:00:00 UTC (Daily repetition)
> Symbol length: 12 s
> Characters: 40
> CRC 16
> Coding 8K19A

A decode after 11 repeats:

Copied 'HI FOLKS, JOIN THE VLF RADIO EXPERIMENTS'

Eb/N0 = -0.3 dB using normalisation by the RMS amplitude.

Eb/N0 = +0.3 dB using normalisation by the power as suggested
by Markus.

Constant reference phase. S/N 23.84 dB in 38.0 uHz,
-54.3dB in audio bandwidth.

...

A slightly better decode, Eb/N0 = +0.7 dB if I use a 2 second
offset, ie the decoder starts work 2 seconds late.  Maybe
a consequence of the leisurely phase switching.

--
Paul Nicholson
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