[Lowfer] Re: Modes, signaling, and data recovery

[Alberto di Bene]

"Stewart Nelson" <sn@scgroup.com> wrote:

> Hi all,
>
> I believe that we can combine what has been learned from WOLF and
> Jason to create a new signaling scheme, which would permit real-time
> QSOs at quite low S/N, and also be capable of detecting a repeated
> message with much better performance than any existing system.
> [...]

Hi Stewart and the group,
   I read with interest your comments and proposals for an evolution of
the protocols used in LF weak signal operations.
If I understand well your scheme, you suggest to use absolute frequencies
as signalling elements, or maybe delta frequencies, as in the present Jason,
could be used ?
The synchronizing pattern seems to be a good idea, but do we really need
four synchronizing symbols ? Aren't they an overkill ? Just asking.

I have another comment on the decoding of repeating messages. Of course,
this is just personal opinion, but I feel a bit like cheating if I have to give
as input to the program the expected length of the message. However, I do
realize that this is needed if you want to do an integration over a long period,
without using a brute force approach, trying all the possible lengths, and
probably this is the only way to achieve (together with GPS synch) a
possible transatlantic reception of a lowfer signal.

You say : "Who will write all this software ?". The answer is not easy, as,
if fully implemented as you describe, it's not a minor task. You offered for
the sigproc part. We could tentatively start a joint effort (with no
guarantees..:-), where I could invoke an entry point of a DLL produced by
you, passing you a pointer either to the time-domain series of values
obtained by the sound card, or to the frequency-domain FFT-processed
output of those values, or a decimated series. We just have to agree on the
details. In return, you could pass me back some status flags and a decoded
data block. But from now on maybe we could continue via private emails.

Let me please know your thoughts,  TNX

73  Alberto  I2PHD