Hi Pieter, Dave G3YXM and I did some quick and dirty estimations of QRSS
about 10 years ago on 136kHz I cant remember whether we did DFCW where the
main advantage is that it is faster, but the decode threshold is about the
same as QRSS It is a little subjective but the results seemed reasonably
what we might suspect.
They may be on his web-site still www.wireless.org I think the we only
considered fully reading the ID and Dave reduced power until it was not
possible to decode. The results were in line with the FFT resolution used,
but we have no measured values.
I believe someone in the States also did some tests, John W1TAG could
probably help there. They may be on the LWCA web-site.
Best Wishes
Alan
G3NYK
G3NYK
----- Original Message -----
From: "Pieter-Tjerk de Boer" <[email protected]>
To: <[email protected]>
Sent: Saturday, January 10, 2015 9:17 PM
Subject: Re: LF: Eb/N0 values for amateur modes
On Fri, Jan 09, 2015 at 10:15:24AM +1100, edgar wrote:
In your email, in which mode grouping would DFCW 180 fit?
Not in any, really. I'm not aware of any (published) experiments having
been done to establish decoding thresholds for it, which I could use
to put it in the table.
Compared to regular CW transmitted at the same (peak) power, DFCW has
about 3 dB more average power because the transmitter is on continuously,
so just because of that, it should give better performance at the same
_peak_ power level. However, whether the performance difference is more
or less than 3 dB, and thus whether it is better or worse than CW at the
same _average_ power (as normally used for Eb/N0 calculation), is harder
to predict.
Regards,
Pieter-Tjerk, PA3FWM
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