RE: LF: QRSS3 "challenge"

[Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>]

Hello Graham,

 

maybe that will be the next step.

But let's start with something "easy".

 

BTW:

I did a test how many bits Opera can miss before decoding fails.

Again, starting "easy" just by ommitting the n first bits and feed Opera with a shorter sequence.

For a no noise signal Opera decoded fine for as less as 96 bit (from the original 239/240). Impressive.

But the I started adding noise and found out that the SNR theshhold increased from -23dB (for the full 239/240 bit sequence) to +15dB (for the 96 bit sequence). I expected some difference (otherwise FEC would be woth nothing), but not as much as 38dB.

It was just a single test for the 96 bit sequence, so that result is give or take some dB.

Next days will be busy, but later I intend to make a better study, take some intermediate steps and more than 1 try.

Cursious what will show up.

 

73, Rik  ON7YD  - OR7T

 

---

Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Graham [g8fzk@g8fzk.fsnet.co.uk]
Verzonden: donderdag 2 februari 2012 18:36
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: QRSS3 "challenge"

Ah.. missing  is the  qsb  , to  remove  sections of the  plot  so  these  must  be  ground wave  tests :- )

From: Rik Strobbe

Sent: Thursday, February 02, 2012 5:17 PM

To: rsgb_lf_group@blacksheep.org

Subject: LF: QRSS3 "challenge"

Dear all,

 

as mentioned some days ago I generated a whole series of Opera, WSPR and QRSS3 audio with a known SNR.

For Opera and WSPR it was easy to determine the lowest SNR for a proper decode. But for QRSS3 it is much more difficult as it depends on the operators "sharp eye". It must be somewhere in the range of -24 to -28dB SNR (@ 2.5kHz BW).

Today I did put all the QRSS3 screenshots in this range in a website, where you can fill in what you see (decode) for each screenshot.

I would like to invite all of you to give it a try and send me the results (the more entries the better the statistics).

After some time (Feb 10th) will put all results into some nice tables and graphs and make them available.

Of course no personal (individual) results will be published. But based on the results every participant (who keeps his results) can see where he ends.

 

The "QRSS3 Challenge" can be found at http://on7yd.strobbe.eu/QRSS/

 

73, Rik  ON7YD - OR7T