Igor wrote, that we miss the sensivity of JT65 in FT8 !
So, we have -21 db in FT8 and in JT65 of around -27db
(92% decoded at -27db, 58% at -28db and 17% at -29db)
And the new proposed FT 2.0 will be another 0.2db (in math) less in
sensivity to the existing FT8. Igor suggested a FT8 protocoll that
could be at around -25 to -26db in sensivity - so again near to the
one of JT65.
Wolfgang, OE1MWW
Wednesday, August 8, 2018, 3:04:19 PM, you wrote:
> Frankly, I don't see where you're getting the idea that JT65
> sensitivity is missing?
> It is still much more sensitive than FT8, and will be for the
> foreseeable future, as are the other WSJT-X modes. JT9A is at -27,
> JT65A is at -25, and QRA64A is at -26. FT8 is -21 .. all this is
> based on a average noise floor.
> I don't see what your 'new mode' is going to accomplish.
> Neil, KN3ILZ
> On 8/8/2018 2:29 AM, Игорь Ч wrote:
>> Hello Joe and all,
>> .
>> We all have been missing JT65 mode sensitivity and proposed WSJT-X 2.0
>> new FT8 approach with 0.2 dB sensitivity penalty can make things even
>> worse.
>> .
>> I would like to ask you to consider a new protocol where callsign hash
>> would be used instead of the real callsign in all messages but CQ and
>> incoming call, this way we can get back to -25..26dB SNR sensitivity
>> although will get more limited with the free message length.
>> .
>> CQ message: 28 bit callsign1 + i5bit + 12 bit CRC = 45 bit
>> incoming call: 10 bit call1 hash + 28 bit callsign2 + i5bit + 12bit
>> CRC = 55 bit
>> report message: 10 bit call2 hash + 10 bit call1 hash + i5bit + (10
>> bit call3 hash for DXpedition) + 6 bit report + 12 bit CRC = 43(53) bit
>> roger+report message: 10 bit call1 hash + 10 bit call2 hash + 6 bit
>> report+ i5bit + 12bit CRC = 43 bit
>> 73 message: 10 bit call2 hash + 10 bit call1 hash + 15 bit GRID +
>> i5bit + 12bit CRC = 55 bit
>> RR73 message: 10 bit call1 hash + 10 bit call2 hash + 15 bit GRID +
>> i5bit + 12bit CRC= 52 bit
>> .
>> Spare bits can be used for nonstandard(special) callsign transmission
>> in CQ message. call1 hash could be omitted in the incoming call
>> message if this message is originated by the nonstandard(special)
>> callsign.
>> .
>> Probably we can optimize protocol even better while a main idea is to
>> transmit a full callsign only once per each QSO and to transmit not
>> more than one full callsign in the message.
>> .
>> 73 Igor UA3DJY
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> wsjt-devel mailing list
> wsjt-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/wsjt-devel
73 de Wolfgang
OE1MWW
----------
Amateur radio is the most expensive type of free-of-charge communication!
Amateurfunk ist die teuerste Art der kostenlosen Kommunikation!
------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
