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
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