New digital mode: Joe Taylor (K1JT) has announced FT4

(Source: Southgate ARC)

Joe Taylor K1JT has announced a new digital mode, FT4, which is 2.5 times faster than FT8 

FT4 is an experimental digital mode designed specifically for radio contesting.  Like FT8, it uses fixed-length transmissions, structured messages with formats optimized for minimal QSOs, and strong forward error correction.  T/R sequences are 6 seconds long, so FT4 is 2.5 × faster than FT8 and about the same speed as RTTY for radio contesting.  

FT4 can work with signals 10 dB weaker than needed for RTTY, while using much less bandwidth.

FT4 message formats are the same as those in FT8 and encoded with the same (174,91) low-density parity check code.  Transmissions last for 4.48 s, compared to 12.64 s for FT8.  Modulation uses 4-tone frequency-shift keying at approximately 23.4 baud, with tones separated by the baud rate.  The occupied  bandwidth (that containing 99% of transmitted power) is 90 Hz

Further information on FT4 is at  
http://physics.princeton.edu/pulsar/k1jt/FT4_Protocol.pdf

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1 Response to New digital mode: Joe Taylor (K1JT) has announced FT4

  1. Frank says:

    hi,

    Some already say FT4 will completely take over FT8, maybe in contests, however FT8 is more sensitive, better for low signals so I think it will be a good alternative. Anyways, I’ve been surprised by the power FT8 has in decoding low signals, where the band is dead for ssb and cw the FT8 portion of the band is still quite occupied, even with signals from far away.
    The discovery goes on …. .. Tnx K1JT & crew

    73
    ON6UU

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