Created by: Peter Martinez G3PLX
Description :
Baud rate : 31.25
Speed : 37 wpm in capital letters and 51 wpm in small letters (average)
Modulation : DBPSK
QPSK31 USB is mandatory
Character set : ASCII characters + ANSI extended characters + an error reset character («
Varicode » characters)
Shape of pulse : raised cosine
Bandwidth : about 80 Hz,
Demodulation : coherent,
Synchronization : automatic using the signal
Correction code : no
Convolution code : QPSK31 (Rate=1/2, Constraint length=5, use of Viterbi decoder with soft decison)
Interleaving : no
Automatic Frequency Correction : about +/- 10 Hz depending on signal-to-noise ratio,
Drift tolerance : 20 Hz/min in QPSK31 (depending on level)
Pmean/Ppeak : 0.35 for QPSK31
Lowest S/N : -11.5 dB
Waterfall range : 200 to 4300 Hz for Multipsk
.
Recommanded frequencies for BPSK31 or QPSK31 (USB) in kHz
1838, 3580, 7040 , 7070 US ( North America , this freq is not same band plan for all parts of the world), 10140, 14070, 18100, 21070, 24920, 28070, 28120, 50290
The mode has the extra two phases to the mode which has a very light desicions built in it is not consider a strong FEC mode. The power is distrubted across four phases , but the soft desicion makes up for distrubted power.
