Closed ghost closed 3 years ago
If I try
./cohpsk_get_test_bits - 56000 | ./cohpsk_mod - - | ./cohpsk_ch - /tmp/scatter.raw -40
and read that into FreeDV as a raw file, the waterfall and spectrum looks OK, but no scatter plot.
You might need to resample to 8000 Hz, cohpsk runs natively at Fs=7500 or something like that IIRC.
Thanks, I'll try that.
Thanks David, that was easy. Yes, scatter plot works fine resampled.
Maybe comments at top of cohpsk_mod.c change to:
Given an input file of bits (note one bit per float, soft decision format),
outputs a raw file (7500 Hz, 16 bit shorts) of COHPSK modem samples
ready to send over a HF radio channel.
I've been working on a side project, and it never produces a scatter plot in Mode 700C, so I tried generating one with:
and using octave
Which shows the GUI scatter diagram correctly.