RRC filter taps have been replaced with the ones generated by Wojciech,
a new baseband for the M17 demodulation testsuite has been generated,
using OpenRTX itself and some further minor changes.
TG-81
Added implementation of the M17 4FSK demodulator, including clock
recovery, phase detection, and quantization algorithms.
A testsuite is also included to do regression testing against a
reference baseband pre-generated and the corresponding reference
bitstream.
A 1% BER is still present due to a fault likely in the RRC filtering,
since the eye diagram of the filtered stream is bad.
TG-81
Silvano Seva
Niccolò Izzo
Alessio Caiazza