WIP: Improve sensitivity
Some improvements are made:
- add Doppler Correction block and change update interval
- Change xlating_decimation to match int(samp_rate_rx/100e3)
- Change waterfall sink bandwidth
- Add BFO to shift CW audio to ~1kHz
- Add Moving Average to sharpen the signal fed into the decoder
This is WIP because the current approach needs some more improvements. Any help is really appreciated!