4 ms·
Automatic classifiers tend to look for power above the background noise and then AM demodulate the signal around it. That demodulated signal, or video as it's c
by anilakar 3y ago
Automatic classifiers tend to look for power above the background noise and then AM demodulate the signal around it. That demodulated signal, or video as it's called, is centered around 0 Hz and can be matched against a database of spectrum masks for various modulations, baud rates and other parameters.
No neural nets required. Just good old regression.
- vdqtp3 3y agoSo how would they fare against something below the noise floor, like FT8
- trothamel 3y agoFT8 isn't actually below the noise floor if you look at the bandwith the signal is detected in, rather than the 2500 Hz reference bandwidth. https://tapr.org/pdf/DCC2018-KC5RUO-TheReal-FT8-JT65-JT9=SNR.pdf https://tapr.org/pdf/DCC2018-KC5RUO-TheReal-FT8-JT65-JT9=SNR... Has details, but basically you should add 26 dB to account for the difference between 2500 Hz and the 6.25 Hz bandwidth each FT8 tone is detected in.