I would consider the FT8 family of amateur radio encodings to be the SOTA. Many of them like WSPR are able to be decoded below the noise floor using forward err

I would consider the FT8 family of amateur radio encodings to be the SOTA. Many of them like WSPR are able to be decoded below the noise floor using forward error correction. It is very limited bandwidth, short messages with callsigns, etc. https://physics.princeton.edu/pulsar/k1jt/ https://physics.princeton.edu/pulsar/k1jt/