The BLE5 has 3 different PHY configurations:
- LE 1M PHY
- LE 2M PHY
- LE Coded PHY
The First 2 are uncoded. Meaning, there is no FEC. The GFSK modulation with modulation index of 0.5 as per the specification is capable of reaching the reciever with the throughput BLE offers for that range.
LE coded PHY is for LE long range feature upto 1Km. In that case, there is convolutional FEC coding, that will add error coding bits to the actual payload resulting in lower throughput of actual payload.