## Soft vs hard decision decoding

As would be expected, a soft decision decoding scheme has a better chance of detecting and correcting errors than a hard decision scheme. If there is unlimited and unquantized weighting information available to the decoder, then the soft decision decoder should provide up to 3 dB coding gain improvement over a hard decision decoder for the same code length. If the weighting information is quantized to only eight levels, the coding gain is reduced to approximately 2.75 dB. It is common for soft decision decoders to use eight or fewer weighting levels to avoid undue complexity in the decoder hardware/software.