Soft information generation for concatenated forward error correction in digiral signal processing

An apparatus for generating soft information from a Maximum Likelihood Sequence Estimation (MLSE) process comprising:

• a feed-forward equalizer receiving signals to produce equalized outputs;
• a filter coupled to the feed-forward equalizer in an adaptive equalizer loop to provide MLSE inputs at a series of time indices based on filtering adaptation of the equalized outputs;
• a MLSE block configured to process the MLSE inputs to generate hard decision coding symbols and intermediate path metric information for the series of time indices;
• a soft information generator configured to generate soft information corresponding to each hard decision coding symbol at each of the series of time indices based on the intermediate path metric information;
• a multiplexer combining the soft information and the hard decision coding symbols;
• and
• a forward error correction decoder configured to use the soft information for inner code decoding of the corresponding coding symbol.