System and method for error correcting a received data stream in a concatenated system

A receiver/decoder for error correcting a received data stream which has been subjected to plural concatenated entities which have encoded said data stream or subjected said data stream to a constraint, comprising:

• a) detector means for sampling signals in said received data stream and assigning discrete data values to sampled signals falling in non-ambiguous amplitude or phase ranges and for assigning ambiguity symbols to sampled signals falling within an ambiguity range of amplitude or phase values, and for outputting a quantized data stream comprising said discrete data values and said ambiguity symbols;
• b) decoder means for decoding and error correcting data values making up said quantized data stream to create an error-corrected data stream, said decoding comprising plural decoding actions for decoding data that has been encoded or subjected to a constraint by said plural concatenated entities;
• c) feedback error correction means coupled between said decoder means and said detector means and receiving a form of said error-corrected data stream from an output of said decoder means, for modifying data values and ambiguity symbols in said quantized data stream through substitution of corrected data values from said error corrected data stream into corresponding data values in said quantized data stream, to thereby create a revised data stream;
• and
• d) control means for iteratively causing said decoder means and said feedback error correction means to operate upon said revised data stream, both as is and as further revised, to improve an error correction state of said revised data stream.