Comparison between different soft decoding algorithms

The authors investigate and compare two different soft decoding schemes. The first approach considered is the algorithm devised by D. Chase (1972). The second approach is based on the idea of generalized minimum distance decoding proposed by D. Forney (1966). This idea was further developed by Blokh-Zyablov (1973) and Zinoviev (1979), who devised a decoding algorithm for concatenated codes. Coding in combination with modulation can be seen as a concatenation with the modulation scheme as an inner code. The algorithm investigated is basically a further adaptation of the Blokh-Zyablov algorithm to the case of soft decision decoding. Both algorithms are investigated with respect to error correcting capability and complexity of implementation