Method and apparatus for constructing efficient slepian-wolf codes with mismatched decoding

A method for constructing Slepian-Wolf codes with one or more inputs, wherein mismatched decoding resulting from imperfect knowledge of joint probability distribution is taken into account, comprising the steps of:

• a) choosing a tentative decoding metric from one of the inputs;
• b) selecting representative probability distributions from one of the inputs;
• c) converting the chosen decoding metric to a cyclic-symmetric channel;
• d) computing a set of probability distributions of the initial message given the initial message value and the representative probability distributions;
• e) optimizing the degree distribution given the set of probability distributions of the initial message;
• and
• f) generating a Slepian-Wolf code according to the said degree of distribution.

An encoding apparatus for source data which constructs Slepian-Wolf codes with two inputs and two outputs comprising:

• input means for receiving a tentative chosen decoding metric belonging to a given decoding metric set;
• selection means for selecting representative probability distributions from a set of possible probability distributions;
• conversion means for converting the chosen decoding metric to a cyclic-symmetric channel;
• computation means for computing a set of probability distributions of an initial message value of the source data and the representative probability distributions;
• optimization means for optimizing a degree distribution given a set of probability distributions of the initial message;
• and
• an encoder for encoding a source data using Slepian-Wolf code induced by the degree distribution to output a syndrome in a data compression system.