ON REDUCING COMPLEXITY OF A SOFT-DECISION DECODING ALGORITHM FOR CYCLIC CODES BASED ON ENERGY MINIMIZATION PRINCIPLE

We propose a novel soft-decision decoding algorithm for cyclic codes b ased on energy minimization principle. The well-known soft-decision de coding algorithms for block codes perform algebraic (hard-decision) de coding several times in order to generate candidate codewords using th e reliability of received symbols. In contrast, the proposed method de fines energy as the Euclidean distance between the received signal and a codeword and alters the values of information symbols so as to decr ease the energy in order to seek the codeword of minimum energy, which is the most likely codeword. We let initial positions be the informat ion parts of signals obtained by cyclically shifting a received signal and look for the point, which represents a codeword, of minimum energ y by moving each point from several initial positions. This paper pres ents and investigates reducing complexity of the soft-decision decodin g algorithm. We rank initial positions in order of reliability and red uce the number of initial positions in decoding. Computer simulation r esults show that this method reduces decoding complexity.