Soft output decoder, iterative decoder, and soft decision value calculating method

摘要

A soft output decoder that receives code words corresponding to information words is provided. The soft output decoder calculates soft decision decoding results of the information words from likelihood values corresponding to candidate values adopted by the information words. The soft output decoder includes a hard decision decoder that decides one of the candidate values as an estimated value. The soft output decoder further includes a likelihood calculator that bans calculation of a likelihood value corresponding to the estimated value and that calculates other likelihood values corresponding to other candidate values in the likelihood values.