Soft-output decoder, iterative decoding apparatus, and a soft decision value calculation method

摘要

Making the operational quantity which is required for likelihood calculation small, the soft output decoder which can assure the reduction of miniaturization of the operational circuit and processing delay time. This soft output decoder (100), the calculation section (101), the timing regulator (102,103), the calculation section (104), and the calculation section (110) it has, the calculation section (110), the decision decoding section (111), is defeated hard and the likelihood calculation section (112), wins and the likelihood memory section (113), and the subtracter (114) has, the plural likelihood which are required in the Max log MAP decoder it wins and distinguishes to likelihood and being defeated likelihood, is defeated and calculates only likelihood. In addition, it wins and the decision which consecutively specifies decoding section (111) it uses the state which maximum likelihood pass passes as the method of distinguishing likelihood and being defeated likelihood, hard.