Patent Document ID: 20080120529
Application ID: 11942500
Patent Flag: 0

Claim One:
1. A soft decision value correction method for correcting a soft decision value generated by demodulating means in a receiver equipped with demodulating means for generating the soft decision value used in decoding an error correcting code, (i) by mapping each symbol of N-bits, N being an integer greater than or equal to 1, for an input bit string that has been coded with the error correcting code and has been rearranged by interleaving at any one of 2 N reference mapping locations on a complex plane, and (ii) by demodulating a reception signal that was modulated so as to become a signal having an amplitude and a phase correlated to the reference mapping location at which mapping was done, the soft decision value correction method comprising: (1) a variation degree calculation process of calculating a variation degree of the reception signal; and (2) a soft decision value correction process of, when the variation degree calculated in the variation degree calculation process is more than or equal to a prespecified normal threshold, determining that interference in the reception signal occurs, and correcting the soft decision value for each symbol so that a contribution to decoding of the error correcting code may decrease.