| 摘要 |
According to an aspect of the present invention, there is provided a decoder for decoding a demodulated signal that has been subjected to a CDM demodulation, the decoder comprising a Viterbi decoding section that subjects a convolutional code to a soft decision Viterbi decoding; a soft decision data acquisition section that acquires soft decision data corresponding to a interval to which the demodulated signal belongs, using soft decision information in which a plurality of intervals obtained by dividing between a highest level and a lowest level according to a plurality of thresholds correspond to pieces of soft decision data to be input to the Viterbi decoding section, respectively; and a threshold changing section that determines whether a situation of a transmission line is suitable, and that changes threshold intervals in the soft decision information if the state of the transmission line does not satisfy a predetermined reference. |
