Patent ID: 6668026
Filing Date: 2003-12-23
Classification: H03M

Abstract:
A decoding method of decoding, in the soft-output Viterbi manner, an input convolutional code to provide a decoded data and likelihood information, comprising steps ofstoring, into a random-accessible path selection information storing means, path selection information indicative of more likely paths selected at each transition of the convolutional code; storing, based on a trace result signal indicative of a result of a tracing effected for a terminating length based on the path selection information, a result of tracing of a most likely path being a sequence most likely to that of the convolutional code into a trace result storing means; selecting, based on a delayed trace result signal indicative of a result of tracing of the most likely path stored in the trace result storing means and thus delayed, a metric difference for the most likely path from a metric difference delay signal resulted from a delay of the metric difference when the more likely paths are selected at each transition of the convolutional code, and storing it into a metric difference storing means; storing, based on the delayed trace result signal and a delayed most likely metric difference signal indicative of a metric difference for the most likely path stored in the metric difference storing means, a minimum value of the metric difference for the most likely path into a minimum value storing means at each transition of the convolutional code; and acquiring the likelihood information based on the minimum value.