Patent ID: 6385753
Filing Date: 2002-05-07
Classification: H03M

Abstract:
A punctured Viterbi decoding method that performs maximum-likelihood decoding using a Viterbi algorithm corresponding to data that has been generated as a result of an operation that thins out data at predetermined intervals of a convolutional code, comprising the steps of:(a) detecting whether received data has been thinned out for each decoding process unit composed of a predetermined number of symbols; (b) calculating a value of a branch metric for each decoding process unit corresponding to the received data; (c) performing ACS calculation for calculating values of path metrics for a plurality of states corresponding to the result of the step of calculating, the number of states having been predetermined corresponding to a convolutional code encoding process, selecting a maximum likelihood state transition corresponding to the values of the calculated path metrics, and generating path selection information that represents a result of the step of selecting; (d) performing a trace-back process for generating decoded data corresponding to the values of the path metrics and the path selection information; (e) prohibiting the step of performing a trace-back process when the decoding process unit has been thinned out as indicated by a determined result of the step of detecting; and (f) setting an initial value corresponding to the decoding process unit and executing the step of performing a trace-back process when the decoding process unit has not been thinned out as indicated by the determined result of the step of detecting.