| 摘要 |
PROBLEM TO BE SOLVED: To execute optimum Viterbi decoding with high stability and reliability in accordance with noise on a transmission line. SOLUTION: A noise intensity measuring unit 12 measures noise intensity contained in multiplex data obtained by multiplexing plural code system which are encoded by a convolution code and in which encoding rates and modulation systems are individually set. When noise intensity that the comparator 14 measures is more than a preset value, the effect is informed and an initialization signal is inputted to a Viterbi decoder 220 at timing when the decoding of the individual code systems is started, and a multiplex control signal generator 205 inputs the initialization signal to the Viterbi decoder 220 at timing when the decoding of the individual code systems is started. Thus, the path metric operated by the Viterbi decoder 220 is initialized.
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