| 摘要 |
PROBLEM TO BE SOLVED: To provide a decoder that makes it possible to simplify/reduce in size an arithmetic circuit for determining an initial value and a generating polynomial to be used for descrambling.SOLUTION: A decoder for decoding a digital data series scrambled using a maximal length series comprises: code generation element storage means that stores a generation polynomial coefficient series and an initial value series for an estimation formula for estimating a decoded data series from a demodulation data series including a scrambled digital data series, and receives a result of correctness determination of the estimation formula to change the generation polynomial coefficient series and the initial value series; decoding calculation means that acquires a generation polynomial coefficient series and an initial value series and decodes a demodulation data series to obtain a decoded data series by using the estimation formula; statistic calculation means for calculating a statistic on randomness of runs with respect to the decoded data series; and determination means that determines correctness of the estimation formula on the basis of the statistic and outputs a result of the determination on correctness of the estimation formula to the code generation element storage means.SELECTED DRAWING: Figure 1 |
