| 摘要 |
PURPOSE:To simplify a correction processing work, by finding the number, the positions, and the values of errors by using a prescribed coefficient of error location polynomial found by recognizing that the errors of two words exist in the information of a received n-words. CONSTITUTION:Four syndromes S0-S3 are found from the parity matrix H of a block of n-words including a root (alpha) which satisfies an irreducible polynomial F(x)=0 on a GF(2) and the information VT by the arithmetic calculation of H.VT, and error correction is performed based on the syndromes. At this time, it is assumed that the errors of two words exist in the information of n-words, and Aalpha<2i>+Balpha<i>+C=0 is found as an error location. Coefficients A, B, and C are found from respective syndrome. lt is decided that no error exists, or the error of one word exists if all of the coefficients are 0s, and when the relation is not satisfied, it is decided that the errors of two or more words exist. The error of one word is corrected when it is decided that the error of one word exists, and the errors of two words are corrected when it is decided that the errors of two or more words exist by using the coefficients A-C, and existence more than that is detected. By such constitution, it is possible to easily and exactly correct the error.
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