| 摘要 |
PURPOSE:To use to the full the error correcting ability of a code by applying a decoding method which satisfies 2p+q=d-1 in case the correction is given to a (p) word whose error position is unknown and a (q) word whose error position is known respectively with a code having its minimum distance (d). CONSTITUTION:A data input/output terminal 14 is connected to a data bus 17 for transfer of data on an error of a reception signal, a pattern, etc., a location bus 18 for transfer of the data on the data position, etc. and a flag bus 19 for transfer of the data on the flag added to the data respectively. A syndrome generating circuit 20 produced syndromes S0-S3 from the reception signal supplied through a data input/output terminal 12. Then these syndromes are used to perform an operation 24 in order to obtain both an error position and an error pattern. For the 1st decoding process, an error detection is given to the 2nd code block as well as a correction given to a (p1) word satisfying p1<=d2-1. At the same time, a flag showing the decoding state is added. For the 2nd decoding process, an error detection is given to the 1st code block together with corrections given to an error of an optional (p2) word satisfying 2p2+q-1<=d1+1 as well as to an error of a (q) word to which the corresponding flag is added. |
