| 摘要 |
<p>Data words encoded in a Bose-Chaudhuri-Hocquenghem (BCH) code are read from a document (14) and applied to a processor (26) and decoder (28) which check the word and correct errors therein, up to two errors being correctable in the embodiment described. Respective modules (46, 48, 50) compute power sum symmetric functions S1, S2, S3 which are utilized to indicate the location of errors. To provide for the location of two errors, the value of S3/S1 is calculated by utilizing a Galois field table (74, 76) arranged in an anti-log and log format. The Galois field table is also utilized in determining the location of a single error by utilizing S1 as an anti-log. Errors which have been located are corrected by inventing the incorrect binary digit. </p> |
