| 摘要 |
A method and apparatus for encoding/decoding data, wherein for one embodiment, during [During] encoding, a microprocessor (201) calculates Ym by standard Reed-Solomon encoding techniques. The microprocessor (201) then utilizes Ym as an index to a look-up table (203), and is returned G0Ym, G1Ym, . . . , GK-1Ym, from the look-up table (203). During syndrome calculation, a second set of parity symbols are generated from the information symbols using the method similar to the encoder, in particular, values for G0Ym, . . . , GK-,Y. are obtained from a first look-up table (503) in a similar manner as encoder to determine the values for G0Ym, G1Ym, . . . , GK-1Ym. A second look-up table (505) is set up to determine roots of the error locator polynomial. The second look-up table consists of several tables and each table contains (Q-1) elements, where Q is the size of the GF(Q) field. The mth look-up table stores Galois Field element alpha-mi at location i if the greatest common denominator between (Q-1) and m (GCD(Q-1,m))=1. If GCD(Q-1,m)<> 1, then the mth look-up table actually consists of (GCD(Q-1,m) sub-tables storing GF element alpha-(mi=i), where j=0, 1, . . ., GCD(Q-1,m)-1.
|
