| 摘要 |
The invention simultaneously calculates error locations and associated error values by solving the error locator polynomial equation re-written as: 1= delta even(x)+ delta odd(x) where delta even(x) and delta odd(x) are the even- and odd-power terms of the error locator polynomial. A first value of x, xa1, is simultaneously inserted into the expression delta even(x) and delta odd(x) and also into an error value polynomial PHI (x). Next, while the error locator equation is evaluated at the calculated values of delta even(xa1) and delta odd(xa1) to determine if xa1 is a solution, the now known values of the error evaluator polynomial PHI (xa1) and delta odd(xa1) are substituted into an error value formula: <IMAGE> Thus as soon as an error location is found, the error value, va1, associated with that location is also known. The error can then be quickly corrected. Next, these calculated terms are used to calculate similar expressions for a next value of x, xa2. If xa2 is a solution, the error value va2 which was simultaneously calculated for xa2 is used to correct the error. If xa2 is not a solution, the calculated error value is ignored. The expression delta odd(x), delta even(x) and the polynominal PHI (x) are similarly evaluated for each of the remaining values of x.
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