Patent ID: 6081920
Filing Date: 2000-06-27
Classification: H03M

Abstract:
A method for error correcting an RS codeword in a communications system comprising the steps of:receiving a signal stream representing a plurality of RS codewords;isolating a single RS codeword;storing the codeword in memory;determining the syndromes of the codeword;determining the number of errors in the codeword using said syndromes, comprising the steps of:returning a value of 0 for said number of errors in the codeword and ending all of said steps if all of said syndromes are equal to 0;determining the determinant for a 3.times.3 matrix containing said syndromes if not all of said syndromes are equal to 0;returning a value of 3 for said number of errors in the codeword if said determinant of said 3.times.3 matrix is not equal to 0;determining the determinant for a 2.times.2 matrix containing said syndromes if said determinant of said 3.times.3 matrix is not equal to 0;returning a value of 2 for said number of errors in the codeword if said determinant of said 2.times.2 matrix is not equal to 0;determining the determinant for a 1.times.1 matrix containing said syndromes if said determinant of said 2.times.2 matrix is not equal to 0;returning a value of 1 for said number of errors in the codeword if said determinant of said 1.times.1 matrix is not equal to 0;returning a condition that errors exist in the codeword, but the errors are unsolvable if said determinant of said 1.times.1 matrix is equal 0;finding the error locator polynomial of the codeword;determining the locations of the errors by finding the inverses of the roots of said error locator polynomial; anddetermining the values of the errors by using the locations of the errors and the syndromes.