Extension of Welch-Berlekamp theorem and universal strategy of decoding algorithm beyond BCH bound

In consideration of decoding cydic codes, a general formula for error pattern prediction is obtained. It extends the Welch-Berlekamp theorem and expands the Welch-Berlekamp algorithm, so that the limitation from BCH bound is broken, and the algorithm turns into a universal one which meets the actual minimum distance as well as complete decoding beyond the minimum distance in the case of decoding BCH codes and general cydic codes.