A decoding method for binary two-error correcting cyclic codes whose generator polynomials have at most two irreducible factors is presented. This class includes binary narrow-sense BCH codes with designed distance 5. The decoding algorithm uses the Zech logarithm for the finite field in which the roots of the code lie.>

The decoding of unequal error protection product codes, which are a combination of linear unequal error protection (UEP) codes and product codes, is addressed. A nonconstructive proof of the existence of a good error-erasure-decoding algorithm is presented; however, obtaining the decoding procedure is still an open research problem. A particular subclass of UEP product codes is considered, including a decoding algorithm that is an extension of the Blokh-Zyablov decoding algorithm for product codes. For this particular subclass the decoding problem is solved.>

It is shown that error-erasure decoding for a cyclic code allows the correction of a combination of t errors and r erasures when 2t+r>

The BCH algorithm is extended to correct more errors than indicated by the BCH bound. In the first step of the decoding procedure, a number of errors corresponding to a particular case of the Hartmann-Tzeng bound are corrected. In the second step full error correction is the goal. A measure for the worst-case number of field elements of an extension field GF(2/sup m/) that must be tested for this purpose is given for binary cyclic linear unequal error protection codes as well as for conventional binary cyclic codes.>