Codes with multi-level error-correcting capabilities (original) (raw)

In conventional channel coding, all the information symbols of a message are regarded equally significant, and hence codes are devised to provide equal protection for each information symbol against channel errors. However, in some circumstances, some information symbols in a message are more significant than the other symbols. As a result, it is desirable to devise codes with multi-level error-correcting capabilities. In this paper, we investigate block codes with multi-level error-correcting capabilities, which are also known as unequal error protection (UEP) codes. Several classes of UEP codes are constructed. One class of codes satisfies the Hamming bound on the number of parity-check symbols for systematic linear UEP codes and hence is optimal.