讲座内容：

Classical error-correcting codes under the Hamming metric are used to correct substitution and erasure errors. Motivated by the limitations of the reading process in high density data storage systems, a different class of codes, called symbol-pair (metric) codes, was designed to protect against pair errors in symbol-pair read channels, where the outputs are overlapping pairs of symbols. As in the classical setting, a q-ary symbol-pair code has three parameters: the code length n, the code size M and the minimum pair distance d; establishing bounds for the parameters of symbol-pair codes is an important issue. In this talk, several new upper and lower bounds on the code size of symbol-pair codes are presented. In addition, we show that any symbol-pair code over Fq can be viewed as a Hamming metric code over Fq2 with the same parameters. Consequently, the theory of classical codes over Fq2 can be used directly to symbol-pair codes; in particular, by virtue of this result, some previously known results can be reobtained immediately. This talk is based on joint work with Bocong Chen.