Sistemnyj Analiz i Prikladnaâ Informatika (May 2020)
Syndrome spectrums of error orbits in RS-codes
Abstract
This article is devoted to the research of the properties of syndromes of errors in Reed-Solomon codes. RS-codes are built on non-binary alphabets. So, unlike BCH-codes, RS-codes contain an extremely large variety of correctable errors. To correct these errors, a systematic application of automorphisms of codes is proposed. Characteristic automorphisms of RS-codes are cyclic and affine substitutions forming cyclic groups Г and A whose orders coincide with the code length. Cyclic and affine substitutions commute with each other and generate a joint АГ group, what is the product of subgroups A and Г. These three groups act on the space of error vectors of RS-codes, breaking this space into three types of error orbits. As a rule, these orbits are complete and contain the maximum possible number of errors. Syndromes are the main indicator of the presence of errors in each message received by the information system, a means of accurately identifying these errors. The specificity of syndromes of double errors in RS-codes is investigated. Determined that syndrome spectrums of error orbits are also complete in most cases. Proved that the structure of the syndrome spectrums copies the structure of the orbits themselves, which in turn copy the structure of groups of code automorphisms. The results obtained are a significant contribution to the construction of the theory of syndrome norms for RS-codes.
Keywords