词条 | Enumerator polynomial |
释义 |
In coding theory, the weight enumerator polynomial of a binary linear code specifies the number of words of each possible Hamming weight. Let be a binary linear code length . The weight distribution is the sequence of numbers giving the number of codewords c in C having weight t as t ranges from 0 to n. The weight enumerator is the bivariate polynomial Basic propertiesMacWilliams identityDenote the dual code of by (where denotes the vector dot product and which is taken over ). The MacWilliams identity states that The identity is named after Jessie MacWilliams. Distance enumeratorThe distance distribution or inner distribution of a code C of size M and length n is the sequence of numbers where i ranges from 0 to n. The distance enumerator polynomial is and when C is linear this is equal to the weight enumerator. The outer distribution of C is the 2n-by-n+1 matrix B with rows indexed by elements of GF(2)n and columns indexed by integers 0...n, and entries The sum of the rows of B is M times the inner distribution vector (A0,...,An). A code C is regular if the rows of B corresponding to the codewords of C are all equal. References
3 : Coding theory|Error detection and correction|Mathematical identities |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。