منابع مشابه
Upper bounds for constant-weight codes
Let ( ) denote the maximum possible number of codewords in an ( ) constant-weight binary code. We improve upon the best known upper bounds on ( ) in numerous instances for 24 and 12, which is the parameter range of existing tables. Most improvements occur for = 8 10 where we reduce the upper bounds in more than half of the unresolved cases. We also extend the existing tables up to 28 and 14. To...
متن کاملUpper Bounds for Constant - Weight
| Let A(n; d; w) denote the maximum possible number of codewords in an (n; d; w) constant-weight binary code. We improve upon the best known upper bounds on A(n; d; w) in numerous instances for n 6 24 and d 6 10, which is the parameter range of existing tables. Most improvements occur for d = 8; 10, where we reduce the upper bounds in more than half of the unresolved cases. We also extend the e...
متن کاملNew lower bounds for constant weight codes
with M (which is expected). However, as M increases beyond Ahstrart -Some new lower bounds are given for A(n,4, IV), the maximum number of codewords in a binary code of length n, min imum distance 4, and constant weight IV. In a number of cases the results significantly 1.0 improve on the best bounds previously known. h=O 1 .
متن کاملUpper bounds for ternary constant weight codes from semidefinite programming and representation theory
In this thesis we use a semidefinite programming approach to find explicit upper bounds on the size of ternary constant weight codes with prescribed minimum distance d. By constructing a graph Γ = (X,E), on the set, X, of all possible ternary words of weight w letting {x, y} ∈ E ⇔ 0 < dH(x, y) < d, we can view this problem as a special case of the stable set problem. Using symmetry, the constra...
متن کاملBounds on the Sizes of Constant Weight Covering Codes
Motivated by applications in universal data compression algorithms we study the problem of bounds on the sizes of constant weight covering codes. We are concerned with the minimal sizes of codes of length n and constant weight u such that every word of length n and weight v is within Hamming distance d from a codeword. In addition to a brief summary of part of the relevant literature, we also g...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: IEEE Transactions on Information Theory
سال: 2000
ISSN: 0018-9448
DOI: 10.1109/18.887851