Recently a construction of optimal non-constant dimension subspace codes, also termed projective space codes, has been reported in a paper of Honold-Kiermaier-Kurz. Restricted to binary codes in a 5-dimensional ambient space with minimum subspace distance 3, these optimal codes may be interpreted in terms of maximal partial spreads of 2-dimensional subspaces. In a parallel development, an optim...

A new class of binary constant weight codes is presented. We establish new lower bound and exact values on A(n, 2k, k + 1), in particular, A(30, 12, 7) = 9, A(48, 16, 9) = 11, A(51,16, 9) = 12, A(58, 18, 10) = 12. An ( ) w d n , , constant weight binary code is a code of length n , code distance d in which all code words have the same number of “ones” . The number of “ones” is w . We will denot...

Binary constant-weight codes have been extensively studied, due to both their numerous applications and to their theoretical significance. In particular, constant-weight codes have been proposed for error correction in store and forward. In this paper, we introduce constant-weight array codes (CWACs), which offer a tradeoff between the rate gain of general constant-weight codes and the low deco...

Let A3(n, d,w) denote the maximum cardinality of a ternary code with length n, minimum distance d, and constant Hamming weight w. Methods for proving upper and lower bounds on A3(n, d,w) are presented, and a table of exact values and bounds in the range n ≤ 10 is given.

In this paper, we propose a class of linear codes and obtain their weight distribution. Some of these codes are almost optimal. Moreover, several classes of constant composition codes(CCCs) are constructed as subcodes of linear codes.