Strongly Conflict-Avoiding Codes

Optimal strongly conflict-avoiding codes of even length and weight three

Strongly conflict-avoiding codes (SCACs) are employed in a slotasynchronous multiple-access collision channel without feedback to guarantee that each active user can send at least one packet successfully in the worst case within a fixed period of time. Assume all users are assigned distinct codewords, the number of codewords in an SCAC is equal to the number of potential users that can be suppo...

Partially user-irrepressible sequence sets and conflict-avoiding codes

In this paper we give a partial shift version of user-irrepressible sequence sets and conflict-avoiding codes. By means of disjoint difference sets, we obtain an infinite number of such user-irrepressible sequence sets whose lengths are shorter than known results in general. Subsequently, the newly defined partially conflict-avoiding codes are discussed.

A tight asymptotic bound on the size of constant-weight conflict-avoiding codes

In the study of multiple-access in the collision channel, conflict-avoiding code is used to guarantee that each transmitting user can send at least one packet successfully in the worst case within a fixed period of time, provided that at most k users out of M potential users are active simultaneously. The number of codewords in a conflict-avoiding code determines the number of potential users t...

Optimal conflict-avoiding codes of length n = 0 (mod 16) and weight 3

A conflict-avoiding code of length n and weight k is defined as a set C ⊆ {0, 1}n of binary vectors, called codewords, all of Hamming weight k such that the distance of arbitrary cyclic shifts of two distinct codewords in C is at least 2k − 2. In this paper, we obtain direct constructions for optimal conflict-avoiding codes of length n = 16m and weight 3 for any m by utilizing Skolem type seque...

Classification of optimal conflict-avoiding codes of weights 6 and 7