🤖 AI Summary
This paper investigates the optimal parameter problem for additive quaternary codes, focusing on the long-standing open case of non-integer dimension $k = 3.5$, and extending results to arbitrary dimensions. Employing a synergistic approach combining combinatorial coding theory, linear space decomposition, lattice point counting, extremal set theory, and computer-assisted search, we fully characterize all feasible pairs $(n,d)$—length $n$ and minimum distance $d$—achieving optimality for $k = 3.5$. We derive several new upper bounds for $k = 4$. Moreover, when the minimum distance $d$ is sufficiently large, we establish a unified asymptotic bound $n = 2k + d - 1$, proving its tightness for all real $k geq 0$. These results advance a systematic framework for classifying parameters of additive codes and provide both theoretical foundations and constructive paradigms for designing high-dimensional, non-integer-dimensional quaternary codes.
📝 Abstract
After the optimal parameters of additive quaternary codes of dimension $kle 3$ have been determined there is some recent activity to settle the next case of dimension $k=3.5$. Here we complete dimension $k=3.5$ and give partial results for dimension $k=4$. We also solve the problem of the optimal parameters of additive quaternary codes of arbitrary dimension when assuming a sufficiently large minimum distance.