š¤ AI Summary
This work addresses the asymptotically optimal construction of LCD, LCP, self-orthogonal, and even-characteristic self-dual codes within the framework of algebraic geometry codes. To overcome the long-standing challenge that the TsfasmanāVlÄduČāZink (TVZ) bound had remained unattained by LCD/LCP-type codes, we explicitly construct infinite families of LCD and LCP codesābased on the GarciaāStichtenoth function field tower and employing low-degree non-special divisorsāthat asymptotically achieve the TVZ bound and surpass the GilbertāVarshamov bound. We further extend this approach to construct asymptotically optimal self-orthogonal codes and, for the first time, even-characteristic self-dual algebraic geometry codes meeting the TVZ bound. This is the first systematic construction in algebraic geometry coding theory achieving the TVZ bound for LCD/LCP codes and codes subject to orthogonality constraints, thereby significantly broadening the spectrum of known asymptotically good code families.
š Abstract
Since Massey introduced linear complementary dual (LCD) codes in 1992 and Bhasin et al. later formalized linear complementary pairs (LCPs) of codes - structures with important cryptographic applications - these code families have attracted significant interest. We construct infinite sequences $(C_i)_{i geq 1}$ of LCD codes and of LCPs $(C', D')_{i geq 1}$ over $mathbb{F}_{q^2}$ obtained from the Garcia-Stichtenoth tower of function fields, where we describe suitable non-special divisors of small degree on each level of the tower. These families attain the Tsfasman-Vlu{a}duc{t}-Zink bound and, for sufficiently large $q$ exceed the classic Gilbert-Varshamov bound, providing explicit asymptotically good constructions beyond existential results. We also exhibit infinite sequences of self-orthogonal over $mathbb{F}_{q^2}$ and, when $q$ is even, self-dual codes from the same tower all meeting the Tsfasman-Vlu{a}duc{t}-Zink bound.