Fractional decoding of algebraic geometry codes over extension fields
Eduardo Camps-Moreno, Gretchen L. Matthews, Welington Santos
TL;DR
The work presents a unified framework for fractional decoding of algebraic geometry codes over extension fields by exploiting virtual projections to base-field codes. By formulating $t$-virtual projections $\mathcal{VP}_t(G,D)$ and organizing evaluation points via annihilator polynomials, the authors show how to recover $\mathrm{ev}(f)$ from a reduced amount of base-field data, with concrete error bounds tied to pole-divisor degrees. They further leverage interleaved-code perspectives to potentially decode more errors with high probability, using established interleaved-AG decoding methods and power-decoding strategies. The approach is applicable to broad families of AG codes, including those from Kummer extensions and Castle curves, and offers practical benefits for distributed storage and network-constrained settings where decoding bandwidth is critical.
Abstract
In this paper, we study algebraic geometry codes from curves over $\mathbb{F}_{q^\ell}$ through their virtual projections which are algebraic geometric codes over $\mathbb{F}_q$. We use the virtual projections to provide fractional decoding algorithms for the codes over $\mathbb{F}_{q^\ell}$. Fractional decoding seeks to perform error correction using a smaller fraction of $\mathbb{F}_q$-symbols than a typical decoding algorithm. In one instance, the bound on the number of correctable errors differs from the usual lower bound by the degree of a pole divisor of an annihilator function. In another, we view the virtual projections as interleaved codes to, with high probability, correct more errors than anticipated.
