Error-Correcting Graph Codes

TL;DR

This paper introduces error-correcting graph codes, extending classical error correction to graph structures, and presents new theoretical bounds, constructions, and analogues of classical codes like Reed-Solomon and BCH for graphs.

Contribution

It provides nonconstructive bounds, new graph code constructions analogous to Reed-Solomon and BCH codes, and explicit large-distance graph codes, advancing the theory of graph-based error correction.

Findings

Determined optimal rate vs. distance trade-offs nonconstructively.

Constructed graph code analogues of Reed-Solomon and concatenated codes.

Developed graph code analogues of dual-BCH codes with near-maximal distance.

Abstract

In this paper, we construct Error-Correcting Graph Codes. An error-correcting graph code of distance $\delta$ is a family $C$ of graphs on a common vertex set of size $n$, such that if we start with any graph in $C$, we would have to modify the neighborhoods of at least $\delta n$ vertices in order to obtain some other graph in $C$. This is a natural graph generalization of the standard Hamming distance error-correcting codes for binary strings. Yohananov and Yaakobi were the first to construct codes in this metric, constructing good codes for $\delta < 1/2$, and optimal codes for a large-alphabet analogue. We extend their work by showing 1. Combinatorial results determining the optimal rate vs. distance trade-off nonconstructively. 2. Graph code analogues of Reed-Solomon codes and code concatenation, leading to positive distance codes for all rates and positive rate codes for all distances. 3. Graph code analogues of dual-BCH codes, yielding large codes with distance $\delta = 1-o(1)$. This gives an explicit ''graph code of Ramsey graphs''. Several recent works, starting with the paper of Alon, Gujgiczer, K\"orner, Milojevi\'c, and Simonyi, have studied more general graph codes; where the symmetric difference between any two graphs in the code is required to have some desired property. Error-correcting graph codes are a particularly interesting instantiation of this concept.