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Related papers: Improved Decoding of Expander Codes

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We give a linear-time erasure list-decoding algorithm for expander codes. More precisely, let $r > 0$ be any integer. Given an inner code $C_0$ of length $d$, and a $d$-regular bipartite expander graph $G$ with $n$ vertices on each side, we…

Information Theory · Computer Science 2020-02-21 Noga Ron-Zewi , Mary Wootters , Gilles Zémor

Expander (Tanner) codes combine sparse graphs with local constraints, enabling linear-time decoding and asymptotically good distance--rate tradeoffs. A standard constraint-counting argument yields the global-rate lower bound $R\ge 2r-1$ for…

Information Theory · Computer Science 2026-03-27 Swastik Kopparty , Itzhak Tamo

We strengthen the notion of "double samplers", first introduced by Dinur and Kaufman [Proc. 58th FOCS, 2017], which are samplers with additional combinatorial properties, and whose existence we prove using high dimensional expanders. The…

Computational Complexity · Computer Science 2022-11-24 Irit Dinur , Prahladh Harsha , Tali Kaufman , Inbal Livni Navon , Amnon Ta Shma

The classical way of extending an $[n, k, d]$ linear code $\C$ is to add an overall parity-check coordinate to each codeword of the linear code $\C$. This extended code, denoted by $\overline{\C}(-\bone)$ and called the standardly extended…

Information Theory · Computer Science 2023-12-05 Zhonghua Sun , Cunsheng Ding , Tingfang Chen

We present a novel error correcting code and decoding algorithm which have construction similar to expander codes. The code is based on a bipartite graph derived from the subsumption relations of finite projective geometry, and Reed-Solomon…

Information Theory · Computer Science 2012-09-18 Swadesh Choudhary , Hrishikesh Sharma , B. S. Adiga , Sachin Patkar

It is shown that the good expander codes introduced by Sipser and Spielman, can be realized as the first homology of a graph with respect to a certain twisted coefficient system.

Combinatorics · Mathematics 2018-03-16 Roy Meshulam

Tanner codes are long error correcting codes obtained from short codes and a graph, with bits on the edges and parity-check constraints from the short codes enforced at the vertices of the graph. Combining good short codes together with a…

Quantum Physics · Physics 2022-09-19 Anthony Leverrier , Gilles Zémor

We study ensembles of codes on graphs (generalized low-density parity-check, or LDPC codes) constructed from random graphs and fixed local constrained codes, and their extension to codes on hypergraphs. It is known that the average minimum…

Information Theory · Computer Science 2011-02-22 Alexander Barg , Arya Mazumdar

Understanding the limits of list-decoding and list-recovery of Reed-Solomon (RS) codes is of prime interest in coding theory and has attracted a lot of attention in recent decades. However, the best possible parameters for these problems…

Information Theory · Computer Science 2021-06-01 Eitan Goldberg , Chong Shangguan , Itzhak Tamo

Consider an ensemble of regular generalized LDPC (GLDPC) codes and assume that the same component code is associated with each parity check node. To decode a GLDPC code from the ensemble, we use the bit flipping bounded distance decoding…

Information Theory · Computer Science 2025-07-17 David Burshtein

A systematic convolutional encoder of rate $(n-1)/n$ and maximum degree $D$ generates a code of free distance at most ${\cal D} = D+2$ and, at best, a column distance profile (CDP) of $[2,3,\ldots,{\cal D}]$. A code is \emph{Maximum…

Information Theory · Computer Science 2017-05-30 Ángela Barbero , Øyvind Ytrehus

Folded Reed-Solomon (FRS) codes are variants of Reed-Solomon codes, known for their optimal list decoding radius. We show explicit FRS codes with rate $R$ that can be list decoded up to radius $1-R-\epsilon$ with lists of size…

Information Theory · Computer Science 2024-10-14 Shashank Srivastava

Length-constrained expander decompositions are a new graph decomposition that has led to several recent breakthroughs in fast graph algorithms. Roughly, an $(h, s)$-length $\phi$-expander decomposition is a small collection of length…

Data Structures and Algorithms · Computer Science 2025-10-14 Greg Bodwin , Bernhard Haeupler , D Ellis Hershkowitz , Zihan Tan

The decoding error probability of codes is studied as a function of their block length. It is shown that the existence of codes with a polynomially small decoding error probability implies the existence of codes with an exponentially small…

Information Theory · Computer Science 2007-07-13 Alexei Ashikhmin , Vitaly Skachek

We study the problem of graph clustering where the goal is to partition a graph into clusters, i.e. disjoint subsets of vertices, such that each cluster is well connected internally while sparsely connected to the rest of the graph. In…

Data Structures and Algorithms · Computer Science 2021-12-17 Thatchaphol Saranurak , Di Wang

Codes on hypergraphs are an extension of the well-studied family of codes on bipartite graphs. Bilu and Hoory (2004) constructed an explicit family of codes on regular t-partite hypergraphs whose minimum distance improves earlier estimates…

Information Theory · Computer Science 2008-12-10 Alexander Barg , Arya Mazumdar , Gilles Zémor

We define multilevel codes on bipartite graphs that have properties analogous to multilevel serial concatenations. A decoding algorithm is described that corrects a proportion of errors equal to half the Blokh-Zyablov bound on the minimum…

Information Theory · Computer Science 2007-07-16 Alexander Barg , Gilles Zemor

The Ulam distance of two permutations on $[n]$ is $n$ minus the length of their longest common subsequence. In this paper, we show that for every $\varepsilon>0$, there exists some $\alpha>0$, and an infinite set $\Gamma\subseteq…

Information Theory · Computer Science 2024-05-14 Elazar Goldenberg , Mursalin Habib , Karthik C. S

This paper improves the antiGriesmer bound for linear anticodes previously established by Chen and Xie (Journal of Algebra, 673 (2025) 304-320). While the original bound required the code length to satisfy $n < q^{k-1}$ and the dual code to…

Information Theory · Computer Science 2025-11-05 Guanghui Zhang , Bocong Chen , Liren Lin , Hongwei Liu

Certain simplicial complexes are used to construct a subset $D$ of $\mathbb{F}_{2^n}^m$ and $D$, in turn, defines the linear code $C_{D}$ over $\mathbb{F}_{2^n}$ that consists of $(v\cdot d)_{d\in D}$ for $v\in \mathbb{F}_{2^n}^m$. Here we…

Information Theory · Computer Science 2022-04-19 Vidya Sagar , Ritumoni Sarma