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Related papers: Subspace codes in PG(2n-1,q)

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In this paper we construct constant dimension space codes with prescribed minimum distance. There is an increased interest in space codes since a paper by Koetter and Kschischang were they gave an application in network coding. There is…

Information Theory · Computer Science 2009-01-13 Axel Kohnert , Sascha Kurz

Constant dimension codes (CDCs), as special subspace codes, have received extensive attention due to their applications in random network coding. The basic problem of CDCs is to determine the maximal possible size $A_q(n,d,\{k\})$ for given…

Information Theory · Computer Science 2025-07-11 Han Li , Fang-Wei Fu

One of the main problems of subspace coding asks for the maximum possible cardinality of a subspace code with minimum distance at least $d$ over $\mathbb{F}_q^n$, where the dimensions of the codewords, which are vector spaces, are contained…

Combinatorics · Mathematics 2019-12-24 Daniel Heinlein , Michael Kiermaier , Sascha Kurz , Alfred Wassermann

We study asymptotic lower and upper bounds for the sizes of constant dimension codes with respect to the subspace or injection distance, which is used in random linear network coding. In this context we review known upper bounds and show…

Combinatorics · Mathematics 2017-12-06 Daniel Heinlein , Sascha Kurz

Subspace codes are the $q$-analog of binary block codes in the Hamming metric. Here the codewords are vector spaces over a finite field. They have e.g. applications in random linear network coding, distributed storage, and cryptography. In…

Information Theory · Computer Science 2025-12-23 Sascha Kurz

A $q$-covering design $\mathbb{C}_q(n, k, r)$, $k \ge r$, is a collection $\mathcal X$ of $(k-1)$-spaces of $\mathrm{PG}(n-1, q)$ such that every $(r-1)$-space of $\mathrm{PG}(n-1, q)$ is contained in at least one element of $\mathcal X$ .…

Combinatorics · Mathematics 2019-04-30 Francesco Pavese

Constant-dimension subspace codes (CDCs), a special class of subspace codes, have attracted significant attention due to their applications in network coding. A fundamental research problem of CDCs is to determine the maximum number of…

Information Theory · Computer Science 2025-08-05 Gang Wang , Hong-Yang Yao , Fang-Wei Fu

Constant dimension codes (CDCs) are essential for error correction in random network coding. A fundamental problem of CDCs is to determine their maximal possible size for given parameters. Inserting construction and multilevel construction…

Information Theory · Computer Science 2025-02-19 Han Li , Fang-Wei Fu

Constant dimension codes (CDCs), as special subspace codes, have received a lot of attention due to their application in random network coding. This paper introduces a family of new codes, called rank metric codes with given ranks (GRMCs),…

Combinatorics · Mathematics 2019-11-06 Shuangqing Liu , Yanxun Chang , Tao Feng

A $t$-intersecting constant dimension subspace code $C$ is a set of $k$-dimensional subspaces in a projective space PG(n,q), where distinct subspaces intersect in a $t$-dimensional subspace. A classical example of such a code is the…

Combinatorics · Mathematics 2021-05-24 Aart Blokhuis , Maarten De Boeck , Jozefien D'haeseleer

A constant-dimension code (CDC) is a set of subspaces of constant dimension in a common vector space with upper bounded pairwise intersection. We improve and generalize two constructions for CDCs, the improved linkage construction and the…

Combinatorics · Mathematics 2019-11-14 Daniel Heinlein

The subspace design property for additive codes is a higher-dimensional generalization of the minimum distance property. As shown recently by Brakensiek, Chen, Dhar and Zhang, it implies that the code has similar performance as random…

Information Theory · Computer Science 2026-04-17 Rohan Goyal , Venkatesan Guruswami , Jun-Ting Hsieh

This paper provides new constructive lower bounds for constant dimension codes, using different techniques such as Ferrers diagram rank metric codes and pending blocks. Constructions for two families of parameters of constant dimension…

Information Theory · Computer Science 2014-09-03 Natalia Silberstein , Anna-Lena Trautmann

A permutation-invariant quantum code on $N$ qudits is any subspace stabilized by the matrix representation of the symmetric group $S_N$ as permutation matrices that permute the underlying $N$ subsystems. When each subsystem is a complex…

Quantum Physics · Physics 2017-07-04 Yingkai Ouyang

One of the main problems of the research area of network coding is to compute good lower and upper bounds of the achievable cardinality of so-called subspace codes in $\operatorname{PG}(n,q)$, i.e., the set of subspaces of $\mathbb{F}_q^n$,…

Combinatorics · Mathematics 2017-09-27 Daniel Heinlein , Sascha Kurz

In this paper, we generalize the method of using two parallel versions of the lifted MRD code from the existing work [1]. The Delsarte theorem of the rank distribution of MRD codes is an important part to count codewords in our…

Information Theory · Computer Science 2019-11-04 Xianmang He , Yindong Chen

In this article, constant dimension subspace codes whose codewords have subspace distance in a prescribed set of integers, are considered. The easiest example of such an object is a {\it junta}; i.e. a subspace code in which all codewords…

Combinatorics · Mathematics 2021-08-09 Giovanni Longobardi , Leo Storme , Rocco Trombetti

We show that $A_2(7,4) \leq 388$ and, more generally, $A_q(7,4) \leq (q^2-q+1)[7]_q + q^4 - 2q^3 + 3q^2 - 4q + 4$ by semidefinite programming for $q \leq 101$. Furthermore, we extend results by Bachoc et al. on SDP bounds for $A_2(n,d)$,…

Combinatorics · Mathematics 2020-11-02 Daniel Heinlein , Ferdinand Ihringer

Constant dimension codes are used for error control in random linear network coding, so that constructions for these codes with large cardinality have achieved wide attention in the last decade. Here, we improve the so-called linkage…

Combinatorics · Mathematics 2020-05-06 Sascha Kurz

Subspace codes are collections of subspaces of a projective space such that any two subspaces satisfy a pairwise minimum distance criterion. Recent results have shown that it is possible to construct optimal $(5,3)$ subspace codes from…

Information Theory · Computer Science 2021-05-05 Anirban Ghatak , Sumanta Mukherjee