Description
Second-smallest nontrivial member of the simplex-code family. The columns of its generator matrix are in one-to-one correspondence with the elements of the projective space \(PG(2,2)\), with each column being a chosen representative of the corresponding element. The codewords form a \((8,9)\) simplex spherical code under the antipodal mapping. As a simplex code, it is equidistant: every nonzero codeword has Hamming weight \(4\).
Its generator matrix is \begin{align} \left(\begin{array}{ccccccc} 1 & 0 & 1 & 1 & 1 & 0 & 0 \\ 1 & 1 & 1 & 0 & 0 & 1 & 0 \\ 0 & 1 & 1 & 1 & 0 & 0 & 1 \\ \end{array}\right)~. \tag*{(1)}\end{align} The automorphism group of the code is \(GL(3,\mathbb{F}_2)\cong PSL(2,\mathbb{F}_7)\), the second-smallest non-abelian finite simple group.
Protection
Being a simplex code, it saturates the Plotkin bound [1; pg. 43].Cousins
- \([7,4,3]\) Hamming code— The \([7,3,4]\) simplex code is the dual of the Hamming code and also its even-weight subcode [2,3].
- \(E_7\) root lattice— The \([7,3,4]\) simplex code yields the \(E_7\) root lattice via Construction A [5][4; Exam. 10.5.3][6; pg. 138].
- Octacode— Codewords of the heptacode with entries 0 and 2 are of the form \(2c\), where \(c\) is a codeword of the \([7,3,4]\) simplex code [7; Exam. 5].
Member of code lists
- Algebraic-geometry codes
- Binary linear codes
- Classical codes
- Cyclic codes
- Evaluation codes
- LDPC codes
- Locally correctable codes and friends
- Locally decodable codes and friends
- Locally recoverable codes
- MDS codes and generalizations
- Orthogonal arrays and friends
- Projective codes
- Small-distance classical codes and friends
- Universally optimal codes
Primary Hierarchy
References
- [1]
- F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes (Elsevier, 1977)
- [2]
- W. Feit. Some remarks on weight functions of spaces over GF(2), unpublished (1972)
- [3]
- C. L. Mallows and N. J. A. Sloane, “Weight enumerators of self-orthogonal codes”, Discrete Mathematics 9, 391 (1974) DOI
- [4]
- T. Ericson and V. Zinoviev, eds., Codes on Euclidean Spheres (Elsevier, 2001)
- [5]
- J. H. Conway and N. J. A. Sloane, “On the Voronoi Regions of Certain Lattices”, SIAM Journal on Algebraic Discrete Methods 5, 294 (1984) DOI
- [6]
- J. H. Conway and N. J. A. Sloane, Sphere Packings, Lattices and Groups (Springer New York, 1999) DOI
- [7]
- M. Shi, T. Honold, P. Sole, Y. Qiu, R. Wu, and Z. Sepasdar, “The Geometry of Two-Weight Codes Over ℤ\({}_{\text{\textit{p}}}\)\({}^{\text{\textit{m}}}\)”, IEEE Transactions on Information Theory 67, 7769 (2021) DOI
Page edit log
- Victor V. Albert (2024-04-26) — most recent
Cite as:
“\([7,3,4]\) simplex code”, The Error Correction Zoo (V. V. Albert & P. Faist, eds.), 2024. https://errorcorrectionzoo.org/c/simplex734