English

Any strongly controllable group system or group shift or any linear block code is isomorphic to a generator group

Information Theory 2022-08-16 v1 math.IT

Abstract

Consider any sequence of finite groups AtA^t, where tt takes values in an integer index set Z\mathbf{Z}. A group system AA is a set of sequences with components in AtA^t that forms a group under componentwise addition in AtA^t, for each tZt\in\mathbf{Z}. As shown previously, any strongly controllable complete group system AA can be decomposed into generators. We study permutations of the generators when sequences in the group system are multiplied. We show that any strongly controllable complete group system AA is isomorphic to a generator group (U,)({\mathcal{U}},\circ). The set U{\mathcal{U}} is a set of tensors, a double Cartesian product space of sets GktG_k^t, with indices kk, for 0k0\le k\le\ell, and time tt, for tZt\in\mathbf{Z}. GktG_k^t is a set of unique generator labels for the generators in AA with nontrivial span for the time interval [t,t+k][t,t+k]. We show the generator group contains a unique elementary system, an infinite collection of elementary groups, one for each kk and tt, defined on small subsets of U{\mathcal{U}}, in the shape of triangles, which form a tile like structure over U{\mathcal{U}}. There is a homomorphism from each elementary group to any elementary group defined on smaller tiles of the former group. The group system AA may be constructed from either the generator group or elementary system. These results have application to linear block codes, any algebraic system that contains a linear block code, group shifts, and harmonic theory in mathematics, and systems theory, coding theory, control theory, and related fields in engineering.

Keywords

Cite

@article{arxiv.2208.06953,
  title  = {Any strongly controllable group system or group shift or any linear block code is isomorphic to a generator group},
  author = {Kenneth M. Mackenthun},
  journal= {arXiv preprint arXiv:2208.06953},
  year   = {2022}
}
R2 v1 2026-06-25T01:42:09.487Z