In this correspondence, we derive some upper bounds of the rates of (generalized) complex orthogonal space–time block codes. We first present some new properties of complex orthogonal designs and then show that the rates of complex orthogonal space–time block codes for more than two transmit antennas are upper-bounded by 3 4. We show that the rates of generalized complex orthogonal space–time b...

In this paper, we give an important isomorphism between contacyclic codes and cyclic codes,over finite principal ideal rings.Necessary and sufficient conditions for the existence of non-trivial cyclic self-dual codes over finite principal ideal rings are given.

LetK/k be a cyclic Galois extension of degree l and θ a generator of Gal(K/k). For any v = (v1, . . . , vm) ∈ K m such that v is linearly independent over k, and any 1 ≤ d < m the Gabidulin-like code C(v, θ, d) ≤ kl×m is a maximum rank distance code of dimension ld over k. This construction unifies the ones available in the literature. We characterise the K-linear codes that are Gabidulinlike c...

| An important problem in the theory and application of block code trellises is to nd a coordinate permutation of a given code to minimize the trellis complexity. In this paper we show that the problem of nding a coordinate permutation that minimizes the number of vertices at a given depth in the minimal trellis for a binary linear block code is NP-complete.

In this article, we study some new properties of the block matrices. Introduce methods for finding matrices any matrix. We prove these by using matrix analysis methods. Some results paper are proved permutations last study, examples introduced to explain work and give MATLAB code in appendix article.