6,423 research outputs found
A Numerical Approach for Designing Unitary Space Time Codes with Large Diversity
A numerical approach to design unitary constellation for any dimension and
any transmission rate under non-coherent Rayleigh flat fading channel.Comment: 32 pages, 6 figure
Construction of isodual codes from polycirculant matrices
Double polycirculant codes are introduced here as a generalization of double
circulant codes. When the matrix of the polyshift is a companion matrix of a
trinomial, we show that such a code is isodual, hence formally self-dual.
Numerical examples show that the codes constructed have optimal or
quasi-optimal parameters amongst formally self-dual codes. Self-duality, the
trivial case of isoduality, can only occur over \F_2 in the double circulant
case. Building on an explicit infinite sequence of irreducible trinomials over
\F_2, we show that binary double polycirculant codes are asymptotically good
- …