Construction criteria and existence results for approximately universal linear space-time codes with reduced decoding complexity
Petros Elia, Joakim Jaldén · 2008
This work presents new eigenvalue bounds, necessary conditions and existence results for approximately universal linear (lattice) codes that can be drawn from lattices of reduced dimension, and can thus incur reduced decoding complexity. Currently for the n times nrMIMO channel, all known n times T approximately universal codes, except for the Alamouti code for n = 2,nr= 1, draw from lattices of dimension equal to or larger than nT, irrespective of nr. Motivated by the case where nr< n, the work describes construction criteria for lattice codes that maintain their approximate universality even when they are drawn from lattices of reduced dimensionality.