A lattice precoding scheme for flat-fading MIMO channels

This paper provides some details of a novel vector perturbation based lattice precoding algorithm based on Eigenvalue decomposition, named EDLP, for single user multiple-input multiple-output (MIMO) systems operating over slowly-varying flat-fading channels. Linear precoding is used in this technique to orthogonalize the fading channel, thus nullifying the interference among spatial channels. A perturbation vector is employed as well to reduce the transmitted power. Joint optimization of the linear precoder and the perturbation vector enhances the performance of the algorithm. As a result, the EDLP features full diversity order and full spatial multiplexing order. Furthermore, compared with other precoding techniques, EDLP requires less computational complexity. In appendixes, a proof validating the transformation from the original optimization metric to the minimization of a quadratic form is provided, as well as an elaborated algorithm to generate perturbation vector.