Lattice-reduction-aided detectors for MIMO communication systems

Lattice-reduction (LR) techniques are developed for enhancing the performance of multiple-input multiple-output (MIMO) digital communication systems. When used in conjunction with traditional linear and nonlinear detectors, LR techniques substantially close the gap to fundamental performance limits with little additional system complexity. Results for individual channels and ensembles are developed, and illustrated in detail for the case of small (2 × 2), uncoded, coherent systems. For example, we show that, relative to the maximum likelihood bound, LR techniques get us within 3dB for any Gaussian channel, and allow us to achieve the same diversity on the Rayleigh fading channel, when sufficiently large constellations are used.