Jyrki T. Lahtonen Roope Vehkalahti Hsiao-feng Lu Camilla Hollanti Emanuele Viterbo On the Decay of the Determinants of Multiuser MIMO Lattice Codes http://arxiv.org/abs/0908.2505 2009 CoRR abs/0908.2505 db/journals/corr/corr0908.html#abs-0908-2505 informal publication