@article {guillen08spherechannels,
	title = {Sphere lower bound for rotated lattice constellations in fading channels},
	journal = {IEEE Transactions on Wireless Communications},
	volume = {7},
	year = {2008},
	pages = {825{\textendash}830},
	publisher = {IEEE},
	issn = {1536-1276},
	doi = {10.1109/TWC.2008.060782},
	url = {http://ieeexplore.ieee.org/servlet/opac?punumber=7693},
	author = {Guill{\'e}n i F{\`a}bregas, Albert and E. Viterbo}
}
