@conference {,
	title = {Discrete Multitone Modulation for Ultrasonic Indoor Positioning Systems},
	booktitle = {Sixth International Conference on Indoor Positioning and Indoor Navigation (IPIN 2015)},
	year = {2015},
	month = {10/2015},
	pages = {1-4},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Banff (Canad{\'a})},
	isbn = {978-1-4673-8401-8},
	author = {E. Garc{\'\i}a and Ure{\~n}a, J. and Gualda, D and {\'A}lvaro Hern{\'a}ndez}
}
