@phdthesis{TUW-108032, author = {Zemen, Thomas}, title = {OFDM Multi-User Communication Over Time-Variant Channels}, school = {Institut f{\"u}r Nachrichtentechnik und Hochfrequenztechnik}, year = {2004}, url = {http://publik.tuwien.ac.at/files/pub-et_8800.pdf} }