Key technologies for IMT-advanced mobile communication systems. - Carl Wijting; Klaus Doppler; Kari Kalliojärvi; Tommy Svensson; Mikael Sternad; Gunther Auer; Niklas Johansson; Johan Nyström; Magnus Olsson; Afif Osseiran; Martin Döttling; Jijun Luo; et al. (IEEE Wirel. Commun., 2009)