Geert Leus, Shengli Zhou, Georgios B. Giannakis. Multiuser spreading codes retaining orthogonality through unknown time- and frequency-selective fading. In Proceedings of the Global Telecommunications Conference, 2001. GLOBECOM '01, San Antonio, TX, USA, 25-29 November, 2001. pages 259-263, IEEE, 2001. [doi]
Abstract is missing.