Aristotle University of Thessaloniki
The authors propose a generalized framework for handling Multiple-Input Multiple-Output (MIMO) schemes defined within the context of the Third Generation Partnership Project (3GPP) physical layer specifications. A detailed review of all the multi-antenna transmission techniques adopted by the 3GPP so far is firstly presented, starting from the Global System for Mobile (GSM) communications and passing through the High-Speed Packet Access (HSPA) releases to the very recent Long Term Evolution (LTE)-Advanced standard. Motivated by the outcome of this overview, they introduce the TRAnsmit Matrix (TRAM) concept, that can include as special cases several MIMO systems (e.g., transmit diversity, spatial-multiplexing, etc.) regardless of the presence or not of a feedback channel.